Merge pull request #1561 from ethereum/develop

Merge develop into release for 0.4.8

40 files changed, 2170 insertions, 661 deletions

diff --git a/.travis.yml b/.travis.yml
index 2160d175..017f1a61 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -26,11 +26,13 @@
 
 language: cpp
 branches:
-    # We need to whitelist the branches which we want to have "push" automation.
+    # We need to whitelist the branches which we want to have "push" automation,
+    # this includes tags (which are treated as branches by travis).
     # Pull request automation is not constrained to this set of branches.
     only:
         - develop
         - release
+        - /^v[0-9]/
 matrix:
     include:
         # Ubuntu 14.04 LTS "Trusty Tahr"
@@ -71,6 +73,7 @@ matrix:
           dist: trusty
           sudo: required
           compiler: gcc
+          node_js: stable
           services:
               - docker
           before_install:
@@ -137,11 +140,12 @@ cache:
     directories:
         - boost_1_57_0
         - build
+        - $HOME/.local
 
 install:
     - test $TRAVIS_INSTALL_DEPS != On || ./scripts/install_deps.sh
+    - test "$TRAVIS_OS_NAME" != "linux" || ./scripts/install_cmake.sh
     - echo -n "$TRAVIS_COMMIT" > commit_hash.txt
-    - test "$TRAVIS_PULL_REQUESTS" != "false" || test "$TRAVIS_BRANCH" != release || echo -n > prerelease.txt # this is a proper release
 before_script:
     - test $TRAVIS_EMSCRIPTEN != On || ./scripts/build_emscripten.sh
     - test $TRAVIS_RELEASE != On || (mkdir -p build
@@ -149,7 +153,8 @@ before_script:
       && cmake .. -DCMAKE_BUILD_TYPE=$TRAVIS_BUILD_TYPE
       && make -j2
       && cd ..
-      && ./scripts/release.sh $ZIP_SUFFIX )
+      && ./scripts/release.sh $ZIP_SUFFIX
+      && ./scripts/create_source_tarball.sh )
 script:
     - test $TRAVIS_DOCS != On || ./scripts/docs.sh
 
@@ -190,43 +195,20 @@ deploy:
             - release
 
     # This is the deploy target for the native build (Linux and macOS)
-    # which generates ZIPs per commit.  We are in agreement that
-    # generating ZIPs per commit for the develop branch is probably
-    # just noise, so we only run this deployment target on 'release'.
-    #
-    # Unlike the Appveyor GitHub Releases target, the support in TravisCI
-    # seemingly doesn't provide a means for passing a description, tag, etc.
-    # In practice, we are letting the Appveyor CI do all that stuff, and
-    # then this deployment flow just seems to find that most recent tag,
-    # and just add our Linux and macOS ZIPs into the same tag, which is
-    # what we want to happen.  But is very accidental and brittle-looking.
-    #
-    # The 'skip_cleanup' stops the workspace being cleaned out prior to
-    # generation of the artifacts.  Strange that we should explicitly
-    # need to do that, but we do.
-    #
-    # Tokens in TravisCI can be generated a few different ways.  Bob had
-    # success using the 'travis' gem, and then using that gem to
-    # create/edit this .travis.yml file, and then cut-and-pasting the
-    # good bits back out of what it generated.  The gem changes all the
-    # whitespace and deletes comments, so cannot be used as-is.  But
-    # it does generate an appropriate auth token.
-    #
-    # TODO - I do not know if the api_key below which work correctly
-    # for ethereum/solidity.   I suspect not, for the same reason as
-    # my auth token does not work for Appveyor.  I don't have enough
-    # permissions to enable this myself.  Christian should be able to.
-    #
-    # See https://docs.travis-ci.com/user/deployment/releases
-    # See https://blog.travis-ci.com/2013-01-28-token-token-token/
-    # See https://github.com/ethereum/webthree-umbrella/issues/658
+    # which generates ZIPs per commit and the source tarball.
     #
+    # This runs for each tag that is created and adds the corresponding files.
     - provider: releases
       api_key:
           secure: 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
-      file: $TRAVIS_BUILD_DIR/solidity-$ZIP_SUFFIX.zip
+
+      overwrite: true
+      file_glob: true
+      file:
+          - $TRAVIS_BUILD_DIR/solidity*.zip
+          - $TRAVIS_BUILD_DIR/solidity*tar.gz
       skip_cleanup: true
       on:
-          repo: ethereum/solidity
-          branch: release
+          all_branches: true
+          tags: true
           condition: $TRAVIS_RELEASE == On
diff --git a/CMakeLists.txt b/CMakeLists.txt
index ee66eebd..ecd857ad 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,7 +8,7 @@ include(EthPolicy)
 eth_policy()
 
 # project name and version should be set after cmake_policy CMP0048
-set(PROJECT_VERSION "0.4.7")
+set(PROJECT_VERSION "0.4.8")
 project(solidity VERSION ${PROJECT_VERSION})
 
 # Let's find our dependencies
diff --git a/Changelog.md b/Changelog.md
index 096c72d4..b8effc19 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,3 +1,15 @@
+### 0.4.8 (2017-01-13)
+
+Features:
+ * Optimiser: Performance improvements.
+ * Output: Print assembly in new standardized Solidity assembly format.
+
+Bugfixes:
+ * Remappings: Prefer longer context over longer prefix.
+ * Type checker, code generator: enable access to events of base contracts' names.
+ * Imports: ``import ".dir/a"`` is not a relative path.  Relative paths begin with directory ``.`` or ``..``.
+ * Type checker, disallow inheritances of different kinds (e.g. a function and a modifier) of members of the same name
+
 ### 0.4.7 (2016-12-15)
 
 Features:
diff --git a/docs/assembly.rst b/docs/assembly.rst
new file mode 100644
index 00000000..57c0bf9b
--- /dev/null
+++ b/docs/assembly.rst
@@ -0,0 +1,950 @@
+#################
+Solidity Assembly
+#################
+
+.. index:: ! assembly, ! asm, ! evmasm
+
+Solidity defines an assembly language that can also be used without Solidity.
+This assembly language can also be used as "inline assembly" inside Solidity
+source code. We start with describing how to use inline assembly and how it
+differs from standalone assembly and then specify assembly itself.
+
+TODO: Write about how scoping rules of inline assembly are a bit different
+and the complications that arise when for example using internal functions
+of libraries. Furhermore, write about the symbols defined by the compiler.
+
+Inline Assembly
+===============
+
+For more fine-grained control especially in order to enhance the language by writing libraries,
+it is possible to interleave Solidity statements with inline assembly in a language close
+to the one of the virtual machine. Due to the fact that the EVM is a stack machine, it is
+often hard to address the correct stack slot and provide arguments to opcodes at the correct
+point on the stack. Solidity's inline assembly tries to facilitate that and other issues
+arising when writing manual assembly by the following features:
+
+* functional-style opcodes: ``mul(1, add(2, 3))`` instead of ``push1 3 push1 2 add push1 1 mul``
+* assembly-local variables: ``let x := add(2, 3)  let y := mload(0x40)  x := add(x, y)``
+* access to external variables: ``function f(uint x) { assembly { x := sub(x, 1) } }``
+* labels: ``let x := 10  repeat: x := sub(x, 1) jumpi(repeat, eq(x, 0))``
+* loops: ``for { let i := 0 } lt(i, x) { i := add(i, 1) } { y := mul(2, y) }``
+* switch statements: ``switch x case 0: { y := mul(x, 2) } default: { y := 0 }``
+* function calls: ``function f(x) -> (y) { switch x case 0: { y := 1 } default: { y := mul(x, f(sub(x, 1))) }   }``
+
+.. note::
+    Of the above, loops, function calls and switch statements are not yet implemented.
+
+We now want to describe the inline assembly language in detail.
+
+.. warning::
+    Inline assembly is still a relatively new feature and might change if it does not prove useful,
+    so please try to keep up to date.
+
+Example
+-------
+
+The following example provides library code to access the code of another contract and
+load it into a ``bytes`` variable. This is not possible at all with "plain Solidity" and the
+idea is that assembly libraries will be used to enhance the language in such ways.
+
+.. code::
+
+    library GetCode {
+        function at(address _addr) returns (bytes o_code) {
+            assembly {
+                // retrieve the size of the code, this needs assembly
+                let size := extcodesize(_addr)
+                // allocate output byte array - this could also be done without assembly
+                // by using o_code = new bytes(size)
+                o_code := mload(0x40)
+                // new "memory end" including padding
+                mstore(0x40, add(o_code, and(add(add(size, 0x20), 0x1f), not(0x1f))))
+                // store length in memory
+                mstore(o_code, size)
+                // actually retrieve the code, this needs assembly
+                extcodecopy(_addr, add(o_code, 0x20), 0, size)
+            }
+        }
+    }
+
+Inline assembly could also be beneficial in cases where the optimizer fails to produce
+efficient code. Please be aware that assembly is much more difficult to write because
+the compiler does not perform checks, so you should use it only if
+you really know what you are doing.
+
+.. code::
+
+    library VectorSum {
+        // This function is less efficient because the optimizer currently fails to
+        // remove the bounds checks in array access.
+        function sumSolidity(uint[] _data) returns (uint o_sum) {
+            for (uint i = 0; i < _data.length; ++i)
+                o_sum += _data[i];
+        }
+
+        // We know that we only access the array in bounds, so we can avoid the check.
+        // 0x20 needs to be added to an array because the first slot contains the
+        // array length.
+        function sumAsm(uint[] _data) returns (uint o_sum) {
+            for (uint i = 0; i < _data.length; ++i) {
+                assembly {
+                    o_sum := mload(add(add(_data, 0x20), mul(i, 0x20)))
+                }
+            }
+        }
+    }
+
+
+Syntax
+------
+
+Assembly parses comments, literals and identifiers exactly as Solidity, so you can use the
+usual ``//`` and ``/* */`` comments. Inline assembly is marked by ``assembly { ... }`` and inside
+these curly braces, the following can be used (see the later sections for more details)
+
+ - literals, i.e. ``0x123``, ``42`` or ``"abc"`` (strings up to 32 characters)
+ - opcodes (in "instruction style"), e.g. ``mload sload dup1 sstore``, for a list see below
+ - opcode in functional style, e.g. ``add(1, mlod(0))``
+ - labels, e.g. ``name:``
+ - variable declarations, e.g. ``let x := 7`` or ``let x := add(y, 3)``
+ - identifiers (labels or assembly-local variables and externals if used as inline assembly), e.g. ``jump(name)``, ``3 x add``
+ - assignments (in "instruction style"), e.g. ``3 =: x``
+ - assignments in functional style, e.g. ``x := add(y, 3)``
+ - blocks where local variables are scoped inside, e.g. ``{ let x := 3 { let y := add(x, 1) } }``
+
+Opcodes
+-------
+
+This document does not want to be a full description of the Ethereum virtual machine, but the
+following list can be used as a reference of its opcodes.
+
+If an opcode takes arguments (always from the top of the stack), they are given in parentheses.
+Note that the order of arguments can be seed to be reversed in non-functional style (explained below).
+Opcodes marked with ``-`` do not push an item onto the stack, those marked with ``*`` are
+special and all others push exactly one item onte the stack.
+
+In the following, ``mem[a...b)`` signifies the bytes of memory starting at position ``a`` up to
+(excluding) position ``b`` and ``storage[p]`` signifies the storage contents at position ``p``.
+
+The opcodes ``pushi`` and ``jumpdest`` cannot be used directly.
+
+In the grammar, opcodes are represented as pre-defined identifiers.
+
++-------------------------+------+-----------------------------------------------------------------+
+| stop                    + `-`  | stop execution, identical to return(0,0)                        |
++-------------------------+------+-----------------------------------------------------------------+
+| add(x, y)               |      | x + y                                                           |
++-------------------------+------+-----------------------------------------------------------------+
+| sub(x, y)               |      | x - y                                                           |
++-------------------------+------+-----------------------------------------------------------------+
+| mul(x, y)               |      | x * y                                                           |
++-------------------------+------+-----------------------------------------------------------------+
+| div(x, y)               |      | x / y                                                           |
++-------------------------+------+-----------------------------------------------------------------+
+| sdiv(x, y)              |      | x / y, for signed numbers in two's complement                   |
++-------------------------+------+-----------------------------------------------------------------+
+| mod(x, y)               |      | x % y                                                           |
++-------------------------+------+-----------------------------------------------------------------+
+| smod(x, y)              |      | x % y, for signed numbers in two's complement                   |
++-------------------------+------+-----------------------------------------------------------------+
+| exp(x, y)               |      | x to the power of y                                             |
++-------------------------+------+-----------------------------------------------------------------+
+| not(x)                  |      | ~x, every bit of x is negated                                   |
++-------------------------+------+-----------------------------------------------------------------+
+| lt(x, y)                |      | 1 if x < y, 0 otherwise                                         |
++-------------------------+------+-----------------------------------------------------------------+
+| gt(x, y)                |      | 1 if x > y, 0 otherwise                                         |
++-------------------------+------+-----------------------------------------------------------------+
+| slt(x, y)               |      | 1 if x < y, 0 otherwise, for signed numbers in two's complement |
++-------------------------+------+-----------------------------------------------------------------+
+| sgt(x, y)               |      | 1 if x > y, 0 otherwise, for signed numbers in two's complement |
++-------------------------+------+-----------------------------------------------------------------+
+| eq(x, y)                |      | 1 if x == y, 0 otherwise                                        |
++-------------------------+------+-----------------------------------------------------------------+
+| iszero(x)               |      | 1 if x == 0, 0 otherwise                                        |
++-------------------------+------+-----------------------------------------------------------------+
+| and(x, y)               |      | bitwise and of x and y                                          |
++-------------------------+------+-----------------------------------------------------------------+
+| or(x, y)                |      | bitwise or of x and y                                           |
++-------------------------+------+-----------------------------------------------------------------+
+| xor(x, y)               |      | bitwise xor of x and y                                          |
++-------------------------+------+-----------------------------------------------------------------+
+| byte(n, x)              |      | nth byte of x, where the most significant byte is the 0th byte  |
++-------------------------+------+-----------------------------------------------------------------+
+| addmod(x, y, m)         |      | (x + y) % m with arbitrary precision arithmetics                |
++-------------------------+------+-----------------------------------------------------------------+
+| mulmod(x, y, m)         |      | (x * y) % m with arbitrary precision arithmetics                |
++-------------------------+------+-----------------------------------------------------------------+
+| signextend(i, x)        |      | sign extend from (i*8+7)th bit counting from least significant  |
++-------------------------+------+-----------------------------------------------------------------+
+| sha3(p, n)              |      | keccak(mem[p...(p+n)))                                          |
++-------------------------+------+-----------------------------------------------------------------+
+| jump(label)             | `-`  | jump to label / code position                                   |
++-------------------------+------+-----------------------------------------------------------------+
+| jumpi(label, cond)      | `-`  | jump to label if cond is nonzero                                |
++-------------------------+------+-----------------------------------------------------------------+
+| pc                      |      | current position in code                                        |
++-------------------------+------+-----------------------------------------------------------------+
+| pop                     | `*`  | remove topmost stack slot                                       |
++-------------------------+------+-----------------------------------------------------------------+
+| dup1 ... dup16          |      | copy ith stack slot to the top (counting from top)              |
++-------------------------+------+-----------------------------------------------------------------+
+| swap1 ... swap16        | `*`  | swap topmost and ith stack slot below it                        |
++-------------------------+------+-----------------------------------------------------------------+
+| mload(p)                |      | mem[p..(p+32))                                                  |
++-------------------------+------+-----------------------------------------------------------------+
+| mstore(p, v)            | `-`  | mem[p..(p+32)) := v                                             |
++-------------------------+------+-----------------------------------------------------------------+
+| mstore8(p, v)           | `-`  | mem[p] := v & 0xff    - only modifies a single byte             |
++-------------------------+------+-----------------------------------------------------------------+
+| sload(p)                |      | storage[p]                                                      |
++-------------------------+------+-----------------------------------------------------------------+
+| sstore(p, v)            | `-`  | storage[p] := v                                                 |
++-------------------------+------+-----------------------------------------------------------------+
+| msize                   |      | size of memory, i.e. largest accessed memory index              |
++-------------------------+------+-----------------------------------------------------------------+
+| gas                     |      | gas still available to execution                                |
++-------------------------+------+-----------------------------------------------------------------+
+| address                 |      | address of the current contract / execution context             |
++-------------------------+------+-----------------------------------------------------------------+
+| balance(a)              |      | wei balance at address a                                        |
++-------------------------+------+-----------------------------------------------------------------+
+| caller                  |      | call sender (excluding delegatecall)                            |
++-------------------------+------+-----------------------------------------------------------------+
+| callvalue               |      | wei sent together with the current call                         |
++-------------------------+------+-----------------------------------------------------------------+
+| calldataload(p)         |      | call data starting from position p (32 bytes)                   |
++-------------------------+------+-----------------------------------------------------------------+
+| calldatasize            |      | size of call data in bytes                                      |
++-------------------------+------+-----------------------------------------------------------------+
+| calldatacopy(t, f, s)   | `-`  | copy s bytes from calldata at position f to mem at position t   |
++-------------------------+------+-----------------------------------------------------------------+
+| codesize                |      | size of the code of the current contract / execution context    |
++-------------------------+------+-----------------------------------------------------------------+
+| codecopy(t, f, s)       | `-`  | copy s bytes from code at position f to mem at position t       |
++-------------------------+------+-----------------------------------------------------------------+
+| extcodesize(a)          |      | size of the code at address a                                   |
++-------------------------+------+-----------------------------------------------------------------+
+| extcodecopy(a, t, f, s) | `-`  | like codecopy(t, f, s) but take code at address a               |
++-------------------------+------+-----------------------------------------------------------------+
+| create(v, p, s)         |      | create new contract with code mem[p..(p+s)) and send v wei      |
+|                         |      | and return the new address                                      |
++-------------------------+------+-----------------------------------------------------------------+
+| call(g, a, v, in,       |      | call contract at address a with input mem[in..(in+insize)]      |
+| insize, out, outsize)   |      | providing g gas and v wei and output area                       |
+|                         |      | mem[out..(out+outsize)] returting 1 on error (out of gas)       |
++-------------------------+------+-----------------------------------------------------------------+
+| callcode(g, a, v, in,   |      | identical to call but only use the code from a and stay         |
+| insize, out, outsize)   |      | in the context of the current contract otherwise                |
++-------------------------+------+-----------------------------------------------------------------+
+| delegatecall(g, a, in,  |      | identical to callcode but also keep ``caller``                  |
+| insize, out, outsize)   |      | and ``callvalue``                                               |
++-------------------------+------+-----------------------------------------------------------------+
+| return(p, s)            | `*`  | end execution, return data mem[p..(p+s))                        |
++-------------------------+------+-----------------------------------------------------------------+
+| selfdestruct(a)         | `*`  | end execution, destroy current contract and send funds to a     |
++-------------------------+------+-----------------------------------------------------------------+
+| log0(p, s)              | `-`  | log without topics and data mem[p..(p+s))                       |
++-------------------------+------+-----------------------------------------------------------------+
+| log1(p, s, t1)          | `-`  | log with topic t1 and data mem[p..(p+s))                        |
++-------------------------+------+-----------------------------------------------------------------+
+| log2(p, s, t1, t2)      | `-`  | log with topics t1, t2 and data mem[p..(p+s))                   |
++-------------------------+------+-----------------------------------------------------------------+
+| log3(p, s, t1, t2, t3)  | `-`  | log with topics t1, t2, t3 and data mem[p..(p+s))               |
++-------------------------+------+-----------------------------------------------------------------+
+| log4(p, s, t1, t2, t3,  | `-`  | log with topics t1, t2, t3, t4 and data mem[p..(p+s))           |
+| t4)                     |      |                                                                 |
++-------------------------+------+-----------------------------------------------------------------+
+| origin                  |      | transaction sender                                              |
++-------------------------+------+-----------------------------------------------------------------+
+| gasprice                |      | gas price of the transaction                                    |
++-------------------------+------+-----------------------------------------------------------------+
+| blockhash(b)            |      | hash of block nr b - only for last 256 blocks excluding current |
++-------------------------+------+-----------------------------------------------------------------+
+| coinbase                |      | current mining beneficiary                                      |
++-------------------------+------+-----------------------------------------------------------------+
+| timestamp               |      | timestamp of the current block in seconds since the epoch       |
++-------------------------+------+-----------------------------------------------------------------+
+| number                  |      | current block number                                            |
++-------------------------+------+-----------------------------------------------------------------+
+| difficulty              |      | difficulty of the current block                                 |
++-------------------------+------+-----------------------------------------------------------------+
+| gaslimit                |      | block gas limit of the current block                            |
++-------------------------+------+-----------------------------------------------------------------+
+
+Literals
+--------
+
+You can use integer constants by typing them in decimal or hexadecimal notation and an
+appropriate ``PUSHi`` instruction will automatically be generated. The following creates code
+to add 2 and 3 resulting in 5 and then computes the bitwise and with the string "abc".
+Strings are stored left-aligned and cannot be longer than 32 bytes.
+
+.. code::
+
+    assembly { 2 3 add "abc" and }
+
+Functional Style
+-----------------
+
+You can type opcode after opcode in the same way they will end up in bytecode. For example
+adding ``3`` to the contents in memory at position ``0x80`` would be
+
+.. code::
+
+    3 0x80 mload add 0x80 mstore
+
+As it is often hard to see what the actual arguments for certain opcodes are,
+Solidity inline assembly also provides a "functional style" notation where the same code
+would be written as follows
+
+.. code::
+
+    mstore(0x80, add(mload(0x80), 3))
+
+Functional style and instructional style can be mixed, but any opcode inside a
+functional style expression has to return exactly one stack slot (most of the opcodes do).
+
+Note that the order of arguments is reversed in functional-style as opposed to the instruction-style
+way. If you use functional-style, the first argument will end up on the stack top.
+
+
+Access to External Variables and Functions
+------------------------------------------
+
+Solidity variables and other identifiers can be accessed by simply using their name.
+For storage and memory variables, this will push the address and not the value onto the
+stack. Also note that non-struct and non-array storage variable addresses occupy two slots
+on the stack: One for the address and one for the byte offset inside the storage slot.
+In assignments (see below), we can even use local Solidity variables to assign to.
+
+Functions external to inline assembly can also be accessed: The assembly will
+push their entry label (with virtual function resolution applied). The calling semantics
+in solidity are:
+
+ - the caller pushes return label, arg1, arg2, ..., argn
+ - the call returns with ret1, ret2, ..., retn
+
+This feature is still a bit cumbersome to use, because the stack offset essentially
+changes during the call, and thus references to local variables will be wrong.
+It is planned that the stack height changes can be specified in inline assembly.
+
+.. code::
+
+    contract C {
+        uint b;
+        function f(uint x) returns (uint r) {
+            assembly {
+                b pop // remove the offset, we know it is zero
+                sload
+                x
+                mul
+                =: r  // assign to return variable r
+            }
+        }
+    }
+
+Labels
+------
+
+Another problem in EVM assembly is that ``jump`` and ``jumpi`` use absolute addresses
+which can change easily. Solidity inline assembly provides labels to make the use of
+jumps easier. The following code computes an element in the Fibonacci series.
+
+.. code::
+
+    {
+        let n := calldataload(4)
+        let a := 1
+        let b := a
+    loop:
+        jumpi(loopend, eq(n, 0))
+        a add swap1
+        n := sub(n, 1)
+        jump(loop)
+    loopend:
+        mstore(0, a)
+        return(0, 0x20)
+    }
+
+Please note that automatically accessing stack variables can only work if the
+assembler knows the current stack height. This fails to work if the jump source
+and target have different stack heights. It is still fine to use such jumps, but
+you should just not access any stack variables (even assembly variables) in that case.
+
+Furthermore, the stack height analyser goes through the code opcode by opcode
+(and not according to control flow), so in the following case, the assembler
+will have a wrong impression about the stack height at label ``two``:
+
+.. code::
+
+    {
+        jump(two)
+        one:
+            // Here the stack height is 1 (because we pushed 7),
+            // but the assembler thinks it is 0 because it reads
+            // from top to bottom.
+            // Accessing stack variables here will lead to errors.
+            jump(three)
+        two:
+            7 // push something onto the stack
+            jump(one)
+        three:
+    }
+
+
+Declaring Assembly-Local Variables
+----------------------------------
+
+You can use the ``let`` keyword to declare variables that are only visible in
+inline assembly and actually only in the current ``{...}``-block. What happens
+is that the ``let`` instruction will create a new stack slot that is reserved
+for the variable and automatically removed again when the end of the block
+is reached. You need to provide an initial value for the variable which can
+be just ``0``, but it can also be a complex functional-style expression.
+
+.. code::
+
+    contract C {
+        function f(uint x) returns (uint b) {
+            assembly {
+                let v := add(x, 1)
+                mstore(0x80, v)
+                {
+                    let y := add(sload(v), 1)
+                    b := y
+                } // y is "deallocated" here
+                b := add(b, v)
+            } // v is "deallocated" here
+        }
+    }
+
+
+Assignments
+-----------
+
+Assignments are possible to assembly-local variables and to function-local
+variables. Take care that when you assign to variables that point to
+memory or storage, you will only change the pointer and not the data.
+
+There are two kinds of assignments: functional-style and instruction-style.
+For functional-style assignments (``variable := value``), you need to provide a value in a
+functional-style expression that results in exactly one stack value
+and for instruction-style (``=: variable``), the value is just taken from the stack top.
+For both ways, the colon points to the name of the variable. The assignment
+is performed by replacing the variable's value on the stack by the new value.
+
+.. code::
+
+    assembly {
+        let v := 0 // functional-style assignment as part of variable declaration
+        let g := add(v, 2)
+        sload(10)
+        =: v // instruction style assignment, puts the result of sload(10) into v
+    }
+
+Switch
+------
+
+You can use a switch statement as a very basic version of "if/else".
+It takes the value of an expression and compares it to several constants.
+The branch corresponding to the matching constant is taken. Contrary to the
+error-prone behaviour of some programming languages, control flow does
+not continue from one case to the next. There can be a fallback or default
+case called ``default``.
+
+.. code::
+
+    assembly {
+        let x := 0
+        switch calldataload(4)
+        case 0: {
+            x := calldataload(0x24)
+        }
+        default: {
+            x := calldataload(0x44)
+        }
+        sstore(0, div(x, 2))
+    }
+
+The list of cases does not require curly braces, but the body of a
+case does require them.
+
+Loops
+-----
+
+Assembly supports a simple for-style loop. For-style loops have
+a header containing an initializing part, a condition and a post-iteration
+part. The condition has to be a functional-style expression, while
+the other two can also be blocks. If the initializing part is a block that
+declares any variables, the scope of these variables is extended into the
+body (including the condition and the post-iteration part).
+
+The following example computes the sum of an area in memory.
+
+.. code::
+
+    assembly {
+        let x := 0
+        for { let i := 0 } lt(i, 0x100) { i := add(i, 0x20) } {
+            x := add(x, mload(i))
+        }
+    }
+
+Functions
+---------
+
+Assembly allows the definition of low-level functions. These take their
+arguments (and a return PC) from the stack and also put the results onto the
+stack. Calling a function looks the same way as executing a functional-style
+opcode.
+
+Functions can be defined anywhere and are visible in the block they are
+declared in. Inside a function, you cannot access local variables
+defined outside of that function. There is no explicit ``return``
+statement.
+
+If you call a function that returns multiple values, you have to assign
+them to a tuple using ``(a, b) := f(x)`` or ``let (a, b) := f(x)``.
+
+The following example implements the power function by square-and-multiply.
+
+.. code::
+
+    assembly {
+        function power(base, exponent) -> (result) {
+            switch exponent
+            0: { result := 1 }
+            1: { result := base }
+            default: {
+                result := power(mul(base, base), div(exponent, 2))
+                switch mod(exponent, 2)
+                    1: { result := mul(base, result) }
+            }
+        }
+    }
+
+Things to Avoid
+---------------
+
+Inline assembly might have a quite high-level look, but it actually is extremely
+low-level. Function calls, loops and switches are converted by simple
+rewriting rules and after that, the only thing the assembler does for you is re-arranging
+functional-style opcodes, managing jump labels, counting stack height for
+variable access and removing stack slots for assembly-local variables when the end
+of their block is reached. Especially for those two last cases, it is important
+to know that the assembler only counts stack height from top to bottom, not
+necessarily following control flow. Furthermore, operations like swap will only
+swap the contents of the stack but not the location of variables.
+
+Conventions in Solidity
+-----------------------
+
+In contrast to EVM assembly, Solidity knows types which are narrower than 256 bits,
+e.g. ``uint24``. In order to make them more efficient, most arithmetic operations just
+treat them as 256 bit numbers and the higher-order bits are only cleaned at the
+point where it is necessary, i.e. just shortly before they are written to memory
+or before comparisons are performed. This means that if you access such a variable
+from within inline assembly, you might have to manually clean the higher order bits
+first.
+
+Solidity manages memory in a very simple way: There is a "free memory pointer"
+at position ``0x40`` in memory. If you want to allocate memory, just use the memory
+from that point on and update the pointer accordingly.
+
+Elements in memory arrays in Solidity always occupy multiples of 32 bytes (yes, this is
+even true for ``byte[]``, but not for ``bytes`` and ``string``). Multi-dimensional memory
+arrays are pointers to memory arrays. The length of a dynamic array is stored at the
+first slot of the array and then only the array elements follow.
+
+.. warning::
+    Statically-sized memory arrays do not have a length field, but it will be added soon
+    to allow better convertibility between statically- and dynamically-sized arrays, so
+    please do not rely on that.
+
+
+Standalone Assembly
+===================
+
+The assembly language described as inline assembly above can also be used
+standalone and in fact, the plan is to use it as an intermediate language
+for the Solidity compiler. In this form, it tries to achieve several goals:
+
+1. Programs written in it should be readable, even if the code is generated by a compiler from Solidity.
+2. The translation from assembly to bytecode should contain as few "surprises" as possible.
+3. Control flow should be easy to detect to help in formal verification and optimization.
+
+In order to achieve the first and last goal, assembly provides high-level constructs
+like ``for`` loops, ``switch`` statements and function calls. It should be possible
+to write assembly programs that do not make use of explicit ``SWAP``, ``DUP``,
+``JUMP`` and ``JUMPI`` statements, because the first two obfuscate the data flow
+and the last two obfuscate control flow. Furthermore, functional statements of
+the form ``mul(add(x, y), 7)`` are preferred over pure opcode statements like
+``7 y x add mul`` because in the first form, it is much easier to see which
+operand is used for which opcode.
+
+The second goal is achieved by introducing a desugaring phase that only removes
+the higher level constructs in a very regular way and still allows inspecting
+the generated low-level assembly code. The only non-local operation performed
+by the assembler is name lookup of user-defined identifiers (functions, variables, ...),
+which follow very simple and regular scoping rules and cleanup of local variables from the stack.
+
+Scoping: An identifier that is declared (label, variable, function, assembly)
+is only visible in the block where it was declared (including nested blocks
+inside the current block). It is not legal to access local variables across
+function borders, even if they would be in scope. Shadowing is allowed, but
+two identifiers with the same name cannot be declared in the same block.
+Local variables cannot be accessed before they were declared, but labels,
+functions and assemblies can. Assemblies are special blocks that are used
+for e.g. returning runtime code or creating contracts. No identifier from an
+outer assembly is visible in a sub-assembly.
+
+If control flow passes over the end of a block, pop instructions are inserted
+that match the number of local variables declared in that block, unless the
+``}`` is directly preceded by an opcode that does not have a continuing control
+flow path. Whenever a local variable is referenced, the code generator needs
+to know its current relative position in the stack and thus it needs to
+keep track of the current so-called stack height.
+At the end of a block, this implicit stack height is always reduced by the number
+of local variables whether ther is a continuing control flow or not.
+
+This means that the stack height before and after the block should be the same.
+If this is not the case, a warning is issued,
+unless the last instruction in the block did not have a continuing control flow path.
+
+Why do we use higher-level constructs like ``switch``, ``for`` and functions:
+
+Using ``switch``, ``for`` and functions, it should be possible to write
+complex code without using ``jump`` or ``jumpi`` manually. This makes it much
+easier to analyze the control flow, which allows for improved formal
+verification and optimization.
+
+Furthermore, if manual jumps are allowed, computing the stack height is rather complicated.
+The position of all local variables on the stack needs to be known, otherwise
+neither references to local variables nor removing local variables automatically
+from the stack at the end of a block will work properly. Because of that,
+every label that is preceded by an instruction that ends or diverts control flow
+should be annotated with the current stack layout. This annotation is performed
+automatically during the desugaring phase.
+
+Example:
+
+We will follow an example compilation from Solidity to desugared assembly.
+We consider the runtime bytecode of the following Solidity program::
+
+    contract C {
+      function f(uint x) returns (uint y) {
+        y = 1;
+        for (uint i = 0; i < x; i++)
+          y = 2 * y;
+      }
+    }
+
+The following assembly will be generated::
+
+    {
+      mstore(0x40, 0x60) // store the "free memory pointer"
+      // function dispatcher
+      switch div(calldataload(0), exp(2, 226))
+      case 0xb3de648b: {
+        let (r) = f(calldataload(4))
+        let ret := $allocate(0x20)
+        mstore(ret, r)
+        return(ret, 0x20)
+      }
+      default: { jump(invalidJumpLabel) }
+      // memory allocator
+      function $allocate(size) -> (pos) {
+        pos := mload(0x40)
+        mstore(0x40, add(pos, size))
+      }
+      // the contract function
+      function f(x) -> (y) {
+        y := 1
+        for { let i := 0 } lt(i, x) { i := add(i, 1) } {
+          y := mul(2, y)
+        }
+      }
+    }
+
+After the desugaring phase it looks as follows::
+
+    {
+      mstore(0x40, 0x60)
+      {
+        let $0 := div(calldataload(0), exp(2, 226))
+        jumpi($case1, eq($0, 0xb3de648b))
+        jump($caseDefault)
+        $case1:
+        {
+          // the function call - we put return label and arguments on the stack
+          $ret1 calldataload(4) jump($fun_f)
+          $ret1 [r]: // a label with a [...]-annotation resets the stack height
+                    // to "current block + number of local variables". It also
+                    // introduces a variable, r:
+                    // r is at top of stack, $0 is below (from enclosing block)
+          $ret2 0x20 jump($fun_allocate)
+          $ret2 [ret]: // stack here: $0, r, ret (top)
+          mstore(ret, r)
+          return(ret, 0x20)
+          // although it is useless, the jump is automatically inserted,
+          // since the desugaring process does not analyze control-flow
+          jump($endswitch)
+        }
+        $caseDefault:
+        {
+          jump(invalidJumpLabel)
+          jump($endswitch)
+        }
+        $endswitch:
+      }
+      jump($afterFunction)
+      $fun_allocate:
+      {
+        $start[$retpos, size]:
+        // output variables live in the same scope as the arguments.
+        let pos := 0
+        {
+          pos := mload(0x40)
+          mstore(0x40, add(pos, size))
+        }
+        swap1 pop swap1 jump
+      }
+      $fun_f:
+      {
+        start [$retpos, x]:
+        let y := 0
+        {
+          let i := 0
+          $for_begin:
+          jumpi($for_end, iszero(lt(i, x)))
+          {
+            y := mul(2, y)
+          }
+          $for_continue:
+          { i := add(i, 1) }
+          jump($for_begin)
+          $for_end:
+        } // Here, a pop instruction is inserted for i
+        swap1 pop swap1 jump
+      }
+      $afterFunction:
+      stop
+    }
+
+
+Assembly happens in four stages:
+
+1. Parsing
+2. Desugaring (removes switch, for and functions)
+3. Opcode stream generation
+4. Bytecode generation
+
+We will specify steps one to three in a pseudo-formal way. More formal
+specifications will follow.
+
+
+Parsing / Grammar
+-----------------
+
+The tasks of the parser are the following:
+
+- Turn the byte stream into a token stream, discarding C++-style comments
+  (a special comment exists for source references, but we will not explain it here).
+- Turn the token stream into an AST according to the grammar below
+- Register identifiers with the block they are defined in (annotation to the
+  AST node) and note from which point on, variables can be accessed.
+
+The assembly lexer follows the one defined by Solidity itself.
+
+Whitespace is used to delimit tokens and it consists of the characters
+Space, Tab and Linefeed. Comments are regular JavaScript/C++ comments and
+are interpreted in the same way as Whitespace.
+
+Grammar::
+
+    AssemblyBlock = '{' AssemblyItem* '}'
+    AssemblyItem =
+        Identifier |
+        AssemblyBlock |
+        FunctionalAssemblyExpression |
+        AssemblyLocalDefinition |
+        FunctionalAssemblyAssignment |
+        AssemblyAssignment |
+        LabelDefinition |
+        AssemblySwitch |
+        AssemblyFunctionDefinition |
+        AssemblyFor |
+        'break' | 'continue' |
+        SubAssembly | 'dataSize' '(' Identifier ')' |
+        LinkerSymbol |
+        'errorLabel' | 'bytecodeSize' |
+        NumberLiteral | StringLiteral | HexLiteral
+    Identifier = [a-zA-Z_$] [a-zA-Z_0-9]*
+    FunctionalAssemblyExpression = Identifier '(' ( AssemblyItem ( ',' AssemblyItem )* )? ')'
+    AssemblyLocalDefinition = 'let' IdentifierOrList ':=' FunctionalAssemblyExpression
+    FunctionalAssemblyAssignment = IdentifierOrList ':=' FunctionalAssemblyExpression
+    IdentifierOrList = Identifier | '(' IdentifierList ')'
+    IdentifierList = Identifier ( ',' Identifier)*
+    AssemblyAssignment = '=:' Identifier
+    LabelDefinition = Identifier ( '[' ( IdentifierList | NumberLiteral ) ']' )? ':'
+    AssemblySwitch = 'switch' FunctionalAssemblyExpression AssemblyCase*
+        ( 'default' ':' AssemblyBlock )?
+    AssemblyCase = 'case' FunctionalAssemblyExpression ':' AssemblyBlock
+    AssemblyFunctionDefinition = 'function' Identifier '(' IdentifierList? ')'
+        ( '->' '(' IdentifierList ')' )? AssemblyBlock
+    AssemblyFor = 'for' ( AssemblyBlock | FunctionalAssemblyExpression)
+        FunctionalAssemblyExpression ( AssemblyBlock | FunctionalAssemblyExpression) AssemblyBlock
+    SubAssembly = 'assembly' Identifier AssemblyBlock
+    LinkerSymbol = 'linkerSymbol' '(' StringLiteral ')'
+    NumberLiteral = HexNumber | DecimalNumber
+    HexLiteral = 'hex' ('"' ([0-9a-fA-F]{2})* '"' | '\'' ([0-9a-fA-F]{2})* '\'')
+    StringLiteral = '"' ([^"\r\n\\] | '\\' .)* '"'
+    HexNumber = '0x' [0-9a-fA-F]+
+    DecimalNumber = [0-9]+
+
+
+Desugaring
+----------
+
+An AST transformation removes for, switch and function constructs. The result
+is still parseable by the same parser, but it will not use certain constructs.
+If jumpdests are added that are only jumped to and not continued at, information
+about the stack content is added, unless no local variables of outer scopes are
+accessed or the stack height is the same as for the previous instruction.
+
+Pseudocode::
+
+    desugar item: AST -> AST =
+    match item {
+    AssemblyFunctionDefinition('function' name '(' arg1, ..., argn ')' '->' ( '(' ret1, ..., retm ')' body) ->
+      <name>:
+      {
+        $<name>_start [$retPC, $argn, ..., arg1]:
+        let ret1 := 0 ... let retm := 0
+        { desugar(body) }
+        swap and pop items so that only ret1, ... retn, $retPC are left on the stack
+        jump 
+      }
+    AssemblyFor('for' { init } condition post body) ->
+      {
+        init // cannot be its own block because we want variable scope to extend into the body
+        // find I such that there are no labels $forI_*
+        $forI_begin:
+        jumpi($forI_end, iszero(condition))
+        { body }
+        $forI_continue:
+        { post }
+        jump($forI_begin)
+        $forI_end:
+      }
+    'break' ->
+      {
+        // find nearest enclosing scope with label $forI_end
+        pop all local variables that are defined at the current point
+        but not at $forI_end
+        jump($forI_end)
+      }
+    'continue' ->
+      {
+        // find nearest enclosing scope with label $forI_continue
+        pop all local variables that are defined at the current point
+        but not at $forI_continue
+        jump($forI_continue)
+      }
+    AssemblySwitch(switch condition cases ( default: defaultBlock )? ) ->
+      {
+        // find I such that there is no $switchI* label or variable
+        let $switchI_value := condition
+        for each of cases match {
+          case val: -> jumpi($switchI_caseJ, eq($switchI_value, val))
+        }
+        if default block present: ->
+          { defaultBlock jump($switchI_end) }
+        for each of cases match {
+          case val: { body } -> $switchI_caseJ: { body jump($switchI_end) }
+        }
+        $switchI_end:
+      }
+    FunctionalAssemblyExpression( identifier(arg1, arg2, ..., argn) ) ->
+      {
+        if identifier is function <name> with n args and m ret values ->
+          {
+            // find I such that $funcallI_* does not exist
+            $funcallI_return argn  ... arg2 arg1 jump(<name>)
+            if the current context is `let (id1, ..., idm) := f(...)` ->
+              $funcallI_return [id1, ..., idm]:
+            else ->
+              $funcallI_return[m - n - 1]:
+              turn the functional expression that leads to the function call
+              into a statement stream
+          }
+        else -> desugar(children of node)
+      }
+    default node ->
+      desugar(children of node)
+    }
+
+Opcode Stream Generation
+------------------------
+
+During opcode stream generation, we keep track of the current stack height,
+so that accessing stack variables by name is possible.
+
+Pseudocode::
+
+    codegen item: AST -> opcode_stream =
+    match item {
+    AssemblyBlock({ items }) ->
+      join(codegen(item) for item in items)
+      if last generated opcode has continuing control flow:
+        POP for all local variables registered at the block (including variables
+        introduced by labels)
+        warn if the stack height at this point is not the same as at the start of the block
+    Identifier(id) ->
+      lookup id in the syntactic stack of blocks
+      match type of id
+        Local Variable ->
+          DUPi where i = 1 + stack_height - stack_height_of_identifier(id)
+        Label ->
+          // reference to be resolved during bytecode generation
+          PUSH<bytecode position of label>
+        SubAssembly ->
+          PUSH<bytecode position of subassembly data>
+    FunctionalAssemblyExpression(id ( arguments ) ) ->
+      join(codegen(arg) for arg in arguments.reversed())
+      id (which has to be an opcode, might be a function name later)
+    AssemblyLocalDefinition(let (id1, ..., idn) := expr) ->
+      register identifiers id1, ..., idn as locals in current block at current stack height
+      codegen(expr) - assert that expr returns n items to the stack
+    FunctionalAssemblyAssignment((id1, ..., idn) := expr) ->
+      lookup id1, ..., idn in the syntactic stack of blocks, assert that they are variables
+      codegen(expr)
+      for j = n, ..., i:
+      SWAPi where i = 1 + stack_height - stack_height_of_identifier(idj)
+      POP
+    AssemblyAssignment(=: id) ->
+      look up id in the syntactic stack of blocks, assert that it is a variable
+      SWAPi where i = 1 + stack_height - stack_height_of_identifier(id)
+      POP
+    LabelDefinition(name [id1, ..., idn] :) ->
+      JUMPDEST
+      // register new variables id1, ..., idn and set the stack height to
+      // stack_height_at_block_start + number_of_local_variables
+    LabelDefinition(name [number] :) ->
+      JUMPDEST
+      // adjust stack height by +number (can be negative)
+    NumberLiteral(num) ->
+      PUSH<num interpreted as decimal and right-aligned>
+    HexLiteral(lit) ->
+      PUSH32<lit interpreted as hex and left-aligned>
+    StringLiteral(lit) ->
+      PUSH32<lit utf-8 encoded and left-aligned>
+    SubAssembly(assembly <name> block) ->
+      append codegen(block) at the end of the code
+    dataSize(<name>) ->
+      assert that <name> is a subassembly ->
+      PUSH32<size of code generated from subassembly <name>>
+    linkerSymbol(<lit>) ->
+      PUSH32<zeros> and append position to linker table
+    }
diff --git a/docs/conf.py b/docs/conf.py
index 2bc79fd9..ecabbb86 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -56,9 +56,9 @@ copyright = '2016, Ethereum'
 # built documents.
 #
 # The short X.Y version.
-version = '0.4.7'
+version = '0.4.8'
 # The full version, including alpha/beta/rc tags.
-release = '0.4.7-develop'
+release = '0.4.8-develop'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/docs/contracts.rst b/docs/contracts.rst
index e82b7495..edc42c3d 100644
--- a/docs/contracts.rst
+++ b/docs/contracts.rst
@@ -877,6 +877,13 @@ cannot be resolved.
 A simple rule to remember is to specify the base classes in
 the order from "most base-like" to "most derived".
 
+Inheriting Different Kinds of Members of the Same Name
+======================================================
+
+When the inheritance results in a contract with a function and a modifier of the same name, it is considered as an error.
+This error is produced also by an event and a modifier of the same name, and a function and an event of the same name.
+As an exception, a state variable accessor can override a public function.
+
 .. index:: ! contract;abstract, ! abstract contract
 
 ******************
diff --git a/docs/control-structures.rst b/docs/control-structures.rst
index 0802c085..6c0b0f27 100644
--- a/docs/control-structures.rst
+++ b/docs/control-structures.rst
@@ -207,8 +207,8 @@ Creating Contracts via ``new``
 ==============================
 
 A contract can create a new contract using the ``new`` keyword. The full
-code of the contract being created has to be known and, thus, recursive
-creation-dependencies are now possible.
+code of the contract being created has to be known in advance, so recursive
+creation-dependencies are not possible.
 
 ::
 
diff --git a/docs/grammar.txt b/docs/grammar.txt
index d15fbaf7..62b4a021 100644
--- a/docs/grammar.txt
+++ b/docs/grammar.txt
@@ -14,7 +14,7 @@ ContractDefinition = ( 'contract' | 'library' ) Identifier
 ContractPart = StateVariableDeclaration | UsingForDeclaration
              | StructDefinition | ModifierDefinition | FunctionDefinition | EventDefinition | EnumDefinition
 
-InheritanceSpecifier = Identifier ( '(' Expression ( ',' Expression )* ')' )?
+InheritanceSpecifier = UserDefinedTypeName ( '(' Expression ( ',' Expression )* ')' )?
 
 StateVariableDeclaration = TypeName ( 'public' | 'internal' | 'private' )? Identifier ('=' Expression)? ';'
 UsingForDeclaration = 'using' Identifier 'for' ('*' | TypeName) ';'
@@ -23,7 +23,7 @@ StructDefinition = 'struct' Identifier '{'
 ModifierDefinition = 'modifier' Identifier ParameterList? Block
 FunctionDefinition = 'function' Identifier? ParameterList
                      ( FunctionCall | Identifier | 'constant' | 'payable' | 'external' | 'public' | 'internal' | 'private' )*
-                     ( 'returns' ParameterList )? Block
+                     ( 'returns' ParameterList )? ( ';' | Block )
 EventDefinition = 'event' Identifier IndexedParameterList 'anonymous'? ';'
 
 EnumValue = Identifier
@@ -35,10 +35,18 @@ TypeNameList =         '(' ( TypeName (',' TypeName )* )? ')'
 
 // semantic restriction: mappings and structs (recursively) containing mappings
 // are not allowed in argument lists
-VariableDeclaration = TypeName Identifier
-TypeName = ElementaryTypeName | Identifier StorageLocation? | Mapping | ArrayTypeName | FunctionTypeName
+VariableDeclaration = TypeName StorageLocation? Identifier
+
+TypeName = ElementaryTypeName
+         | UserDefinedTypeName
+         | Mapping
+         | ArrayTypeName
+         | FunctionTypeName
+
+UserDefinedTypeName = Identifier ( '.' Identifier )*
+
 Mapping = 'mapping' '(' ElementaryTypeName '=>' TypeName ')'
-ArrayTypeName = TypeName StorageLocation? '[' Expression? ']'
+ArrayTypeName = TypeName '[' Expression? ']'
 FunctionTypeName = 'function' TypeNameList ( 'internal' | 'external' | 'constant' | 'payable' )*
                    ( 'returns' TypeNameList )?
 StorageLocation = 'memory' | 'storage'
@@ -69,7 +77,7 @@ Expression =
   | Expression '**' Expression
   | Expression ('*' | '/' | '%') Expression
   | Expression ('+' | '-') Expression
-  | Expression ('<<' | '>>')
+  | Expression ('<<' | '>>') Expression
   | Expression '&' Expression
   | Expression '^' Expression
   | Expression '|' Expression
@@ -82,21 +90,37 @@ Expression =
   | Expression? (',' Expression)
   | PrimaryExpression
 
-PrimaryExpression = Identifier | BooleanLiteral | NumberLiteral | HexLiteral | StringLiteral
+PrimaryExpression = Identifier
+                  | BooleanLiteral
+                  | NumberLiteral
+                  | HexLiteral
+                  | StringLiteral
+                  | ElementaryTypeNameExpression
+
+ExpressionList = Expression ( ',' Expression )*
+NameValueList = Identifier ':' Expression ( ',' Identifier ':' Expression )*
 
-FunctionCall = ( PrimaryExpression | NewExpression | TypeName ) ( ( '.' Identifier ) | ( '[' Expression ']' ) )* '(' Expression? ( ',' Expression )* ')'
-NewExpression = 'new' Identifier
+FunctionCall = ( PrimaryExpression | NewExpression | TypeName ) ( ( '.' Identifier ) | ( '[' Expression ']' ) )* '(' FunctionCallArguments ')'
+FunctionCallArguments = '{' NameValueList? '}'
+                      | ExpressionList?
+
+NewExpression = 'new' TypeName
 MemberAccess = Expression '.' Identifier
 IndexAccess = Expression '[' Expression? ']'
 
 BooleanLiteral = 'true' | 'false'
-NumberLiteral = '0x'? [0-9]+ (' ' NumberUnit)?
+NumberLiteral = ( HexNumber | DecimalNumber ) (' ' NumberUnit)?
 NumberUnit = 'wei' | 'szabo' | 'finney' | 'ether'
            | 'seconds' | 'minutes' | 'hours' | 'days' | 'weeks' | 'years'
 HexLiteral = 'hex' ('"' ([0-9a-fA-F]{2})* '"' | '\'' ([0-9a-fA-F]{2})* '\'')
 StringLiteral = '"' ([^"\r\n\\] | '\\' .)* '"'
 Identifier = [a-zA-Z_] [a-zA-Z_0-9]*
 
+HexNumber = '0x' [0-9a-fA-F]+
+DecimalNumber = [0-9]+
+
+ElementaryTypeNameExpression = ElementaryTypeName
+
 ElementaryTypeName = 'address' | 'bool' | 'string' | 'var'
                    | Int | Uint | Byte | Fixed | Ufixed
 
diff --git a/docs/index.rst b/docs/index.rst
index 9bee1515..cb79687b 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -87,6 +87,15 @@ Solidity Tools
 * `evmdis <https://github.com/Arachnid/evmdis>`_
     EVM Disassembler that performs static analysis on the bytecode to provide a higher level of abstraction than raw EVM operations.
 
+Third-Party Solidity Parsers and Grammars
+-----------------------------------------
+
+* `solidity-parser <https://github.com/ConsenSys/solidity-parser>`_
+    Solidity parser for JavaScript
+
+* `Solidity Grammar for ANTLR 4 <https://github.com/federicobond/solidity-antlr4>`_
+    Solidity grammar for the ANTLR 4 parser generator
+
 Language Documentation
 ----------------------
 
diff --git a/docs/introduction-to-smart-contracts.rst b/docs/introduction-to-smart-contracts.rst
index aee1e03b..4c134abc 100644
--- a/docs/introduction-to-smart-contracts.rst
+++ b/docs/introduction-to-smart-contracts.rst
@@ -283,8 +283,8 @@ determined at the time the contract is created
 (it is derived from the creator address and the number
 of transactions sent from that address, the so-called "nonce").
 
-Apart from the fact whether an account stores code or not,
-the EVM treats the two types equally, though.
+Regardless of whether or not the account stores code, the two types are
+treated equally by the EVM.
 
 Every account has a persistent key-value store mapping 256-bit words to 256-bit
 words called **storage**.
diff --git a/docs/layout-of-source-files.rst b/docs/layout-of-source-files.rst
index 17ac8c6f..1e27b7c0 100644
--- a/docs/layout-of-source-files.rst
+++ b/docs/layout-of-source-files.rst
@@ -79,8 +79,9 @@ Paths
 -----
 
 In the above, ``filename`` is always treated as a path with ``/`` as directory separator,
-``.`` as the current and ``..`` as the parent directory. Path names that do not start
-with ``.`` are treated as absolute paths.
+``.`` as the current and ``..`` as the parent directory.  When ``.`` or ``..`` is followed by a character except ``/``,
+it is not considered as the current or the parent directory.
+All path names are treated as absolute paths unless they start with the current ``.`` or the parent directory ``..``.
 
 To import a file ``x`` from the same directory as the current file, use ``import "./x" as x;``.
 If you use ``import "x" as x;`` instead, a different file could be referenced
@@ -96,8 +97,8 @@ Use in Actual Compilers
 When the compiler is invoked, it is not only possible to specify how to
 discover the first element of a path, but it is possible to specify path prefix
 remappings so that e.g. ``github.com/ethereum/dapp-bin/library`` is remapped to
-``/usr/local/dapp-bin/library`` and the compiler will read the files from there. If
-remapping keys are prefixes of each other, the longest is tried first. This
+``/usr/local/dapp-bin/library`` and the compiler will read the files from there.
+If multiple remappings can be applied, the one with the longest key is tried first. This
 allows for a "fallback-remapping" with e.g. ``""`` maps to
 ``"/usr/local/include/solidity"``. Furthermore, these remappings can
 depend on the context, which allows you to configure packages to
diff --git a/docs/miscellaneous.rst b/docs/miscellaneous.rst
index 4a9dad87..378c3c96 100644
--- a/docs/miscellaneous.rst
+++ b/docs/miscellaneous.rst
@@ -570,3 +570,4 @@ Language Grammar
 ================
 
 .. literalinclude:: grammar.txt
+   :language: none
diff --git a/docs/solidity-in-depth.rst b/docs/solidity-in-depth.rst
index 40704698..b6217b47 100644
--- a/docs/solidity-in-depth.rst
+++ b/docs/solidity-in-depth.rst
@@ -16,4 +16,5 @@ If something is missing here, please contact us on
    units-and-global-variables.rst
    control-structures.rst
    contracts.rst
+   assembly.rst
    miscellaneous.rst
diff --git a/docs/types.rst b/docs/types.rst
index 069a9190..6b67e684 100644
--- a/docs/types.rst
+++ b/docs/types.rst
@@ -765,7 +765,7 @@ assigning it to a local variable, as in
 Mappings
 ========
 
-Mapping types are declared as ``mapping _KeyType => _ValueType``.
+Mapping types are declared as ``mapping(_KeyType => _ValueType)``.
 Here ``_KeyType`` can be almost any type except for a mapping, a dynamically sized array, a contract, an enum and a struct.
 ``_ValueType`` can actually be any type, including mappings.
 
diff --git a/libdevcore/Assertions.h b/libdevcore/Assertions.h
index 05e0b0e5..0fb5837c 100644
--- a/libdevcore/Assertions.h
+++ b/libdevcore/Assertions.h
@@ -73,27 +73,19 @@ inline bool assertEqualAux(A const& _a, B const& _b, char const* _aStr, char con
 /// Use it as assertThrow(1 == 1, ExceptionType, "Mathematics is wrong.");
 /// Do NOT supply an exception object as the second parameter.
 #define assertThrow(_condition, _ExceptionType, _description) \
-	::dev::assertThrowAux<_ExceptionType>(!!(_condition), _description, __LINE__, __FILE__, ETH_FUNC)
+	do \
+	{ \
+		if (!(_condition)) \
+			::boost::throw_exception( \
+				_ExceptionType() << \
+				::dev::errinfo_comment(_description) << \
+				::boost::throw_function(ETH_FUNC) << \
+				::boost::throw_file(__FILE__) << \
+				::boost::throw_line(__LINE__) \
+			); \
+	} \
+	while (false)
 
 using errinfo_comment = boost::error_info<struct tag_comment, std::string>;
 
-template <class _ExceptionType>
-inline void assertThrowAux(
-	bool _condition,
-	::std::string const& _errorDescription,
-	unsigned _line,
-	char const* _file,
-	char const* _function
-)
-{
-	if (!_condition)
-		::boost::throw_exception(
-			_ExceptionType() <<
-			::dev::errinfo_comment(_errorDescription) <<
-			::boost::throw_function(_function) <<
-			::boost::throw_file(_file) <<
-			::boost::throw_line(_line)
-		);
-}
-
 }
diff --git a/libevmasm/Assembly.cpp b/libevmasm/Assembly.cpp
index a9ca24dc..845abfd4 100644
--- a/libevmasm/Assembly.cpp
+++ b/libevmasm/Assembly.cpp
@@ -117,69 +117,36 @@ string Assembly::locationFromSources(StringMap const& _sourceCodes, SourceLocati
 
 ostream& Assembly::streamAsm(ostream& _out, string const& _prefix, StringMap const& _sourceCodes) const
 {
-	_out << _prefix << ".code:" << endl;
-	for (AssemblyItem const& i: m_items)
+	for (size_t i = 0; i < m_items.size(); ++i)
 	{
-		_out << _prefix;
-		switch (i.type())
+		AssemblyItem const& item = m_items[i];
+		if (!item.location().isEmpty() && (i == 0 || m_items[i - 1].location() != item.location()))
 		{
-		case Operation:
-			_out << "  " << instructionInfo(i.instruction()).name  << "\t" << i.getJumpTypeAsString();
-			break;
-		case Push:
-			_out << "  PUSH" << dec << max<unsigned>(1, dev::bytesRequired(i.data())) << " 0x" << hex << i.data();
-			break;
-		case PushString:
-			_out << "  PUSH \"" << m_strings.at((h256)i.data()) << "\"";
-			break;
-		case PushTag:
-			if (i.data() == 0)
-				_out << "  PUSH [ErrorTag]";
-			else
-			{
-				size_t subId = i.splitForeignPushTag().first;
-				if (subId == size_t(-1))
-					_out << "  PUSH [tag" << dec << i.splitForeignPushTag().second << "]";
-				else
-					_out << "  PUSH [tag" << dec << subId << ":" << i.splitForeignPushTag().second << "]";
-			}
-			break;
-		case PushSub:
-			_out << "  PUSH [$" << size_t(i.data()) << "]";
-			break;
-		case PushSubSize:
-			_out << "  PUSH #[$" << size_t(i.data()) << "]";
-			break;
-		case PushProgramSize:
-			_out << "  PUSHSIZE";
-			break;
-		case PushLibraryAddress:
-			_out << "  PUSHLIB \"" << m_libraries.at(h256(i.data())) << "\"";
-			break;
-		case Tag:
-			_out << "tag" << dec << i.data() << ": " << endl << _prefix << "  JUMPDEST";
-			break;
-		case PushData:
-			_out << "  PUSH [" << hex << (unsigned)i.data() << "]";
-			break;
-		default:
-			BOOST_THROW_EXCEPTION(InvalidOpcode());
+			_out << _prefix << "    /*";
+			if (item.location().sourceName)
+				_out << " \"" + *item.location().sourceName + "\"";
+			if (!item.location().isEmpty())
+				_out << ":" << to_string(item.location().start) + ":" + to_string(item.location().end);
+			_out << " */" << endl;
 		}
-		_out << "\t\t" << locationFromSources(_sourceCodes, i.location()) << endl;
+		_out << _prefix << (item.type() == Tag ? "" : "  ") << item.toAssemblyText() << endl;
 	}
 
 	if (!m_data.empty() || !m_subs.empty())
 	{
-		_out << _prefix << ".data:" << endl;
+		_out << _prefix << "stop" << endl;
+		Json::Value data;
 		for (auto const& i: m_data)
-			if (u256(i.first) >= m_subs.size())
-				_out << _prefix << "  " << hex << (unsigned)(u256)i.first << ": " << dev::toHex(i.second) << endl;
+			assertThrow(u256(i.first) < m_subs.size(), AssemblyException, "Data not yet implemented.");
+
 		for (size_t i = 0; i < m_subs.size(); ++i)
 		{
-			_out << _prefix << "  " << hex << i << ": " << endl;
-			m_subs[i]->stream(_out, _prefix + "  ", _sourceCodes);
+			_out << endl << _prefix << "sub_" << i << ": assembly {\n";
+			m_subs[i]->streamAsm(_out, _prefix + "    ", _sourceCodes);
+			_out << _prefix << "}" << endl;
 		}
 	}
+
 	return _out;
 }
 
@@ -449,7 +416,7 @@ LinkerObject const& Assembly::assemble() const
 		switch (i.type())
 		{
 		case Operation:
-			ret.bytecode.push_back((byte)i.data());
+			ret.bytecode.push_back((byte)i.instruction());
 			break;
 		case PushString:
 		{
diff --git a/libevmasm/AssemblyItem.cpp b/libevmasm/AssemblyItem.cpp
index 54e38de8..6c7d5425 100644
--- a/libevmasm/AssemblyItem.cpp
+++ b/libevmasm/AssemblyItem.cpp
@@ -20,6 +20,7 @@
  */
 
 #include "AssemblyItem.h"
+#include <libevmasm/SemanticInformation.h>
 #include <fstream>
 
 using namespace std;
@@ -28,19 +29,19 @@ using namespace dev::eth;
 
 AssemblyItem AssemblyItem::toSubAssemblyTag(size_t _subId) const
 {
-	assertThrow(m_data < (u256(1) << 64), Exception, "Tag already has subassembly set.");
+	assertThrow(data() < (u256(1) << 64), Exception, "Tag already has subassembly set.");
 
 	assertThrow(m_type == PushTag || m_type == Tag, Exception, "");
 	AssemblyItem r = *this;
 	r.m_type = PushTag;
-	r.setPushTagSubIdAndTag(_subId, size_t(m_data));
+	r.setPushTagSubIdAndTag(_subId, size_t(data()));
 	return r;
 }
 
 pair<size_t, size_t> AssemblyItem::splitForeignPushTag() const
 {
 	assertThrow(m_type == PushTag || m_type == Tag, Exception, "");
-	return make_pair(size_t(m_data / (u256(1) << 64)) - 1, size_t(m_data));
+	return make_pair(size_t((data()) / (u256(1) << 64)) - 1, size_t(data()));
 }
 
 void AssemblyItem::setPushTagSubIdAndTag(size_t _subId, size_t _tag)
@@ -59,7 +60,7 @@ unsigned AssemblyItem::bytesRequired(unsigned _addressLength) const
 	case PushString:
 		return 33;
 	case Push:
-		return 1 + max<unsigned>(1, dev::bytesRequired(m_data));
+		return 1 + max<unsigned>(1, dev::bytesRequired(data()));
 	case PushSubSize:
 	case PushProgramSize:
 		return 4;		// worst case: a 16MB program
@@ -97,6 +98,28 @@ int AssemblyItem::deposit() const
 	return 0;
 }
 
+bool AssemblyItem::canBeFunctional() const
+{
+	switch (m_type)
+	{
+	case Operation:
+		return !SemanticInformation::isDupInstruction(*this) && !SemanticInformation::isSwapInstruction(*this);
+	case Push:
+	case PushString:
+	case PushTag:
+	case PushData:
+	case PushSub:
+	case PushSubSize:
+	case PushProgramSize:
+	case PushLibraryAddress:
+		return true;
+	case Tag:
+		return false;
+	default:;
+	}
+	return 0;
+}
+
 string AssemblyItem::getJumpTypeAsString() const
 {
 	switch (m_jumpType)
@@ -111,6 +134,65 @@ string AssemblyItem::getJumpTypeAsString() const
 	}
 }
 
+string AssemblyItem::toAssemblyText() const
+{
+	string text;
+	switch (type())
+	{
+	case Operation:
+	{
+		assertThrow(isValidInstruction(instruction()), AssemblyException, "Invalid instruction.");
+		string name = instructionInfo(instruction()).name;
+		transform(name.begin(), name.end(), name.begin(), [](unsigned char _c) { return tolower(_c); });
+		text = name;
+		break;
+	}
+	case Push:
+		text = toHex(toCompactBigEndian(data(), 1), 1, HexPrefix::Add);
+		break;
+	case PushString:
+		assertThrow(false, AssemblyException, "Push string assembly output not implemented.");
+		break;
+	case PushTag:
+		assertThrow(data() < 0x10000, AssemblyException, "Sub-assembly tags not yet implemented.");
+		text = string("tag_") + to_string(size_t(data()));
+		break;
+	case Tag:
+		assertThrow(data() < 0x10000, AssemblyException, "Sub-assembly tags not yet implemented.");
+		text = string("tag_") + to_string(size_t(data())) + ":";
+		break;
+	case PushData:
+		assertThrow(false, AssemblyException, "Push data not implemented.");
+		break;
+	case PushSub:
+		text = string("dataOffset(sub_") + to_string(size_t(data())) + ")";
+		break;
+	case PushSubSize:
+		text = string("dataSize(sub_") + to_string(size_t(data())) + ")";
+		break;
+	case PushProgramSize:
+		text = string("bytecodeSize");
+		break;
+	case PushLibraryAddress:
+		text = string("linkerSymbol(\"") + toHex(data()) + string("\")");
+		break;
+	case UndefinedItem:
+		assertThrow(false, AssemblyException, "Invalid assembly item.");
+		break;
+	default:
+		BOOST_THROW_EXCEPTION(InvalidOpcode());
+	}
+	if (m_jumpType == JumpType::IntoFunction || m_jumpType == JumpType::OutOfFunction)
+	{
+		text += "\t//";
+		if (m_jumpType == JumpType::IntoFunction)
+			text += " in";
+		else
+			text += " out";
+	}
+	return text;
+}
+
 ostream& dev::eth::operator<<(ostream& _out, AssemblyItem const& _item)
 {
 	switch (_item.type())
diff --git a/libevmasm/AssemblyItem.h b/libevmasm/AssemblyItem.h
index b5bd3ed8..002b3c87 100644
--- a/libevmasm/AssemblyItem.h
+++ b/libevmasm/AssemblyItem.h
@@ -59,16 +59,22 @@ public:
 	AssemblyItem(u256 _push, SourceLocation const& _location = SourceLocation()):
 		AssemblyItem(Push, _push, _location) { }
 	AssemblyItem(solidity::Instruction _i, SourceLocation const& _location = SourceLocation()):
-		AssemblyItem(Operation, byte(_i), _location) { }
+		m_type(Operation),
+		m_instruction(_i),
+		m_location(_location)
+	{}
 	AssemblyItem(AssemblyItemType _type, u256 _data = 0, SourceLocation const& _location = SourceLocation()):
 		m_type(_type),
-		m_data(_data),
 		m_location(_location)
 	{
+		if (m_type == Operation)
+			m_instruction = Instruction(byte(_data));
+		else
+			m_data = std::make_shared<u256>(_data);
 	}
 
-	AssemblyItem tag() const { assertThrow(m_type == PushTag || m_type == Tag, Exception, ""); return AssemblyItem(Tag, m_data); }
-	AssemblyItem pushTag() const { assertThrow(m_type == PushTag || m_type == Tag, Exception, ""); return AssemblyItem(PushTag, m_data); }
+	AssemblyItem tag() const { assertThrow(m_type == PushTag || m_type == Tag, Exception, ""); return AssemblyItem(Tag, data()); }
+	AssemblyItem pushTag() const { assertThrow(m_type == PushTag || m_type == Tag, Exception, ""); return AssemblyItem(PushTag, data()); }
 	/// Converts the tag to a subassembly tag. This has to be called in order to move a tag across assemblies.
 	/// @param _subId the identifier of the subassembly the tag is taken from.
 	AssemblyItem toSubAssemblyTag(size_t _subId) const;
@@ -79,25 +85,42 @@ public:
 	void setPushTagSubIdAndTag(size_t _subId, size_t _tag);
 
 	AssemblyItemType type() const { return m_type; }
-	u256 const& data() const { return m_data; }
-	void setType(AssemblyItemType const _type) { m_type = _type; }
-	void setData(u256 const& _data) { m_data = _data; }
+	u256 const& data() const { assertThrow(m_type != Operation, Exception, ""); return *m_data; }
+	void setData(u256 const& _data) { assertThrow(m_type != Operation, Exception, ""); m_data = std::make_shared<u256>(_data); }
 
 	/// @returns the instruction of this item (only valid if type() == Operation)
-	Instruction instruction() const { return Instruction(byte(m_data)); }
+	Instruction instruction() const { assertThrow(m_type == Operation, Exception, ""); return m_instruction; }
 
 	/// @returns true if the type and data of the items are equal.
-	bool operator==(AssemblyItem const& _other) const { return m_type == _other.m_type && m_data == _other.m_data; }
+	bool operator==(AssemblyItem const& _other) const
+	{
+		if (type() != _other.type())
+			return false;
+		if (type() == Operation)
+			return instruction() == _other.instruction();
+		else
+			return data() == _other.data();
+	}
 	bool operator!=(AssemblyItem const& _other) const { return !operator==(_other); }
 	/// Less-than operator compatible with operator==.
-	bool operator<(AssemblyItem const& _other) const { return std::tie(m_type, m_data) < std::tie(_other.m_type, _other.m_data); }
+	bool operator<(AssemblyItem const& _other) const
+	{
+		if (type() != _other.type())
+			return type() < _other.type();
+		else if (type() == Operation)
+			return instruction() < _other.instruction();
+		else
+			return data() < _other.data();
+	}
 
 	/// @returns an upper bound for the number of bytes required by this item, assuming that
 	/// the value of a jump tag takes @a _addressLength bytes.
 	unsigned bytesRequired(unsigned _addressLength) const;
 	int deposit() const;
 
-	bool match(AssemblyItem const& _i) const { return _i.m_type == UndefinedItem || (m_type == _i.m_type && (m_type != Operation || m_data == _i.m_data)); }
+	/// @returns true if the assembly item can be used in a functional context.
+	bool canBeFunctional() const;
+
 	void setLocation(SourceLocation const& _location) { m_location = _location; }
 	SourceLocation const& location() const { return m_location; }
 
@@ -108,9 +131,12 @@ public:
 	void setPushedValue(u256 const& _value) const { m_pushedValue = std::make_shared<u256>(_value); }
 	u256 const* pushedValue() const { return m_pushedValue.get(); }
 
+	std::string toAssemblyText() const;
+
 private:
 	AssemblyItemType m_type;
-	u256 m_data;
+	Instruction m_instruction; ///< Only valid if m_type == Operation
+	std::shared_ptr<u256> m_data; ///< Only valid if m_type != Operation
 	SourceLocation m_location;
 	JumpType m_jumpType = JumpType::Ordinary;
 	/// Pushed value for operations with data to be determined during assembly stage,
diff --git a/libevmasm/CommonSubexpressionEliminator.cpp b/libevmasm/CommonSubexpressionEliminator.cpp
index 6294e579..fd4fffa6 100644
--- a/libevmasm/CommonSubexpressionEliminator.cpp
+++ b/libevmasm/CommonSubexpressionEliminator.cpp
@@ -303,7 +303,9 @@ void CSECodeGenerator::generateClassElement(Id _c, bool _allowSequenced)
 	for (auto it: m_classPositions)
 		for (auto p: it.second)
 			if (p > m_stackHeight)
+			{
 				assertThrow(false, OptimizerException, "");
+			}
 	// do some cleanup
 	removeStackTopIfPossible();
 
diff --git a/libevmasm/ConstantOptimiser.cpp b/libevmasm/ConstantOptimiser.cpp
index f4a50c2d..86244e17 100644
--- a/libevmasm/ConstantOptimiser.cpp
+++ b/libevmasm/ConstantOptimiser.cpp
@@ -38,6 +38,7 @@ unsigned ConstantOptimisationMethod::optimiseConstants(
 	for (AssemblyItem const& item: _items)
 		if (item.type() == Push)
 			pushes[item]++;
+	map<u256, AssemblyItems> pendingReplacements;
 	for (auto it: pushes)
 	{
 		AssemblyItem const& item = it.first;
@@ -53,17 +54,22 @@ unsigned ConstantOptimisationMethod::optimiseConstants(
 		bigint copyGas = copy.gasNeeded();
 		ComputeMethod compute(params, item.data());
 		bigint computeGas = compute.gasNeeded();
+		AssemblyItems replacement;
 		if (copyGas < literalGas && copyGas < computeGas)
 		{
-			copy.execute(_assembly, _items);
+			replacement = copy.execute(_assembly);
 			optimisations++;
 		}
-		else if (computeGas < literalGas && computeGas < copyGas)
+		else if (computeGas < literalGas && computeGas <= copyGas)
 		{
-			compute.execute(_assembly, _items);
+			replacement = compute.execute(_assembly);
 			optimisations++;
 		}
+		if (!replacement.empty())
+			pendingReplacements[item.data()] = replacement;
 	}
+	if (!pendingReplacements.empty())
+		replaceConstants(_items, pendingReplacements);
 	return optimisations;
 }
 
@@ -101,18 +107,24 @@ size_t ConstantOptimisationMethod::bytesRequired(AssemblyItems const& _items)
 
 void ConstantOptimisationMethod::replaceConstants(
 	AssemblyItems& _items,
-	AssemblyItems const& _replacement
-) const
+	map<u256, AssemblyItems> const& _replacements
+)
 {
-	assertThrow(_items.size() > 0, OptimizerException, "");
-	for (size_t i = 0; i < _items.size(); ++i)
+	AssemblyItems replaced;
+	for (AssemblyItem const& item: _items)
 	{
-		if (_items.at(i) != AssemblyItem(m_value))
-			continue;
-		_items[i] = _replacement[0];
-		_items.insert(_items.begin() + i + 1, _replacement.begin() + 1, _replacement.end());
-		i += _replacement.size() - 1;
+		if (item.type() == Push)
+		{
+			auto it = _replacements.find(item.data());
+			if (it != _replacements.end())
+			{
+				replaced += it->second;
+				continue;
+			}
+		}
+		replaced.push_back(item);
 	}
+	_items = std::move(replaced);
 }
 
 bigint LiteralMethod::gasNeeded()
@@ -128,38 +140,44 @@ bigint LiteralMethod::gasNeeded()
 CodeCopyMethod::CodeCopyMethod(Params const& _params, u256 const& _value):
 	ConstantOptimisationMethod(_params, _value)
 {
-	m_copyRoutine = AssemblyItems{
-		u256(0),
-		Instruction::DUP1,
-		Instruction::MLOAD, // back up memory
-		u256(32),
-		AssemblyItem(PushData, u256(1) << 16), // has to be replaced
-		Instruction::DUP4,
-		Instruction::CODECOPY,
-		Instruction::DUP2,
-		Instruction::MLOAD,
-		Instruction::SWAP2,
-		Instruction::MSTORE
-	};
 }
 
 bigint CodeCopyMethod::gasNeeded()
 {
 	return combineGas(
 		// Run gas: we ignore memory increase costs
-		simpleRunGas(m_copyRoutine) + GasCosts::copyGas,
+		simpleRunGas(copyRoutine()) + GasCosts::copyGas,
 		// Data gas for copy routines: Some bytes are zero, but we ignore them.
-		bytesRequired(m_copyRoutine) * (m_params.isCreation ? GasCosts::txDataNonZeroGas : GasCosts::createDataGas),
+		bytesRequired(copyRoutine()) * (m_params.isCreation ? GasCosts::txDataNonZeroGas : GasCosts::createDataGas),
 		// Data gas for data itself
 		dataGas(toBigEndian(m_value))
 	);
 }
 
-void CodeCopyMethod::execute(Assembly& _assembly, AssemblyItems& _items)
+AssemblyItems CodeCopyMethod::execute(Assembly& _assembly)
 {
 	bytes data = toBigEndian(m_value);
-	m_copyRoutine[4] = _assembly.newData(data);
-	replaceConstants(_items, m_copyRoutine);
+	AssemblyItems actualCopyRoutine = copyRoutine();
+	actualCopyRoutine[4] = _assembly.newData(data);
+	return actualCopyRoutine;
+}
+
+AssemblyItems const& CodeCopyMethod::copyRoutine() const
+{
+	AssemblyItems static copyRoutine{
+		u256(0),
+		Instruction::DUP1,
+		Instruction::MLOAD, // back up memory
+		u256(32),
+		AssemblyItem(PushData, u256(1) << 16), // has to be replaced
+		Instruction::DUP4,
+		Instruction::CODECOPY,
+		Instruction::DUP2,
+		Instruction::MLOAD,
+		Instruction::SWAP2,
+		Instruction::MSTORE
+	};
+	return copyRoutine;
 }
 
 AssemblyItems ComputeMethod::findRepresentation(u256 const& _value)
diff --git a/libevmasm/ConstantOptimiser.h b/libevmasm/ConstantOptimiser.h
index b35b2a69..dfa2fbf8 100644
--- a/libevmasm/ConstantOptimiser.h
+++ b/libevmasm/ConstantOptimiser.h
@@ -60,7 +60,10 @@ public:
 	explicit ConstantOptimisationMethod(Params const& _params, u256 const& _value):
 		m_params(_params), m_value(_value) {}
 	virtual bigint gasNeeded() = 0;
-	virtual void execute(Assembly& _assembly, AssemblyItems& _items) = 0;
+	/// Executes the method, potentially appending to the assembly and returns a vector of
+	/// assembly items the constant should be relpaced with in one sweep.
+	/// If the vector is empty, the constants will not be deleted.
+	virtual AssemblyItems execute(Assembly& _assembly) = 0;
 
 protected:
 	size_t dataSize() const { return std::max<size_t>(1, dev::bytesRequired(m_value)); }
@@ -83,8 +86,8 @@ protected:
 		return m_params.runs * _runGas + m_params.multiplicity * _repeatedDataGas + _uniqueDataGas;
 	}
 
-	/// Replaces the constant by the code given in @a _replacement.
-	void replaceConstants(AssemblyItems& _items, AssemblyItems const& _replacement) const;
+	/// Replaces all constants i by the code given in @a _replacement[i].
+	static void replaceConstants(AssemblyItems& _items, std::map<u256, AssemblyItems> const& _replacement);
 
 	Params m_params;
 	u256 const& m_value;
@@ -100,7 +103,7 @@ public:
 	explicit LiteralMethod(Params const& _params, u256 const& _value):
 		ConstantOptimisationMethod(_params, _value) {}
 	virtual bigint gasNeeded() override;
-	virtual void execute(Assembly&, AssemblyItems&) override {}
+	virtual AssemblyItems execute(Assembly&) override { return AssemblyItems{}; }
 };
 
 /**
@@ -111,10 +114,10 @@ class CodeCopyMethod: public ConstantOptimisationMethod
 public:
 	explicit CodeCopyMethod(Params const& _params, u256 const& _value);
 	virtual bigint gasNeeded() override;
-	virtual void execute(Assembly& _assembly, AssemblyItems& _items) override;
+	virtual AssemblyItems execute(Assembly& _assembly) override;
 
 protected:
-	AssemblyItems m_copyRoutine;
+	AssemblyItems const& copyRoutine() const;
 };
 
 /**
@@ -130,9 +133,9 @@ public:
 	}
 
 	virtual bigint gasNeeded() override { return gasNeeded(m_routine); }
-	virtual void execute(Assembly&, AssemblyItems& _items) override
+	virtual AssemblyItems execute(Assembly&) override
 	{
-		replaceConstants(_items, m_routine);
+		return m_routine;
 	}
 
 protected:
diff --git a/libevmasm/ExpressionClasses.cpp b/libevmasm/ExpressionClasses.cpp
index d5ccd7e3..fc283b0b 100644
--- a/libevmasm/ExpressionClasses.cpp
+++ b/libevmasm/ExpressionClasses.cpp
@@ -29,6 +29,7 @@
 #include <boost/noncopyable.hpp>
 #include <libevmasm/Assembly.h>
 #include <libevmasm/CommonSubexpressionEliminator.h>
+#include <libevmasm/SimplificationRules.h>
 
 using namespace std;
 using namespace dev;
@@ -40,8 +41,18 @@ bool ExpressionClasses::Expression::operator<(ExpressionClasses::Expression cons
 	assertThrow(!!item && !!_other.item, OptimizerException, "");
 	auto type = item->type();
 	auto otherType = _other.item->type();
-	return std::tie(type, item->data(), arguments, sequenceNumber) <
-		std::tie(otherType, _other.item->data(), _other.arguments, _other.sequenceNumber);
+	if (type != otherType)
+		return type < otherType;
+	else if (type == Operation)
+	{
+		auto instr = item->instruction();
+		auto otherInstr = _other.item->instruction();
+		return std::tie(instr, arguments, sequenceNumber) <
+			std::tie(otherInstr, _other.arguments, _other.sequenceNumber);
+	}
+	else
+		return std::tie(item->data(), arguments, sequenceNumber) <
+			std::tie(_other.item->data(), _other.arguments, _other.sequenceNumber);
 }
 
 ExpressionClasses::Id ExpressionClasses::find(
@@ -170,191 +181,6 @@ string ExpressionClasses::fullDAGToString(ExpressionClasses::Id _id) const
 	return str.str();
 }
 
-class Rules: public boost::noncopyable
-{
-public:
-	Rules();
-	void resetMatchGroups() { m_matchGroups.clear(); }
-	vector<pair<Pattern, function<Pattern()>>> rules() const { return m_rules; }
-
-private:
-	using Expression = ExpressionClasses::Expression;
-	map<unsigned, Expression const*> m_matchGroups;
-	vector<pair<Pattern, function<Pattern()>>> m_rules;
-};
-
-template <class S> S divWorkaround(S const& _a, S const& _b)
-{
-	return (S)(bigint(_a) / bigint(_b));
-}
-
-template <class S> S modWorkaround(S const& _a, S const& _b)
-{
-	return (S)(bigint(_a) % bigint(_b));
-}
-
-Rules::Rules()
-{
-	// Multiple occurences of one of these inside one rule must match the same equivalence class.
-	// Constants.
-	Pattern A(Push);
-	Pattern B(Push);
-	Pattern C(Push);
-	// Anything.
-	Pattern X;
-	Pattern Y;
-	Pattern Z;
-	A.setMatchGroup(1, m_matchGroups);
-	B.setMatchGroup(2, m_matchGroups);
-	C.setMatchGroup(3, m_matchGroups);
-	X.setMatchGroup(4, m_matchGroups);
-	Y.setMatchGroup(5, m_matchGroups);
-	Z.setMatchGroup(6, m_matchGroups);
-
-	m_rules = vector<pair<Pattern, function<Pattern()>>>{
-		// arithmetics on constants
-		{{Instruction::ADD, {A, B}}, [=]{ return A.d() + B.d(); }},
-		{{Instruction::MUL, {A, B}}, [=]{ return A.d() * B.d(); }},
-		{{Instruction::SUB, {A, B}}, [=]{ return A.d() - B.d(); }},
-		{{Instruction::DIV, {A, B}}, [=]{ return B.d() == 0 ? 0 : divWorkaround(A.d(), B.d()); }},
-		{{Instruction::SDIV, {A, B}}, [=]{ return B.d() == 0 ? 0 : s2u(divWorkaround(u2s(A.d()), u2s(B.d()))); }},
-		{{Instruction::MOD, {A, B}}, [=]{ return B.d() == 0 ? 0 : modWorkaround(A.d(), B.d()); }},
-		{{Instruction::SMOD, {A, B}}, [=]{ return B.d() == 0 ? 0 : s2u(modWorkaround(u2s(A.d()), u2s(B.d()))); }},
-		{{Instruction::EXP, {A, B}}, [=]{ return u256(boost::multiprecision::powm(bigint(A.d()), bigint(B.d()), bigint(1) << 256)); }},
-		{{Instruction::NOT, {A}}, [=]{ return ~A.d(); }},
-		{{Instruction::LT, {A, B}}, [=]() { return A.d() < B.d() ? u256(1) : 0; }},
-		{{Instruction::GT, {A, B}}, [=]() -> u256 { return A.d() > B.d() ? 1 : 0; }},
-		{{Instruction::SLT, {A, B}}, [=]() -> u256 { return u2s(A.d()) < u2s(B.d()) ? 1 : 0; }},
-		{{Instruction::SGT, {A, B}}, [=]() -> u256 { return u2s(A.d()) > u2s(B.d()) ? 1 : 0; }},
-		{{Instruction::EQ, {A, B}}, [=]() -> u256 { return A.d() == B.d() ? 1 : 0; }},
-		{{Instruction::ISZERO, {A}}, [=]() -> u256 { return A.d() == 0 ? 1 : 0; }},
-		{{Instruction::AND, {A, B}}, [=]{ return A.d() & B.d(); }},
-		{{Instruction::OR, {A, B}}, [=]{ return A.d() | B.d(); }},
-		{{Instruction::XOR, {A, B}}, [=]{ return A.d() ^ B.d(); }},
-		{{Instruction::BYTE, {A, B}}, [=]{ return A.d() >= 32 ? 0 : (B.d() >> unsigned(8 * (31 - A.d()))) & 0xff; }},
-		{{Instruction::ADDMOD, {A, B, C}}, [=]{ return C.d() == 0 ? 0 : u256((bigint(A.d()) + bigint(B.d())) % C.d()); }},
-		{{Instruction::MULMOD, {A, B, C}}, [=]{ return C.d() == 0 ? 0 : u256((bigint(A.d()) * bigint(B.d())) % C.d()); }},
-		{{Instruction::MULMOD, {A, B, C}}, [=]{ return A.d() * B.d(); }},
-		{{Instruction::SIGNEXTEND, {A, B}}, [=]() -> u256 {
-			if (A.d() >= 31)
-				return B.d();
-			unsigned testBit = unsigned(A.d()) * 8 + 7;
-			u256 mask = (u256(1) << testBit) - 1;
-			return u256(boost::multiprecision::bit_test(B.d(), testBit) ? B.d() | ~mask : B.d() & mask);
-		}},
-
-		// invariants involving known constants
-		{{Instruction::ADD, {X, 0}}, [=]{ return X; }},
-		{{Instruction::SUB, {X, 0}}, [=]{ return X; }},
-		{{Instruction::MUL, {X, 1}}, [=]{ return X; }},
-		{{Instruction::DIV, {X, 1}}, [=]{ return X; }},
-		{{Instruction::SDIV, {X, 1}}, [=]{ return X; }},
-		{{Instruction::OR, {X, 0}}, [=]{ return X; }},
-		{{Instruction::XOR, {X, 0}}, [=]{ return X; }},
-		{{Instruction::AND, {X, ~u256(0)}}, [=]{ return X; }},
-		{{Instruction::AND, {X, 0}}, [=]{ return u256(0); }},
-		{{Instruction::MUL, {X, 0}}, [=]{ return u256(0); }},
-		{{Instruction::DIV, {X, 0}}, [=]{ return u256(0); }},
-		{{Instruction::DIV, {0, X}}, [=]{ return u256(0); }},
-		{{Instruction::MOD, {X, 0}}, [=]{ return u256(0); }},
-		{{Instruction::MOD, {0, X}}, [=]{ return u256(0); }},
-		{{Instruction::OR, {X, ~u256(0)}}, [=]{ return ~u256(0); }},
-		{{Instruction::EQ, {X, 0}}, [=]() -> Pattern { return {Instruction::ISZERO, {X}}; } },
-		// operations involving an expression and itself
-		{{Instruction::AND, {X, X}}, [=]{ return X; }},
-		{{Instruction::OR, {X, X}}, [=]{ return X; }},
-		{{Instruction::XOR, {X, X}}, [=]{ return u256(0); }},
-		{{Instruction::SUB, {X, X}}, [=]{ return u256(0); }},
-		{{Instruction::EQ, {X, X}}, [=]{ return u256(1); }},
-		{{Instruction::LT, {X, X}}, [=]{ return u256(0); }},
-		{{Instruction::SLT, {X, X}}, [=]{ return u256(0); }},
-		{{Instruction::GT, {X, X}}, [=]{ return u256(0); }},
-		{{Instruction::SGT, {X, X}}, [=]{ return u256(0); }},
-		{{Instruction::MOD, {X, X}}, [=]{ return u256(0); }},
-
-		{{Instruction::NOT, {{Instruction::NOT, {X}}}}, [=]{ return X; }},
-		{{Instruction::XOR, {{{X}, {Instruction::XOR, {X, Y}}}}}, [=]{ return Y; }},
-		{{Instruction::OR, {{{X}, {Instruction::AND, {X, Y}}}}}, [=]{ return X; }},
-		{{Instruction::AND, {{{X}, {Instruction::OR, {X, Y}}}}}, [=]{ return X; }},
-		{{Instruction::AND, {{{X}, {Instruction::NOT, {X}}}}}, [=]{ return u256(0); }},
-		{{Instruction::OR, {{{X}, {Instruction::NOT, {X}}}}}, [=]{ return ~u256(0); }},
-	};
-	// Double negation of opcodes with binary result
-	for (auto const& op: vector<Instruction>{
-		Instruction::EQ,
-		Instruction::LT,
-		Instruction::SLT,
-		Instruction::GT,
-		Instruction::SGT
-	})
-		m_rules.push_back({
-			{Instruction::ISZERO, {{Instruction::ISZERO, {{op, {X, Y}}}}}},
-			[=]() -> Pattern { return {op, {X, Y}}; }
-		});
-	m_rules.push_back({
-		{Instruction::ISZERO, {{Instruction::ISZERO, {{Instruction::ISZERO, {X}}}}}},
-		[=]() -> Pattern { return {Instruction::ISZERO, {X}}; }
-	});
-	m_rules.push_back({
-		{Instruction::ISZERO, {{Instruction::XOR, {X, Y}}}},
-		[=]() -> Pattern { return { Instruction::EQ, {X, Y} }; }
-	});
-	// Associative operations
-	for (auto const& opFun: vector<pair<Instruction,function<u256(u256 const&,u256 const&)>>>{
-		{Instruction::ADD, plus<u256>()},
-		{Instruction::MUL, multiplies<u256>()},
-		{Instruction::AND, bit_and<u256>()},
-		{Instruction::OR, bit_or<u256>()},
-		{Instruction::XOR, bit_xor<u256>()}
-	})
-	{
-		auto op = opFun.first;
-		auto fun = opFun.second;
-		// Moving constants to the outside, order matters here!
-		// we need actions that return expressions (or patterns?) here, and we need also reversed rules
-		// (X+A)+B -> X+(A+B)
-		m_rules += vector<pair<Pattern, function<Pattern()>>>{{
-			{op, {{op, {X, A}}, B}},
-			[=]() -> Pattern { return {op, {X, fun(A.d(), B.d())}}; }
-		}, {
-		// X+(Y+A) -> (X+Y)+A
-			{op, {{op, {X, A}}, Y}},
-			[=]() -> Pattern { return {op, {{op, {X, Y}}, A}}; }
-		}, {
-		// For now, we still need explicit commutativity for the inner pattern
-			{op, {{op, {A, X}}, B}},
-			[=]() -> Pattern { return {op, {X, fun(A.d(), B.d())}}; }
-		}, {
-			{op, {{op, {A, X}}, Y}},
-			[=]() -> Pattern { return {op, {{op, {X, Y}}, A}}; }
-		}};
-	}
-	// move constants across subtractions
-	m_rules += vector<pair<Pattern, function<Pattern()>>>{
-		{
-			// X - A -> X + (-A)
-			{Instruction::SUB, {X, A}},
-			[=]() -> Pattern { return {Instruction::ADD, {X, 0 - A.d()}}; }
-		}, {
-			// (X + A) - Y -> (X - Y) + A
-			{Instruction::SUB, {{Instruction::ADD, {X, A}}, Y}},
-			[=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, A}}; }
-		}, {
-			// (A + X) - Y -> (X - Y) + A
-			{Instruction::SUB, {{Instruction::ADD, {A, X}}, Y}},
-			[=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, A}}; }
-		}, {
-			// X - (Y + A) -> (X - Y) + (-A)
-			{Instruction::SUB, {X, {Instruction::ADD, {Y, A}}}},
-			[=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, 0 - A.d()}}; }
-		}, {
-			// X - (A + Y) -> (X - Y) + (-A)
-			{Instruction::SUB, {X, {Instruction::ADD, {A, Y}}}},
-			[=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, 0 - A.d()}}; }
-		}
-	};
-}
-
 ExpressionClasses::Id ExpressionClasses::tryToSimplify(Expression const& _expr, bool _secondRun)
 {
 	static Rules rules;
@@ -366,21 +192,17 @@ ExpressionClasses::Id ExpressionClasses::tryToSimplify(Expression const& _expr,
 	)
 		return -1;
 
-	for (auto const& rule: rules.rules())
+	if (auto match = rules.findFirstMatch(_expr, *this))
 	{
-		rules.resetMatchGroups();
-		if (rule.first.matches(_expr, *this))
-		{
-			// Debug info
-			//cout << "Simplifying " << *_expr.item << "(";
-			//for (Id arg: _expr.arguments)
-			//	cout << fullDAGToString(arg) << ", ";
-			//cout << ")" << endl;
-			//cout << "with rule " << rule.first.toString() << endl;
-			//ExpressionTemplate t(rule.second());
-			//cout << "to " << rule.second().toString() << endl;
-			return rebuildExpression(ExpressionTemplate(rule.second(), _expr.item->location()));
-		}
+		// Debug info
+		//cout << "Simplifying " << *_expr.item << "(";
+		//for (Id arg: _expr.arguments)
+		//	cout << fullDAGToString(arg) << ", ";
+		//cout << ")" << endl;
+		//cout << "with rule " << match->first.toString() << endl;
+		//ExpressionTemplate t(match->second());
+		//cout << "to " << match->second().toString() << endl;
+		return rebuildExpression(ExpressionTemplate(match->second(), _expr.item->location()));
 	}
 
 	if (!_secondRun && _expr.arguments.size() == 2 && SemanticInformation::isCommutativeOperation(*_expr.item))
@@ -403,122 +225,3 @@ ExpressionClasses::Id ExpressionClasses::rebuildExpression(ExpressionTemplate co
 		arguments.push_back(rebuildExpression(t));
 	return find(_template.item, arguments);
 }
-
-
-Pattern::Pattern(Instruction _instruction, std::vector<Pattern> const& _arguments):
-	m_type(Operation),
-	m_requireDataMatch(true),
-	m_data(_instruction),
-	m_arguments(_arguments)
-{
-}
-
-void Pattern::setMatchGroup(unsigned _group, map<unsigned, Expression const*>& _matchGroups)
-{
-	m_matchGroup = _group;
-	m_matchGroups = &_matchGroups;
-}
-
-bool Pattern::matches(Expression const& _expr, ExpressionClasses const& _classes) const
-{
-	if (!matchesBaseItem(_expr.item))
-		return false;
-	if (m_matchGroup)
-	{
-		if (!m_matchGroups->count(m_matchGroup))
-			(*m_matchGroups)[m_matchGroup] = &_expr;
-		else if ((*m_matchGroups)[m_matchGroup]->id != _expr.id)
-			return false;
-	}
-	assertThrow(m_arguments.size() == 0 || _expr.arguments.size() == m_arguments.size(), OptimizerException, "");
-	for (size_t i = 0; i < m_arguments.size(); ++i)
-		if (!m_arguments[i].matches(_classes.representative(_expr.arguments[i]), _classes))
-			return false;
-	return true;
-}
-
-AssemblyItem Pattern::toAssemblyItem(SourceLocation const& _location) const
-{
-	return AssemblyItem(m_type, m_data, _location);
-}
-
-string Pattern::toString() const
-{
-	stringstream s;
-	switch (m_type)
-	{
-	case Operation:
-		s << instructionInfo(Instruction(unsigned(m_data))).name;
-		break;
-	case Push:
-		s << "PUSH " << hex << m_data;
-		break;
-	case UndefinedItem:
-		s << "ANY";
-		break;
-	default:
-		s << "t=" << dec << m_type << " d=" << hex << m_data;
-		break;
-	}
-	if (!m_requireDataMatch)
-		s << " ~";
-	if (m_matchGroup)
-		s << "[" << dec << m_matchGroup << "]";
-	s << "(";
-	for (Pattern const& p: m_arguments)
-		s << p.toString() << ", ";
-	s << ")";
-	return s.str();
-}
-
-bool Pattern::matchesBaseItem(AssemblyItem const* _item) const
-{
-	if (m_type == UndefinedItem)
-		return true;
-	if (!_item)
-		return false;
-	if (m_type != _item->type())
-		return false;
-	if (m_requireDataMatch && m_data != _item->data())
-		return false;
-	return true;
-}
-
-Pattern::Expression const& Pattern::matchGroupValue() const
-{
-	assertThrow(m_matchGroup > 0, OptimizerException, "");
-	assertThrow(!!m_matchGroups, OptimizerException, "");
-	assertThrow((*m_matchGroups)[m_matchGroup], OptimizerException, "");
-	return *(*m_matchGroups)[m_matchGroup];
-}
-
-
-ExpressionTemplate::ExpressionTemplate(Pattern const& _pattern, SourceLocation const& _location)
-{
-	if (_pattern.matchGroup())
-	{
-		hasId = true;
-		id = _pattern.id();
-	}
-	else
-	{
-		hasId = false;
-		item = _pattern.toAssemblyItem(_location);
-	}
-	for (auto const& arg: _pattern.arguments())
-		arguments.push_back(ExpressionTemplate(arg, _location));
-}
-
-string ExpressionTemplate::toString() const
-{
-	stringstream s;
-	if (hasId)
-		s << id;
-	else
-		s << item;
-	s << "(";
-	for (auto const& arg: arguments)
-		s << arg.toString();
-	s << ")";
-	return s.str();
-}
diff --git a/libevmasm/ExpressionClasses.h b/libevmasm/ExpressionClasses.h
index 11a698dd..5d53b292 100644
--- a/libevmasm/ExpressionClasses.h
+++ b/libevmasm/ExpressionClasses.h
@@ -121,70 +121,5 @@ private:
 	std::vector<std::shared_ptr<AssemblyItem>> m_spareAssemblyItems;
 };
 
-/**
- * Pattern to match against an expression.
- * Also stores matched expressions to retrieve them later, for constructing new expressions using
- * ExpressionTemplate.
- */
-class Pattern
-{
-public:
-	using Expression = ExpressionClasses::Expression;
-	using Id = ExpressionClasses::Id;
-
-	// Matches a specific constant value.
-	Pattern(unsigned _value): Pattern(u256(_value)) {}
-	// Matches a specific constant value.
-	Pattern(u256 const& _value): m_type(Push), m_requireDataMatch(true), m_data(_value) {}
-	// Matches a specific assembly item type or anything if not given.
-	Pattern(AssemblyItemType _type = UndefinedItem): m_type(_type) {}
-	// Matches a given instruction with given arguments
-	Pattern(Instruction _instruction, std::vector<Pattern> const& _arguments = {});
-	/// Sets this pattern to be part of the match group with the identifier @a _group.
-	/// Inside one rule, all patterns in the same match group have to match expressions from the
-	/// same expression equivalence class.
-	void setMatchGroup(unsigned _group, std::map<unsigned, Expression const*>& _matchGroups);
-	unsigned matchGroup() const { return m_matchGroup; }
-	bool matches(Expression const& _expr, ExpressionClasses const& _classes) const;
-
-	AssemblyItem toAssemblyItem(SourceLocation const& _location) const;
-	std::vector<Pattern> arguments() const { return m_arguments; }
-
-	/// @returns the id of the matched expression if this pattern is part of a match group.
-	Id id() const { return matchGroupValue().id; }
-	/// @returns the data of the matched expression if this pattern is part of a match group.
-	u256 const& d() const { return matchGroupValue().item->data(); }
-
-	std::string toString() const;
-
-private:
-	bool matchesBaseItem(AssemblyItem const* _item) const;
-	Expression const& matchGroupValue() const;
-
-	AssemblyItemType m_type;
-	bool m_requireDataMatch = false;
-	u256 m_data = 0;
-	std::vector<Pattern> m_arguments;
-	unsigned m_matchGroup = 0;
-	std::map<unsigned, Expression const*>* m_matchGroups = nullptr;
-};
-
-/**
- * Template for a new expression that can be built from matched patterns.
- */
-struct ExpressionTemplate
-{
-	using Expression = ExpressionClasses::Expression;
-	using Id = ExpressionClasses::Id;
-	explicit ExpressionTemplate(Pattern const& _pattern, SourceLocation const& _location);
-	std::string toString() const;
-	bool hasId = false;
-	/// Id of the matched expression, if available.
-	Id id = Id(-1);
-	// Otherwise, assembly item.
-	AssemblyItem item = UndefinedItem;
-	std::vector<ExpressionTemplate> arguments;
-};
-
 }
 }
diff --git a/libevmasm/PeepholeOptimiser.cpp b/libevmasm/PeepholeOptimiser.cpp
index b96b0295..923ffa67 100644
--- a/libevmasm/PeepholeOptimiser.cpp
+++ b/libevmasm/PeepholeOptimiser.cpp
@@ -120,7 +120,7 @@ struct OpPop: SimplePeepholeOptimizerMethod<OpPop, 2>
 			if (instructionInfo(instr).ret == 1 && !instructionInfo(instr).sideEffects)
 			{
 				for (int j = 0; j < instructionInfo(instr).args; j++)
-					*_out = Instruction::POP;
+					*_out = {Instruction::POP, _op.location()};
 				return true;
 			}
 		}
diff --git a/libevmasm/SimplificationRules.cpp b/libevmasm/SimplificationRules.cpp
new file mode 100644
index 00000000..2976d95f
--- /dev/null
+++ b/libevmasm/SimplificationRules.cpp
@@ -0,0 +1,370 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @file ExpressionClasses.cpp
+ * @author Christian <c@ethdev.com>
+ * @date 2015
+ * Container for equivalence classes of expressions for use in common subexpression elimination.
+ */
+
+#include <libevmasm/ExpressionClasses.h>
+#include <utility>
+#include <tuple>
+#include <functional>
+#include <boost/range/adaptor/reversed.hpp>
+#include <boost/noncopyable.hpp>
+#include <libevmasm/Assembly.h>
+#include <libevmasm/CommonSubexpressionEliminator.h>
+#include <libevmasm/SimplificationRules.h>
+
+using namespace std;
+using namespace dev;
+using namespace dev::eth;
+
+
+pair<Pattern, function<Pattern()> > const* Rules::findFirstMatch(
+	Expression const& _expr,
+	ExpressionClasses const& _classes
+)
+{
+	resetMatchGroups();
+
+	assertThrow(_expr.item, OptimizerException, "");
+	for (auto const& rule: m_rules[byte(_expr.item->instruction())])
+	{
+		if (rule.first.matches(_expr, _classes))
+			return &rule;
+		resetMatchGroups();
+	}
+	return nullptr;
+}
+
+void Rules::addRules(std::vector<std::pair<Pattern, std::function<Pattern ()> > > const& _rules)
+{
+	for (auto const& r: _rules)
+		addRule(r);
+}
+
+void Rules::addRule(std::pair<Pattern, std::function<Pattern()> > const& _rule)
+{
+	m_rules[byte(_rule.first.instruction())].push_back(_rule);
+}
+
+template <class S> S divWorkaround(S const& _a, S const& _b)
+{
+	return (S)(bigint(_a) / bigint(_b));
+}
+
+template <class S> S modWorkaround(S const& _a, S const& _b)
+{
+	return (S)(bigint(_a) % bigint(_b));
+}
+
+Rules::Rules()
+{
+	// Multiple occurences of one of these inside one rule must match the same equivalence class.
+	// Constants.
+	Pattern A(Push);
+	Pattern B(Push);
+	Pattern C(Push);
+	// Anything.
+	Pattern X;
+	Pattern Y;
+	Pattern Z;
+	A.setMatchGroup(1, m_matchGroups);
+	B.setMatchGroup(2, m_matchGroups);
+	C.setMatchGroup(3, m_matchGroups);
+	X.setMatchGroup(4, m_matchGroups);
+	Y.setMatchGroup(5, m_matchGroups);
+	Z.setMatchGroup(6, m_matchGroups);
+
+	addRules(vector<pair<Pattern, function<Pattern()>>>{
+		// arithmetics on constants
+		{{Instruction::ADD, {A, B}}, [=]{ return A.d() + B.d(); }},
+		{{Instruction::MUL, {A, B}}, [=]{ return A.d() * B.d(); }},
+		{{Instruction::SUB, {A, B}}, [=]{ return A.d() - B.d(); }},
+		{{Instruction::DIV, {A, B}}, [=]{ return B.d() == 0 ? 0 : divWorkaround(A.d(), B.d()); }},
+		{{Instruction::SDIV, {A, B}}, [=]{ return B.d() == 0 ? 0 : s2u(divWorkaround(u2s(A.d()), u2s(B.d()))); }},
+		{{Instruction::MOD, {A, B}}, [=]{ return B.d() == 0 ? 0 : modWorkaround(A.d(), B.d()); }},
+		{{Instruction::SMOD, {A, B}}, [=]{ return B.d() == 0 ? 0 : s2u(modWorkaround(u2s(A.d()), u2s(B.d()))); }},
+		{{Instruction::EXP, {A, B}}, [=]{ return u256(boost::multiprecision::powm(bigint(A.d()), bigint(B.d()), bigint(1) << 256)); }},
+		{{Instruction::NOT, {A}}, [=]{ return ~A.d(); }},
+		{{Instruction::LT, {A, B}}, [=]() { return A.d() < B.d() ? u256(1) : 0; }},
+		{{Instruction::GT, {A, B}}, [=]() -> u256 { return A.d() > B.d() ? 1 : 0; }},
+		{{Instruction::SLT, {A, B}}, [=]() -> u256 { return u2s(A.d()) < u2s(B.d()) ? 1 : 0; }},
+		{{Instruction::SGT, {A, B}}, [=]() -> u256 { return u2s(A.d()) > u2s(B.d()) ? 1 : 0; }},
+		{{Instruction::EQ, {A, B}}, [=]() -> u256 { return A.d() == B.d() ? 1 : 0; }},
+		{{Instruction::ISZERO, {A}}, [=]() -> u256 { return A.d() == 0 ? 1 : 0; }},
+		{{Instruction::AND, {A, B}}, [=]{ return A.d() & B.d(); }},
+		{{Instruction::OR, {A, B}}, [=]{ return A.d() | B.d(); }},
+		{{Instruction::XOR, {A, B}}, [=]{ return A.d() ^ B.d(); }},
+		{{Instruction::BYTE, {A, B}}, [=]{ return A.d() >= 32 ? 0 : (B.d() >> unsigned(8 * (31 - A.d()))) & 0xff; }},
+		{{Instruction::ADDMOD, {A, B, C}}, [=]{ return C.d() == 0 ? 0 : u256((bigint(A.d()) + bigint(B.d())) % C.d()); }},
+		{{Instruction::MULMOD, {A, B, C}}, [=]{ return C.d() == 0 ? 0 : u256((bigint(A.d()) * bigint(B.d())) % C.d()); }},
+		{{Instruction::MULMOD, {A, B, C}}, [=]{ return A.d() * B.d(); }},
+		{{Instruction::SIGNEXTEND, {A, B}}, [=]() -> u256 {
+			if (A.d() >= 31)
+				return B.d();
+			unsigned testBit = unsigned(A.d()) * 8 + 7;
+			u256 mask = (u256(1) << testBit) - 1;
+			return u256(boost::multiprecision::bit_test(B.d(), testBit) ? B.d() | ~mask : B.d() & mask);
+		}},
+
+		// invariants involving known constants
+		{{Instruction::ADD, {X, 0}}, [=]{ return X; }},
+		{{Instruction::SUB, {X, 0}}, [=]{ return X; }},
+		{{Instruction::MUL, {X, 1}}, [=]{ return X; }},
+		{{Instruction::DIV, {X, 1}}, [=]{ return X; }},
+		{{Instruction::SDIV, {X, 1}}, [=]{ return X; }},
+		{{Instruction::OR, {X, 0}}, [=]{ return X; }},
+		{{Instruction::XOR, {X, 0}}, [=]{ return X; }},
+		{{Instruction::AND, {X, ~u256(0)}}, [=]{ return X; }},
+		{{Instruction::AND, {X, 0}}, [=]{ return u256(0); }},
+		{{Instruction::MUL, {X, 0}}, [=]{ return u256(0); }},
+		{{Instruction::DIV, {X, 0}}, [=]{ return u256(0); }},
+		{{Instruction::DIV, {0, X}}, [=]{ return u256(0); }},
+		{{Instruction::MOD, {X, 0}}, [=]{ return u256(0); }},
+		{{Instruction::MOD, {0, X}}, [=]{ return u256(0); }},
+		{{Instruction::OR, {X, ~u256(0)}}, [=]{ return ~u256(0); }},
+		{{Instruction::EQ, {X, 0}}, [=]() -> Pattern { return {Instruction::ISZERO, {X}}; } },
+		// operations involving an expression and itself
+		{{Instruction::AND, {X, X}}, [=]{ return X; }},
+		{{Instruction::OR, {X, X}}, [=]{ return X; }},
+		{{Instruction::XOR, {X, X}}, [=]{ return u256(0); }},
+		{{Instruction::SUB, {X, X}}, [=]{ return u256(0); }},
+		{{Instruction::EQ, {X, X}}, [=]{ return u256(1); }},
+		{{Instruction::LT, {X, X}}, [=]{ return u256(0); }},
+		{{Instruction::SLT, {X, X}}, [=]{ return u256(0); }},
+		{{Instruction::GT, {X, X}}, [=]{ return u256(0); }},
+		{{Instruction::SGT, {X, X}}, [=]{ return u256(0); }},
+		{{Instruction::MOD, {X, X}}, [=]{ return u256(0); }},
+
+		{{Instruction::NOT, {{Instruction::NOT, {X}}}}, [=]{ return X; }},
+		{{Instruction::XOR, {{{X}, {Instruction::XOR, {X, Y}}}}}, [=]{ return Y; }},
+		{{Instruction::OR, {{{X}, {Instruction::AND, {X, Y}}}}}, [=]{ return X; }},
+		{{Instruction::AND, {{{X}, {Instruction::OR, {X, Y}}}}}, [=]{ return X; }},
+		{{Instruction::AND, {{{X}, {Instruction::NOT, {X}}}}}, [=]{ return u256(0); }},
+		{{Instruction::OR, {{{X}, {Instruction::NOT, {X}}}}}, [=]{ return ~u256(0); }},
+	});
+	// Double negation of opcodes with binary result
+	for (auto const& op: vector<Instruction>{
+		Instruction::EQ,
+		Instruction::LT,
+		Instruction::SLT,
+		Instruction::GT,
+		Instruction::SGT
+	})
+		addRule({
+			{Instruction::ISZERO, {{Instruction::ISZERO, {{op, {X, Y}}}}}},
+			[=]() -> Pattern { return {op, {X, Y}}; }
+		});
+	addRule({
+		{Instruction::ISZERO, {{Instruction::ISZERO, {{Instruction::ISZERO, {X}}}}}},
+		[=]() -> Pattern { return {Instruction::ISZERO, {X}}; }
+	});
+	addRule({
+		{Instruction::ISZERO, {{Instruction::XOR, {X, Y}}}},
+		[=]() -> Pattern { return { Instruction::EQ, {X, Y} }; }
+	});
+	// Associative operations
+	for (auto const& opFun: vector<pair<Instruction,function<u256(u256 const&,u256 const&)>>>{
+		{Instruction::ADD, plus<u256>()},
+		{Instruction::MUL, multiplies<u256>()},
+		{Instruction::AND, bit_and<u256>()},
+		{Instruction::OR, bit_or<u256>()},
+		{Instruction::XOR, bit_xor<u256>()}
+	})
+	{
+		auto op = opFun.first;
+		auto fun = opFun.second;
+		// Moving constants to the outside, order matters here!
+		// we need actions that return expressions (or patterns?) here, and we need also reversed rules
+		// (X+A)+B -> X+(A+B)
+		addRules(vector<pair<Pattern, function<Pattern()>>>{{
+			{op, {{op, {X, A}}, B}},
+			[=]() -> Pattern { return {op, {X, fun(A.d(), B.d())}}; }
+		}, {
+		// X+(Y+A) -> (X+Y)+A
+			{op, {{op, {X, A}}, Y}},
+			[=]() -> Pattern { return {op, {{op, {X, Y}}, A}}; }
+		}, {
+		// For now, we still need explicit commutativity for the inner pattern
+			{op, {{op, {A, X}}, B}},
+			[=]() -> Pattern { return {op, {X, fun(A.d(), B.d())}}; }
+		}, {
+			{op, {{op, {A, X}}, Y}},
+			[=]() -> Pattern { return {op, {{op, {X, Y}}, A}}; }
+		}});
+	}
+	// move constants across subtractions
+	addRules(vector<pair<Pattern, function<Pattern()>>>{
+		{
+			// X - A -> X + (-A)
+			{Instruction::SUB, {X, A}},
+			[=]() -> Pattern { return {Instruction::ADD, {X, 0 - A.d()}}; }
+		}, {
+			// (X + A) - Y -> (X - Y) + A
+			{Instruction::SUB, {{Instruction::ADD, {X, A}}, Y}},
+			[=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, A}}; }
+		}, {
+			// (A + X) - Y -> (X - Y) + A
+			{Instruction::SUB, {{Instruction::ADD, {A, X}}, Y}},
+			[=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, A}}; }
+		}, {
+			// X - (Y + A) -> (X - Y) + (-A)
+			{Instruction::SUB, {X, {Instruction::ADD, {Y, A}}}},
+			[=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, 0 - A.d()}}; }
+		}, {
+			// X - (A + Y) -> (X - Y) + (-A)
+			{Instruction::SUB, {X, {Instruction::ADD, {A, Y}}}},
+			[=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, 0 - A.d()}}; }
+		}
+	});
+}
+
+Pattern::Pattern(Instruction _instruction, std::vector<Pattern> const& _arguments):
+	m_type(Operation),
+	m_instruction(_instruction),
+	m_arguments(_arguments)
+{
+}
+
+void Pattern::setMatchGroup(unsigned _group, map<unsigned, Expression const*>& _matchGroups)
+{
+	m_matchGroup = _group;
+	m_matchGroups = &_matchGroups;
+}
+
+bool Pattern::matches(Expression const& _expr, ExpressionClasses const& _classes) const
+{
+	if (!matchesBaseItem(_expr.item))
+		return false;
+	if (m_matchGroup)
+	{
+		if (!m_matchGroups->count(m_matchGroup))
+			(*m_matchGroups)[m_matchGroup] = &_expr;
+		else if ((*m_matchGroups)[m_matchGroup]->id != _expr.id)
+			return false;
+	}
+	assertThrow(m_arguments.size() == 0 || _expr.arguments.size() == m_arguments.size(), OptimizerException, "");
+	for (size_t i = 0; i < m_arguments.size(); ++i)
+		if (!m_arguments[i].matches(_classes.representative(_expr.arguments[i]), _classes))
+			return false;
+	return true;
+}
+
+AssemblyItem Pattern::toAssemblyItem(SourceLocation const& _location) const
+{
+	if (m_type == Operation)
+		return AssemblyItem(m_instruction, _location);
+	else
+		return AssemblyItem(m_type, data(), _location);
+}
+
+string Pattern::toString() const
+{
+	stringstream s;
+	switch (m_type)
+	{
+	case Operation:
+		s << instructionInfo(m_instruction).name;
+		break;
+	case Push:
+		if (m_data)
+			s << "PUSH " << hex << data();
+		else
+			s << "PUSH ";
+		break;
+	case UndefinedItem:
+		s << "ANY";
+		break;
+	default:
+		if (m_data)
+			s << "t=" << dec << m_type << " d=" << hex << data();
+		else
+			s << "t=" << dec << m_type << " d: nullptr";
+		break;
+	}
+	if (!m_requireDataMatch)
+		s << " ~";
+	if (m_matchGroup)
+		s << "[" << dec << m_matchGroup << "]";
+	s << "(";
+	for (Pattern const& p: m_arguments)
+		s << p.toString() << ", ";
+	s << ")";
+	return s.str();
+}
+
+bool Pattern::matchesBaseItem(AssemblyItem const* _item) const
+{
+	if (m_type == UndefinedItem)
+		return true;
+	if (!_item)
+		return false;
+	if (m_type != _item->type())
+		return false;
+	else if (m_type == Operation)
+		return m_instruction == _item->instruction();
+	else if (m_requireDataMatch)
+		return data() == _item->data();
+	return true;
+}
+
+Pattern::Expression const& Pattern::matchGroupValue() const
+{
+	assertThrow(m_matchGroup > 0, OptimizerException, "");
+	assertThrow(!!m_matchGroups, OptimizerException, "");
+	assertThrow((*m_matchGroups)[m_matchGroup], OptimizerException, "");
+	return *(*m_matchGroups)[m_matchGroup];
+}
+
+u256 const& Pattern::data() const
+{
+	assertThrow(m_data, OptimizerException, "");
+	return *m_data;
+}
+
+ExpressionTemplate::ExpressionTemplate(Pattern const& _pattern, SourceLocation const& _location)
+{
+	if (_pattern.matchGroup())
+	{
+		hasId = true;
+		id = _pattern.id();
+	}
+	else
+	{
+		hasId = false;
+		item = _pattern.toAssemblyItem(_location);
+	}
+	for (auto const& arg: _pattern.arguments())
+		arguments.push_back(ExpressionTemplate(arg, _location));
+}
+
+string ExpressionTemplate::toString() const
+{
+	stringstream s;
+	if (hasId)
+		s << id;
+	else
+		s << item;
+	s << "(";
+	for (auto const& arg: arguments)
+		s << arg.toString();
+	s << ")";
+	return s.str();
+}
diff --git a/libevmasm/SimplificationRules.h b/libevmasm/SimplificationRules.h
new file mode 100644
index 00000000..a4da5849
--- /dev/null
+++ b/libevmasm/SimplificationRules.h
@@ -0,0 +1,140 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @file SimplificationRules
+ * @author Christian <chris@ethereum.org>
+ * @date 2017
+ * Module for applying replacement rules against Expressions.
+ */
+
+#pragma once
+
+#include <libevmasm/ExpressionClasses.h>
+
+#include <functional>
+#include <vector>
+
+namespace dev
+{
+namespace eth
+{
+
+class Pattern;
+
+/**
+ * Container for all simplification rules.
+ */
+class Rules: public boost::noncopyable
+{
+public:
+	using Expression = ExpressionClasses::Expression;
+
+	Rules();
+
+	/// @returns a pointer to the first matching pattern and sets the match
+	/// groups accordingly.
+	std::pair<Pattern, std::function<Pattern()>> const* findFirstMatch(
+		Expression const& _expr,
+		ExpressionClasses const& _classes
+	);
+
+private:
+	void addRules(std::vector<std::pair<Pattern, std::function<Pattern()>>> const& _rules);
+	void addRule(std::pair<Pattern, std::function<Pattern()>> const& _rule);
+
+	void resetMatchGroups() { m_matchGroups.clear(); }
+
+	std::map<unsigned, Expression const*> m_matchGroups;
+	std::vector<std::pair<Pattern, std::function<Pattern()>>> m_rules[256];
+};
+
+/**
+ * Pattern to match against an expression.
+ * Also stores matched expressions to retrieve them later, for constructing new expressions using
+ * ExpressionTemplate.
+ */
+class Pattern
+{
+public:
+	using Expression = ExpressionClasses::Expression;
+	using Id = ExpressionClasses::Id;
+
+	// Matches a specific constant value.
+	Pattern(unsigned _value): Pattern(u256(_value)) {}
+	// Matches a specific constant value.
+	Pattern(u256 const& _value): m_type(Push), m_requireDataMatch(true), m_data(std::make_shared<u256>(_value)) {}
+	// Matches a specific assembly item type or anything if not given.
+	Pattern(AssemblyItemType _type = UndefinedItem): m_type(_type) {}
+	// Matches a given instruction with given arguments
+	Pattern(Instruction _instruction, std::vector<Pattern> const& _arguments = {});
+	/// Sets this pattern to be part of the match group with the identifier @a _group.
+	/// Inside one rule, all patterns in the same match group have to match expressions from the
+	/// same expression equivalence class.
+	void setMatchGroup(unsigned _group, std::map<unsigned, Expression const*>& _matchGroups);
+	unsigned matchGroup() const { return m_matchGroup; }
+	bool matches(Expression const& _expr, ExpressionClasses const& _classes) const;
+
+	AssemblyItem toAssemblyItem(SourceLocation const& _location) const;
+	std::vector<Pattern> arguments() const { return m_arguments; }
+
+	/// @returns the id of the matched expression if this pattern is part of a match group.
+	Id id() const { return matchGroupValue().id; }
+	/// @returns the data of the matched expression if this pattern is part of a match group.
+	u256 const& d() const { return matchGroupValue().item->data(); }
+
+	std::string toString() const;
+
+	AssemblyItemType type() const { return m_type; }
+	Instruction instruction() const
+	{
+		assertThrow(type() == Operation, OptimizerException, "");
+		return m_instruction;
+	}
+
+private:
+	bool matchesBaseItem(AssemblyItem const* _item) const;
+	Expression const& matchGroupValue() const;
+	u256 const& data() const;
+
+	AssemblyItemType m_type;
+	bool m_requireDataMatch = false;
+	Instruction m_instruction; ///< Only valid if m_type is Operation
+	std::shared_ptr<u256> m_data; ///< Only valid if m_type is not Operation
+	std::vector<Pattern> m_arguments;
+	unsigned m_matchGroup = 0;
+	std::map<unsigned, Expression const*>* m_matchGroups = nullptr;
+};
+
+/**
+ * Template for a new expression that can be built from matched patterns.
+ */
+struct ExpressionTemplate
+{
+	using Expression = ExpressionClasses::Expression;
+	using Id = ExpressionClasses::Id;
+	explicit ExpressionTemplate(Pattern const& _pattern, SourceLocation const& _location);
+	std::string toString() const;
+	bool hasId = false;
+	/// Id of the matched expression, if available.
+	Id id = Id(-1);
+	// Otherwise, assembly item.
+	AssemblyItem item = UndefinedItem;
+	std::vector<ExpressionTemplate> arguments;
+};
+
+}
+}
diff --git a/libsolidity/analysis/DeclarationContainer.cpp b/libsolidity/analysis/DeclarationContainer.cpp
index 1599b83a..f8c12c5b 100644
--- a/libsolidity/analysis/DeclarationContainer.cpp
+++ b/libsolidity/analysis/DeclarationContainer.cpp
@@ -44,10 +44,19 @@ Declaration const* DeclarationContainer::conflictingDeclaration(
 
 	if (dynamic_cast<FunctionDefinition const*>(&_declaration))
 	{
-		// check that all other declarations with the same name are functions
+		// check that all other declarations with the same name are functions or a public state variable
 		for (Declaration const* declaration: declarations)
-			if (!dynamic_cast<FunctionDefinition const*>(declaration))
+		{
+			if (dynamic_cast<FunctionDefinition const*>(declaration))
+				continue;
+			if (auto variableDeclaration = dynamic_cast<VariableDeclaration const*>(declaration))
+			{
+				if (variableDeclaration->isStateVariable() && !variableDeclaration->isConstant() && variableDeclaration->isPublic())
+					continue;
 				return declaration;
+			}
+			return declaration;
+		}
 	}
 	else if (declarations.size() == 1 && declarations.front() == &_declaration)
 		return nullptr;
diff --git a/libsolidity/analysis/NameAndTypeResolver.cpp b/libsolidity/analysis/NameAndTypeResolver.cpp
index 2a33a501..08323243 100644
--- a/libsolidity/analysis/NameAndTypeResolver.cpp
+++ b/libsolidity/analysis/NameAndTypeResolver.cpp
@@ -260,10 +260,16 @@ vector<Declaration const*> NameAndTypeResolver::cleanedDeclarations(
 	for (auto it = _declarations.begin(); it != _declarations.end(); ++it)
 	{
 		solAssert(*it, "");
-		// the declaration is functionDefinition while declarations > 1
-		FunctionDefinition const& functionDefinition = dynamic_cast<FunctionDefinition const&>(**it);
-		FunctionType functionType(functionDefinition);
-		for (auto parameter: functionType.parameterTypes() + functionType.returnParameterTypes())
+		// the declaration is functionDefinition or a VariableDeclaration while declarations > 1
+		solAssert(dynamic_cast<FunctionDefinition const*>(*it) || dynamic_cast<VariableDeclaration const*>(*it),
+			"Found overloading involving something not a function or a variable");
+
+		shared_ptr<FunctionType const> functionType { (*it)->functionType(false) };
+		if (!functionType)
+			functionType = (*it)->functionType(true);
+		solAssert(functionType, "failed to determine the function type of the overloaded");
+
+		for (auto parameter: functionType->parameterTypes() + functionType->returnParameterTypes())
 			if (!parameter)
 				reportFatalDeclarationError(_identifier.location(), "Function type can not be used in this context");
 
@@ -272,8 +278,10 @@ vector<Declaration const*> NameAndTypeResolver::cleanedDeclarations(
 			uniqueFunctions.end(),
 			[&](Declaration const* d)
 			{
-				FunctionType newFunctionType(dynamic_cast<FunctionDefinition const&>(*d));
-				return functionType.hasEqualArgumentTypes(newFunctionType);
+				shared_ptr<FunctionType const> newFunctionType { d->functionType(false) };
+				if (!newFunctionType)
+					newFunctionType = d->functionType(true);
+				return newFunctionType && functionType->hasEqualArgumentTypes(*newFunctionType);
 			}
 		))
 			uniqueFunctions.push_back(*it);
@@ -289,7 +297,39 @@ void NameAndTypeResolver::importInheritedScope(ContractDefinition const& _base)
 		for (auto const& declaration: nameAndDeclaration.second)
 			// Import if it was declared in the base, is not the constructor and is visible in derived classes
 			if (declaration->scope() == &_base && declaration->isVisibleInDerivedContracts())
-				m_currentScope->registerDeclaration(*declaration);
+				if (!m_currentScope->registerDeclaration(*declaration))
+				{
+					SourceLocation firstDeclarationLocation;
+					SourceLocation secondDeclarationLocation;
+					Declaration const* conflictingDeclaration = m_currentScope->conflictingDeclaration(*declaration);
+					solAssert(conflictingDeclaration, "");
+
+					// Usual shadowing is not an error
+					if (dynamic_cast<VariableDeclaration const*>(declaration) && dynamic_cast<VariableDeclaration const*>(conflictingDeclaration))
+						continue;
+
+					// Usual shadowing is not an error
+					if (dynamic_cast<ModifierDefinition const*>(declaration) && dynamic_cast<ModifierDefinition const*>(conflictingDeclaration))
+						continue;
+
+					if (declaration->location().start < conflictingDeclaration->location().start)
+					{
+						firstDeclarationLocation = declaration->location();
+						secondDeclarationLocation = conflictingDeclaration->location();
+					}
+					else
+					{
+						firstDeclarationLocation = conflictingDeclaration->location();
+						secondDeclarationLocation = declaration->location();
+					}
+
+					reportDeclarationError(
+						secondDeclarationLocation,
+						"Identifier already declared.",
+						firstDeclarationLocation,
+						"The previous declaration is here:"
+					);
+				}
 }
 
 void NameAndTypeResolver::linearizeBaseContracts(ContractDefinition& _contract)
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index e414e27c..67c8ac17 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -1500,8 +1500,23 @@ bool TypeChecker::visit(Identifier const& _identifier)
 	if (!annotation.referencedDeclaration)
 	{
 		if (!annotation.argumentTypes)
-			fatalTypeError(_identifier.location(), "Unable to determine overloaded type.");
-		if (annotation.overloadedDeclarations.empty())
+		{
+			// The identifier should be a public state variable shadowing other functions
+			vector<Declaration const*> candidates;
+
+			for (Declaration const* declaration: annotation.overloadedDeclarations)
+			{
+				if (VariableDeclaration const* variableDeclaration = dynamic_cast<decltype(variableDeclaration)>(declaration))
+					candidates.push_back(declaration);
+			}
+			if (candidates.empty())
+				fatalTypeError(_identifier.location(), "No matching declaration found after variable lookup.");
+			else if (candidates.size() == 1)
+				annotation.referencedDeclaration = candidates.front();
+			else
+				fatalTypeError(_identifier.location(), "No unique declaration found after variable lookup.");
+		}
+		else if (annotation.overloadedDeclarations.empty())
 			fatalTypeError(_identifier.location(), "No candidates for overload resolution found.");
 		else if (annotation.overloadedDeclarations.size() == 1)
 			annotation.referencedDeclaration = *annotation.overloadedDeclarations.begin();
diff --git a/libsolidity/ast/AST.cpp b/libsolidity/ast/AST.cpp
index 3cd1dfbe..6f7a64dc 100644
--- a/libsolidity/ast/AST.cpp
+++ b/libsolidity/ast/AST.cpp
@@ -217,6 +217,9 @@ vector<Declaration const*> const& ContractDefinition::inheritableMembers() const
 
 		for (EnumDefinition const* e: definedEnums())
 			addInheritableMember(e);
+
+		for (EventDefinition const* e: events())
+			addInheritableMember(e);
 	}
 	return *m_inheritableMembers;
 }
@@ -271,6 +274,45 @@ TypeDeclarationAnnotation& EnumDefinition::annotation() const
 	return static_cast<TypeDeclarationAnnotation&>(*m_annotation);
 }
 
+shared_ptr<FunctionType> FunctionDefinition::functionType(bool _internal) const
+{
+	if (_internal)
+	{
+		switch (visibility())
+		{
+		case Declaration::Visibility::Default:
+			solAssert(false, "visibility() should not return Default");
+		case Declaration::Visibility::Private:
+		case Declaration::Visibility::Internal:
+		case Declaration::Visibility::Public:
+			return make_shared<FunctionType>(*this, _internal);
+		case Declaration::Visibility::External:
+			return {};
+		default:
+			solAssert(false, "visibility() should not return a Visibility");
+		}
+	}
+	else
+	{
+		switch (visibility())
+		{
+		case Declaration::Visibility::Default:
+			solAssert(false, "visibility() should not return Default");
+		case Declaration::Visibility::Private:
+		case Declaration::Visibility::Internal:
+			return {};
+		case Declaration::Visibility::Public:
+		case Declaration::Visibility::External:
+			return make_shared<FunctionType>(*this, _internal);
+		default:
+			solAssert(false, "visibility() should not return a Visibility");
+		}
+	}
+
+	// To make the compiler happy
+	return {};
+}
+
 TypePointer FunctionDefinition::type() const
 {
 	return make_shared<FunctionType>(*this);
@@ -305,6 +347,14 @@ TypePointer EventDefinition::type() const
 	return make_shared<FunctionType>(*this);
 }
 
+std::shared_ptr<FunctionType> EventDefinition::functionType(bool _internal) const
+{
+	if (_internal)
+		return make_shared<FunctionType>(*this);
+	else
+		return {};
+}
+
 EventDefinitionAnnotation& EventDefinition::annotation() const
 {
 	if (!m_annotation)
@@ -362,6 +412,28 @@ TypePointer VariableDeclaration::type() const
 	return annotation().type;
 }
 
+shared_ptr<FunctionType> VariableDeclaration::functionType(bool _internal) const
+{
+	if (_internal)
+		return {};
+	switch (visibility())
+	{
+	case Declaration::Visibility::Default:
+		solAssert(false, "visibility() should not return Default");
+	case Declaration::Visibility::Private:
+	case Declaration::Visibility::Internal:
+		return {};
+	case Declaration::Visibility::Public:
+	case Declaration::Visibility::External:
+		return make_shared<FunctionType>(*this);
+	default:
+		solAssert(false, "visibility() should not return a Visibility");
+	}
+
+	// To make the compiler happy
+	return {};
+}
+
 VariableDeclarationAnnotation& VariableDeclaration::annotation() const
 {
 	if (!m_annotation)
diff --git a/libsolidity/ast/AST.h b/libsolidity/ast/AST.h
index ab4be1ea..2d092408 100644
--- a/libsolidity/ast/AST.h
+++ b/libsolidity/ast/AST.h
@@ -171,6 +171,10 @@ public:
 	/// This can only be called once types of variable declarations have already been resolved.
 	virtual TypePointer type() const = 0;
 
+	/// @param _internal false indicates external interface is concerned, true indicates internal interface is concerned.
+	/// @returns null when it is not accessible as a function.
+	virtual std::shared_ptr<FunctionType> functionType(bool /*_internal*/) const { return {}; }
+
 protected:
 	virtual Visibility defaultVisibility() const { return Visibility::Public; }
 
@@ -581,6 +585,10 @@ public:
 
 	virtual TypePointer type() const override;
 
+	/// @param _internal false indicates external interface is concerned, true indicates internal interface is concerned.
+	/// @returns null when it is not accessible as a function.
+	virtual std::shared_ptr<FunctionType> functionType(bool /*_internal*/) const override;
+
 	virtual FunctionDefinitionAnnotation& annotation() const override;
 
 private:
@@ -643,6 +651,10 @@ public:
 
 	virtual TypePointer type() const override;
 
+	/// @param _internal false indicates external interface is concerned, true indicates internal interface is concerned.
+	/// @returns null when it is not accessible as a function.
+	virtual std::shared_ptr<FunctionType> functionType(bool /*_internal*/) const override;
+
 	virtual VariableDeclarationAnnotation& annotation() const override;
 
 protected:
@@ -740,6 +752,7 @@ public:
 	bool isAnonymous() const { return m_anonymous; }
 
 	virtual TypePointer type() const override;
+	virtual std::shared_ptr<FunctionType> functionType(bool /*_internal*/) const override;
 
 	virtual EventDefinitionAnnotation& annotation() const override;
 
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index a7fb8408..3922da88 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -908,19 +908,43 @@ bool ExpressionCompiler::visit(MemberAccess const& _memberAccess)
 			solAssert(_memberAccess.annotation().type, "_memberAccess has no type");
 			if (auto funType = dynamic_cast<FunctionType const*>(_memberAccess.annotation().type.get()))
 			{
-				if (funType->location() != FunctionType::Location::Internal)
-				{
-					_memberAccess.expression().accept(*this);
-					m_context << funType->externalIdentifier();
-				}
-				else
+				switch (funType->location())
 				{
+				case FunctionType::Location::Internal:
 					// We do not visit the expression here on purpose, because in the case of an
 					// internal library function call, this would push the library address forcing
 					// us to link against it although we actually do not need it.
-					auto const* function = dynamic_cast<FunctionDefinition const*>(_memberAccess.annotation().referencedDeclaration);
-					solAssert(!!function, "Function not found in member access");
-					utils().pushCombinedFunctionEntryLabel(*function);
+					if (auto const* function = dynamic_cast<FunctionDefinition const*>(_memberAccess.annotation().referencedDeclaration))
+						utils().pushCombinedFunctionEntryLabel(*function);
+					else
+						solAssert(false, "Function not found in member access");
+					break;
+				case FunctionType::Location::Event:
+					if (!dynamic_cast<EventDefinition const*>(_memberAccess.annotation().referencedDeclaration))
+						solAssert(false, "event not found");
+					// no-op, because the parent node will do the job
+					break;
+				case FunctionType::Location::External:
+				case FunctionType::Location::Creation:
+				case FunctionType::Location::DelegateCall:
+				case FunctionType::Location::CallCode:
+				case FunctionType::Location::Send:
+				case FunctionType::Location::Bare:
+				case FunctionType::Location::BareCallCode:
+				case FunctionType::Location::BareDelegateCall:
+					_memberAccess.expression().accept(*this);
+					m_context << funType->externalIdentifier();
+					break;
+				case FunctionType::Location::Log0:
+				case FunctionType::Location::Log1:
+				case FunctionType::Location::Log2:
+				case FunctionType::Location::Log3:
+				case FunctionType::Location::Log4:
+				case FunctionType::Location::ECRecover:
+				case FunctionType::Location::SHA256:
+				case FunctionType::Location::RIPEMD160:
+				default:
+					solAssert(false, "unsupported member function");
 				}
 			}
 			else if (dynamic_cast<TypeType const*>(_memberAccess.annotation().type.get()))
diff --git a/libsolidity/interface/CompilerStack.cpp b/libsolidity/interface/CompilerStack.cpp
index 4095844f..a31df584 100644
--- a/libsolidity/interface/CompilerStack.cpp
+++ b/libsolidity/interface/CompilerStack.cpp
@@ -509,23 +509,32 @@ string CompilerStack::applyRemapping(string const& _path, string const& _context
 	};
 
 	size_t longestPrefix = 0;
-	string longestPrefixTarget;
+	size_t longestContext = 0;
+	string bestMatchTarget;
+
 	for (auto const& redir: m_remappings)
 	{
-		// Skip if we already have a closer match.
-		if (longestPrefix > 0 && redir.prefix.length() <= longestPrefix)
+		string context = sanitizePath(redir.context);
+		string prefix = sanitizePath(redir.prefix);
+
+		// Skip if current context is closer
+		if (context.length() < longestContext)
 			continue;
 		// Skip if redir.context is not a prefix of _context
-		if (!isPrefixOf(redir.context, _context))
+		if (!isPrefixOf(context, _context))
+			continue;
+		// Skip if we already have a closer prefix match.
+		if (prefix.length() < longestPrefix && context.length() == longestContext)
 			continue;
 		// Skip if the prefix does not match.
-		if (!isPrefixOf(redir.prefix, _path))
+		if (!isPrefixOf(prefix, _path))
 			continue;
 
-		longestPrefix = redir.prefix.length();
-		longestPrefixTarget = redir.target;
+		longestContext = context.length();
+		longestPrefix = prefix.length();
+		bestMatchTarget = sanitizePath(redir.target);
 	}
-	string path = longestPrefixTarget;
+	string path = bestMatchTarget;
 	path.append(_path.begin() + longestPrefix, _path.end());
 	return path;
 }
@@ -593,11 +602,11 @@ bool CompilerStack::checkLibraryNameClashes()
 
 string CompilerStack::absolutePath(string const& _path, string const& _reference) const
 {
-	// Anything that does not start with `.` is an absolute path.
-	if (_path.empty() || _path.front() != '.')
-		return _path;
 	using path = boost::filesystem::path;
 	path p(_path);
+	// Anything that does not start with `.` is an absolute path.
+	if (p.begin() == p.end() || (*p.begin() != "." && *p.begin() != ".."))
+		return _path;
 	path result(_reference);
 	result.remove_filename();
 	for (path::iterator it = p.begin(); it != p.end(); ++it)
diff --git a/libsolidity/interface/CompilerStack.h b/libsolidity/interface/CompilerStack.h
index f98a457a..d49a8df1 100644
--- a/libsolidity/interface/CompilerStack.h
+++ b/libsolidity/interface/CompilerStack.h
@@ -29,6 +29,7 @@
 #include <vector>
 #include <functional>
 #include <boost/noncopyable.hpp>
+#include <boost/filesystem.hpp>
 #include <json/json.h>
 #include <libdevcore/Common.h>
 #include <libdevcore/FixedHash.h>
@@ -234,12 +235,14 @@ private:
 	bool checkLibraryNameClashes();
 	/// @returns the absolute path corresponding to @a _path relative to @a _reference.
 	std::string absolutePath(std::string const& _path, std::string const& _reference) const;
+	/// Helper function to return path converted strings.
+	std::string sanitizePath(std::string const& _path) const { return boost::filesystem::path(_path).generic_string(); }
+
 	/// Compile a single contract and put the result in @a _compiledContracts.
 	void compileContract(
 		ContractDefinition const& _contract,
 		std::map<ContractDefinition const*, eth::Assembly const*>& _compiledContracts
 	);
-
 	void link();
 
 	Contract const& contract(std::string const& _contractName = "") const;
diff --git a/libsolidity/parsing/Parser.cpp b/libsolidity/parsing/Parser.cpp
index f02a4a45..e26e2908 100644
--- a/libsolidity/parsing/Parser.cpp
+++ b/libsolidity/parsing/Parser.cpp
@@ -1153,9 +1153,9 @@ ASTPointer<Expression> Parser::parseLeftHandSideExpression(
 	else if (m_scanner->currentToken() == Token::New)
 	{
 		expectToken(Token::New);
-		ASTPointer<TypeName> contractName(parseTypeName(false));
-		nodeFactory.setEndPositionFromNode(contractName);
-		expression = nodeFactory.createNode<NewExpression>(contractName);
+		ASTPointer<TypeName> typeName(parseTypeName(false));
+		nodeFactory.setEndPositionFromNode(typeName);
+		expression = nodeFactory.createNode<NewExpression>(typeName);
 	}
 	else
 		expression = parsePrimaryExpression();
diff --git a/scripts/create_source_tarball.sh b/scripts/create_source_tarball.sh
new file mode 100755
index 00000000..1f78e12c
--- /dev/null
+++ b/scripts/create_source_tarball.sh
@@ -0,0 +1,34 @@
+#!/usr/bin/env sh
+#
+
+set -e
+
+REPO_ROOT="$(dirname "$0")"/..
+(
+    cd "$REPO_ROOT"
+    version=$(grep -oP "PROJECT_VERSION \"?\K[0-9.]+(?=\")"? CMakeLists.txt)
+    commithash=$(git rev-parse --short=8 HEAD)
+    commitdate=$(git show --format=%ci HEAD | head -n 1 | cut - -b1-10 | sed -e 's/-0?/./' | sed -e 's/-0?/./')
+
+    # file exists and has zero size -> not a prerelease
+    if [ -e prerelease.txt -a ! -s prerelease.txt ]
+    then
+        versionstring="$version"
+    else
+        versionstring="$version-develop-$commitdate-$commithash"
+    fi
+
+    TEMPDIR=$(mktemp -d)
+    SOLDIR="$TEMPDIR/solidity_$versionstring/"
+    mkdir "$SOLDIR"
+    # Store the current source
+    git checkout-index -a --prefix="$SOLDIR"
+    git submodule foreach 'git checkout-index -a --prefix="'"$SOLDIR"'/$path/"'
+    # Store the commit hash
+    echo "$commithash" > "$SOLDIR/commit_hash.txt"
+    # Add dependencies
+    mkdir -p "$SOLDIR/deps/downloads/" 2>/dev/null || true
+    wget -O "$SOLDIR/deps/downloads/jsoncpp-1.7.7.tar.gz" https://github.com/open-source-parsers/jsoncpp/archive/1.7.7.tar.gz
+    tar czf "$REPO_ROOT/solidity_$versionstring.tar.gz" -C "$TEMPDIR" "solidity_$versionstring"
+    rm -r "$TEMPDIR"
+)
diff --git a/scripts/install_cmake.sh b/scripts/install_cmake.sh
new file mode 100755
index 00000000..00d013b9
--- /dev/null
+++ b/scripts/install_cmake.sh
@@ -0,0 +1,37 @@
+#!/usr/bin/env sh
+
+# This script downloads the CMake binary and installs it in ~/.local directory
+# (the cmake executable will be in ~/.local/bin).
+# This is mostly suitable for CIs, not end users.
+
+set -e
+
+VERSION=3.7.1
+PREFIX=~/.local
+
+OS=$(uname -s)
+case $OS in
+Linux)  SHA256=7b4b7a1d9f314f45722899c0521c261e4bfab4a6b532609e37fef391da6bade2;;
+Darwin) SHA256=1851d1448964893fdc5a8c05863326119f397a3790e0c84c40b83499c7960267;;
+esac
+
+
+BIN=$PREFIX/bin
+
+if test -f $BIN/cmake && ($BIN/cmake --version | grep -q "$VERSION"); then
+    echo "CMake $VERSION already installed in $BIN"
+else
+    FILE=cmake-$VERSION-$OS-x86_64.tar.gz
+    URL=https://cmake.org/files/v3.7/$FILE
+    ERROR=0
+    TMPFILE=$(mktemp --tmpdir cmake-$VERSION-$OS-x86_64.XXXXXXXX.tar.gz)
+    echo "Downloading CMake ($URL)..."
+    wget "$URL" -O "$TMPFILE" -nv
+    if ! (shasum -a256 "$TMPFILE" | grep -q "$SHA256"); then
+        echo "Checksum mismatch ($TMPFILE)"
+        exit 1
+    fi
+    mkdir -p "$PREFIX"
+    tar xzf "$TMPFILE" -C "$PREFIX" --strip 1
+    rm $TMPFILE
+fi
diff --git a/test/libsolidity/Imports.cpp b/test/libsolidity/Imports.cpp
index bc6adc26..56895fdc 100644
--- a/test/libsolidity/Imports.cpp
+++ b/test/libsolidity/Imports.cpp
@@ -164,6 +164,43 @@ BOOST_AUTO_TEST_CASE(context_dependent_remappings)
 	BOOST_CHECK(c.compile());
 }
 
+BOOST_AUTO_TEST_CASE(filename_with_period)
+{
+	CompilerStack c;
+	c.addSource("a/a.sol", "import \".b.sol\"; contract A is B {} pragma solidity >=0.0;");
+	c.addSource("a/.b.sol", "contract B {} pragma solidity >=0.0;");
+	BOOST_CHECK(!c.compile());
+}
+
+BOOST_AUTO_TEST_CASE(context_dependent_remappings_ensure_default_and_module_preserved)
+{
+	CompilerStack c;
+	c.setRemappings(vector<string>{"foo=vendor/foo_2.0.0", "vendor/bar:foo=vendor/foo_1.0.0", "bar=vendor/bar"});
+	c.addSource("main.sol", "import \"foo/foo.sol\"; import {Bar} from \"bar/bar.sol\"; contract Main is Foo2, Bar {} pragma solidity >=0.0;");
+	c.addSource("vendor/bar/bar.sol", "import \"foo/foo.sol\"; contract Bar {Foo1 foo;} pragma solidity >=0.0;");
+	c.addSource("vendor/foo_1.0.0/foo.sol", "contract Foo1 {} pragma solidity >=0.0;");
+	c.addSource("vendor/foo_2.0.0/foo.sol", "contract Foo2 {} pragma solidity >=0.0;");
+	BOOST_CHECK(c.compile());
+}
+
+BOOST_AUTO_TEST_CASE(context_dependent_remappings_order_independent)
+{
+	CompilerStack c;
+	c.setRemappings(vector<string>{"a:x/y/z=d", "a/b:x=e"});
+	c.addSource("a/main.sol", "import \"x/y/z/z.sol\"; contract Main is D {} pragma solidity >=0.0;");
+	c.addSource("a/b/main.sol", "import \"x/y/z/z.sol\"; contract Main is E {} pragma solidity >=0.0;");
+	c.addSource("d/z.sol", "contract D {} pragma solidity >=0.0;");
+	c.addSource("e/y/z/z.sol", "contract E {} pragma solidity >=0.0;");
+	BOOST_CHECK(c.compile());
+	CompilerStack d;
+	d.setRemappings(vector<string>{"a/b:x=e", "a:x/y/z=d"});
+	d.addSource("a/main.sol", "import \"x/y/z/z.sol\"; contract Main is D {} pragma solidity >=0.0;");
+	d.addSource("a/b/main.sol", "import \"x/y/z/z.sol\"; contract Main is E {} pragma solidity >=0.0;");
+	d.addSource("d/z.sol", "contract D {} pragma solidity >=0.0;");
+	d.addSource("e/y/z/z.sol", "contract E {} pragma solidity >=0.0;");
+	BOOST_CHECK(d.compile());
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }
diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp
index 94d4fb7f..19161831 100644
--- a/test/libsolidity/SolidityEndToEndTest.cpp
+++ b/test/libsolidity/SolidityEndToEndTest.cpp
@@ -2770,6 +2770,28 @@ BOOST_AUTO_TEST_CASE(event_no_arguments)
 	BOOST_CHECK_EQUAL(m_logs[0].topics[0], dev::keccak256(string("Deposit()")));
 }
 
+BOOST_AUTO_TEST_CASE(event_access_through_base_name)
+{
+	char const* sourceCode = R"(
+		contract A {
+			event x();
+		}
+		contract B is A {
+			function f() returns (uint) {
+				A.x();
+				return 1;
+			}
+		}
+	)";
+	compileAndRun(sourceCode);
+	callContractFunction("f()");
+	BOOST_REQUIRE_EQUAL(m_logs.size(), 1);
+	BOOST_CHECK_EQUAL(m_logs[0].address, m_contractAddress);
+	BOOST_CHECK(m_logs[0].data.empty());
+	BOOST_REQUIRE_EQUAL(m_logs[0].topics.size(), 1);
+	BOOST_CHECK_EQUAL(m_logs[0].topics[0], dev::keccak256(string("x()")));
+}
+
 BOOST_AUTO_TEST_CASE(event_anonymous)
 {
 	char const* sourceCode = R"(
@@ -4847,60 +4869,6 @@ BOOST_AUTO_TEST_CASE(proper_order_of_overwriting_of_attributes)
 	BOOST_CHECK(callContractFunction("ok()") == encodeArgs(false));
 }
 
-BOOST_AUTO_TEST_CASE(proper_overwriting_accessor_by_function)
-{
-	// bug #1798
-	char const* sourceCode = R"(
-		contract attribute {
-			bool ok = false;
-		}
-		contract func {
-			function ok() returns (bool) { return true; }
-		}
-
-		contract attr_func is attribute, func {
-			function checkOk() returns (bool) { return ok(); }
-		}
-		contract func_attr is func, attribute {
-			function checkOk() returns (bool) { return ok; }
-		}
-	)";
-	compileAndRun(sourceCode, 0, "attr_func");
-	BOOST_CHECK(callContractFunction("ok()") == encodeArgs(true));
-	compileAndRun(sourceCode, 0, "func_attr");
-	BOOST_CHECK(callContractFunction("checkOk()") == encodeArgs(false));
-}
-
-
-BOOST_AUTO_TEST_CASE(overwriting_inheritance)
-{
-	// bug #1798
-	char const* sourceCode = R"(
-		contract A {
-			function ok() returns (uint) { return 1; }
-		}
-		contract B {
-			function ok() returns (uint) { return 2; }
-		}
-		contract C {
-			uint ok = 6;
-		}
-		contract AB is A, B {
-			function ok() returns (uint) { return 4; }
-		}
-		contract reversedE is C, AB {
-			function checkOk() returns (uint) { return ok(); }
-		}
-		contract E is AB, C {
-			function checkOk() returns (uint) { return ok; }
-		}
-	)";
-	compileAndRun(sourceCode, 0, "reversedE");
-	BOOST_CHECK(callContractFunction("checkOk()") == encodeArgs(4));
-	compileAndRun(sourceCode, 0, "E");
-	BOOST_CHECK(callContractFunction("checkOk()") == encodeArgs(6));
-}
-
 BOOST_AUTO_TEST_CASE(struct_assign_reference_to_struct)
 {
 	char const* sourceCode = R"(
diff --git a/test/libsolidity/SolidityNameAndTypeResolution.cpp b/test/libsolidity/SolidityNameAndTypeResolution.cpp
index 576421fd..9f6ea2b3 100644
--- a/test/libsolidity/SolidityNameAndTypeResolution.cpp
+++ b/test/libsolidity/SolidityNameAndTypeResolution.cpp
@@ -1056,7 +1056,9 @@ BOOST_AUTO_TEST_CASE(modifier_overrides_function)
 		contract A { modifier mod(uint a) { _; } }
 		contract B is A { function mod(uint a) { } }
 	)";
-	CHECK_ERROR(text, TypeError, "");
+	// Error: Identifier already declared.
+	// Error: Override changes modifier to function.
+	CHECK_ERROR_ALLOW_MULTI(text, DeclarationError, "");
 }
 
 BOOST_AUTO_TEST_CASE(function_overrides_modifier)
@@ -1065,7 +1067,9 @@ BOOST_AUTO_TEST_CASE(function_overrides_modifier)
 		contract A { function mod(uint a) { } }
 		contract B is A { modifier mod(uint a) { _; } }
 	)";
-	CHECK_ERROR(text, TypeError, "");
+	// Error: Identifier already declared.
+	// Error: Override changes function to modifier.
+	CHECK_ERROR_ALLOW_MULTI(text, DeclarationError, "");
 }
 
 BOOST_AUTO_TEST_CASE(modifier_returns_value)
@@ -4304,6 +4308,25 @@ BOOST_AUTO_TEST_CASE(illegal_override_payable_nonpayable)
 	CHECK_ERROR(text, TypeError, "");
 }
 
+BOOST_AUTO_TEST_CASE(function_variable_mixin)
+{
+       // bug #1798 (cpp-ethereum), related to #1286 (solidity)
+       char const* text = R"(
+               contract attribute {
+                       bool ok = false;
+               }
+               contract func {
+                       function ok() returns (bool) { return true; }
+               }
+
+               contract attr_func is attribute, func {
+                       function checkOk() returns (bool) { return ok(); }
+               }
+       )";
+       CHECK_ERROR(text, DeclarationError, "");
+}
+
+
 BOOST_AUTO_TEST_CASE(payable_constant_conflict)
 {
 	char const* text = R"(