diff options
| -rw-r--r-- | liblll/CodeFragment.cpp | 28 | ||||
| -rw-r--r-- | liblll/CompilerState.cpp | 2 | ||||
| -rw-r--r-- | test/liblll/EndToEndTest.cpp | 55 |
3 files changed, 79 insertions, 6 deletions
diff --git a/liblll/CodeFragment.cpp b/liblll/CodeFragment.cpp index 56c1e26a..f637dfb1 100644 --- a/liblll/CodeFragment.cpp +++ b/liblll/CodeFragment.cpp @@ -523,14 +523,30 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s) requireSize(1); requireDeposit(0, 1); - m_asm.append(Instruction::MSIZE); - m_asm.append(u256(0)); + // (alloc N): + // - Evaluates to (msize) before the allocation - the start of the allocated memory + // - Does not allocate memory when N is zero + // - Size of memory allocated is N bytes rounded up to a multiple of 32 + // - Uses MLOAD to expand MSIZE to avoid modifying memory. + + auto end = m_asm.newTag(); + m_asm.append(Instruction::MSIZE); // Result will be original top of memory + m_asm.append(code[0].m_asm, 1); // The alloc argument N + m_asm.append(Instruction::DUP1); + m_asm.append(Instruction::ISZERO);// (alloc 0) does not change MSIZE + m_asm.appendJumpI(end); m_asm.append(u256(1)); - m_asm.append(code[0].m_asm, 1); - m_asm.append(Instruction::MSIZE); + m_asm.append(Instruction::DUP2); // Copy N + m_asm.append(Instruction::SUB); // N-1 + m_asm.append(u256(0x1f)); // Bit mask + m_asm.append(Instruction::NOT); // Invert + m_asm.append(Instruction::AND); // Align N-1 on 32 byte boundary + m_asm.append(Instruction::MSIZE); // MSIZE is cheap m_asm.append(Instruction::ADD); - m_asm.append(Instruction::SUB); - m_asm.append(Instruction::MSTORE8); + m_asm.append(Instruction::MLOAD); // Updates MSIZE + m_asm.append(Instruction::POP); // Discard the result of the MLOAD + m_asm.append(end); + m_asm.append(Instruction::POP); // Discard duplicate N _s.usedAlloc = true; } diff --git a/liblll/CompilerState.cpp b/liblll/CompilerState.cpp index 5d38bb8c..9701e16b 100644 --- a/liblll/CompilerState.cpp +++ b/liblll/CompilerState.cpp @@ -46,6 +46,8 @@ void CompilerState::populateStandard() { static const string s = "{" "(def 'panic () (asm INVALID))" + // Alternative macro version of alloc, which is currently implemented in the parser + // "(def 'alloc (n) (raw (msize) (when n (pop (mload (+ (msize) (& (- n 1) (~ 0x1f))))))))" "(def 'allgas (- (gas) 21))" "(def 'send (to value) (call allgas to value 0 0 0 0))" "(def 'send (gaslimit to value) (call gaslimit to value 0 0 0 0))" diff --git a/test/liblll/EndToEndTest.cpp b/test/liblll/EndToEndTest.cpp index 7f4dd91a..4e896fd0 100644 --- a/test/liblll/EndToEndTest.cpp +++ b/test/liblll/EndToEndTest.cpp @@ -467,6 +467,61 @@ BOOST_AUTO_TEST_CASE(send_three_args) BOOST_CHECK(balanceAt(Address(0xdead)) == 42); } +// Regression test for edge case that previously failed +BOOST_AUTO_TEST_CASE(alloc_zero) +{ + char const* sourceCode = R"( + (returnlll + (seq + (mstore 0x00 (~ 0)) + (alloc 0) + (return 0x00 0x20))) + )"; + compileAndRun(sourceCode); + BOOST_CHECK(callFallback() == encodeArgs(u256(-1))); +} + +BOOST_AUTO_TEST_CASE(alloc_size) +{ + char const* sourceCode = R"( + (returnlll + (seq + (mstore 0x00 0) ; reserve space for the result of the alloc + (mstore 0x00 (alloc (calldataload 0x04))) + (return (- (msize) (mload 0x00))))) + )"; + compileAndRun(sourceCode); + BOOST_CHECK(callContractFunction("test()", 0) == encodeArgs(u256(0))); + BOOST_CHECK(callContractFunction("test()", 1) == encodeArgs(u256(32))); + BOOST_CHECK(callContractFunction("test()", 32) == encodeArgs(u256(32))); + BOOST_CHECK(callContractFunction("test()", 33) == encodeArgs(u256(64))); +} + +BOOST_AUTO_TEST_CASE(alloc_start) +{ + char const* sourceCode = R"( + (returnlll + (seq + (mstore 0x40 0) ; Set initial MSIZE to 0x60 + (return (alloc 1)))) + )"; + compileAndRun(sourceCode); + BOOST_CHECK(callFallback() == encodeArgs(96)); +} + +BOOST_AUTO_TEST_CASE(alloc_with_variable) +{ + char const* sourceCode = R"( + (returnlll + (seq + (set 'x (alloc 1)) + (mstore8 @x 42) ; ASCII '*' + (return @x 0x20))) + )"; + compileAndRun(sourceCode); + BOOST_CHECK(callFallback() == encodeArgs("*")); +} + BOOST_AUTO_TEST_CASE(msg_six_args) { char const* sourceCode = R"( |