Merge pull request #4409 from ethereum/viewPureChecker

Enforce state mutability in view pure checker.

19 files changed, 163 insertions, 11 deletions

diff --git a/test/libsolidity/syntaxTests/viewPureChecker/assembly_jump.sol b/test/libsolidity/syntaxTests/viewPureChecker/assembly_jump_no_restrict_warning.sol
index 418be561..418be561 100644
--- a/test/libsolidity/syntaxTests/viewPureChecker/assembly_jump.sol
+++ b/test/libsolidity/syntaxTests/viewPureChecker/assembly_jump_no_restrict_warning.sol
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/assembly_jump_view_fail.sol b/test/libsolidity/syntaxTests/viewPureChecker/assembly_jump_view_fail.sol
new file mode 100644
index 00000000..c1729db7
--- /dev/null
+++ b/test/libsolidity/syntaxTests/viewPureChecker/assembly_jump_view_fail.sol
@@ -0,0 +1,8 @@
+contract C {
+    function k() public view {
+        assembly { jump(2) }
+    }
+}
+// ----
+// Warning: (63-70): Jump instructions and labels are low-level EVM features that can lead to incorrect stack access. Because of that they are discouraged. Please consider using "switch", "if" or "for" statements instead.
+// TypeError: (63-70): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/builtin_functions_restrict_warning.sol b/test/libsolidity/syntaxTests/viewPureChecker/builtin_functions_restrict_warning.sol
new file mode 100644
index 00000000..0b834022
--- /dev/null
+++ b/test/libsolidity/syntaxTests/viewPureChecker/builtin_functions_restrict_warning.sol
@@ -0,0 +1,21 @@
+contract C {
+    function f() view public {
+        bytes32 x = keccak256("abc");
+        bytes32 y = sha256("abc");
+        address z = ecrecover(bytes32(1), uint8(2), bytes32(3), bytes32(4));
+        require(true);
+        assert(true);
+        x; y; z;
+    }
+    function g() public {
+        bytes32 x = keccak256("abc");
+        bytes32 y = sha256("abc");
+        address z = ecrecover(bytes32(1), uint8(2), bytes32(3), bytes32(4));
+        require(true);
+        assert(true);
+        x; y; z;
+    }
+}
+// ----
+// Warning: (17-261): Function state mutability can be restricted to pure
+// Warning: (266-505): Function state mutability can be restricted to pure
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/builtin_functions_view_fail.sol b/test/libsolidity/syntaxTests/viewPureChecker/builtin_functions_view_fail.sol
new file mode 100644
index 00000000..9b00fd6d
--- /dev/null
+++ b/test/libsolidity/syntaxTests/viewPureChecker/builtin_functions_view_fail.sol
@@ -0,0 +1,23 @@
+contract C {
+    function f() view public {
+        address(this).transfer(1);
+    }
+    function g() view public {
+        require(address(this).send(2));
+    }
+    function h() view public {
+        selfdestruct(address(this));
+    }
+    function i() view public {
+        require(address(this).delegatecall(""));
+    }
+    function j() view public {
+        require(address(this).call(""));
+    }
+}
+// ----
+// TypeError: (52-77): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
+// TypeError: (132-153): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
+// TypeError: (201-228): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
+// TypeError: (283-313): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
+// TypeError: (369-391): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/call_internal_functions_fail.sol b/test/libsolidity/syntaxTests/viewPureChecker/call_internal_functions_fail.sol
index 22855c34..e21037bd 100644
--- a/test/libsolidity/syntaxTests/viewPureChecker/call_internal_functions_fail.sol
+++ b/test/libsolidity/syntaxTests/viewPureChecker/call_internal_functions_fail.sol
@@ -1,7 +1,10 @@
 contract C {
+    uint x;
     function f() pure public { g(); }
-    function g() view public {}
+    function g() view public { x; }
+    function h() view public { i(); }
+    function i() public { x = 2; }
 }
 // ----
-// TypeError: (44-47): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// Warning: (55-82): Function state mutability can be restricted to pure
+// TypeError: (56-59): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError: (130-133): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/constant_restrict_warning.sol b/test/libsolidity/syntaxTests/viewPureChecker/constant_restrict_warning.sol
new file mode 100644
index 00000000..a4b4a353
--- /dev/null
+++ b/test/libsolidity/syntaxTests/viewPureChecker/constant_restrict_warning.sol
@@ -0,0 +1,12 @@
+contract C {
+    uint constant x = 2;
+    function f() view public returns (uint) {
+        return x;
+    }
+    function g() public returns (uint) {
+        return x;
+    }
+}
+// ----
+// Warning: (42-107): Function state mutability can be restricted to pure
+// Warning: (112-172): Function state mutability can be restricted to pure
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/creation.sol b/test/libsolidity/syntaxTests/viewPureChecker/creation_no_restrict_warning.sol
index d80edd1b..d80edd1b 100644
--- a/test/libsolidity/syntaxTests/viewPureChecker/creation.sol
+++ b/test/libsolidity/syntaxTests/viewPureChecker/creation_no_restrict_warning.sol
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/creation_view_fail.sol b/test/libsolidity/syntaxTests/viewPureChecker/creation_view_fail.sol
new file mode 100644
index 00000000..08e45ea1
--- /dev/null
+++ b/test/libsolidity/syntaxTests/viewPureChecker/creation_view_fail.sol
@@ -0,0 +1,6 @@
+contract D {}
+contract C {
+    function f() public view { new D(); }
+}
+// ----
+// TypeError: (58-65): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/function_types_fail.sol b/test/libsolidity/syntaxTests/viewPureChecker/function_types_fail.sol
new file mode 100644
index 00000000..d00f65c9
--- /dev/null
+++ b/test/libsolidity/syntaxTests/viewPureChecker/function_types_fail.sol
@@ -0,0 +1,18 @@
+contract C {
+    function f() pure public {
+        function () external nonpayFun;
+        nonpayFun();
+    }
+    function g() pure public {
+        function () external view viewFun;
+        viewFun();
+    }
+    function h() view public {
+        function () external nonpayFun;
+        nonpayFun();
+    }
+}
+// ----
+// TypeError: (92-103): Function declared as pure, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
+// TypeError: (193-202): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError: (289-300): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/local_storage_variables_fail.sol b/test/libsolidity/syntaxTests/viewPureChecker/local_storage_variables_fail.sol
new file mode 100644
index 00000000..0ff1ac24
--- /dev/null
+++ b/test/libsolidity/syntaxTests/viewPureChecker/local_storage_variables_fail.sol
@@ -0,0 +1,15 @@
+contract C {
+    struct S { uint a; }
+    S s;
+    function f() pure public {
+        S storage x = s;
+        x;
+    }
+    function g() view public {
+        S storage x = s;
+        x.a = 1;
+    }
+}
+// ----
+// TypeError: (100-101): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError: (184-187): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/modifiers_fail.sol b/test/libsolidity/syntaxTests/viewPureChecker/modifiers_fail.sol
new file mode 100644
index 00000000..513850f7
--- /dev/null
+++ b/test/libsolidity/syntaxTests/viewPureChecker/modifiers_fail.sol
@@ -0,0 +1,12 @@
+contract D {
+    uint x;
+    modifier viewm(uint) { uint a = x; _; a; }
+    modifier nonpayablem(uint) { x = 2; _; }
+}
+contract C is D {
+    function f() viewm(0) pure public {}
+    function g() nonpayablem(0) view public {}
+}
+// ----
+// TypeError: (154-162): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError: (195-209): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/overriding_fail.sol b/test/libsolidity/syntaxTests/viewPureChecker/overriding_fail.sol
new file mode 100644
index 00000000..61702495
--- /dev/null
+++ b/test/libsolidity/syntaxTests/viewPureChecker/overriding_fail.sol
@@ -0,0 +1,16 @@
+contract D {
+    uint x;
+    function f() public view { x; }
+    function g() public pure {}
+}
+contract C1 is D {
+    function f() public {}
+    function g() public view {}
+}
+contract C2 is D {
+    function g() public {}
+}
+// ----
+// TypeError: (118-140): Overriding function changes state mutability from "view" to "nonpayable".
+// TypeError: (145-172): Overriding function changes state mutability from "pure" to "view".
+// TypeError: (198-220): Overriding function changes state mutability from "pure" to "nonpayable".
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/overriding.sol b/test/libsolidity/syntaxTests/viewPureChecker/overriding_no_restrict_warning.sol
index c82c7908..c82c7908 100644
--- a/test/libsolidity/syntaxTests/viewPureChecker/overriding.sol
+++ b/test/libsolidity/syntaxTests/viewPureChecker/overriding_no_restrict_warning.sol
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/read_storage_pure_fail.sol b/test/libsolidity/syntaxTests/viewPureChecker/read_storage_pure_fail.sol
new file mode 100644
index 00000000..785656b9
--- /dev/null
+++ b/test/libsolidity/syntaxTests/viewPureChecker/read_storage_pure_fail.sol
@@ -0,0 +1,8 @@
+contract C {
+    uint x;
+    function f() public pure returns (uint) {
+        return x;
+    }
+}
+// ----
+// TypeError: (86-87): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/returning_structs_fail.sol b/test/libsolidity/syntaxTests/viewPureChecker/returning_structs_fail.sol
new file mode 100644
index 00000000..e04d0825
--- /dev/null
+++ b/test/libsolidity/syntaxTests/viewPureChecker/returning_structs_fail.sol
@@ -0,0 +1,13 @@
+contract C {
+    struct S { uint x; }
+    S s;
+    function f() pure internal returns (S storage) {
+        return s;
+    }
+    function g() pure public {
+        f().x;
+    }
+}
+// ----
+// TypeError: (115-116): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError: (163-168): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/returning_structs.sol b/test/libsolidity/syntaxTests/viewPureChecker/returning_structs_no_restrict_warning.sol
index 9b4eb466..9b4eb466 100644
--- a/test/libsolidity/syntaxTests/viewPureChecker/returning_structs.sol
+++ b/test/libsolidity/syntaxTests/viewPureChecker/returning_structs_no_restrict_warning.sol
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/selector.sol b/test/libsolidity/syntaxTests/viewPureChecker/selector.sol
index 2ad4518d..c4e30075 100644
--- a/test/libsolidity/syntaxTests/viewPureChecker/selector.sol
+++ b/test/libsolidity/syntaxTests/viewPureChecker/selector.sol
@@ -5,4 +5,8 @@ contract C {
     function g() pure public returns (bytes4) {
         return this.f.selector ^ this.x.selector;
     }
+    function h() view public returns (bytes4) {
+        x;
+        return this.f.selector ^ this.x.selector;
+    }
 }
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/write_storage_fail.sol b/test/libsolidity/syntaxTests/viewPureChecker/write_storage_fail.sol
index 2a8bba31..3fed4d29 100644
--- a/test/libsolidity/syntaxTests/viewPureChecker/write_storage_fail.sol
+++ b/test/libsolidity/syntaxTests/viewPureChecker/write_storage_fail.sol
@@ -3,4 +3,4 @@ contract C {
     function f() view public { x = 2; }
 }
 // ----
-// Warning: (56-57): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
+// TypeError: (56-57): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
diff --git a/test/libsolidity/syntaxTests/viewPureChecker/write_storage_fail_v050.sol b/test/libsolidity/syntaxTests/viewPureChecker/write_storage_fail_v050.sol
deleted file mode 100644
index b85078ed..00000000
--- a/test/libsolidity/syntaxTests/viewPureChecker/write_storage_fail_v050.sol
+++ /dev/null
@@ -1,7 +0,0 @@
-pragma experimental "v0.5.0";
-contract C {
-    uint x;
-    function f() view public { x = 2; }
-}
-// ----
-// TypeError: (86-87): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.