Merge pull request #12861 from ethereum/disallow-returndatacopy-in-pure-functions

Disallow RETURNDATACOPY and RETURNDATASIZE in inline assembly in pure functions

Changelog.md

@@ -13,6 +13,7 @@ Compiler Features:
 Bugfixes:
 * Assembly-Json: Fix assembly json export to store jump types of operations in `jumpType` field instead of `value`.
 * TypeChecker: Convert parameters of function type to how they would be called for ``abi.encodeCall``.
+* View Pure Checker: Mark ``returndatasize`` and ``returndatacopy`` as view to disallow them in inline assembly blocks in pure functions.
 
 
 

libevmasm/SemanticInformation.cpp

@@ -479,6 +479,8 @@ bool SemanticInformation::invalidInPureFunctions(Instruction _instruction)
 	case Instruction::EXTCODESIZE:
 	case Instruction::EXTCODECOPY:
 	case Instruction::EXTCODEHASH:
+	case Instruction::RETURNDATASIZE:
+	case Instruction::RETURNDATACOPY:
 	case Instruction::BLOCKHASH:
 	case Instruction::COINBASE:
 	case Instruction::TIMESTAMP:

test/libsolidity/syntaxTests/inlineAssembly/evm_byzantium.sol

@@ -1,5 +1,5 @@
 contract C {
-    function f() pure external {
+    function f() view external {
         assembly {
             let s := returndatasize()
             returndatacopy(0, 0, s)

test/libsolidity/syntaxTests/inlineAssembly/evm_byzantium_on_homestead.sol

@@ -1,5 +1,5 @@
 contract C {
-    function f() pure external {
+    function f() view external {
         assembly {
             let s := returndatasize()
             returndatacopy(0, 0, s)

test/libsolidity/syntaxTests/inlineAssembly/returndatasize_as_variable_call_post_byzantium.sol.sol

@@ -1,5 +1,5 @@
 contract C {
-    function f() public pure {
+    function f() public view {
         uint returndatasize;
         returndatasize;
         assembly {

test/libsolidity/syntaxTests/inlineAssembly/returndatasize_as_variable_post_byzantium.sol

@@ -1,5 +1,5 @@
 contract C {
-    function f() public pure {
+    function f() public view {
         uint returndatasize;
         returndatasize;
         assembly {

test/libsolidity/syntaxTests/inlineAssembly/returndatasize_as_variable_pre_byzantium.sol

@@ -1,4 +1,4 @@
-contract C { function f() public pure { uint returndatasize; returndatasize; assembly { pop(returndatasize()) }}}
+contract C { function f() public view { uint returndatasize; returndatasize; assembly { pop(returndatasize()) }}}
 // ====
 // EVMVersion: =homestead
 // ----

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_allowed.sol

@@ -0,0 +1,92 @@
+contract C {
+    function f() public {
+        assembly {
+            stop()
+            pop(add(0, 1))
+            pop(sub(0, 1))
+            pop(mul(0, 1))
+            pop(div(0, 1))
+            pop(sdiv(0, 1))
+            pop(mod(0, 1))
+            pop(smod(0, 1))
+            pop(exp(0, 1))
+            pop(not(0))
+            pop(lt(0, 1))
+            pop(gt(0, 1))
+            pop(slt(0, 1))
+            pop(sgt(0, 1))
+            pop(eq(0, 1))
+            pop(iszero(0))
+            pop(and(0, 1))
+            pop(or(0, 1))
+            pop(xor(0, 1))
+            pop(byte(0, 1))
+            pop(shl(0, 1))
+            pop(shr(0, 1))
+            pop(sar(0, 1))
+            pop(addmod(0, 1, 2))
+            pop(mulmod(0, 1, 2))
+            pop(signextend(0, 1))
+            pop(keccak256(0, 1))
+            pop(0)
+            pop(mload(0))
+            mstore(0, 1)
+            mstore8(0, 1)
+            pop(sload(0))
+            sstore(0, 1)
+            pop(gas())
+            pop(address())
+            pop(balance(0))
+            pop(selfbalance())
+            pop(caller())
+            pop(callvalue())
+            pop(calldataload(0))
+            pop(calldatasize())
+            calldatacopy(0, 1, 2)
+            pop(codesize())
+            codecopy(0, 1, 2)
+            pop(extcodesize(0))
+            extcodecopy(0, 1, 2, 3)
+            pop(returndatasize())
+            returndatacopy(0, 1, 2)
+            pop(extcodehash(0))
+            pop(create(0, 1, 2))
+            pop(create2(0, 1, 2, 3))
+            pop(call(0, 1, 2, 3, 4, 5, 6))
+            pop(callcode(0, 1, 2, 3, 4, 5, 6))
+            pop(delegatecall(0, 1, 2, 3, 4, 5))
+            pop(staticcall(0, 1, 2, 3, 4, 5))
+            return(0, 1)
+            revert(0, 1)
+            selfdestruct(0)
+            invalid()
+            log0(0, 1)
+            log1(0, 1, 2)
+            log2(0, 1, 2, 3)
+            log3(0, 1, 2, 3, 4)
+            log4(0, 1, 2, 3, 4, 5)
+            pop(chainid())
+            pop(basefee())
+            pop(origin())
+            pop(gasprice())
+            pop(blockhash(0))
+            pop(coinbase())
+            pop(timestamp())
+            pop(number())
+            pop(difficulty())
+            pop(gaslimit())
+
+            // NOTE: msize() is allowed only with optimizer disabled
+            //pop(msize())
+            //pop(pc())
+        }
+    }
+}
+// ====
+// EVMVersion: >=london
+// ----
+// Warning 5740: (89-1716): Unreachable code.
+// Warning 5740: (1729-1741): Unreachable code.
+// Warning 5740: (1754-1769): Unreachable code.
+// Warning 5740: (1782-1791): Unreachable code.
+// Warning 5740: (1804-2215): Unreachable code.

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_allowed_pure.sol

@@ -0,0 +1,90 @@
+contract C {
+    function f() public pure {
+        assembly {
+            stop()
+            pop(add(0, 1))
+            pop(sub(0, 1))
+            pop(mul(0, 1))
+            pop(div(0, 1))
+            pop(sdiv(0, 1))
+            pop(mod(0, 1))
+            pop(smod(0, 1))
+            pop(exp(0, 1))
+            pop(not(0))
+            pop(lt(0, 1))
+            pop(gt(0, 1))
+            pop(slt(0, 1))
+            pop(sgt(0, 1))
+            pop(eq(0, 1))
+            pop(iszero(0))
+            pop(and(0, 1))
+            pop(or(0, 1))
+            pop(xor(0, 1))
+            pop(byte(0, 1))
+            pop(shl(0, 1))
+            pop(shr(0, 1))
+            pop(sar(0, 1))
+            pop(addmod(0, 1, 2))
+            pop(mulmod(0, 1, 2))
+            pop(signextend(0, 1))
+            pop(keccak256(0, 1))
+            pop(0)
+            pop(mload(0))
+            mstore(0, 1)
+            mstore8(0, 1)
+            //pop(sload(0))
+            //sstore(0, 1)
+            //pop(gas())
+            //pop(address())
+            //pop(balance(0))
+            //pop(selfbalance())
+            //pop(caller())
+            //pop(callvalue())
+            pop(calldataload(0))
+            pop(calldatasize())
+            calldatacopy(0, 1, 2)
+            pop(codesize())
+            codecopy(0, 1, 2)
+            //pop(extcodesize(0))
+            //extcodecopy(0, 1, 2, 3)
+            //pop(returndatasize())
+            //returndatacopy(0, 1, 2)
+            //pop(extcodehash(0))
+            //pop(create(0, 1, 2))
+            //pop(create2(0, 1, 2, 3))
+            //pop(call(0, 1, 2, 3, 4, 5, 6))
+            //pop(callcode(0, 1, 2, 3, 4, 5, 6))
+            //pop(delegatecall(0, 1, 2, 3, 4, 5))
+            //pop(staticcall(0, 1, 2, 3, 4, 5))
+            return(0, 1)
+            revert(0, 1)
+            //selfdestruct(0)
+            invalid()
+            //log0(0, 1)
+            //log1(0, 1, 2)
+            //log2(0, 1, 2, 3)
+            //log3(0, 1, 2, 3, 4)
+            //log4(0, 1, 2, 3, 4, 5)
+            //pop(chainid())
+            //pop(basefee())
+            //pop(origin())
+            //pop(gasprice())
+            //pop(blockhash(0))
+            //pop(coinbase())
+            //pop(timestamp())
+            //pop(number())
+            //pop(difficulty())
+            //pop(gaslimit())
+
+            // NOTE: msize() is allowed only with optimizer disabled
+            //pop(msize())
+            //pop(pc())
+        }
+    }
+}
+// ====
+// EVMVersion: >=london
+// ----
+// Warning 5740: (94-1759): Unreachable code.
+// Warning 5740: (1772-1784): Unreachable code.
+// Warning 5740: (1827-1836): Unreachable code.

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_allowed_view.sol

@@ -0,0 +1,91 @@
+contract C {
+    function f() public view {
+        assembly {
+            stop()
+            pop(add(0, 1))
+            pop(sub(0, 1))
+            pop(mul(0, 1))
+            pop(div(0, 1))
+            pop(sdiv(0, 1))
+            pop(mod(0, 1))
+            pop(smod(0, 1))
+            pop(exp(0, 1))
+            pop(not(0))
+            pop(lt(0, 1))
+            pop(gt(0, 1))
+            pop(slt(0, 1))
+            pop(sgt(0, 1))
+            pop(eq(0, 1))
+            pop(iszero(0))
+            pop(and(0, 1))
+            pop(or(0, 1))
+            pop(xor(0, 1))
+            pop(byte(0, 1))
+            pop(shl(0, 1))
+            pop(shr(0, 1))
+            pop(sar(0, 1))
+            pop(addmod(0, 1, 2))
+            pop(mulmod(0, 1, 2))
+            pop(signextend(0, 1))
+            pop(keccak256(0, 1))
+            pop(0)
+            pop(mload(0))
+            mstore(0, 1)
+            mstore8(0, 1)
+            pop(sload(0))
+            //sstore(0, 1)
+            pop(gas())
+            pop(address())
+            pop(balance(0))
+            pop(selfbalance())
+            pop(caller())
+            pop(callvalue())
+            pop(calldataload(0))
+            pop(calldatasize())
+            calldatacopy(0, 1, 2)
+            pop(codesize())
+            codecopy(0, 1, 2)
+            pop(extcodesize(0))
+            extcodecopy(0, 1, 2, 3)
+            pop(returndatasize())
+            returndatacopy(0, 1, 2)
+            pop(extcodehash(0))
+            //pop(create(0, 1, 2))
+            //pop(create2(0, 1, 2, 3))
+            //pop(call(0, 1, 2, 3, 4, 5, 6))
+            //pop(callcode(0, 1, 2, 3, 4, 5, 6))
+            //pop(delegatecall(0, 1, 2, 3, 4, 5))
+            pop(staticcall(0, 1, 2, 3, 4, 5))
+            return(0, 1)
+            revert(0, 1)
+            //selfdestruct(0)
+            invalid()
+            //log0(0, 1)
+            //log1(0, 1, 2)
+            //log2(0, 1, 2, 3)
+            //log3(0, 1, 2, 3, 4)
+            //log4(0, 1, 2, 3, 4, 5)
+            pop(chainid())
+            pop(basefee())
+            pop(origin())
+            pop(gasprice())
+            pop(blockhash(0))
+            pop(coinbase())
+            pop(timestamp())
+            pop(number())
+            pop(difficulty())
+            pop(gaslimit())
+
+            // NOTE: msize() is allowed only with optimizer disabled
+            //pop(msize())
+            //pop(pc())
+        }
+    }
+}
+// ====
+// EVMVersion: >=london
+// ----
+// Warning 5740: (94-1733): Unreachable code.
+// Warning 5740: (1746-1758): Unreachable code.
+// Warning 5740: (1801-1810): Unreachable code.
+// Warning 5740: (1978-2244): Unreachable code.

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed.sol

@@ -0,0 +1,28 @@
+contract C {
+    function f() public {
+        assembly {
+            datasize(0)
+            dataoffset(0)
+            datacopy(0, 1, 2)
+            setimmutable(0, "x", 1)
+            loadimmutable("x")
+            linkersymbol("x")
+            memoryguard(0)
+            verbatim_1i_1o(hex"600202", 0)
+
+            pop(msize())
+            pop(pc())
+        }
+    }
+}
+// ----
+// SyntaxError 6553: (47-362): The msize instruction cannot be used when the Yul optimizer is activated because it can change its semantics. Either disable the Yul optimizer or do not use the instruction.
+// DeclarationError 4619: (70-78): Function "datasize" not found.
+// DeclarationError 4619: (94-104): Function "dataoffset" not found.
+// DeclarationError 4619: (120-128): Function "datacopy" not found.
+// DeclarationError 4619: (150-162): Function "setimmutable" not found.
+// DeclarationError 4619: (186-199): Function "loadimmutable" not found.
+// DeclarationError 4619: (217-229): Function "linkersymbol" not found.
+// DeclarationError 4619: (247-258): Function "memoryguard" not found.
+// DeclarationError 4619: (274-288): Function "verbatim_1i_1o" not found.
+// SyntaxError 2450: (347-349): PC instruction is a low-level EVM feature. Because of that PC is disallowed in strict assembly.

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_pure.sol

@@ -0,0 +1,84 @@
+contract C {
+    function f() public pure {
+        assembly {
+            pop(sload(0))
+            sstore(0, 1)
+            pop(gas())
+            pop(address())
+            pop(balance(0))
+            pop(selfbalance())
+            pop(caller())
+            pop(callvalue())
+            pop(extcodesize(0))
+            extcodecopy(0, 1, 2, 3)
+            pop(returndatasize())
+            returndatacopy(0, 1, 2)
+            pop(extcodehash(0))
+            pop(create(0, 1, 2))
+            pop(create2(0, 1, 2, 3))
+            pop(call(0, 1, 2, 3, 4, 5, 6))
+            pop(callcode(0, 1, 2, 3, 4, 5, 6))
+            pop(delegatecall(0, 1, 2, 3, 4, 5))
+            pop(staticcall(0, 1, 2, 3, 4, 5))
+            selfdestruct(0)
+            log0(0, 1)
+            log1(0, 1, 2)
+            log2(0, 1, 2, 3)
+            log3(0, 1, 2, 3, 4)
+            log4(0, 1, 2, 3, 4, 5)
+            pop(chainid())
+            pop(basefee())
+            pop(origin())
+            pop(gasprice())
+            pop(blockhash(0))
+            pop(coinbase())
+            pop(timestamp())
+            pop(number())
+            pop(difficulty())
+            pop(gaslimit())
+
+            // These two are disallowed too but the error suppresses other errors.
+            //pop(msize())
+            //pop(pc())
+        }
+    }
+}
+// ====
+// EVMVersion: >=london
+// ----
+// Warning 5740: (742-1153): Unreachable code.
+// TypeError 2527: (79-87): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 8961: (101-113): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 2527: (130-135): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (153-162): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (180-190): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (208-221): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (239-247): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (265-276): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (294-308): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (322-345): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (362-378): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (392-415): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (432-446): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 8961: (464-479): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (497-516): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (534-559): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (577-606): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (624-654): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 2527: (672-700): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 8961: (714-729): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (742-752): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (765-778): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (791-807): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (820-839): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (852-874): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 2527: (891-900): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (918-927): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (945-953): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (971-981): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (999-1011): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (1029-1039): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (1057-1068): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (1086-1094): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (1112-1124): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (1142-1152): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_view.sol

@@ -0,0 +1,38 @@
+contract C {
+    function f() public view {
+        assembly {
+            sstore(0, 1)
+            pop(create(0, 1, 2))
+            pop(create2(0, 1, 2, 3))
+            pop(call(0, 1, 2, 3, 4, 5, 6))
+            pop(callcode(0, 1, 2, 3, 4, 5, 6))
+            pop(delegatecall(0, 1, 2, 3, 4, 5))
+            selfdestruct(0)
+            log0(0, 1)
+            log1(0, 1, 2)
+            log2(0, 1, 2, 3)
+            log3(0, 1, 2, 3, 4)
+            log4(0, 1, 2, 3, 4, 5)
+
+            // These two are disallowed too but the error suppresses other errors.
+            //pop(msize())
+            //pop(pc())
+        }
+    }
+}
+// ====
+// EVMVersion: >=london
+// ----
+// Warning 5740: (336-468): Unreachable code.
+// TypeError 8961: (75-87): Function cannot be declared as view because this expression (potentially) modifies the state.
+// TypeError 8961: (104-119): Function cannot be declared as view because this expression (potentially) modifies the state.
+// TypeError 8961: (137-156): Function cannot be declared as view because this expression (potentially) modifies the state.
+// TypeError 8961: (174-199): Function cannot be declared as view because this expression (potentially) modifies the state.
+// TypeError 8961: (217-246): Function cannot be declared as view because this expression (potentially) modifies the state.
+// TypeError 8961: (264-294): Function cannot be declared as view because this expression (potentially) modifies the state.
+// TypeError 8961: (308-323): Function cannot be declared as view because this expression (potentially) modifies the state.
+// TypeError 8961: (336-346): Function cannot be declared as view because this expression (potentially) modifies the state.
+// TypeError 8961: (359-372): Function cannot be declared as view because this expression (potentially) modifies the state.
+// TypeError 8961: (385-401): Function cannot be declared as view because this expression (potentially) modifies the state.
+// TypeError 8961: (414-433): Function cannot be declared as view because this expression (potentially) modifies the state.
+// TypeError 8961: (446-468): Function cannot be declared as view because this expression (potentially) modifies the state.