Merge pull request #10240 from ethereum/immutablesPureValue

Immutables with literal values are pure.

Changelog.md

@@ -2,6 +2,7 @@
 
 Language Features:
  * Ability to select the abi coder using ``pragma abicoder v1`` and ``pragma abicoder v2``.
+ * Immutable variables with literal number values are considered pure.
 
 Compiler Features:
  * Command Line Interface: Report error if file could not be read in ``--standard-json`` mode.

libsolidity/analysis/ViewPureChecker.cpp

@@ -186,7 +186,13 @@ void ViewPureChecker::endVisit(Identifier const& _identifier)
 	bool writes = _identifier.annotation().willBeWrittenTo;
 	if (VariableDeclaration const* varDecl = dynamic_cast<VariableDeclaration const*>(declaration))
 	{
-		if (varDecl->isStateVariable() && !varDecl->isConstant())
+		if (varDecl->immutable())
+		{
+			// Immutables that are assigned literals are pure.
+			if (!(varDecl->value() && varDecl->value()->annotation().type->category() == Type::Category::RationalNumber))
+				mutability = StateMutability::View;
+		}
+		else if (varDecl->isStateVariable() && !varDecl->isConstant())
 			mutability = writes ? StateMutability::NonPayable : StateMutability::View;
 	}
 	else if (MagicVariableDeclaration const* magicVar = dynamic_cast<MagicVariableDeclaration const*>(declaration))
@@ -291,7 +297,7 @@ void ViewPureChecker::reportMutability(
 		m_currentFunction->stateMutability() == StateMutability::Pure ||
 		m_currentFunction->stateMutability() == StateMutability::NonPayable,
 		""
-				);
+	);
 }
 
 ViewPureChecker::MutabilityAndLocation const& ViewPureChecker::modifierMutability(

test/cmdlineTests/standard_immutable_references/input.json

@@ -2,7 +2,7 @@
  "language": "Solidity",
  "sources": {
   "a.sol": {
-   "content": "// SPDX-License-Identifier: GPL-3.0\ncontract A { uint256 immutable x = 1; function f() public view returns (uint256) { return x; } }"
+   "content": "// SPDX-License-Identifier: GPL-3.0\ncontract A { uint256 immutable x = 1 + 3; function f() public pure returns (uint256) { return x; } }"
   }
  },
  "settings": {

test/cmdlineTests/standard_immutable_references/output.json

@@ -1,2 +1,2 @@
-{"contracts":{"a.sol":{"A":{"evm":{"deployedBytecode":{"generatedSources":[],"immutableReferences":{"3":[{"length":32,"start":77}]},"linkReferences":{},"object":"<BYTECODE REMOVED>","opcodes":"<OPCODES REMOVED>","sourceMap":"36:96:0:-:0;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;74:56;;;:::i;:::-;;;;;;;;;;;;;;;;;;;;108:7;126:1;119:8;;74:56;:::o"}}}}},"errors":[{"component":"general","errorCode":"3420","formattedMessage":"a.sol: Warning: Source file does not specify required compiler version!
+{"contracts":{"a.sol":{"A":{"evm":{"deployedBytecode":{"generatedSources":[],"immutableReferences":{"5":[{"length":32,"start":77}]},"linkReferences":{},"object":"<BYTECODE REMOVED>","opcodes":"<OPCODES REMOVED>","sourceMap":"36:100:0:-:0;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;78:56;;;:::i;:::-;;;;;;;;;;;;;;;;;;;;112:7;130:1;123:8;;78:56;:::o"}}}}},"errors":[{"component":"general","errorCode":"3420","formattedMessage":"a.sol: Warning: Source file does not specify required compiler version!
 ","message":"Source file does not specify required compiler version!","severity":"warning","sourceLocation":{"end":-1,"file":"a.sol","start":-1},"type":"Warning"}],"sources":{"a.sol":{"id":0}}}

test/libsolidity/syntaxTests/immutable/unrelated_reading.sol

@@ -1,7 +1,7 @@
 contract C {
     uint immutable x = 1;
 
-    function readX() internal view returns(uint) {
+    function readX() internal pure returns(uint) {
         return x + 3;
     }
 }

test/libsolidity/syntaxTests/viewPureChecker/immutable.sol

@@ -5,4 +5,3 @@ contract B {
     }
 }
 // ----
-// TypeError 2527: (100-101): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".