Merge pull request #15074 from clonker/14702-produce-compiler-error-c…

…ompound-div-mod-zero

Produce compiler error for compound division and mod zero operations

Changelog.md

@@ -13,6 +13,7 @@ Bugfixes:
  * SMTChecker: Fix internal error when using an empty tuple in a conditional operator.
  * SMTChecker: Fix internal error when using bitwise operators with an array element as argument.
  * Standard JSON Interface: Fix ICE when the optimizer is disabled and an empty/blank string is used for ``optimizerSteps`` sequence.
+ * StaticAnalyzer: Only raise a compile time error for division and modulo by zero when it's between literals.
  * Yul Optimizer: Fix the order of assignments generated by ``SSATransform`` being dependent on AST IDs, sometimes resulting in different (but equivalent) bytecode when unrelated files were added to the compilation pipeline.
 
 

libsolidity/analysis/StaticAnalyzer.cpp

@@ -298,7 +298,8 @@ bool StaticAnalyzer::visit(BinaryOperation const& _operation)
 {
 	if (
 		*_operation.rightExpression().annotation().isPure &&
-		(_operation.getOperator() == Token::Div || _operation.getOperator() == Token::Mod)
+		(_operation.getOperator() == Token::Div || _operation.getOperator() == Token::Mod) &&
+		ConstantEvaluator::evaluate(m_errorReporter, _operation.leftExpression())
 	)
 		if (auto rhs = ConstantEvaluator::evaluate(m_errorReporter, _operation.rightExpression()))
 			if (rhs->value == 0)

test/libsolidity/syntaxTests/literalOperations/division_by_zero_complex_compound.sol

@@ -0,0 +1,5 @@
+contract A {
+    uint a;
+    constructor() { a /= (((2)*2)%4); }
+}
+// ----

test/libsolidity/syntaxTests/literalOperations/division_by_zero_compound.sol

@@ -0,0 +1,5 @@
+contract A {
+    uint a = 5;
+    constructor() { a /= uint(0); }
+}
+// ----

test/libsolidity/syntaxTests/literalOperations/division_by_zero_nonliteral.sol

@@ -0,0 +1,4 @@
+contract A {
+    constructor() { uint a; a / 0; }
+}
+// ----

test/libsolidity/syntaxTests/literalOperations/mod_zero_complex_compound.sol

@@ -0,0 +1,5 @@
+contract A {
+    uint a = 5;
+    constructor() { a %= uint(((2)*2)%4); }
+}
+// ----

test/libsolidity/syntaxTests/literalOperations/mod_zero_compound.sol

@@ -0,0 +1,5 @@
+contract A {
+    uint a;
+    constructor() { a = 5; a %= 0; }
+}
+// ----

test/libsolidity/syntaxTests/literalOperations/mod_zero_nonliteral.sol

@@ -0,0 +1,4 @@
+contract A {
+    constructor() { uint a; a % 0; }
+}
+// ----