[analyzer] handle modification of vars inside an expr with comma operator
We should track mutation of a variable within a comma operator expression.
Current code in ExprMutationAnalyzer does not handle it.
This will handle cases like:
(a, b) ++ < == b is modified
(a, b) = c < == b is modifed
Patch by Djordje Todorovic.
Differential Revision: https://reviews.llvm.org/D58894
llvm-svn: 355605
diff --git a/clang/lib/Analysis/ExprMutationAnalyzer.cpp b/clang/lib/Analysis/ExprMutationAnalyzer.cpp
index f8d75f4..fb5a139 100644
--- a/clang/lib/Analysis/ExprMutationAnalyzer.cpp
+++ b/clang/lib/Analysis/ExprMutationAnalyzer.cpp
@@ -24,6 +24,18 @@
return InnerMatcher.matches(*Range, Finder, Builder);
}
+AST_MATCHER_P(Expr, maybeEvalCommaExpr,
+ ast_matchers::internal::Matcher<Expr>, InnerMatcher) {
+ const Expr* Result = &Node;
+ while (const auto *BOComma =
+ dyn_cast_or_null<BinaryOperator>(Result->IgnoreParens())) {
+ if (!BOComma->isCommaOp())
+ break;
+ Result = BOComma->getRHS();
+ }
+ return InnerMatcher.matches(*Result, Finder, Builder);
+}
+
const ast_matchers::internal::VariadicDynCastAllOfMatcher<Stmt, CXXTypeidExpr>
cxxTypeidExpr;
@@ -193,24 +205,28 @@
const Stmt *ExprMutationAnalyzer::findDirectMutation(const Expr *Exp) {
// LHS of any assignment operators.
const auto AsAssignmentLhs =
- binaryOperator(isAssignmentOperator(), hasLHS(equalsNode(Exp)));
+ binaryOperator(isAssignmentOperator(),
+ hasLHS(maybeEvalCommaExpr(equalsNode(Exp))));
// Operand of increment/decrement operators.
const auto AsIncDecOperand =
unaryOperator(anyOf(hasOperatorName("++"), hasOperatorName("--")),
- hasUnaryOperand(equalsNode(Exp)));
+ hasUnaryOperand(maybeEvalCommaExpr(equalsNode(Exp))));
// Invoking non-const member function.
// A member function is assumed to be non-const when it is unresolved.
const auto NonConstMethod = cxxMethodDecl(unless(isConst()));
const auto AsNonConstThis =
- expr(anyOf(cxxMemberCallExpr(callee(NonConstMethod), on(equalsNode(Exp))),
+ expr(anyOf(cxxMemberCallExpr(callee(NonConstMethod),
+ on(maybeEvalCommaExpr(equalsNode(Exp)))),
cxxOperatorCallExpr(callee(NonConstMethod),
- hasArgument(0, equalsNode(Exp))),
+ hasArgument(0,
+ maybeEvalCommaExpr(equalsNode(Exp)))),
callExpr(callee(expr(anyOf(
- unresolvedMemberExpr(hasObjectExpression(equalsNode(Exp))),
+ unresolvedMemberExpr(
+ hasObjectExpression(maybeEvalCommaExpr(equalsNode(Exp)))),
cxxDependentScopeMemberExpr(
- hasObjectExpression(equalsNode(Exp)))))))));
+ hasObjectExpression(maybeEvalCommaExpr(equalsNode(Exp))))))))));
// Taking address of 'Exp'.
// We're assuming 'Exp' is mutated as soon as its address is taken, though in
@@ -220,10 +236,11 @@
unaryOperator(hasOperatorName("&"),
// A NoOp implicit cast is adding const.
unless(hasParent(implicitCastExpr(hasCastKind(CK_NoOp)))),
- hasUnaryOperand(equalsNode(Exp)));
+ hasUnaryOperand(maybeEvalCommaExpr(equalsNode(Exp))));
const auto AsPointerFromArrayDecay =
castExpr(hasCastKind(CK_ArrayToPointerDecay),
- unless(hasParent(arraySubscriptExpr())), has(equalsNode(Exp)));
+ unless(hasParent(arraySubscriptExpr())),
+ has(maybeEvalCommaExpr(equalsNode(Exp))));
// Treat calling `operator->()` of move-only classes as taking address.
// These are typically smart pointers with unique ownership so we treat
// mutation of pointee as mutation of the smart pointer itself.
@@ -231,7 +248,8 @@
cxxOperatorCallExpr(hasOverloadedOperatorName("->"),
callee(cxxMethodDecl(ofClass(isMoveOnly()),
returns(nonConstPointerType()))),
- argumentCountIs(1), hasArgument(0, equalsNode(Exp)));
+ argumentCountIs(1),
+ hasArgument(0, maybeEvalCommaExpr(equalsNode(Exp))));
// Used as non-const-ref argument when calling a function.
// An argument is assumed to be non-const-ref when the function is unresolved.
@@ -239,7 +257,8 @@
// findFunctionArgMutation which has additional smarts for handling forwarding
// references.
const auto NonConstRefParam = forEachArgumentWithParam(
- equalsNode(Exp), parmVarDecl(hasType(nonConstReferenceType())));
+ maybeEvalCommaExpr(equalsNode(Exp)),
+ parmVarDecl(hasType(nonConstReferenceType())));
const auto NotInstantiated = unless(hasDeclaration(isInstantiated()));
const auto AsNonConstRefArg = anyOf(
callExpr(NonConstRefParam, NotInstantiated),
@@ -247,8 +266,8 @@
callExpr(callee(expr(anyOf(unresolvedLookupExpr(), unresolvedMemberExpr(),
cxxDependentScopeMemberExpr(),
hasType(templateTypeParmType())))),
- hasAnyArgument(equalsNode(Exp))),
- cxxUnresolvedConstructExpr(hasAnyArgument(equalsNode(Exp))));
+ hasAnyArgument(maybeEvalCommaExpr(equalsNode(Exp)))),
+ cxxUnresolvedConstructExpr(hasAnyArgument(maybeEvalCommaExpr(equalsNode(Exp)))));
// Captured by a lambda by reference.
// If we're initializing a capture with 'Exp' directly then we're initializing
@@ -261,7 +280,8 @@
// For returning by value there will be an ImplicitCastExpr <LValueToRValue>.
// For returning by const-ref there will be an ImplicitCastExpr <NoOp> (for
// adding const.)
- const auto AsNonConstRefReturn = returnStmt(hasReturnValue(equalsNode(Exp)));
+ const auto AsNonConstRefReturn = returnStmt(hasReturnValue(
+ maybeEvalCommaExpr(equalsNode(Exp))));
const auto Matches =
match(findAll(stmt(anyOf(AsAssignmentLhs, AsIncDecOperand, AsNonConstThis,