Fix: <rdar://problem/6740387>. Sending nil to an object that returns a struct
should only be an error if that value is consumed. This fix was largely
accomplished by moving 'isConsumedExpr' back to ParentMap.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68195 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/CheckDeadStores.cpp b/lib/Analysis/CheckDeadStores.cpp
index 504de3c..d1b3be5 100644
--- a/lib/Analysis/CheckDeadStores.cpp
+++ b/lib/Analysis/CheckDeadStores.cpp
@@ -38,10 +38,7 @@
: Ctx(ctx), BR(br), Parents(parents) {}
virtual ~DeadStoreObs() {}
-
- bool isConsumedExpr(Expr* E) const;
-
-
+
void Report(VarDecl* V, DeadStoreKind dsk, SourceLocation L, SourceRange R) {
std::string name = V->getNameAsString();
@@ -148,7 +145,7 @@
return;
// Otherwise, issue a warning.
- DeadStoreKind dsk = isConsumedExpr(B)
+ DeadStoreKind dsk = Parents.isConsumedExpr(B)
? Enclosing
: (isIncrement(VD,B) ? DeadIncrement : Standard);
@@ -163,7 +160,7 @@
// about preincrements to dead variables when the preincrement occurs
// as a subexpression. This can lead to false negatives, e.g. "(++x);"
// A generalized dead code checker should find such issues.
- if (U->isPrefix() && isConsumedExpr(U))
+ if (U->isPrefix() && Parents.isConsumedExpr(U))
return;
Expr *Ex = U->getSubExpr()->IgnoreParenCasts();
@@ -218,43 +215,6 @@
} // end anonymous namespace
-bool DeadStoreObs::isConsumedExpr(Expr* E) const {
- Stmt *P = Parents.getParent(E);
- Stmt *DirectChild = E;
-
- // Ignore parents that are parentheses or casts.
- while (P && (isa<ParenExpr>(E) || isa<CastExpr>(E))) {
- DirectChild = P;
- P = Parents.getParent(P);
- }
-
- if (!P)
- return false;
-
- switch (P->getStmtClass()) {
- default:
- return isa<Expr>(P);
- case Stmt::BinaryOperatorClass: {
- BinaryOperator *BE = cast<BinaryOperator>(P);
- return BE->getOpcode()==BinaryOperator::Comma && DirectChild==BE->getLHS();
- }
- case Stmt::ForStmtClass:
- return DirectChild == cast<ForStmt>(P)->getCond();
- case Stmt::WhileStmtClass:
- return DirectChild == cast<WhileStmt>(P)->getCond();
- case Stmt::DoStmtClass:
- return DirectChild == cast<DoStmt>(P)->getCond();
- case Stmt::IfStmtClass:
- return DirectChild == cast<IfStmt>(P)->getCond();
- case Stmt::IndirectGotoStmtClass:
- return DirectChild == cast<IndirectGotoStmt>(P)->getTarget();
- case Stmt::SwitchStmtClass:
- return DirectChild == cast<SwitchStmt>(P)->getCond();
- case Stmt::ReturnStmtClass:
- return true;
- }
-}
-
//===----------------------------------------------------------------------===//
// Driver function to invoke the Dead-Stores checker on a CFG.
//===----------------------------------------------------------------------===//