Don't flag dead stores when the result of a preincrement/predecrement is used in an enclosing expression.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@53964 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/CheckDeadStores.cpp b/lib/Analysis/CheckDeadStores.cpp
index 005c71a..433e611 100644
--- a/lib/Analysis/CheckDeadStores.cpp
+++ b/lib/Analysis/CheckDeadStores.cpp
@@ -153,6 +153,11 @@
if (!U->isIncrementOp())
return;
+ // Don't flag dead stores when the result of a preincrement/predecrement
+ // is used in an enclosing expression.
+ if (U->isPrefix() && Parents.isSubExpr(U))
+ return;
+
Expr *Ex = U->getSubExpr()->IgnoreParenCasts();
if (DeclRefExpr* DR = dyn_cast<DeclRefExpr>(Ex))
@@ -161,7 +166,7 @@
else if (DeclStmt* DS = dyn_cast<DeclStmt>(S))
// Iterate through the decls. Warn if any initializers are complex
// expressions that are not live (never used).
- for (ScopedDecl* SD = DS->getDecl(); SD; SD = SD->getNextDeclarator()) {
+ for (ScopedDecl* SD = DS->getDecl(); SD; SD = SD->getNextDeclarator()) {
VarDecl* V = dyn_cast<VarDecl>(SD);
if (!V) continue;