A minor tweak to the new volatile lvalue warning: don't warn on "(void)x", where "x" refers to a local variable. This should silence a useless warning in compiler-rt and other places.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@157414 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 729030b..111f338 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -1883,43 +1883,40 @@
return true;
}
case CStyleCastExprClass: {
- // Ignore an explicit cast to void, as long as the operand isn't a
+ // Ignore an explicit cast to void unless the operand is a non-trivial
// volatile lvalue.
- const CStyleCastExpr *CE = cast<CStyleCastExpr>(this);
+ const CastExpr *CE = cast<CastExpr>(this);
if (CE->getCastKind() == CK_ToVoid) {
if (CE->getSubExpr()->isGLValue() &&
- CE->getSubExpr()->getType().isVolatileQualified())
- return CE->getSubExpr()->isUnusedResultAWarning(WarnE, Loc,
- R1, R2, Ctx);
+ CE->getSubExpr()->getType().isVolatileQualified()) {
+ const DeclRefExpr *DRE =
+ dyn_cast<DeclRefExpr>(CE->getSubExpr()->IgnoreParens());
+ if (!(DRE && isa<VarDecl>(DRE->getDecl()) &&
+ cast<VarDecl>(DRE->getDecl())->hasLocalStorage())) {
+ return CE->getSubExpr()->isUnusedResultAWarning(WarnE, Loc,
+ R1, R2, Ctx);
+ }
+ }
return false;
}
- WarnE = this;
- Loc = CE->getLParenLoc();
- R1 = CE->getSubExpr()->getSourceRange();
- return true;
- }
- case CXXFunctionalCastExprClass: {
- // Ignore an explicit cast to void, as long as the operand isn't a
- // volatile lvalue.
- const CXXFunctionalCastExpr *CE = cast<CXXFunctionalCastExpr>(this);
- if (CE->getCastKind() == CK_ToVoid) {
- if (CE->getSubExpr()->isGLValue() &&
- CE->getSubExpr()->getType().isVolatileQualified())
- return CE->getSubExpr()->isUnusedResultAWarning(WarnE, Loc,
- R1, R2, Ctx);
- return false;
- }
-
+
// If this is a cast to a constructor conversion, check the operand.
// Otherwise, the result of the cast is unused.
if (CE->getCastKind() == CK_ConstructorConversion)
return CE->getSubExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
+
WarnE = this;
- Loc = CE->getTypeBeginLoc();
- R1 = CE->getSubExpr()->getSourceRange();
+ if (const CXXFunctionalCastExpr *CXXCE =
+ dyn_cast<CXXFunctionalCastExpr>(this)) {
+ Loc = CXXCE->getTypeBeginLoc();
+ R1 = CXXCE->getSubExpr()->getSourceRange();
+ } else {
+ const CStyleCastExpr *CStyleCE = cast<CStyleCastExpr>(this);
+ Loc = CStyleCE->getLParenLoc();
+ R1 = CStyleCE->getSubExpr()->getSourceRange();
+ }
return true;
}
-
case ImplicitCastExprClass: {
const CastExpr *ICE = cast<ImplicitCastExpr>(this);