Look through CXXBindTemporaryExprs when checking CXXFunctionCastExprs
for unused values.
This fixes a regression caused by r298676, where constructor calls to
classes with non-trivial dtor were marked as unused if the first
argument is an initializer list. This is inconsistent (as the test
shows) and also warns on a reasonbly common code pattern where people
just call constructors to create and immediately destroy an object.
llvm-svn: 298853
diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index f393e3e..4cf1ad9 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -290,9 +290,15 @@
DiagID = diag::warn_unused_property_expr;
} else if (const CXXFunctionalCastExpr *FC
= dyn_cast<CXXFunctionalCastExpr>(E)) {
- if (isa<CXXConstructExpr>(FC->getSubExpr()) ||
- isa<CXXTemporaryObjectExpr>(FC->getSubExpr()))
+ const Expr *E = FC->getSubExpr();
+ if (const CXXBindTemporaryExpr *TE = dyn_cast<CXXBindTemporaryExpr>(E))
+ E = TE->getSubExpr();
+ if (isa<CXXTemporaryObjectExpr>(E))
return;
+ if (const CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(E))
+ if (const CXXRecordDecl *RD = CE->getType()->getAsCXXRecordDecl())
+ if (!RD->getAttr<WarnUnusedAttr>())
+ return;
}
// Diagnose "(void*) blah" as a typo for "(void) blah".
else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) {