Warn when an expression result in a LabelStmt is unused.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@114314 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 4c6822c..b31ec23 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -1225,9 +1225,13 @@
// however, if the result of the stmt expr is dead, we don't want to emit a
// warning.
const CompoundStmt *CS = cast<StmtExpr>(this)->getSubStmt();
- if (!CS->body_empty())
+ if (!CS->body_empty()) {
if (const Expr *E = dyn_cast<Expr>(CS->body_back()))
return E->isUnusedResultAWarning(Loc, R1, R2, Ctx);
+ if (const LabelStmt *Label = dyn_cast<LabelStmt>(CS->body_back()))
+ if (const Expr *E = dyn_cast<Expr>(Label->getSubStmt()))
+ return E->isUnusedResultAWarning(Loc, R1, R2, Ctx);
+ }
if (getType()->isVoidType())
return false;
diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index 8ec12a4..47ea4f2 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -67,6 +67,9 @@
}
void Sema::DiagnoseUnusedExprResult(const Stmt *S) {
+ if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S))
+ return DiagnoseUnusedExprResult(Label->getSubStmt());
+
const Expr *E = dyn_cast_or_null<Expr>(S);
if (!E)
return;
diff --git a/test/Sema/warn-unused-value.c b/test/Sema/warn-unused-value.c
index 1a7e745..7c36b69 100644
--- a/test/Sema/warn-unused-value.c
+++ b/test/Sema/warn-unused-value.c
@@ -52,6 +52,9 @@
volatile int* pj = &j;
*pi; // expected-warning {{expression result unused}}
*pj;
+
+ foo_label:
+ i; // expected-warning {{expression result unused}}
}
// Don't warn about unused '||', '&&' expressions that contain assignments.