Consider used attributes in hidden decls.

Without this patch we would warn and fail to output the function in the test.

llvm-svn: 193388

2 files changed, 16 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index ba789284060..2edebaba343 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -2099,6 +2099,12 @@ static void checkNewAttributesAfterDef(Sema &S, Decl *New, const Decl *Old) {
 /// mergeDeclAttributes - Copy attributes from the Old decl to the New one.
 void Sema::mergeDeclAttributes(NamedDecl *New, Decl *Old,
                                AvailabilityMergeKind AMK) {
+  if (UsedAttr *OldAttr = Old->getMostRecentDecl()->getAttr<UsedAttr>()) {
+    UsedAttr *NewAttr = OldAttr->clone(Context);
+    NewAttr->setInherited(true);
+    New->addAttr(NewAttr);
+  }
+
   if (!Old->hasAttrs() && !New->hasAttrs())
     return;
 
@@ -2136,6 +2142,10 @@ void Sema::mergeDeclAttributes(NamedDecl *New, Decl *Old,
       }
     }
 
+    // Already handled.
+    if (isa<UsedAttr>(*i))
+      continue;
+
     if (mergeDeclAttribute(*this, New, *i, Override))
       foundAny = true;
   }
diff --git a/clang/test/SemaCXX/warn-unused-filescoped.cpp b/clang/test/SemaCXX/warn-unused-filescoped.cpp
index 65f10e6695a..b0af5b33227 100644
--- a/clang/test/SemaCXX/warn-unused-filescoped.cpp
+++ b/clang/test/SemaCXX/warn-unused-filescoped.cpp
@@ -187,4 +187,10 @@ namespace UndefinedInternalStaticMember {
   }
 }
 
+namespace test8 {
+static void func();
+void bar() { void func() __attribute__((used)); }
+static void func() {}
+}
+
 #endif