From de6a39f759c1f2aa5873d1c35ef21083144fe508 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Sat, 2 Mar 2013 21:41:48 +0000
Subject: [PATCH] Process #pragma weak only after we know the linkage of the
 function or variable we are looking at.

llvm-svn: 176414
---
 clang/include/clang/Sema/Sema.h    |  1 +
 clang/lib/Sema/SemaDecl.cpp        |  2 ++
 clang/lib/Sema/SemaDeclAttr.cpp    | 48 +++++++++++++++++++-------------------
 clang/test/SemaCXX/pragma-weak.cpp |  8 +++++++
 4 files changed, 35 insertions(+), 24 deletions(-)
 create mode 100644 clang/test/SemaCXX/pragma-weak.cpp

diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 12a787e..df74692 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -2340,6 +2340,7 @@ public:
 
   // More parsing and symbol table subroutines.
 
+  void ProcessPragmaWeak(Scope *S, Decl *D);
   // Decl attributes - this routine is the top level dispatcher.
   void ProcessDeclAttributes(Scope *S, Decl *D, const Declarator &PD,
                              bool NonInheritable = true,
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 2416f39..c21cf03 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -4900,6 +4900,7 @@ Sema::ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
       NewVD->setInvalidDecl();
   }
 
+  ProcessPragmaWeak(S, NewVD);
   checkAttributesAfterMerging(*this, *NewVD);
 
   // If this is a locally-scoped extern C variable, update the map of
@@ -6368,6 +6369,7 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
     }
   }
 
+  ProcessPragmaWeak(S, NewFD);
   checkAttributesAfterMerging(*this, *NewFD);
 
   AddKnownFunctionAttributes(NewFD);
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 25202b1..2778d6e6 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -5087,37 +5087,37 @@ void Sema::DeclApplyPragmaWeak(Scope *S, NamedDecl *ND, WeakInfo &W) {
   }
 }
 
-/// ProcessDeclAttributes - Given a declarator (PD) with attributes indicated in
-/// it, apply them to D.  This is a bit tricky because PD can have attributes
-/// specified in many different places, and we need to find and apply them all.
-void Sema::ProcessDeclAttributes(Scope *S, Decl *D, const Declarator &PD,
-                                 bool NonInheritable, bool Inheritable) {
+void Sema::ProcessPragmaWeak(Scope *S, Decl *D) {
   // It's valid to "forward-declare" #pragma weak, in which case we
   // have to do this.
-  if (Inheritable) {
-    LoadExternalWeakUndeclaredIdentifiers();
-    if (!WeakUndeclaredIdentifiers.empty()) {
-      NamedDecl *ND = NULL;
-      if (VarDecl *VD = dyn_cast<VarDecl>(D))
-        if (VD->isExternC())
-          ND = VD;
-      if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
-        if (FD->isExternC())
-          ND = FD;
-      if (ND) {
-        if (IdentifierInfo *Id = ND->getIdentifier()) {
-          llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator I
-            = WeakUndeclaredIdentifiers.find(Id);
-          if (I != WeakUndeclaredIdentifiers.end()) {
-            WeakInfo W = I->second;
-            DeclApplyPragmaWeak(S, ND, W);
-            WeakUndeclaredIdentifiers[Id] = W;
-          }
+  LoadExternalWeakUndeclaredIdentifiers();
+  if (!WeakUndeclaredIdentifiers.empty()) {
+    NamedDecl *ND = NULL;
+    if (VarDecl *VD = dyn_cast<VarDecl>(D))
+      if (VD->isExternC())
+        ND = VD;
+    if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
+      if (FD->isExternC())
+        ND = FD;
+    if (ND) {
+      if (IdentifierInfo *Id = ND->getIdentifier()) {
+        llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator I
+          = WeakUndeclaredIdentifiers.find(Id);
+        if (I != WeakUndeclaredIdentifiers.end()) {
+          WeakInfo W = I->second;
+          DeclApplyPragmaWeak(S, ND, W);
+          WeakUndeclaredIdentifiers[Id] = W;
         }
       }
     }
   }
+}
 
+/// ProcessDeclAttributes - Given a declarator (PD) with attributes indicated in
+/// it, apply them to D.  This is a bit tricky because PD can have attributes
+/// specified in many different places, and we need to find and apply them all.
+void Sema::ProcessDeclAttributes(Scope *S, Decl *D, const Declarator &PD,
+                                 bool NonInheritable, bool Inheritable) {
   // Apply decl attributes from the DeclSpec if present.
   if (const AttributeList *Attrs = PD.getDeclSpec().getAttributes().getList())
     ProcessDeclAttributeList(S, D, Attrs, NonInheritable, Inheritable);
diff --git a/clang/test/SemaCXX/pragma-weak.cpp b/clang/test/SemaCXX/pragma-weak.cpp
new file mode 100644
index 0000000..057cf6b
--- /dev/null
+++ b/clang/test/SemaCXX/pragma-weak.cpp
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 %s
+
+#pragma weak foo
+static void foo();
+extern "C" {
+  void foo() {
+  };
+}
-- 
2.7.4