commit e9591b33e29cf72c6b3bab60d9625c706dc00d87
author Reid Kleckner <reid@kleckner.net> Wed Apr 23 18:22:11 2014 +0000
committer Reid Kleckner <reid@kleckner.net> Wed Apr 23 18:22:11 2014 +0000
tree 053e4de4a440918a73c19438ddf9259189d53bb3
parent 5b21db89d04f6b0923e333b55f8c500e968243f7

MS ABI: Use a different guard variable for each weak global

We were using the same guard variable and failing to initialize the
second global.

Clang is still not MS ABI compatible in this area.  Fixing that is
PR16959, which will require LLVM changes to @llvm.global_ctors.

llvm-svn: 207008

clang/lib/CodeGen/MicrosoftCXXABI.cpp

diff --git a/clang/lib/CodeGen/MicrosoftCXXABI.cpp b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
index 9832969..528cdf6 100644
--- a/clang/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -1273,10 +1273,14 @@
   llvm::ConstantInt *Zero = llvm::ConstantInt::get(GuardTy, 0);
 
   // Get the guard variable for this function if we have one already.
-  GuardInfo &GI = GuardVariableMap[D.getDeclContext()];
+  GuardInfo EmptyGuardInfo;
+  GuardInfo *GI = &EmptyGuardInfo;
+  if (isa<FunctionDecl>(D.getDeclContext())) {
+    GI = &GuardVariableMap[D.getDeclContext()];
+  }
 
   unsigned BitIndex;
-  if (D.isExternallyVisible()) {
+  if (D.isStaticLocal() && D.isExternallyVisible()) {
     // Externally visible variables have to be numbered in Sema to properly
     // handle unreachable VarDecls.
     BitIndex = getContext().getStaticLocalNumber(&D);
@@ -1284,18 +1288,18 @@
     BitIndex--;
   } else {
     // Non-externally visible variables are numbered here in CodeGen.
-    BitIndex = GI.BitIndex++;
+    BitIndex = GI->BitIndex++;
   }
 
   if (BitIndex >= 32) {
     if (D.isExternallyVisible())
       ErrorUnsupportedABI(CGF, "more than 32 guarded initializations");
     BitIndex %= 32;
-    GI.Guard = 0;
+    GI->Guard = 0;
   }
 
   // Lazily create the i32 bitfield for this function.
-  if (!GI.Guard) {
+  if (!GI->Guard) {
     // Mangle the name for the guard.
     SmallString<256> GuardName;
     {
@@ -1306,11 +1310,12 @@
 
     // Create the guard variable with a zero-initializer.  Just absorb linkage
     // and visibility from the guarded variable.
-    GI.Guard = new llvm::GlobalVariable(CGM.getModule(), GuardTy, false,
-                                     GV->getLinkage(), Zero, GuardName.str());
-    GI.Guard->setVisibility(GV->getVisibility());
+    GI->Guard =
+        new llvm::GlobalVariable(CGM.getModule(), GuardTy, false,
+                                 GV->getLinkage(), Zero, GuardName.str());
+    GI->Guard->setVisibility(GV->getVisibility());
   } else {
-    assert(GI.Guard->getLinkage() == GV->getLinkage() &&
+    assert(GI->Guard->getLinkage() == GV->getLinkage() &&
            "static local from the same function had different linkage");
   }
 
@@ -1322,7 +1327,7 @@
 
   // Test our bit from the guard variable.
   llvm::ConstantInt *Bit = llvm::ConstantInt::get(GuardTy, 1U << BitIndex);
-  llvm::LoadInst *LI = Builder.CreateLoad(GI.Guard);
+  llvm::LoadInst *LI = Builder.CreateLoad(GI->Guard);
   llvm::Value *IsInitialized =
       Builder.CreateICmpNE(Builder.CreateAnd(LI, Bit), Zero);
   llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
@@ -1332,7 +1337,7 @@
   // Set our bit in the guard variable and emit the initializer and add a global
   // destructor if appropriate.
   CGF.EmitBlock(InitBlock);
-  Builder.CreateStore(Builder.CreateOr(LI, Bit), GI.Guard);
+  Builder.CreateStore(Builder.CreateOr(LI, Bit), GI->Guard);
   CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
   Builder.CreateBr(EndBlock);