From: Hans Wennborg <hans@hanshq.net>
Date: Wed, 18 Jun 2014 01:21:33 +0000 (+0000)
Subject: Fix bug in code for avoiding dynamic initialization of dllimport globals
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ceddfe355d53662af717edaf7fbb1222f0b7cec9;p=clang

Fix bug in code for avoiding dynamic initialization of dllimport globals

When instantiating dllimport variables with dynamic initializers, don't
bail out of Sema::InstantiateVariableInitializer without calling
PopExpressionEvaluationContext().

This was causing a stale object to stay on the ExprEvalContexts stack,
causing subsequent calls to getCurrentMangleNumberContext() to fail,
resulting in incorrect numbering of static locals (and probably other
broken things).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211137 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index bce2fd552e..29a10d0daa 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -3688,7 +3688,6 @@ void Sema::InstantiateVariableInitializer(
       if (Var->hasAttr<DLLImportAttr>() && InitExpr &&
           !InitExpr->isConstantInitializer(getASTContext(), false)) {
         // Do not dynamically initialize dllimport variables.
-        return;
       } else if (InitExpr) {
         bool DirectInit = OldVar->isDirectInit();
         AddInitializerToDecl(Var, InitExpr, DirectInit, TypeMayContainAuto);
diff --git a/test/CodeGenCXX/microsoft-abi-static-initializers.cpp b/test/CodeGenCXX/microsoft-abi-static-initializers.cpp
index b353d0c9c2..a3127c7937 100644
--- a/test/CodeGenCXX/microsoft-abi-static-initializers.cpp
+++ b/test/CodeGenCXX/microsoft-abi-static-initializers.cpp
@@ -189,6 +189,23 @@ inline void switch_test2() {
   switch (1) default: static int x = f();
 }
 
+namespace DynamicDLLImportInitVSMangling {
+  // Failing to pop the ExprEvalContexts when instantiating a dllimport var with
+  // dynamic initializer would cause subsequent static local numberings to be
+  // incorrect.
+  struct NonPOD { NonPOD(); };
+  template <typename T> struct A { static NonPOD x; };
+  template <typename T> NonPOD A<T>::x;
+  template struct __declspec(dllimport) A<int>;
+
+  inline int switch_test3() {
+    // CHECK-LABEL: define linkonce_odr i32 @"\01?switch_test3@DynamicDLLImportInitVSMangling@@YAHXZ"
+    static int local;
+    // CHECK: @"\01?local@?1??switch_test3@DynamicDLLImportInitVSMangling@@YAHXZ@4HA"
+    return local++;
+  }
+}
+
 void force_usage() {
   UnreachableStatic();
   getS();
@@ -197,6 +214,7 @@ void force_usage() {
   (void)&T::enum_in_struct;
   switch_test(1);
   switch_test2();
+  DynamicDLLImportInitVSMangling::switch_test3();
 }
 
 // CHECK: define linkonce_odr void @"\01??__Efoo@?$B@H@@2VA@@A@YAXXZ"()