r211137 - Fix bug in code for avoiding dynamic initialization of dllimport globals

[Hans Wennborg]

Author: hans
Date: Tue Jun 17 20:21:33 2014
New Revision: 211137

URL: http://llvm.org/viewvc/llvm-project?rev=211137&view=rev
Log:
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).

Modified:
    cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp
    cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp

Modified: cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp?rev=211137&r1=211136&r2=211137&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp Tue Jun 17 20:21:33 2014
@@ -3688,7 +3688,6 @@ void Sema::InstantiateVariableInitialize
       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);

Modified: cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp?rev=211137&r1=211136&r2=211137&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp Tue Jun 17 20:21:33 2014
@@ -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 at DynamicDLLImportInitVSMangling@@YAHXZ"
+    static int local;
+    // CHECK: @"\01?local@?1??switch_test3 at DynamicDLLImportInitVSMangling@@YAHXZ at 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 at H@@2VA@@A at YAXXZ"()