For thread-safe static initialization of local statics with

destructors, place the __cxa_atexit call after the __cxa_guard_release
call, mimicking GCC/LLVM-GCC behavior. Noticed while debugging
something related.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@103088 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CGDeclCXX.cpp

@@ -22,7 +22,6 @@ static void EmitDeclInit(CodeGenFunction &CGF, const VarDecl &D,
   assert(!D.getType()->isReferenceType() && 
          "Should not call EmitDeclInit on a reference!");
   
-  CodeGenModule &CGM = CGF.CGM;
   ASTContext &Context = CGF.getContext();
     
   const Expr *Init = D.getInit();
@@ -36,6 +35,18 @@ static void EmitDeclInit(CodeGenFunction &CGF, const VarDecl &D,
     CGF.EmitComplexExprIntoAddr(Init, DeclPtr, isVolatile);
   } else {
     CGF.EmitAggExpr(Init, DeclPtr, isVolatile);
+  }
+}
+
+static void EmitDeclDestroy(CodeGenFunction &CGF, const VarDecl &D,
+                            llvm::Constant *DeclPtr) {
+  CodeGenModule &CGM = CGF.CGM;
+  ASTContext &Context = CGF.getContext();
+  
+  const Expr *Init = D.getInit();
+  QualType T = D.getType();
+  if (!CGF.hasAggregateLLVMType(T) || T->isAnyComplexType())
+    return;
                                 
   // Avoid generating destructor(s) for initialized objects. 
   if (!isa<CXXConstructExpr>(Init))
@@ -68,7 +79,6 @@ static void EmitDeclInit(CodeGenFunction &CGF, const VarDecl &D,
     DtorFn = CGM.GetAddrOfCXXDestructor(Dtor, Dtor_Complete);
   
   CGF.EmitCXXGlobalDtorRegistration(DtorFn, DeclPtr);
-  }
 }
 
 void CodeGenFunction::EmitCXXGlobalVarDeclInit(const VarDecl &D,
@@ -79,6 +89,7 @@ void CodeGenFunction::EmitCXXGlobalVarDeclInit(const VarDecl &D,
 
   if (!T->isReferenceType()) {
     EmitDeclInit(*this, D, DeclPtr);
+    EmitDeclDestroy(*this, D, DeclPtr);
     return;
   }
   if (Init->isLvalue(getContext()) == Expr::LV_Valid) {
@@ -349,5 +360,9 @@ CodeGenFunction::EmitStaticCXXBlockVarDeclInit(const VarDecl &D,
     Builder.CreateStore(One, Builder.CreateBitCast(GuardVariable, PtrTy));
   }
 
+  // Register the call to the destructor.
+  if (!D.getType()->isReferenceType())
+    EmitDeclDestroy(*this, D, GV);
+  
   EmitBlock(EndBlock);
 }

test/CodeGenCXX/static-init.cpp

@@ -11,7 +11,9 @@ struct A {
 };
 
 void f() {
-  // CHECK: call void @_ZN1AC1Ev(
+  // CHECK: call i32 @__cxa_guard_acquire
+  // CHECK: call void @_ZN1AC1Ev
+  // CHECK: call void @__cxa_guard_release
   // CHECK: call i32 @__cxa_atexit(void (i8*)* bitcast (void (%struct.A*)* @_ZN1AD1Ev to void (i8*)*), i8* getelementptr inbounds (%struct.A* @_ZZ1fvE1a, i32 0, i32 0), i8* bitcast (i8** @__dso_handle to i8*))
   static A a;
 }