r340181 - [OPENMP][BLOCKS]Fix PR38923: reference to a global variable is captured

[Alexey Bataev via cfe-commits]

Author: abataev
Date: Mon Aug 20 09:00:22 2018
New Revision: 340181

URL: http://llvm.org/viewvc/llvm-project?rev=340181&view=rev
Log:
[OPENMP][BLOCKS]Fix PR38923: reference to a global variable is captured
by a block.

Added checks for capturing of the variable in the block when trying to
emit correct address for the variable with the reference type. This
extra check allows correctly identify the variables that are not
captured in the block context.

Added:
    cfe/trunk/test/CodeGenCXX/block-byref.cpp
Modified:
    cfe/trunk/lib/CodeGen/CGExpr.cpp

Modified: cfe/trunk/lib/CodeGen/CGExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExpr.cpp?rev=340181&r1=340180&r2=340181&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExpr.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExpr.cpp Mon Aug 20 09:00:22 2018
@@ -2437,6 +2437,7 @@ LValue CodeGenFunction::EmitDeclRefLValu
     // A DeclRefExpr for a reference initialized by a constant expression can
     // appear without being odr-used. Directly emit the constant initializer.
     const Expr *Init = VD->getAnyInitializer(VD);
+    const auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl);
     if (Init && !isa<ParmVarDecl>(VD) && VD->getType()->isReferenceType() &&
         VD->isUsableInConstantExpressions(getContext()) &&
         VD->checkInitIsICE() &&
@@ -2446,7 +2447,7 @@ LValue CodeGenFunction::EmitDeclRefLValu
             (LocalDeclMap.count(VD->getCanonicalDecl()) ||
              CapturedStmtInfo->lookup(VD->getCanonicalDecl()))) ||
            LambdaCaptureFields.lookup(VD->getCanonicalDecl()) ||
-           isa<BlockDecl>(CurCodeDecl)))) {
+           (BD && BD->capturesVariable(VD))))) {
       llvm::Constant *Val =
         ConstantEmitter(*this).emitAbstract(E->getLocation(),
                                             *VD->evaluateValue(),

Added: cfe/trunk/test/CodeGenCXX/block-byref.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/block-byref.cpp?rev=340181&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/block-byref.cpp (added)
+++ cfe/trunk/test/CodeGenCXX/block-byref.cpp Mon Aug 20 09:00:22 2018
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 %s -fblocks -triple x86_64-apple-darwin -std=c++11 -emit-llvm -o - | FileCheck %s
+// REQUIRES: x86-registered-target
+
+// CHECK: @b = global i32 0,
+
+// CHECK: define {{.*}}void @{{.*}}test{{.*}}_block_invoke(
+// CHECK: store i32 2, i32* @b,
+// CHECK: ret void
+
+int b;
+
+void test() {
+  int &a = b;
+  ^{ a = 2; };
+}