[clang] af954e4 - [WPD] Emit vcall_visibility metadata for MicrosoftCXXABI
Teresa Johnson via cfe-commits
cfe-commits at lists.llvm.org
Mon Jan 27 06:23:13 PST 2020
Author: Teresa Johnson
Date: 2020-01-27T06:22:24-08:00
New Revision: af954e441a5170a75687699d91d85e0692929d43
URL: https://github.com/llvm/llvm-project/commit/af954e441a5170a75687699d91d85e0692929d43
DIFF: https://github.com/llvm/llvm-project/commit/af954e441a5170a75687699d91d85e0692929d43.diff
LOG: [WPD] Emit vcall_visibility metadata for MicrosoftCXXABI
Summary:
The MicrosoftCXXABI uses a separate mechanism for emitting vtable
type metadata, and thus didn't pick up the change from D71907
to emit the vcall_visibility metadata under -fwhole-program-vtables.
I believe this is the cause of a Windows bot failure when I committed
follow on change D71913 that required a revert. The failure occurred
in a CFI test that was expecting to not abort because it expected a
devirtualization to occur, and without the necessary vcall_visibility
metadata we would not get devirtualization.
Note in the equivalent code in CodeGenModule::EmitVTableTypeMetadata
(used by the ItaniumCXXABI), we also emit the vcall_visibility metadata
when Virtual Function Elimination is enabled. Since I am not as familiar
with the details of that optimization, I have marked that as a TODO and
am only inserting under -fwhole-program-vtables.
Reviewers: evgeny777
Subscribers: Prazek, ostannard, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73418
Added:
Modified:
clang/lib/CodeGen/MicrosoftCXXABI.cpp
clang/test/CodeGenCXX/vcall-visibility-metadata.cpp
Removed:
################################################################################
diff --git a/clang/lib/CodeGen/MicrosoftCXXABI.cpp b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
index aff46135705a..b083a5893cf7 100644
--- a/clang/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -1621,6 +1621,15 @@ void MicrosoftCXXABI::emitVTableTypeMetadata(const VPtrInfo &Info,
if (!CGM.getCodeGenOpts().LTOUnit)
return;
+ // TODO: Should VirtualFunctionElimination also be supported here?
+ // See similar handling in CodeGenModule::EmitVTableTypeMetadata.
+ if (CGM.getCodeGenOpts().WholeProgramVTables) {
+ llvm::GlobalObject::VCallVisibility TypeVis =
+ CGM.GetVCallVisibilityLevel(RD);
+ if (TypeVis != llvm::GlobalObject::VCallVisibilityPublic)
+ VTable->setVCallVisibilityMetadata(TypeVis);
+ }
+
// The location of the first virtual function pointer in the virtual table,
// aka the "address point" on Itanium. This is at offset 0 if RTTI is
// disabled, or sizeof(void*) if RTTI is enabled.
diff --git a/clang/test/CodeGenCXX/vcall-visibility-metadata.cpp b/clang/test/CodeGenCXX/vcall-visibility-metadata.cpp
index b770ad767fc2..84d9a2196309 100644
--- a/clang/test/CodeGenCXX/vcall-visibility-metadata.cpp
+++ b/clang/test/CodeGenCXX/vcall-visibility-metadata.cpp
@@ -1,5 +1,6 @@
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -emit-llvm -fvirtual-function-elimination -fwhole-program-vtables -o - %s | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-VFE
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -emit-llvm -fwhole-program-vtables -o - %s | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-NOVFE
+// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-pc-windows-msvc -emit-llvm -fwhole-program-vtables -o - %s | FileCheck %s --check-prefix=CHECK-MS --check-prefix=CHECK-NOVFE
// Check that in ThinLTO we also get vcall_visibility summary entries in the bitcode
// RUN: %clang_cc1 -flto=thin -flto-unit -triple x86_64-unknown-linux -emit-llvm-bc -fwhole-program-vtables -o - %s | llvm-dis -o - | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-NOVFE --check-prefix=CHECK-SUMMARY
@@ -8,6 +9,7 @@
// Anonymous namespace.
namespace {
// CHECK: @_ZTVN12_GLOBAL__N_11AE = {{.*}} !vcall_visibility [[VIS_TU:![0-9]+]]
+// CHECK-MS: @anon.{{.*}} = private unnamed_addr constant {{.*}}struct.(anonymous namespace)::A{{.*}} !vcall_visibility [[VIS_TU:![0-9]+]]
struct A {
A() {}
virtual int f() { return 1; }
@@ -20,6 +22,7 @@ void *construct_A() {
// Hidden visibility.
// CHECK: @_ZTV1B = {{.*}} !vcall_visibility [[VIS_DSO:![0-9]+]]
+// CHECK-MS: @anon.{{.*}} = private unnamed_addr constant {{.*}}struct.B{{.*}} !vcall_visibility [[VIS_DSO:![0-9]+]]
struct __attribute__((visibility("hidden"))) B {
B() {}
virtual int f() { return 1; }
@@ -31,6 +34,8 @@ B *construct_B() {
// Default visibility.
// CHECK-NOT: @_ZTV1C = {{.*}} !vcall_visibility
+// On MS default is hidden
+// CHECK-MS: @anon.{{.*}} = private unnamed_addr constant {{.*}}struct.C{{.*}} !vcall_visibility [[VIS_DSO]]
struct __attribute__((visibility("default"))) C {
C() {}
virtual int f() { return 1; }
@@ -42,6 +47,7 @@ C *construct_C() {
// Hidden visibility, public LTO visibility.
// CHECK-NOT: @_ZTV1D = {{.*}} !vcall_visibility
+// CHECK-MS-NOT: @anon.{{.*}} = private unnamed_addr constant {{.*}}struct.D{{.*}} !vcall_visibility
struct __attribute__((visibility("hidden"))) [[clang::lto_visibility_public]] D {
D() {}
virtual int f() { return 1; }
@@ -53,6 +59,8 @@ D *construct_D() {
// Hidden visibility, but inherits from class with default visibility.
// CHECK-NOT: @_ZTV1E = {{.*}} !vcall_visibility
+// On MS default is hidden
+// CHECK-MS: @anon.{{.*}} = private unnamed_addr constant {{.*}}struct.E{{.*}} !vcall_visibility [[VIS_DSO]]
struct __attribute__((visibility("hidden"))) E : C {
E() {}
virtual int f() { return 1; }
@@ -64,6 +72,8 @@ E *construct_E() {
// Anonymous namespace, but inherits from class with default visibility.
// CHECK-NOT: @_ZTVN12_GLOBAL__N_11FE = {{.*}} !vcall_visibility
+// On MS default is hidden
+// CHECK-MS: @anon.{{.*}} = private unnamed_addr constant {{.*}}struct.(anonymous namespace)::F{{.*}} !vcall_visibility [[VIS_DSO]]
namespace {
struct __attribute__((visibility("hidden"))) F : C {
F() {}
@@ -77,6 +87,7 @@ void *construct_F() {
// Anonymous namespace, but inherits from class with hidden visibility.
// CHECK: @_ZTVN12_GLOBAL__N_11GE = {{.*}} !vcall_visibility [[VIS_DSO:![0-9]+]]
+// CHECK-MS: @anon.{{.*}} = private unnamed_addr constant {{.*}}struct.(anonymous namespace)::G{{.*}} !vcall_visibility [[VIS_DSO]]
namespace {
struct __attribute__((visibility("hidden"))) G : B {
G() {}
@@ -87,6 +98,8 @@ void *construct_G() {
return new G();
}
+// CHECK-MS-DAG: [[VIS_DSO]] = !{i64 1}
+// CHECK-MS-DAG: [[VIS_TU]] = !{i64 2}
// CHECK-DAG: [[VIS_DSO]] = !{i64 1}
// CHECK-DAG: [[VIS_TU]] = !{i64 2}
// CHECK-VFE-DAG: !{i32 1, !"Virtual Function Elim", i32 1}
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