https://github.com/asavonic updated
https://github.com/llvm/llvm-project/pull/136689
>From 348c94f4ef9b3fda5538813251360ccd8f6ffc44 Mon Sep 17 00:00:00 2001
From: Andrew Savonichev <andrew.savonic...@gmail.com>
Date: Mon, 21 Apr 2025 19:45:05 +0900
Subject: [PATCH 1/2] [clang] Fix computeTypeLinkageInfo for dependent member
pointers
MemberPointerType may refer to a dependent class (qualifier), for
which getMostRecentCXXRecordDecl returns NULL. It seems that the
compiler never executed this code path before patch #136128 where the
issue was reported.
LIT tests 74 and 75 are reduced from Chromium and LLVM libc test
harness as reported in #136128.
Function member (test74):
MemberPointerType 'type-parameter-0-0 (type-parameter-0-1::*)(void)'
dependent
|-TemplateTypeParmType 'type-parameter-0-1' dependent depth 0 index 1
`-FunctionProtoType 'type-parameter-0-0 (void)' dependent cdecl
`-TemplateTypeParmType 'type-parameter-0-0' dependent depth 0 index 0
Template parameter (test75):
MemberPointerType 'type-parameter-0-1 type-parameter-0-0::*' dependent
|-TemplateTypeParmType 'type-parameter-0-0' dependent depth 0 index 0
`-TemplateTypeParmType 'type-parameter-0-1' dependent depth 0 index 1
---
clang/lib/AST/Type.cpp | 8 ++++--
clang/test/CodeGenCXX/visibility.cpp | 37 ++++++++++++++++++++++++++++
2 files changed, 43 insertions(+), 2 deletions(-)
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index fe1dc7e2fe786..871b0e00f3970 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -4787,8 +4787,12 @@ LinkageInfo
LinkageComputer::computeTypeLinkageInfo(const Type *T) {
return computeTypeLinkageInfo(cast<ReferenceType>(T)->getPointeeType());
case Type::MemberPointer: {
const auto *MPT = cast<MemberPointerType>(T);
- LinkageInfo LV =
- getDeclLinkageAndVisibility(MPT->getMostRecentCXXRecordDecl());
+ LinkageInfo LV;
+ if (auto *D = MPT->getMostRecentCXXRecordDecl()) {
+ LV.merge(getDeclLinkageAndVisibility(D));
+ } else if (auto *Ty = MPT->getQualifier()->getAsType()) {
+ LV.merge(computeTypeLinkageInfo(Ty));
+ }
LV.merge(computeTypeLinkageInfo(MPT->getPointeeType()));
return LV;
}
diff --git a/clang/test/CodeGenCXX/visibility.cpp
b/clang/test/CodeGenCXX/visibility.cpp
index e1061f3dbd18f..b4c6fdcbcdf33 100644
--- a/clang/test/CodeGenCXX/visibility.cpp
+++ b/clang/test/CodeGenCXX/visibility.cpp
@@ -1463,3 +1463,40 @@ namespace test71 {
// CHECK-HIDDEN-LABEL: define linkonce_odr hidden noundef i64
@_ZN6test713fooIlE3zedEv(
// CHECK-HIDDEN-LABEL: define linkonce_odr hidden noundef i32
@_ZN6test713fooIlE3barIiEET_v(
}
+
+namespace test74 {
+ template <typename> struct T;
+ template <typename R>
+ struct T<void (R::*)()> {
+ template <typename M>
+ static __attribute__((__visibility__("hidden"))) void Invoke(M) {
+ }
+ };
+
+ struct C;
+ void (C::*MM)();
+
+ void Fun() {
+ T<decltype(MM)>::Invoke(0);
+ }
+ // CHECK-LABEL: define linkonce_odr void
@_ZN6test741TIMNS_1CEFvvEE6InvokeIiEEvT_(
+ // CHECK-HIDDEN-LABEL: define linkonce_odr hidden void
@_ZN6test741TIMNS_1CEFvvEE6InvokeIiEEvT_(
+}
+
+namespace test75 {
+ template <class> struct T;
+ template <class C, class Ret>
+ struct T<Ret C::*> {
+ template <class M>
+ static __attribute__((__visibility__("hidden")))
+ void Invoke(M) {
+ }
+ };
+
+ struct A;
+ void Fun() {
+ T<void (A::*)()>::Invoke(0);
+ }
+ // CHECK-LABEL: define linkonce_odr void
@_ZN6test751TIMNS_1AEFvvEE6InvokeIiEEvT_(
+ // CHECK-HIDDEN-LABEL: define linkonce_odr hidden void
@_ZN6test751TIMNS_1AEFvvEE6InvokeIiEEvT_(
+}
>From b58ab38fa54eb28da87ce719f57ff12de4f40d54 Mon Sep 17 00:00:00 2001
From: Andrew Savonichev <andrew.savonic...@gmail.com>
Date: Thu, 17 Apr 2025 20:18:52 +0900
Subject: [PATCH 2/2] Reland [clang] Handle instantiated members to determine
visibility (#136128)
As reported in issue #103477, visibility of instantiated member
functions used to be ignored when calculating visibility of a
specialization.
This patch modifies `getLVForClassMember` to look up for a source
template for an instantiated member, and changes `mergeTemplateLV` to
apply it.
A similar issue was reported in #31462, but it seems that `extern`
declaration with visibility prevents the function from being emitted
as hidden. This behavior seems correct, even though GCC emits it as
with default visibility instead.
Both tests from #103477 and #31462 are added as LIT tests `test72` and
`test73` respectively.
---
clang/docs/ReleaseNotes.rst | 1 +
clang/lib/AST/Decl.cpp | 13 +++++++--
clang/test/CodeGenCXX/visibility.cpp | 42 ++++++++++++++++++++++++++--
3 files changed, 50 insertions(+), 6 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 86d37f5616356..9ecd78c13d4e5 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -458,6 +458,7 @@ Bug Fixes in This Version
- Fixed a crash when ``#embed`` appears as a part of a failed constant
evaluation. The crashes were happening during diagnostics emission due to
unimplemented statement printer. (#GH132641)
+- Fixed visibility calculation for template functions. (#GH103477)
Bug Fixes to Compiler Builtins
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 1d9208f0e1c72..61d497999b669 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -400,9 +400,9 @@ void LinkageComputer::mergeTemplateLV(
FunctionTemplateDecl *temp = specInfo->getTemplate();
// Merge information from the template declaration.
LinkageInfo tempLV = getLVForDecl(temp, computation);
- // The linkage of the specialization should be consistent with the
- // template declaration.
- LV.setLinkage(tempLV.getLinkage());
+ // The linkage and visibility of the specialization should be
+ // consistent with the template declaration.
+ LV.mergeMaybeWithVisibility(tempLV, considerVisibility);
// Merge information from the template parameters.
LinkageInfo paramsLV =
@@ -1051,6 +1051,13 @@ LinkageComputer::getLVForClassMember(const NamedDecl *D,
if (const auto *redeclTemp = dyn_cast<RedeclarableTemplateDecl>(temp)) {
if (isExplicitMemberSpecialization(redeclTemp)) {
explicitSpecSuppressor = temp->getTemplatedDecl();
+ } else if (const RedeclarableTemplateDecl *from =
+ redeclTemp->getInstantiatedFromMemberTemplate()) {
+ // If no explicit visibility is specified yet, and this is an
+ // instantiated member of a template, look up visibility there
+ // as well.
+ LinkageInfo fromLV = from->getLinkageAndVisibility();
+ LV.mergeMaybeWithVisibility(fromLV, considerVisibility);
}
}
}
diff --git a/clang/test/CodeGenCXX/visibility.cpp
b/clang/test/CodeGenCXX/visibility.cpp
index b4c6fdcbcdf33..442e2a5aaa2b3 100644
--- a/clang/test/CodeGenCXX/visibility.cpp
+++ b/clang/test/CodeGenCXX/visibility.cpp
@@ -1457,13 +1457,49 @@ namespace test71 {
// CHECK-LABEL: declare hidden noundef i32 @_ZN6test713fooIiE3zedEv(
// CHECK-LABEL: define linkonce_odr noundef i32
@_ZN6test713fooIiE3barIiEET_v(
// CHECK-LABEL: define linkonce_odr hidden noundef i64
@_ZN6test713fooIlE3zedEv(
- // CHECK-LABEL: define linkonce_odr noundef i32
@_ZN6test713fooIlE3barIiEET_v(
+ // CHECK-LABEL: define linkonce_odr hidden noundef i32
@_ZN6test713fooIlE3barIiEET_v(
// CHECK-HIDDEN-LABEL: declare hidden noundef i32 @_ZN6test713fooIiE3zedEv(
// CHECK-HIDDEN-LABEL: define linkonce_odr noundef i32
@_ZN6test713fooIiE3barIiEET_v(
// CHECK-HIDDEN-LABEL: define linkonce_odr hidden noundef i64
@_ZN6test713fooIlE3zedEv(
// CHECK-HIDDEN-LABEL: define linkonce_odr hidden noundef i32
@_ZN6test713fooIlE3barIiEET_v(
}
+// https://github.com/llvm/llvm-project/issues/103477
+namespace test72 {
+ template <class a>
+ struct t {
+ template <int>
+ static HIDDEN void bar() {}
+ };
+
+ void test() {
+ t<char>::bar<1>();
+ }
+ // CHECK-LABEL: define linkonce_odr hidden void
@_ZN6test721tIcE3barILi1EEEvv(
+ // CHECK-HIDDEN-LABEL: define linkonce_odr hidden void
@_ZN6test721tIcE3barILi1EEEvv(
+}
+
+// https://github.com/llvm/llvm-project/issues/31462
+namespace test73 {
+ template <class T> struct s {
+ template <class U>
+ __attribute__((__visibility__("hidden"))) U should_not_be_exported();
+ };
+
+ template <class T> template <class U> U s<T>::should_not_be_exported() {
+ return U();
+ }
+
+ extern template struct __attribute__((__visibility__("default"))) s<int>;
+
+ int f() {
+ s<int> o;
+ return o.should_not_be_exported<int>();
+ }
+ // CHECK-LABEL: define linkonce_odr noundef i32
@_ZN6test731sIiE22should_not_be_exportedIiEET_v(
+ // CHECK-HIDDEN-LABEL: define linkonce_odr noundef i32
@_ZN6test731sIiE22should_not_be_exportedIiEET_v(
+}
+
namespace test74 {
template <typename> struct T;
template <typename R>
@@ -1479,7 +1515,7 @@ namespace test74 {
void Fun() {
T<decltype(MM)>::Invoke(0);
}
- // CHECK-LABEL: define linkonce_odr void
@_ZN6test741TIMNS_1CEFvvEE6InvokeIiEEvT_(
+ // CHECK-LABEL: define linkonce_odr hidden void
@_ZN6test741TIMNS_1CEFvvEE6InvokeIiEEvT_(
// CHECK-HIDDEN-LABEL: define linkonce_odr hidden void
@_ZN6test741TIMNS_1CEFvvEE6InvokeIiEEvT_(
}
@@ -1497,6 +1533,6 @@ namespace test75 {
void Fun() {
T<void (A::*)()>::Invoke(0);
}
- // CHECK-LABEL: define linkonce_odr void
@_ZN6test751TIMNS_1AEFvvEE6InvokeIiEEvT_(
+ // CHECK-LABEL: define linkonce_odr hidden void
@_ZN6test751TIMNS_1AEFvvEE6InvokeIiEEvT_(
// CHECK-HIDDEN-LABEL: define linkonce_odr hidden void
@_ZN6test751TIMNS_1AEFvvEE6InvokeIiEEvT_(
}
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