[clang] [Clang] Add explicit visibility symbol macros (PR #108276)
Thomas Fransham via cfe-commits
cfe-commits at lists.llvm.org
Fri Sep 13 09:58:25 PDT 2024
https://github.com/fsfod updated https://github.com/llvm/llvm-project/pull/108276
>From 35af05f255db5aef2841212ff35f04eb5e967d93 Mon Sep 17 00:00:00 2001
From: Thomas Fransham <tfransham at gmail.com>
Date: Tue, 10 Sep 2024 02:22:18 +0100
Subject: [PATCH 1/3] [Clang] Add explicit visibility symbol macros and update
CMake to control them
Add explicit symbol visibility macros definitions that are defined in a new
header and will be used to for shared library builds of clang to export
symbols.
Updated clang cmake to define a macro to enable the symbol visibility macros
---
clang/cmake/modules/AddClang.cmake | 4 ++
clang/include/clang/Support/Compiler.h | 69 ++++++++++++++++++++++++++
clang/tools/libclang/CMakeLists.txt | 2 +-
3 files changed, 74 insertions(+), 1 deletion(-)
create mode 100644 clang/include/clang/Support/Compiler.h
diff --git a/clang/cmake/modules/AddClang.cmake b/clang/cmake/modules/AddClang.cmake
index 5327b5d2f08928..dcdea3eeee78fb 100644
--- a/clang/cmake/modules/AddClang.cmake
+++ b/clang/cmake/modules/AddClang.cmake
@@ -108,6 +108,10 @@ macro(add_clang_library name)
endif()
llvm_add_library(${name} ${LIBTYPE} ${ARG_UNPARSED_ARGUMENTS} ${srcs})
+ if(NOT ARG_SHARED AND NOT ARG_STATIC)
+ target_compile_definitions("obj.${name}" PRIVATE CLANG_EXPORTS)
+ endif()
+
set(libs ${name})
if(ARG_SHARED AND ARG_STATIC)
list(APPEND libs ${name}_static)
diff --git a/clang/include/clang/Support/Compiler.h b/clang/include/clang/Support/Compiler.h
new file mode 100644
index 00000000000000..4a584e190dc16e
--- /dev/null
+++ b/clang/include/clang/Support/Compiler.h
@@ -0,0 +1,69 @@
+//===-- clang/Support/Compiler.h - Compiler abstraction support -*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines explicit visibility macros used to export symbols from
+// clang-cpp
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CLANG_SUPPORT_COMPILER_H
+#define CLANG_SUPPORT_COMPILER_H
+
+#include "llvm/Support/Compiler.h"
+
+/// CLANG_ABI is the main export/visibility macro to mark something as
+/// explicitly exported when clang is built as a shared library with everything
+/// else that is unannotated will have internal visibility.
+///
+/// CLANG_EXPORT_TEMPLATE is used on explicit template instantiations in source
+/// files that were declared extern in a header. This macro is only set as a
+/// compiler export attribute on windows, on other platforms it does nothing.
+///
+/// CLANG_TEMPLATE_ABI is for annotating extern template declarations in headers
+/// for both functions and classes. On windows its turned in to dllimport for
+/// library consumers, for other platforms its a default visibility attribute.
+#ifndef CLANG_ABI_GENERATING_ANNOTATIONS
+// Marker to add to classes or functions in public headers that should not have
+// export macros added to them by the clang tool
+#define CLANG_ABI_NOT_EXPORTED
+#if defined(LLVM_BUILD_LLVM_DYLIB) || defined(LLVM_BUILD_SHARED_LIBS)
+// Some libraries like those for tablegen are linked in to tools that used
+// in the build so can't depend on the llvm shared library. If export macros
+// were left enabled when building these we would get duplicate or
+// missing symbol linker errors on windows.
+#if defined(CLANG_BUILD_STATIC)
+#define CLANG_ABI
+#define CLANG_TEMPLATE_ABI
+#define CLANG_EXPORT_TEMPLATE
+#elif defined(_WIN32) && !defined(__MINGW32__)
+#if defined(CLANG_EXPORTS)
+#define CLANG_ABI __declspec(dllexport)
+#define CLANG_TEMPLATE_ABI
+#define CLANG_EXPORT_TEMPLATE __declspec(dllexport)
+#else
+#define CLANG_ABI __declspec(dllimport)
+#define CLANG_TEMPLATE_ABI __declspec(dllimport)
+#define CLANG_EXPORT_TEMPLATE
+#endif
+#elif defined(__ELF__) || defined(__MINGW32__) || defined(_AIX)
+#define CLANG_ABI LLVM_ATTRIBUTE_VISIBILITY_DEFAULT
+#define CLANG_TEMPLATE_ABI LLVM_ATTRIBUTE_VISIBILITY_DEFAULT
+#define CLANG_EXPORT_TEMPLATE
+#elif defined(__MACH__) || defined(__WASM__)
+#define CLANG_ABI LLVM_ATTRIBUTE_VISIBILITY_DEFAULT
+#define CLANG_TEMPLATE_ABI
+#define CLANG_EXPORT_TEMPLATE
+#endif
+#else
+#define CLANG_ABI
+#define CLANG_TEMPLATE_ABI
+#define CLANG_EXPORT_TEMPLATE
+#endif
+#endif
+
+#endif
\ No newline at end of file
diff --git a/clang/tools/libclang/CMakeLists.txt b/clang/tools/libclang/CMakeLists.txt
index 968b46acb784cb..8c6a07f9e52a8c 100644
--- a/clang/tools/libclang/CMakeLists.txt
+++ b/clang/tools/libclang/CMakeLists.txt
@@ -166,7 +166,7 @@ if(ENABLE_SHARED)
set_target_properties(libclang
PROPERTIES
VERSION ${LIBCLANG_LIBRARY_VERSION}
- DEFINE_SYMBOL _CINDEX_LIB_)
+ DEFINE_SYMBOL _CINDEX_LIB_ DEFINE_SYMBOL CLANG_EXPORTS)
elseif(APPLE)
set(LIBCLANG_LINK_FLAGS " -Wl,-compatibility_version -Wl,1")
set(LIBCLANG_LINK_FLAGS "${LIBCLANG_LINK_FLAGS} -Wl,-current_version -Wl,${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}")
>From 04eef45fea5563a0a7d2ccc7aa9059798eb02933 Mon Sep 17 00:00:00 2001
From: Thomas Fransham <tfransham at gmail.com>
Date: Wed, 11 Sep 2024 19:54:27 +0100
Subject: [PATCH 2/3] Add a option to add_clang_tool CMake macro to force
static linking to clang libraries
---
clang/cmake/modules/AddClang.cmake | 21 ++++++++++++++-----
clang/tools/amdgpu-arch/CMakeLists.txt | 3 ++-
.../tools/clang-linker-wrapper/CMakeLists.txt | 2 +-
clang/tools/nvptx-arch/CMakeLists.txt | 3 ++-
4 files changed, 21 insertions(+), 8 deletions(-)
diff --git a/clang/cmake/modules/AddClang.cmake b/clang/cmake/modules/AddClang.cmake
index dcdea3eeee78fb..ee6397a7c543bd 100644
--- a/clang/cmake/modules/AddClang.cmake
+++ b/clang/cmake/modules/AddClang.cmake
@@ -155,20 +155,27 @@ macro(add_clang_executable name)
endmacro(add_clang_executable)
macro(add_clang_tool name)
- cmake_parse_arguments(ARG "DEPENDS;GENERATE_DRIVER" "" "" ${ARGN})
+ cmake_parse_arguments(ARG "DEPENDS;GENERATE_DRIVER;DISABLE_CLANG_LINK_DYLIB" "" "" ${ARGN})
if (NOT CLANG_BUILD_TOOLS)
set(EXCLUDE_FROM_ALL ON)
endif()
+
+ set(args_list ${ARGN})
+
+ if(ARG_DISABLE_CLANG_LINK_DYLIB)
+ # Remove this so the llvm argument parsing doesn't get confused
+ list(REMOVE_ITEM args_list DISABLE_CLANG_LINK_DYLIB)
+ endif()
+
if(ARG_GENERATE_DRIVER
AND LLVM_TOOL_LLVM_DRIVER_BUILD
AND (NOT LLVM_DISTRIBUTION_COMPONENTS OR ${name} IN_LIST LLVM_DISTRIBUTION_COMPONENTS)
)
- set(get_obj_args ${ARGN})
- list(FILTER get_obj_args EXCLUDE REGEX "^SUPPORT_PLUGINS$")
- generate_llvm_objects(${name} ${get_obj_args})
+ list(FILTER args_list EXCLUDE REGEX "^SUPPORT_PLUGINS$")
+ generate_llvm_objects(${name} ${args_list})
add_custom_target(${name} DEPENDS llvm-driver clang-resource-headers)
else()
- add_clang_executable(${name} ${ARGN})
+ add_clang_executable(${name} ${args_list})
add_dependencies(${name} clang-resource-headers)
if (CLANG_BUILD_TOOLS)
@@ -187,6 +194,10 @@ macro(add_clang_tool name)
endif()
endif()
set_target_properties(${name} PROPERTIES XCODE_GENERATE_SCHEME ON)
+
+ if(ARG_DISABLE_CLANG_LINK_DYLIB)
+ target_compile_definitions(${name} PRIVATE CLANG_BUILD_STATIC)
+ endif()
endmacro()
macro(add_clang_symlink name dest)
diff --git a/clang/tools/amdgpu-arch/CMakeLists.txt b/clang/tools/amdgpu-arch/CMakeLists.txt
index 1657c701251308..6b7bed99544cee 100644
--- a/clang/tools/amdgpu-arch/CMakeLists.txt
+++ b/clang/tools/amdgpu-arch/CMakeLists.txt
@@ -8,6 +8,7 @@
set(LLVM_LINK_COMPONENTS Support)
-add_clang_tool(amdgpu-arch AMDGPUArch.cpp AMDGPUArchByHSA.cpp AMDGPUArchByHIP.cpp)
+add_clang_tool(amdgpu-arch DISABLE_CLANG_LINK_DYLIB
+AMDGPUArch.cpp AMDGPUArchByHSA.cpp AMDGPUArchByHIP.cpp)
target_link_libraries(amdgpu-arch PRIVATE clangBasic)
diff --git a/clang/tools/clang-linker-wrapper/CMakeLists.txt b/clang/tools/clang-linker-wrapper/CMakeLists.txt
index bf37d8031025ed..61926a5b8a6b58 100644
--- a/clang/tools/clang-linker-wrapper/CMakeLists.txt
+++ b/clang/tools/clang-linker-wrapper/CMakeLists.txt
@@ -26,7 +26,7 @@ if(NOT CLANG_BUILT_STANDALONE)
set(tablegen_deps intrinsics_gen LinkerWrapperOpts)
endif()
-add_clang_tool(clang-linker-wrapper
+add_clang_tool(clang-linker-wrapper DISABLE_CLANG_LINK_DYLIB
ClangLinkerWrapper.cpp
DEPENDS
diff --git a/clang/tools/nvptx-arch/CMakeLists.txt b/clang/tools/nvptx-arch/CMakeLists.txt
index 8f756be2c86d04..0fd9951b631b22 100644
--- a/clang/tools/nvptx-arch/CMakeLists.txt
+++ b/clang/tools/nvptx-arch/CMakeLists.txt
@@ -7,6 +7,7 @@
# //===--------------------------------------------------------------------===//
set(LLVM_LINK_COMPONENTS Support)
-add_clang_tool(nvptx-arch NVPTXArch.cpp)
+add_clang_tool(nvptx-arch DISABLE_CLANG_LINK_DYLIB
+NVPTXArch.cpp)
target_link_libraries(nvptx-arch PRIVATE clangBasic)
>From 19ed43aa1847f11879c3674dcc7355c8061a8d5c Mon Sep 17 00:00:00 2001
From: Thomas Fransham <tfransham at gmail.com>
Date: Fri, 13 Sep 2024 17:58:05 +0100
Subject: [PATCH 3/3] Fix defining the macro in cmake to control c++ symbol
visibility for libclang on windows
---
clang/tools/libclang/CMakeLists.txt | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/clang/tools/libclang/CMakeLists.txt b/clang/tools/libclang/CMakeLists.txt
index 8c6a07f9e52a8c..00a1223c0831a7 100644
--- a/clang/tools/libclang/CMakeLists.txt
+++ b/clang/tools/libclang/CMakeLists.txt
@@ -166,7 +166,11 @@ if(ENABLE_SHARED)
set_target_properties(libclang
PROPERTIES
VERSION ${LIBCLANG_LIBRARY_VERSION}
- DEFINE_SYMBOL _CINDEX_LIB_ DEFINE_SYMBOL CLANG_EXPORTS)
+ DEFINE_SYMBOL _CINDEX_LIB_)
+ # Avoid declaring clang c++ symbols that are statically linked into libclang as dllimport'ed.
+ # If llvm/libclang-cpp dll is also being built for windows clang c++ symbols will still be
+ # implicitly be exported from libclang.
+ target_compile_definitions(libclang PRIVATE CLANG_BUILD_STATIC)
elseif(APPLE)
set(LIBCLANG_LINK_FLAGS " -Wl,-compatibility_version -Wl,1")
set(LIBCLANG_LINK_FLAGS "${LIBCLANG_LINK_FLAGS} -Wl,-current_version -Wl,${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}")
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