[compiler-rt] Add CMake option to enable execute-only code generation on AArch64 #140555
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… on AArch64 For a full toolchain supporting execute-only code generation the runtime libraries also need to be pre-compiled with it enabled. For compiler-rt this can now be enabled with the `COMPILER_RT_EXECUTE_ONLY_CODE` CMake option during build configuration. The build option can only be enabled for a runtimes build of compiler-rt, because a recent version of Clang is needed to correctly compile assembly files with execute-only code support. Related RFC: https://discourse.llvm.org/t/rfc-execute-only-code-support-for-runtime-libraries-on-aarch64/86180
llvmbot
added
compiler-rt
compiler-rt:builtins
compiler-rt:fuzzer
compiler-rt:tsan
|
@llvm/pr-subscribers-xray @llvm/pr-subscribers-compiler-rt-sanitizer Author: Csanád Hajdú (Il-Capitano) ChangesFor a full toolchain supporting execute-only code generation the runtime libraries also need to be pre-compiled with it enabled. For compiler-rt this can now be enabled with the The build option can only be enabled for a runtimes build of compiler-rt, because a recent version of Clang is needed to correctly compile assembly files with execute-only code support. Related RFC: https://discourse.llvm.org/t/rfc-execute-only-code-support-for-runtime-libraries-on-aarch64/86180 Full diff: https://github.com/llvm/llvm-project/pull/140555.diff 15 Files Affected:
diff --git a/compiler-rt/CMakeLists.txt b/compiler-rt/CMakeLists.txt
index 9f8e8334d75ba..0e91e419fa373 100644
--- a/compiler-rt/CMakeLists.txt
+++ b/compiler-rt/CMakeLists.txt
@@ -307,6 +307,12 @@ option(COMPILER_RT_USE_BUILTINS_LIBRARY
option(COMPILER_RT_USE_ATOMIC_LIBRARY "Use compiler-rt atomic instead of libatomic" OFF)
+option(COMPILER_RT_EXECUTE_ONLY_CODE "Compile compiler-rt as execute-only" OFF)
+if (COMPILER_RT_EXECUTE_ONLY_CODE AND NOT LLVM_RUNTIMES_BUILD)
+ message(SEND_ERROR "COMPILER_RT_EXECUTE_ONLY_CODE is only supported "
+ "for runtimes build of compiler-rt.")
+endif()
+
include(config-ix)
#================================
@@ -603,6 +609,20 @@ string(REGEX REPLACE "-stdlib=[a-zA-Z+]*" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}
list(APPEND COMPILER_RT_COMMON_CFLAGS ${stdlib_flag})
list(APPEND COMPILER_RT_COMMON_LINK_FLAGS ${stdlib_flag})
+# Add flags for execute-only code generation.
+# We need to add to both COMPILER_RT_COMMON_CFLAGS and CMAKE_<LANG>_FLAGS.
+if (COMPILER_RT_HAS_MEXECUTE_ONLY_FLAG)
+ append_list_if(COMPILER_RT_EXECUTE_ONLY_CODE -mexecute-only COMPILER_RT_COMMON_CFLAGS)
+ append_list_if(COMPILER_RT_EXECUTE_ONLY_CODE -DCOMPILER_RT_EXECUTE_ONLY_CODE COMPILER_RT_COMMON_CFLAGS)
+ append_string_if(COMPILER_RT_EXECUTE_ONLY_CODE -mexecute-only CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+ append_string_if(COMPILER_RT_EXECUTE_ONLY_CODE -DCOMPILER_RT_EXECUTE_ONLY_CODE CMAKE_ASM_FLAGS)
+elseif (COMPILER_RT_HAS_MPURE_CODE_FLAG)
+ append_list_if(COMPILER_RT_EXECUTE_ONLY_CODE -mpure-code COMPILER_RT_COMMON_CFLAGS)
+ append_list_if(COMPILER_RT_EXECUTE_ONLY_CODE -DCOMPILER_RT_EXECUTE_ONLY_CODE COMPILER_RT_COMMON_CFLAGS)
+ append_string_if(COMPILER_RT_EXECUTE_ONLY_CODE -mpure-code CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+ append_string_if(COMPILER_RT_EXECUTE_ONLY_CODE -DCOMPILER_RT_EXECUTE_ONLY_CODE CMAKE_ASM_FLAGS)
+endif()
+
# TODO: There's a lot of duplication across lib/*/tests/CMakeLists.txt files,
# move some of the common flags to COMPILER_RT_UNITTEST_CFLAGS.
diff --git a/compiler-rt/cmake/builtin-config-ix.cmake b/compiler-rt/cmake/builtin-config-ix.cmake
index 8c9c84ad64bc0..82fde12d85bf0 100644
--- a/compiler-rt/cmake/builtin-config-ix.cmake
+++ b/compiler-rt/cmake/builtin-config-ix.cmake
@@ -26,6 +26,8 @@ builtin_check_c_compiler_flag("-Xclang -mcode-object-version=none" COMPILER_RT_H
builtin_check_c_compiler_flag(-Wbuiltin-declaration-mismatch COMPILER_RT_HAS_WBUILTIN_DECLARATION_MISMATCH_FLAG)
builtin_check_c_compiler_flag(/Zl COMPILER_RT_HAS_ZL_FLAG)
builtin_check_c_compiler_flag(-fcf-protection=full COMPILER_RT_HAS_FCF_PROTECTION_FLAG)
+builtin_check_c_compiler_flag(-mexecute-only COMPILER_RT_HAS_MEXECUTE_ONLY_FLAG)
+builtin_check_c_compiler_flag(-mpure-code COMPILER_RT_HAS_MPURE_CODE_FLAG)
builtin_check_c_compiler_source(COMPILER_RT_HAS_ATOMIC_KEYWORD
"
diff --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
index e3310b1ff0e2c..e44eeb0ab1c20 100644
--- a/compiler-rt/cmake/config-ix.cmake
+++ b/compiler-rt/cmake/config-ix.cmake
@@ -115,6 +115,8 @@ check_cxx_compiler_flag(--sysroot=. COMPILER_RT_HAS_SYSROOT_FLAG)
check_cxx_compiler_flag("-Werror -mcrc" COMPILER_RT_HAS_MCRC_FLAG)
check_cxx_compiler_flag(-fno-partial-inlining COMPILER_RT_HAS_FNO_PARTIAL_INLINING_FLAG)
check_cxx_compiler_flag("-Werror -ftrivial-auto-var-init=pattern" COMPILER_RT_HAS_TRIVIAL_AUTO_INIT)
+check_cxx_compiler_flag(-mexecute-only COMPILER_RT_HAS_MEXECUTE_ONLY_FLAG)
+check_cxx_compiler_flag(-mpure-code COMPILER_RT_HAS_MPURE_CODE_FLAG)
if(NOT WIN32 AND NOT CYGWIN)
# MinGW warns if -fvisibility-inlines-hidden is used.
diff --git a/compiler-rt/lib/builtins/CMakeLists.txt b/compiler-rt/lib/builtins/CMakeLists.txt
index d9b7800a95565..3842c089c1fbf 100644
--- a/compiler-rt/lib/builtins/CMakeLists.txt
+++ b/compiler-rt/lib/builtins/CMakeLists.txt
@@ -885,6 +885,7 @@ else ()
cmake_push_check_state()
# TODO: we should probably make most of the checks in builtin-config depend on the target flags.
set(BUILTIN_CFLAGS_${arch} ${BUILTIN_CFLAGS})
+ set(BUILTIN_DEFS_${arch} ${BUILTIN_DEFS})
# CMAKE_REQUIRED_FLAGS must be a space separated string
# Join BUILTIN_CFLAGS_${arch} and TARGET_${arch}_CFLAGS as a
# space-separated string.
@@ -922,6 +923,13 @@ else ()
if(COMPILER_RT_HAS_${arch}_BFLOAT16)
list(APPEND ${arch}_SOURCES ${BF16_SOURCES})
endif()
+ if (COMPILER_RT_HAS_MEXECUTE_ONLY_FLAG)
+ append_list_if(COMPILER_RT_EXECUTE_ONLY_CODE -mexecute-only BUILTIN_CFLAGS_${arch})
+ append_list_if(COMPILER_RT_EXECUTE_ONLY_CODE COMPILER_RT_EXECUTE_ONLY_CODE BUILTIN_DEFS_${arch})
+ elseif (COMPILER_RT_HAS_MPURE_CODE_FLAG)
+ append_list_if(COMPILER_RT_EXECUTE_ONLY_CODE -mpure-code BUILTIN_CFLAGS_${arch})
+ append_list_if(COMPILER_RT_EXECUTE_ONLY_CODE COMPILER_RT_EXECUTE_ONLY_CODE BUILTIN_DEFS_${arch})
+ endif()
# Remove a generic C builtin when an arch-specific builtin is specified.
filter_builtin_sources(${arch}_SOURCES ${arch})
@@ -943,7 +951,7 @@ else ()
ARCHS ${arch}
DEPS ${deps_${arch}}
SOURCES ${${arch}_SOURCES}
- DEFS ${BUILTIN_DEFS}
+ DEFS ${BUILTIN_DEFS_${arch}}
CFLAGS ${BUILTIN_CFLAGS_${arch}}
PARENT_TARGET builtins)
cmake_pop_check_state()
@@ -1015,6 +1023,11 @@ if (COMPILER_RT_BUILD_CRT)
if (COMPILER_RT_HAS_FCF_PROTECTION_FLAG)
append_list_if(COMPILER_RT_ENABLE_CET -fcf-protection=full CRT_CFLAGS)
endif()
+ if (COMPILER_RT_HAS_MEXECUTE_ONLY_FLAG)
+ append_list_if(COMPILER_RT_EXECUTE_ONLY_CODE -mexecute-only CRT_CFLAGS)
+ elseif (COMPILER_RT_HAS_MPURE_CODE_FLAG)
+ append_list_if(COMPILER_RT_EXECUTE_ONLY_CODE -mpure-code CRT_CFLAGS)
+ endif()
foreach(arch ${BUILTIN_SUPPORTED_ARCH})
add_compiler_rt_runtime(clang_rt.crtbegin
diff --git a/compiler-rt/lib/builtins/assembly.h b/compiler-rt/lib/builtins/assembly.h
index 385dc190369d9..2e4195d0ba6a8 100644
--- a/compiler-rt/lib/builtins/assembly.h
+++ b/compiler-rt/lib/builtins/assembly.h
@@ -71,9 +71,17 @@
#endif
+#if defined(__aarch64__) && defined(__ELF__) && \
+ defined(COMPILER_RT_EXECUTE_ONLY_CODE)
+#define TEXT_SECTION \
+ .section .text,"axy",@progbits,unique,0
+#else
+#define TEXT_SECTION \
+ .text
+#endif
+
#if defined(__arm__) || defined(__aarch64__) || defined(__arm64ec__)
#define FUNC_ALIGN \
- .text SEPARATOR \
.balign 16 SEPARATOR
#else
#define FUNC_ALIGN
@@ -230,6 +238,7 @@
#endif
#define DEFINE_COMPILERRT_FUNCTION(name) \
+ TEXT_SECTION SEPARATOR \
DEFINE_CODE_STATE \
FILE_LEVEL_DIRECTIVE SEPARATOR \
.globl FUNC_SYMBOL(SYMBOL_NAME(name)) SEPARATOR \
@@ -239,6 +248,7 @@
FUNC_SYMBOL(SYMBOL_NAME(name)):
#define DEFINE_COMPILERRT_THUMB_FUNCTION(name) \
+ TEXT_SECTION SEPARATOR \
DEFINE_CODE_STATE \
FILE_LEVEL_DIRECTIVE SEPARATOR \
.globl FUNC_SYMBOL(SYMBOL_NAME(name)) SEPARATOR \
@@ -248,6 +258,7 @@
FUNC_SYMBOL(SYMBOL_NAME(name)):
#define DEFINE_COMPILERRT_PRIVATE_FUNCTION(name) \
+ TEXT_SECTION SEPARATOR \
DEFINE_CODE_STATE \
FILE_LEVEL_DIRECTIVE SEPARATOR \
.globl FUNC_SYMBOL(SYMBOL_NAME(name)) SEPARATOR \
@@ -257,6 +268,7 @@
FUNC_SYMBOL(SYMBOL_NAME(name)):
#define DEFINE_COMPILERRT_PRIVATE_FUNCTION_UNMANGLED(name) \
+ TEXT_SECTION SEPARATOR \
DEFINE_CODE_STATE \
.globl FUNC_SYMBOL(name) SEPARATOR \
SYMBOL_IS_FUNC(name) SEPARATOR \
@@ -265,6 +277,7 @@
FUNC_SYMBOL(name):
#define DEFINE_COMPILERRT_OUTLINE_FUNCTION_UNMANGLED(name) \
+ TEXT_SECTION SEPARATOR \
DEFINE_CODE_STATE \
FUNC_ALIGN \
.globl FUNC_SYMBOL(name) SEPARATOR \
diff --git a/compiler-rt/lib/fuzzer/CMakeLists.txt b/compiler-rt/lib/fuzzer/CMakeLists.txt
index 6db24610df1f0..adfba850861ac 100644
--- a/compiler-rt/lib/fuzzer/CMakeLists.txt
+++ b/compiler-rt/lib/fuzzer/CMakeLists.txt
@@ -163,8 +163,10 @@ if(OS_NAME MATCHES "Android|Linux|Fuchsia" AND
CMAKE_ARGS -DCMAKE_CXX_COMPILER_WORKS=ON
-DCMAKE_POSITION_INDEPENDENT_CODE=ON
-DLIBCXXABI_ENABLE_EXCEPTIONS=OFF
+ -DLIBCXXABI_EXECUTE_ONLY_CODE=${COMPILER_RT_EXECUTE_ONLY_CODE}
-DLIBCXX_ABI_NAMESPACE=__Fuzzer
- -DLIBCXX_ENABLE_EXCEPTIONS=OFF)
+ -DLIBCXX_ENABLE_EXCEPTIONS=OFF
+ -DLIBCXX_EXECUTE_ONLY_CODE=${COMPILER_RT_EXECUTE_ONLY_CODE})
target_compile_options(RTfuzzer.${arch} PRIVATE -isystem ${LIBCXX_${arch}_PREFIX}/include/c++/v1)
add_dependencies(RTfuzzer.${arch} libcxx_fuzzer_${arch}-install-cmake326-workaround)
target_compile_options(RTfuzzer_main.${arch} PRIVATE -isystem ${LIBCXX_${arch}_PREFIX}/include/c++/v1)
diff --git a/compiler-rt/lib/hwasan/hwasan_setjmp_aarch64.S b/compiler-rt/lib/hwasan/hwasan_setjmp_aarch64.S
index 0c0abb6de861f..75ee6bc50baa8 100644
--- a/compiler-rt/lib/hwasan/hwasan_setjmp_aarch64.S
+++ b/compiler-rt/lib/hwasan/hwasan_setjmp_aarch64.S
@@ -28,7 +28,7 @@
// stack pointer when compiling a C function.
// Hence we have to write this function in assembly.
-.section .text
+TEXT_SECTION
.file "hwasan_setjmp_aarch64.S"
.global ASM_WRAPPER_NAME(setjmp)
diff --git a/compiler-rt/lib/hwasan/hwasan_tag_mismatch_aarch64.S b/compiler-rt/lib/hwasan/hwasan_tag_mismatch_aarch64.S
index fd060c51cd8e2..d38767f9378fa 100644
--- a/compiler-rt/lib/hwasan/hwasan_tag_mismatch_aarch64.S
+++ b/compiler-rt/lib/hwasan/hwasan_tag_mismatch_aarch64.S
@@ -70,7 +70,7 @@
// clobbering the x17 register in error reports, and that the program will have
// a runtime dependency on the __hwasan_tag_mismatch_v2 symbol therefore it will
// fail to start up given an older (i.e. incompatible) runtime.
-.section .text
+TEXT_SECTION
.file "hwasan_tag_mismatch_aarch64.S"
.global __hwasan_tag_mismatch
.type __hwasan_tag_mismatch, %function
diff --git a/compiler-rt/lib/msan/tests/CMakeLists.txt b/compiler-rt/lib/msan/tests/CMakeLists.txt
index a8500225337e6..53f570cfff27f 100644
--- a/compiler-rt/lib/msan/tests/CMakeLists.txt
+++ b/compiler-rt/lib/msan/tests/CMakeLists.txt
@@ -139,6 +139,8 @@ if(COMPILER_RT_CAN_EXECUTE_TESTS AND
add_custom_libcxx(libcxx_msan_${arch} ${LIBCXX_PREFIX}
DEPS ${MSAN_RUNTIME_LIBRARIES}
CFLAGS ${MSAN_LIBCXX_CFLAGS} ${TARGET_CFLAGS}
+ CMAKE_ARGS -DLIBCXX_EXECUTE_ONLY_CODE=${COMPILER_RT_EXECUTE_ONLY_CODE}
+ -DLIBCXXABI_EXECUTE_ONLY_CODE=${COMPILER_RT_EXECUTE_ONLY_CODE}
USE_TOOLCHAIN)
set(MSAN_LIBCXX_DIR ${LIBCXX_PREFIX}/lib/)
diff --git a/compiler-rt/lib/orc/elfnix_tls.aarch64.S b/compiler-rt/lib/orc/elfnix_tls.aarch64.S
index 8dcdd535be8ae..22bd5b560c852 100644
--- a/compiler-rt/lib/orc/elfnix_tls.aarch64.S
+++ b/compiler-rt/lib/orc/elfnix_tls.aarch64.S
@@ -15,7 +15,11 @@
#define REGISTER_SAVE_SPACE_SIZE 32 * 24
+#if defined(COMPILER_RT_EXECUTE_ONLY_CODE)
+ .section .text,"axy",@progbits,unique,0
+#else
.text
+#endif
// returns address of TLV in x0, all other registers preserved
// TODO: add fast-path for repeat access
diff --git a/compiler-rt/lib/orc/sysv_reenter.arm64.S b/compiler-rt/lib/orc/sysv_reenter.arm64.S
index 74941c459d6ac..87a857c56ac61 100644
--- a/compiler-rt/lib/orc/sysv_reenter.arm64.S
+++ b/compiler-rt/lib/orc/sysv_reenter.arm64.S
@@ -13,7 +13,11 @@
// The content of this file is arm64-only
#if defined(__arm64__) || defined(__aarch64__)
+#if defined(__ELF__) && defined(COMPILER_RT_EXECUTE_ONLY_CODE)
+ .section .text,"axy",@progbits,unique,0
+#else
.text
+#endif
// Saves GPRs, calls __orc_rt_resolve
.globl __orc_rt_sysv_reenter
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors_vfork_aarch64.inc.S b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors_vfork_aarch64.inc.S
index cdfa6f1d7f53b..99d0aae0d2faa 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors_vfork_aarch64.inc.S
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors_vfork_aarch64.inc.S
@@ -5,6 +5,7 @@
ASM_HIDDEN(COMMON_INTERCEPTOR_SPILL_AREA)
+TEXT_SECTION
.comm _ZN14__interception10real_vforkE,8,8
.globl ASM_WRAPPER_NAME(vfork)
ASM_TYPE_FUNCTION(ASM_WRAPPER_NAME(vfork))
diff --git a/compiler-rt/lib/tsan/CMakeLists.txt b/compiler-rt/lib/tsan/CMakeLists.txt
index 7928116879c09..686543e15fa6c 100644
--- a/compiler-rt/lib/tsan/CMakeLists.txt
+++ b/compiler-rt/lib/tsan/CMakeLists.txt
@@ -30,6 +30,8 @@ if(COMPILER_RT_LIBCXX_PATH AND
add_custom_libcxx(libcxx_tsan_${arch} ${LIBCXX_PREFIX}
DEPS ${TSAN_RUNTIME_LIBRARIES}
CFLAGS ${TARGET_CFLAGS} -fsanitize=thread
+ CMAKE_ARGS -DLIBCXX_EXECUTE_ONLY_CODE=${COMPILER_RT_EXECUTE_ONLY_CODE}
+ -DLIBCXXABI_EXECUTE_ONLY_CODE=${COMPILER_RT_EXECUTE_ONLY_CODE}
USE_TOOLCHAIN)
list(APPEND libcxx_tsan_deps libcxx_tsan_${arch}-install-cmake326-workaround)
endforeach()
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_aarch64.S b/compiler-rt/lib/tsan/rtl/tsan_rtl_aarch64.S
index 7d920bee4a2db..93ad0d663c7a8 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_aarch64.S
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_aarch64.S
@@ -4,10 +4,8 @@
#include "sanitizer_common/sanitizer_asm.h"
#include "builtins/assembly.h"
-#if !defined(__APPLE__)
-.section .text
-#else
-.section __TEXT,__text
+TEXT_SECTION
+#if defined(__APPLE__)
.align 3
#endif
diff --git a/compiler-rt/lib/xray/xray_trampoline_AArch64.S b/compiler-rt/lib/xray/xray_trampoline_AArch64.S
index 2586def04cbb1..5d951f3821a50 100644
--- a/compiler-rt/lib/xray/xray_trampoline_AArch64.S
+++ b/compiler-rt/lib/xray/xray_trampoline_AArch64.S
@@ -37,7 +37,7 @@
#endif
.endm
-.text
+TEXT_SECTION
.p2align 2
.global ASM_SYMBOL(__xray_FunctionEntry)
ASM_HIDDEN(__xray_FunctionEntry)
|
Il-Capitano
requested review from
petrhosek,
compnerd,
lhames,
arichardson and
yingcong-wu
You can test this locally with the following command:git-clang-format --diff HEAD~1 HEAD --extensions h -- compiler-rt/lib/builtins/assembly.hView the diff from clang-format here.diff --git a/compiler-rt/lib/builtins/assembly.h b/compiler-rt/lib/builtins/assembly.h
index 7f3af0141..38579211d 100644
--- a/compiler-rt/lib/builtins/assembly.h
+++ b/compiler-rt/lib/builtins/assembly.h
@@ -80,16 +80,13 @@
// differentiate the two sections. The output will therefore have two separate
// sections named '.text', where code will be placed into the execute-only
// '.text' section, and the implicitly-created one will be empty.
-#define TEXT_SECTION \
- .section .text,"axy",@progbits,unique,0
+#define TEXT_SECTION .section.text, "axy", @progbits, unique, 0
#else
-#define TEXT_SECTION \
- .text
+#define TEXT_SECTION .text
#endif
#if defined(__arm__) || defined(__aarch64__) || defined(__arm64ec__)
-#define FUNC_ALIGN \
- .balign 16 SEPARATOR
+#define FUNC_ALIGN .balign 16 SEPARATOR
#else
#define FUNC_ALIGN
#endif
@@ -245,55 +242,45 @@
#endif
#define DEFINE_COMPILERRT_FUNCTION(name) \
- TEXT_SECTION SEPARATOR \
- DEFINE_CODE_STATE \
- FILE_LEVEL_DIRECTIVE SEPARATOR \
- .globl FUNC_SYMBOL(SYMBOL_NAME(name)) SEPARATOR \
- SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR \
- DECLARE_SYMBOL_VISIBILITY(name) \
+ TEXT_SECTION SEPARATOR DEFINE_CODE_STATE FILE_LEVEL_DIRECTIVE \
+ SEPARATOR.globl \
+ FUNC_SYMBOL(SYMBOL_NAME(name)) \
+ SEPARATOR SYMBOL_IS_FUNC(SYMBOL_NAME(name)) \
+ SEPARATOR DECLARE_SYMBOL_VISIBILITY(name) \
DECLARE_FUNC_ENCODING \
- FUNC_SYMBOL(SYMBOL_NAME(name)):
+ FUNC_SYMBOL(SYMBOL_NAME(name)) :
#define DEFINE_COMPILERRT_THUMB_FUNCTION(name) \
- TEXT_SECTION SEPARATOR \
- DEFINE_CODE_STATE \
- FILE_LEVEL_DIRECTIVE SEPARATOR \
- .globl FUNC_SYMBOL(SYMBOL_NAME(name)) SEPARATOR \
- SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR \
- DECLARE_SYMBOL_VISIBILITY(name) SEPARATOR \
- .thumb_func SEPARATOR \
- FUNC_SYMBOL(SYMBOL_NAME(name)):
+ TEXT_SECTION SEPARATOR DEFINE_CODE_STATE FILE_LEVEL_DIRECTIVE SEPARATOR \
+ .globl \
+ FUNC_SYMBOL(SYMBOL_NAME(name)) SEPARATOR SYMBOL_IS_FUNC( \
+ SYMBOL_NAME(name)) SEPARATOR DECLARE_SYMBOL_VISIBILITY(name) \
+ SEPARATOR.thumb_func SEPARATOR FUNC_SYMBOL(SYMBOL_NAME(name)) \
+ :
#define DEFINE_COMPILERRT_PRIVATE_FUNCTION(name) \
- TEXT_SECTION SEPARATOR \
- DEFINE_CODE_STATE \
- FILE_LEVEL_DIRECTIVE SEPARATOR \
- .globl FUNC_SYMBOL(SYMBOL_NAME(name)) SEPARATOR \
- SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR \
- HIDDEN(SYMBOL_NAME(name)) SEPARATOR \
- DECLARE_FUNC_ENCODING \
- FUNC_SYMBOL(SYMBOL_NAME(name)):
+ TEXT_SECTION SEPARATOR DEFINE_CODE_STATE FILE_LEVEL_DIRECTIVE \
+ SEPARATOR.globl \
+ FUNC_SYMBOL(SYMBOL_NAME(name)) SEPARATOR SYMBOL_IS_FUNC( \
+ SYMBOL_NAME(name)) SEPARATOR HIDDEN(SYMBOL_NAME(name)) \
+ SEPARATOR DECLARE_FUNC_ENCODING FUNC_SYMBOL(SYMBOL_NAME(name)) \
+ :
#define DEFINE_COMPILERRT_PRIVATE_FUNCTION_UNMANGLED(name) \
- TEXT_SECTION SEPARATOR \
- DEFINE_CODE_STATE \
- .globl FUNC_SYMBOL(name) SEPARATOR \
- SYMBOL_IS_FUNC(name) SEPARATOR \
- HIDDEN(name) SEPARATOR \
+ TEXT_SECTION SEPARATOR DEFINE_CODE_STATE.globl FUNC_SYMBOL(name) \
+ SEPARATOR \
+ SYMBOL_IS_FUNC(name) SEPARATOR HIDDEN(name) \
+ SEPARATOR \
DECLARE_FUNC_ENCODING \
- FUNC_SYMBOL(name):
+ FUNC_SYMBOL(name) :
#define DEFINE_COMPILERRT_OUTLINE_FUNCTION_UNMANGLED(name) \
- TEXT_SECTION SEPARATOR \
- DEFINE_CODE_STATE \
- FUNC_ALIGN \
- .globl FUNC_SYMBOL(name) SEPARATOR \
- SYMBOL_IS_FUNC(name) SEPARATOR \
- DECLARE_SYMBOL_VISIBILITY_UNMANGLED(FUNC_SYMBOL(name)) SEPARATOR \
- DECLARE_FUNC_ENCODING \
- FUNC_SYMBOL(name): \
- SEPARATOR CFI_START \
- SEPARATOR BTI_C
+ TEXT_SECTION SEPARATOR DEFINE_CODE_STATE FUNC_ALIGN.globl FUNC_SYMBOL(name) \
+ SEPARATOR \
+ SYMBOL_IS_FUNC(name) \
+ SEPARATOR DECLARE_SYMBOL_VISIBILITY_UNMANGLED(FUNC_SYMBOL(name)) \
+ SEPARATOR DECLARE_FUNC_ENCODING FUNC_SYMBOL(name) \
+ : SEPARATOR CFI_START SEPARATOR BTI_C
#define DEFINE_COMPILERRT_FUNCTION_ALIAS(name, target) \
.globl FUNC_SYMBOL(SYMBOL_NAME(name)) SEPARATOR \
|
Can you expand on this more? MachO doesn't have execute-only code AFAIK. This is intended for AArch64 ELF targets only.
This also matches what LLVM outputs when it generates execute-only code: https://godbolt.org/z/a8xa7qsxG |
These macros are not ELF specific is the issue. You are changing macros that are shared across all architectures and file formats. If you could scope this down somehow to not touch these global macros, that might be easier.
Ah, I see. I think that deserves a comment explaining why we need those flags are being added. I do wonder if we should simply drop the |
The change is adding a The cases where functions are put in differently named sections don't seem to use these macros anyways.
You're right, I'll add a comment clarifying this. For dropping |
Part of the change does impact a place where there was no use of the macro and we placed text into
Right, that is what I was thinking. For static linking, that might also enable DCE, which can be a benefit. |
Is there a meaningful difference between
This is an orthogonal change to mine though. Would you be fine with merging this PR as is, and you/someone else preparing a separate patch for that? Alternatively that change could be done first, and I'd be happy to do a rebase on this PR accommodating those changes. |
Oh, if
Well, it is only coming up due to the changes you are making. I am thinking about how to simplify and make the code easier to maintain. |
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@ldionne commented on my RFC about using a single CMake option for all runtime libraries. If there aren't any opposing views, I'm fine with making that change, so if you have any thoughts (either in support of the change or opposing it), please comment on the RFC. Thanks! |
For a full toolchain supporting execute-only code generation the runtime libraries also need to be pre-compiled with it enabled. For compiler-rt this can now be enabled with the
COMPILER_RT_EXECUTE_ONLY_CODECMake option during build configuration.The build option can only be enabled for a runtimes build of compiler-rt, because a recent version of Clang is needed to correctly compile assembly files with execute-only code support.
Related RFC: https://discourse.llvm.org/t/rfc-execute-only-code-support-for-runtime-libraries-on-aarch64/86180