pyrox.dev
1From a56bb19a9dc303a50ef12d83cd24c2395bf81076 Mon Sep 17 00:00:00 2001
2From: Ben Wolsieffer <benwolsieffer@gmail.com>
3Date: Wed, 7 Dec 2022 21:25:46 -0500
4Subject: [PATCH] [scudo][standalone] Use CheckAtomic to decide to link to
5 libatomic
6
7Standalone scudo uses the atomic operation builtin functions, which require
8linking to libatomic on some platforms. Currently, this is done in an ad-hoc
9manner. MIPS platforms always link to libatomic, and the tests are always linked
10to it as well. libatomic is required on base ARMv6 (but not ARMv6K), but it is
11currently not linked, causing the build to fail.
12
13This patch replaces this ad-hoc logic with the CheckAtomic CMake module already
14used in other parts of LLVM. The CheckAtomic module checks whether std::atomic
15requires libatomic, which is not strictly the same as checking the atomic
16builtins, but should have the same results as far as I know. If this is
17problematic, a custom version of CheckAtomic could be used to specifically test
18the builtins.
19---
20 compiler-rt/lib/scudo/standalone/CMakeLists.txt | 7 +++++++
21 compiler-rt/lib/scudo/standalone/tests/CMakeLists.txt | 4 +---
22 2 files changed, 8 insertions(+), 3 deletions(-)
23
24diff --git a/lib/scudo/standalone/CMakeLists.txt b/lib/scudo/standalone/CMakeLists.txt
25index ae5c354768c8..eb27374ca520 100644
26--- a/lib/scudo/standalone/CMakeLists.txt
27+++ b/lib/scudo/standalone/CMakeLists.txt
28@@ -1,5 +1,8 @@
29 add_compiler_rt_component(scudo_standalone)
30
31+include(DetermineGCCCompatible)
32+include(CheckAtomic)
33+
34 include_directories(../.. include)
35
36 set(SCUDO_CFLAGS)
37@@ -34,6 +37,10 @@ list(APPEND SCUDO_LINK_FLAGS -Wl,-z,defs,-z,now,-z,relro)
38
39 list(APPEND SCUDO_LINK_FLAGS -ffunction-sections -fdata-sections -Wl,--gc-sections)
40
41+if(HAVE_CXX_ATOMICS_WITH_LIB OR HAVE_CXX_ATOMICS64_WITH_LIB)
42+ list(APPEND SCUDO_LINK_FLAGS -latomic)
43+endif()
44+
45 # We don't use the C++ standard library, so avoid including it by mistake.
46 append_list_if(COMPILER_RT_HAS_NOSTDLIBXX_FLAG -nostdlib++ SCUDO_LINK_FLAGS)
47 append_list_if(CXX_SUPPORTS_UNWINDLIB_NONE_FLAG --unwindlib=none SCUDO_LINK_FLAGS)
48diff --git a/lib/scudo/standalone/tests/CMakeLists.txt b/lib/scudo/standalone/tests/CMakeLists.txt
49index 8200cd2588b3..73b3e9403c35 100644
50--- a/lib/scudo/standalone/tests/CMakeLists.txt
51+++ b/lib/scudo/standalone/tests/CMakeLists.txt
52@@ -39,9 +39,7 @@ set(SCUDO_UNITTEST_LINK_FLAGS
53 ${COMPILER_RT_UNWINDER_LINK_LIBS}
54 ${SANITIZER_TEST_CXX_LIBRARIES})
55 list(APPEND SCUDO_UNITTEST_LINK_FLAGS -pthread -no-pie)
56-# Linking against libatomic is required with some compilers
57-check_library_exists(atomic __atomic_load_8 "" COMPILER_RT_HAS_LIBATOMIC)
58-if (COMPILER_RT_HAS_LIBATOMIC)
59+if (HAVE_CXX_ATOMICS_WITH_LIB OR HAVE_CXX_ATOMICS64_WITH_LIB)
60 list(APPEND SCUDO_UNITTEST_LINK_FLAGS -latomic)
61 endif()
62
63--
642.38.1
65