[compiler-rt] [compiler-rt] Fix incorrect usages of check_cxx_compiler_flag (PR #83779)

Sun Mar 3 23:57:07 PST 2024

https://github.com/arichardson created https://github.com/llvm/llvm-project/pull/83779

These checks have been broken since 6afe972195454a1110ed8d20c6f2a547e6366379.
The check_cxx_compiler_flag macro only takes two arguments and passing
three to it ends up calling
`cmake_check_compiler_flag(CXX "${_FLAG}" ${_RESULT})` with ${_FLAG}
equal to `-Werror` and the result variable being the actually tested
compiler flag.

I noticed this because some of the flags that I know should be supported
were being flagged as not supported. `--debug-trycompile` shows the
following surprising line in the generated CMakeLists.txt:
`add_definitions([==[-D-Wempty-body]==] [==[-Werror]==])` which then
results in the following error while running the check:
```
FAILED: CMakeFiles/cmTC_72736.dir/src.cxx.o
tmp/upstream-llvm-readonly/bin/clang++   -nodefaultlibs -std=c++17 -fcolor-diagnostics   -D-Wempty-body -Werror -MD -MT CMakeFiles/cmTC_72736.dir/src.cxx.o -MF CMakeFiles/cmTC_72736.dir/src.cxx.o.d -o CMakeFiles/cmTC_72736.dir/src.cxx.o -c .../cmake-build-all-sanitizers/CMakeFiles/CMakeScratch/TryCompile-nyh3QR/src.cxx
In file included from <built-in>:450:
<command line>:1:9: error: macro name must be an identifier
    1 | #define -Wempty-body 1
      |         ^
   1 error generated.
```

It would be great if CMake could be a bit more helpful here so I've
filed https://gitlab.kitware.com/cmake/cmake/-/issues/25735.


>From 59a207a8b5c47f9df58f4644229e57d81e8a2bdc Mon Sep 17 00:00:00 2001
From: Alex Richardson <alexrichardson at google.com>
Date: Sun, 3 Mar 2024 23:56:50 -0800
Subject: [PATCH] =?UTF-8?q?[=F0=9D=98=80=F0=9D=97=BD=F0=9D=97=BF]=20initia?=
 =?UTF-8?q?l=20version?=
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Created using spr 1.3.6-beta.1
---
 compiler-rt/cmake/config-ix.cmake | 32 +++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
index 2ca18ebb4ad489..4f47142850a55e 100644
--- a/compiler-rt/cmake/config-ix.cmake
+++ b/compiler-rt/cmake/config-ix.cmake
@@ -103,7 +103,7 @@ check_cxx_compiler_flag("-Werror -msse4.2"   COMPILER_RT_HAS_MSSE4_2_FLAG)
 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("-Werror -ftrivial-auto-var-init=pattern" COMPILER_RT_HAS_TRIVIAL_AUTO_INIT)
 
 if(NOT WIN32 AND NOT CYGWIN)
   # MinGW warns if -fvisibility-inlines-hidden is used.
@@ -150,21 +150,21 @@ check_cxx_compiler_flag(/wd4391 COMPILER_RT_HAS_WD4391_FLAG)
 check_cxx_compiler_flag(/wd4722 COMPILER_RT_HAS_WD4722_FLAG)
 check_cxx_compiler_flag(/wd4800 COMPILER_RT_HAS_WD4800_FLAG)
 
-check_cxx_compiler_flag(-Werror -Warray-bounds COMPILER_RT_HAS_ARRAY_BOUNDS_FLAG)
-check_cxx_compiler_flag(-Werror -Wuninitialized COMPILER_RT_HAS_UNINITIALIZED_FLAG)
-check_cxx_compiler_flag(-Werror -Wshadow COMPILER_RT_HAS_SHADOW_FLAG)
-check_cxx_compiler_flag(-Werror -Wempty-body COMPILER_RT_HAS_EMPTY_BODY_FLAG)
-check_cxx_compiler_flag(-Werror -Wsizeof-pointer-memaccess COMPILER_RT_HAS_SIZEOF_POINTER_MEMACCESS_FLAG)
-check_cxx_compiler_flag(-Werror -Wsizeof-array-argument COMPILER_RT_HAS_SIZEOF_ARRAY_ARGUMENT_FLAG)
-check_cxx_compiler_flag(-Werror -Wsuspicious-memaccess COMPILER_RT_HAS_SUSPICIOUS_MEMACCESS_FLAG)
-check_cxx_compiler_flag(-Werror -Wbuiltin-memcpy-chk-size COMPILER_RT_HAS_BUILTIN_MEMCPY_CHK_SIZE_FLAG)
-check_cxx_compiler_flag(-Werror -Warray-bounds-pointer-arithmetic COMPILER_RT_HAS_ARRAY_BOUNDS_POINTER_ARITHMETIC_FLAG)
-check_cxx_compiler_flag(-Werror -Wreturn-stack-address COMPILER_RT_HAS_RETURN_STACK_ADDRESS_FLAG)
-check_cxx_compiler_flag(-Werror -Wsizeof-array-decay COMPILER_RT_HAS_SIZEOF_ARRAY_DECAY_FLAG)
-check_cxx_compiler_flag(-Werror -Wformat-insufficient-args COMPILER_RT_HAS_FORMAT_INSUFFICIENT_ARGS_FLAG)
-check_cxx_compiler_flag(-Werror -Wformat-security COMPILER_RT_HAS_BUILTIN_FORMAL_SECURITY_FLAG)
-check_cxx_compiler_flag(-Werror -Wsizeof-array-div COMPILER_RT_HAS_SIZEOF_ARRAY_DIV_FLAG)
-check_cxx_compiler_flag(-Werror -Wsizeof-pointer-div COMPILER_RT_HAS_SIZEOF_POINTER_DIV_FLAG)
+check_cxx_compiler_flag("-Werror -Warray-bounds" COMPILER_RT_HAS_ARRAY_BOUNDS_FLAG)
+check_cxx_compiler_flag("-Werror -Wuninitialized" COMPILER_RT_HAS_UNINITIALIZED_FLAG)
+check_cxx_compiler_flag("-Werror -Wshadow" COMPILER_RT_HAS_SHADOW_FLAG)
+check_cxx_compiler_flag("-Werror -Wempty-body" COMPILER_RT_HAS_EMPTY_BODY_FLAG)
+check_cxx_compiler_flag("-Werror -Wsizeof-pointer-memaccess" COMPILER_RT_HAS_SIZEOF_POINTER_MEMACCESS_FLAG)
+check_cxx_compiler_flag("-Werror -Wsizeof-array-argument" COMPILER_RT_HAS_SIZEOF_ARRAY_ARGUMENT_FLAG)
+check_cxx_compiler_flag("-Werror -Wsuspicious-memaccess" COMPILER_RT_HAS_SUSPICIOUS_MEMACCESS_FLAG)
+check_cxx_compiler_flag("-Werror -Wbuiltin-memcpy-chk-size" COMPILER_RT_HAS_BUILTIN_MEMCPY_CHK_SIZE_FLAG)
+check_cxx_compiler_flag("-Werror -Warray-bounds-pointer-arithmetic" COMPILER_RT_HAS_ARRAY_BOUNDS_POINTER_ARITHMETIC_FLAG)
+check_cxx_compiler_flag("-Werror -Wreturn-stack-address" COMPILER_RT_HAS_RETURN_STACK_ADDRESS_FLAG)
+check_cxx_compiler_flag("-Werror -Wsizeof-array-decay" COMPILER_RT_HAS_SIZEOF_ARRAY_DECAY_FLAG)
+check_cxx_compiler_flag("-Werror -Wformat-insufficient-args" COMPILER_RT_HAS_FORMAT_INSUFFICIENT_ARGS_FLAG)
+check_cxx_compiler_flag("-Werror -Wformat-security" COMPILER_RT_HAS_BUILTIN_FORMAL_SECURITY_FLAG)
+check_cxx_compiler_flag("-Werror -Wsizeof-array-div" COMPILER_RT_HAS_SIZEOF_ARRAY_DIV_FLAG)
+check_cxx_compiler_flag("-Werror -Wsizeof-pointer-div" COMPILER_RT_HAS_SIZEOF_POINTER_DIV_FLAG)
 
 # Symbols.
 check_symbol_exists(__func__ "" COMPILER_RT_HAS_FUNC_SYMBOL)

