[compiler-rt] Use C_STANDARD instead of custom logic for adding -std=c11

[mstorsjo]

Summary

Apply this in add_compiler_rt_runtime instead of manually adding it
to the individual projects. This applies the option on more
parts of compiler-rt than before, but should ideally not make any
difference assuming the other runtimes that lacked the option
also were C11 compatible.

Not marking this as required, to match the existing behaviour (where
-std=c11 was added only if supported by the compiler).

This was suggested during the review of D110005.

[phosek]

LGTM

[phosek]

compiler-rt/cmake/Modules/AddCompilerRT.cmake

382–385

This can be combined into a single invocation.

[mstorsjo]

Merged the two set_target_properties statements into one.

[maryammo]

@mstorsjo, it seems this patch broke the following builds, can you please take a look?

https://lab.llvm.org/buildbot/#/builders/105/builds/24538
https://lab.llvm.org/buildbot/#/builders/121/builds/18755

[mstorsjo]

In D124343#3475438, @maryammo wrote:

@mstorsjo, it seems this patch broke the following builds, can you please take a look?

https://lab.llvm.org/buildbot/#/builders/105/builds/24538
https://lab.llvm.org/buildbot/#/builders/121/builds/18755

Sorry about that! I've pushed a revert commit now.

Are you able to figure out why this change broke that configuration?

[maryammo]

In D124343#3475584, @mstorsjo wrote:

In D124343#3475438, @maryammo wrote:

@mstorsjo, it seems this patch broke the following builds, can you please take a look?

https://lab.llvm.org/buildbot/#/builders/105/builds/24538
https://lab.llvm.org/buildbot/#/builders/121/builds/18755

Sorry about that! I've pushed a revert commit now.

Are you able to figure out why this change broke that configuration?

Thanks.
No, I just reverted it locally to make sure this is the one that broke the build and did not look into the configuration.

compiler-rt/cmake/Modules/AddCompilerRT.cmake

else()
         LIBRARY DESTINATION ${install_dir_${libname}}
                 ${COMPONENT_OPTION}
         RUNTIME DESTINATION ${install_dir_${libname}}
                 ${COMPONENT_OPTION})
     endif()
     if(LIB_DEPS)
       add_dependencies(${libname} ${LIB_DEPS})
     endif()
     set_target_properties(${libname} PROPERTIES
         OUTPUT_NAME ${output_name_${libname}})
+    set_target_properties(${libname} PROPERTIES
+        C_STANDARD 11)
     set_target_properties(${libname} PROPERTIES FOLDER "Compiler-RT Runtime")
     if(LIB_LINK_LIBS)
       target_link_libraries(${libname} PRIVATE ${LIB_LINK_LIBS})
     endif()
     if(builtins_${libname})
       target_link_libraries(${libname} PRIVATE ${builtins_${libname}})
     endif()
     if(${type} STREQUAL "SHARED")

compiler-rt/cmake/builtin-config-ix.cmake

 include(BuiltinTests)
 include(CheckCSourceCompiles)
 
 # Make all the tests only check the compiler
 set(TEST_COMPILE_ONLY On)
 
 # Check host compiler support for certain flags
 builtin_check_c_compiler_flag(-fPIC                 COMPILER_RT_HAS_FPIC_FLAG)
 builtin_check_c_compiler_flag(-fPIE                 COMPILER_RT_HAS_FPIE_FLAG)
 builtin_check_c_compiler_flag(-fno-builtin          COMPILER_RT_HAS_FNO_BUILTIN_FLAG)
-builtin_check_c_compiler_flag(-std=c11              COMPILER_RT_HAS_STD_C11_FLAG)
 builtin_check_c_compiler_flag(-fvisibility=hidden   COMPILER_RT_HAS_VISIBILITY_HIDDEN_FLAG)
 builtin_check_c_compiler_flag(-fomit-frame-pointer  COMPILER_RT_HAS_OMIT_FRAME_POINTER_FLAG)
 builtin_check_c_compiler_flag(-ffreestanding        COMPILER_RT_HAS_FFREESTANDING_FLAG)
 builtin_check_c_compiler_flag(-fxray-instrument     COMPILER_RT_HAS_XRAY_COMPILER_FLAG)
 
 builtin_check_c_compiler_source(COMPILER_RT_HAS_ATOMIC_KEYWORD
 "
 int foo(int x, int y) {

compiler-rt/cmake/config-ix.cmake

set(MINGW_LIBRARIES mingw32 ${MINGW_RUNTIME} moldname mingwex msvcrt advapi32
                         moldname mingwex msvcrt)
     list(APPEND CMAKE_REQUIRED_LIBRARIES ${MINGW_LIBRARIES})
   endif()
 endif ()
 
 # CodeGen options.
 check_c_compiler_flag(-ffreestanding         COMPILER_RT_HAS_FFREESTANDING_FLAG)
 check_c_compiler_flag(-fomit-frame-pointer   COMPILER_RT_HAS_OMIT_FRAME_POINTER_FLAG)
-check_c_compiler_flag(-std=c11               COMPILER_RT_HAS_STD_C11_FLAG)
 check_c_compiler_flag(-fcf-protection=full   COMPILER_RT_HAS_FCF_PROTECTION_FLAG)
 check_cxx_compiler_flag(-fPIC                COMPILER_RT_HAS_FPIC_FLAG)
 check_cxx_compiler_flag(-fPIE                COMPILER_RT_HAS_FPIE_FLAG)
 check_cxx_compiler_flag(-fno-builtin         COMPILER_RT_HAS_FNO_BUILTIN_FLAG)
 check_cxx_compiler_flag(-fno-exceptions      COMPILER_RT_HAS_FNO_EXCEPTIONS_FLAG)
 check_cxx_compiler_flag(-fomit-frame-pointer COMPILER_RT_HAS_FOMIT_FRAME_POINTER_FLAG)
 check_cxx_compiler_flag(-funwind-tables      COMPILER_RT_HAS_FUNWIND_TABLES_FLAG)
 check_cxx_compiler_flag(-fno-stack-protector COMPILER_RT_HAS_FNO_STACK_PROTECTOR_FLAG)

compiler-rt/cmake/crt-config-ix.cmake

 include(BuiltinTests)
 include(CheckCSourceCompiles)
 
 # Make all the tests only check the compiler
 set(TEST_COMPILE_ONLY On)
 
 builtin_check_c_compiler_flag(-fPIC                 COMPILER_RT_HAS_FPIC_FLAG)
-builtin_check_c_compiler_flag(-std=c11              COMPILER_RT_HAS_STD_C11_FLAG)
 builtin_check_c_compiler_flag(-Wno-pedantic         COMPILER_RT_HAS_WNO_PEDANTIC)
 builtin_check_c_compiler_flag(-fno-lto              COMPILER_RT_HAS_FNO_LTO_FLAG)
 builtin_check_c_compiler_flag(-fno-profile-generate COMPILER_RT_HAS_FNO_PROFILE_GENERATE_FLAG)
 builtin_check_c_compiler_flag(-fno-profile-instr-generate COMPILER_RT_HAS_FNO_PROFILE_INSTR_GENERATE_FLAG)
 builtin_check_c_compiler_flag(-fno-profile-instr-use COMPILER_RT_HAS_FNO_PROFILE_INSTR_USE_FLAG)
 
 if(ANDROID)
   set(OS_NAME "Android")

compiler-rt/lib/builtins/CMakeLists.txt

else ()
   set(BUILTIN_CFLAGS "")
 
   if (COMPILER_RT_HAS_FCF_PROTECTION_FLAG)
     append_list_if(COMPILER_RT_ENABLE_CET -fcf-protection=full BUILTIN_CFLAGS)
   endif()
 
   append_list_if(COMPILER_RT_HAS_FLOAT16 -DCOMPILER_RT_HAS_FLOAT16 BUILTIN_CFLAGS)
 
-  append_list_if(COMPILER_RT_HAS_STD_C11_FLAG -std=c11 BUILTIN_CFLAGS)
-
   # These flags would normally be added to CMAKE_C_FLAGS by the llvm
   # cmake step. Add them manually if this is a standalone build.
   if(COMPILER_RT_STANDALONE_BUILD)
     if(COMPILER_RT_BUILTINS_ENABLE_PIC)
       append_list_if(COMPILER_RT_HAS_FPIC_FLAG -fPIC BUILTIN_CFLAGS)
     endif()
     append_list_if(COMPILER_RT_HAS_FNO_BUILTIN_FLAG -fno-builtin BUILTIN_CFLAGS)
     if(COMPILER_RT_BUILTINS_HIDE_SYMBOLS)

compiler-rt/lib/crt/CMakeLists.txt

 
 if(COMPILER_RT_HAS_CRT)
   add_compiler_rt_component(crt)
 
   include(CheckSectionExists)
   check_section_exists(".init_array" COMPILER_RT_HAS_INITFINI_ARRAY
     SOURCE "volatile int x;\n__attribute__((constructor)) void f(void) {x = 0;}\nint main(void) { return 0; }\n")
 
-  append_list_if(COMPILER_RT_HAS_STD_C11_FLAG -std=c11 CRT_CFLAGS)
   append_list_if(COMPILER_RT_HAS_INITFINI_ARRAY -DCRT_HAS_INITFINI_ARRAY CRT_CFLAGS)
   append_list_if(COMPILER_RT_CRT_USE_EH_FRAME_REGISTRY -DEH_USE_FRAME_REGISTRY CRT_CFLAGS)
   append_list_if(COMPILER_RT_HAS_FPIC_FLAG -fPIC CRT_CFLAGS)
   append_list_if(COMPILER_RT_HAS_WNO_PEDANTIC -Wno-pedantic CRT_CFLAGS)
   if (COMPILER_RT_HAS_FCF_PROTECTION_FLAG)
     append_list_if(COMPILER_RT_ENABLE_CET -fcf-protection=full CRT_CFLAGS)
   endif()