[compiler-rt][cmake] Don't pass --version-script to Illumos ld

[ro]

Summary

Neither the Illumos ld nor the Solaris 11.3 one support the --version-script and
z gnu-linker-script-compat options, which breaks the compiler-rt build.

This patch checks for both options instead of hardcoding their use.

Tested on amd-pc-solaris2.11 (all of Solaris 11.4, 11.3, and Illumos).

It should be possible to remove the UNIX resp. FUCHSIA OR UNIX conditions in
compiler-rt/lib/asan/CMakeLists.txt and compiler-rt/lib/ubsan/CMakeLists.txt.
However, until this has been tested on a wider range of platforms, I've kept them to
be safe.

[ro]

I forgot: also tested on x86_64-pc-linux-gnu.

[vitalybuka]

compiler-rt/lib/asan/CMakeLists.txt

227

Not sure who is going to test this.
I'd suggested to try and see that is broken

compiler-rt/lib/ubsan/CMakeLists.txt

203

same

[vitalybuka]

feel free to move suggested changes into a separate patch

[ro]

In D84559#2177842, @vitalybuka wrote:

feel free to move suggested changes into a separate patch

Will do: this allows to quickly revert just this part in case there's fallout. What's the best way to handle this? Create a new patch in Phabricator
or just commit it separately with "Differential Revision: " set to this one?

[aeubanks]

I'm seeing
ld.lld: error: unknown -z value: gnu-version-script-compat
for a build with -DLLVM_ENABLE_LLD=On
and
/usr/bin/ld: warning: -z gnu-version-script-compat ignored
in a build without one.
$ ninja lib/clang/12.0.0/lib/linux/libclang_rt.ubsan_standalone-i386.so

[ro]

In D84559#2180630, @aeubanks wrote:

I'm seeing
ld.lld: error: unknown -z value: gnu-version-script-compat
for a build with -DLLVM_ENABLE_LLD=On

So far I cannot reproduce this: in a build with -DLLVM_ENABLE_LLD=On and clang-10 as the build compiler, COMPILER_RT_HAS_VERSION_SCRIPT is 1 in CMakeCache.txt while COMPILER_RT_HAS_GNU_VERSION_SCRIPT_COMPAT is
empty, just as expected.

/usr/bin/ld: warning: -z gnu-version-script-compat ignored
in a build without one.

While ugly, this one is expected. I consider gld no-so-silently accepting unknown -z options a serious bug: it has no way of knowing if the
unknown option is crucial to the link or can be ignored without causing harm. However, this seems to date back to binutils 2.22 from 2011,
so is unlikely to change.

$ ninja lib/clang/12.0.0/lib/linux/libclang_rt.ubsan_standalone-i386.so

Works for me just fine. I even tried a 2-stage build with -DLLVM_ENABLE_LLD=On in CLANG_BOOTSTRAP_PASSTHROUGH, but that
consistently fails during the stage 2 cmake run:

CMake Error at cmake/modules/HandleLLVMOptions.cmake:277 (message):
  Host compiler does not support '-fuse-ld=lld'

The stage 2 CMakeFiles/CMakeError.log has

Performing C++ SOURCE FILE Test CXX_SUPPORTS_CUSTOM_LINKER failed with the following output:
Change Dir: /var/llvm/local-x86_64-release-stage2-lld/tools/clang/stage2-bins/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/ninja-build cmTC_1d566 && [1/2] Building CXX object CMakeFiles/cmTC_1d566.dir/src.cxx.o
clang-12: warning: argument unused during compilation: '-fuse-ld=lld' [-Wunused-command-line-argument]
[2/2] Linking CXX executable cmTC_1d566
FAILED: cmTC_1d566
: && /var/llvm/local-x86_64-release-stage2-lld/./bin/clang++  -DCXX_SUPPORTS_CUSTOM_LINKER  -Werror=unguarded-availability-new -fuse-ld=lld   CMakeFiles/cmTC_1d566.dir/src.cxx.o  -o cmTC_1d566  -lm && :
clang-12: error: invalid linker name in argument '-fuse-ld=lld'
ninja: build stopped: subcommand failed.

which is really weird given that the same command works just fine if repeated manually. This might be related to @MaskRay 's recent
-fuse-ld changes.

[ro]

Could you check your CMakeFiles/CMake{Output,Error}.log files for the -z gnu-version-script-compat test? In mine it fails as expected:

FAILED: cmTC_2dc7b
: && /vol/llvm-10.0/bin/clang++  -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wstring-conversion -fdiagnostics-color -ffunction-sections -fdata-sections -DCOMPILER_RT_HAS_GNU_VERSION_SCRIPT_COMPAT  -Werror=unguarded-availability-new -nodefaultlibs -Wl,-z,gnu-version-script-compat  -fuse-ld=lld -Wl,--color-diagnostics -Wl,-allow-shlib-undefined CMakeFiles/cmTC_2dc7b.dir/src.cxx.o  -o cmTC_2dc7b  -lm  -lc  -lgcc_s && :
ld.lld: error: unknown -z value: gnu-version-script-compat
clang-10: error: linker command failed with exit code 1 (use -v to see invocation)
ninja: build stopped: subcommand failed.

[ro]

In D84559#2181226, @ro wrote:

Works for me just fine. I even tried a 2-stage build with -DLLVM_ENABLE_LLD=On in CLANG_BOOTSTRAP_PASSTHROUGH, but that
consistently fails during the stage 2 cmake run:

[...]

which is really weird given that the same command works just fine if repeated manually. This might be related to @MaskRay 's recent
-fuse-ld changes.

Scratch that: pilot error. I didn't have lld in system paths and the script I use to run llvm builds didn't include the full llvm-10 bin directory
in PATH.

[aeubanks]

I killed everything and started again from scratch, seems like it's not an issue anymore. Might be CMake caching not working well between CMake changes?
Sorry for the false alarm.

[ro]

In D84559#2182131, @aeubanks wrote:

I killed everything and started again from scratch, seems like it's not an issue anymore. Might be CMake caching not working well between CMake changes?
Sorry for the false alarm.

No worries: glad it wasn't my fault. I've always been wary of rebuilds correctly picking up configuration changes, both in the cmake and autotools worlds.

compiler-rt/cmake/config-ix.cmake

 endif()
 check_library_exists(c++ __cxa_throw "" COMPILER_RT_HAS_LIBCXX)
 check_library_exists(stdc++ __cxa_throw "" COMPILER_RT_HAS_LIBSTDCXX)
 
 # Linker flags.
 check_linker_flag("-Wl,-z,text" COMPILER_RT_HAS_Z_TEXT)
 check_linker_flag("-fuse-ld=lld" COMPILER_RT_HAS_FUSE_LD_LLD_FLAG)
 
+set(VERS_COMPAT_OPTION "-Wl,-z,gnu-version-script-compat")
+check_linker_flag("${VERS_COMPAT_OPTION}" COMPILER_RT_HAS_GNU_VERSION_SCRIPT_COMPAT)
+
+set(DUMMY_VERS ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/dummy.vers)
+file(WRITE ${DUMMY_VERS} "{};")
+set(VERS_OPTION "-Wl,--version-script,${DUMMY_VERS}")
+if(COMPILER_RT_HAS_GNU_VERSION_SCRIPT_COMPAT)
+  # Solaris 11.4 ld only supports --version-script with
+  # -z gnu-version-script-compat. 
+  string(APPEND VERS_OPTION " ${VERS_COMPAT_OPTION}")
+endif()
+check_linker_flag("${VERS_OPTION}" COMPILER_RT_HAS_VERSION_SCRIPT)
+
 if(ANDROID)
   check_linker_flag("-Wl,-z,global" COMPILER_RT_HAS_Z_GLOBAL)
   check_library_exists(log __android_log_write "" COMPILER_RT_HAS_LIBLOG)
 endif()
 
 # Architectures.
 
 # List of all architectures we can target.

compiler-rt/lib/asan/CMakeLists.txt

add_compiler_rt_runtime(clang_rt.asan-preinit
     STATIC
     ARCHS ${ASAN_SUPPORTED_ARCH}
     OBJECT_LIBS RTAsan_preinit
     CFLAGS ${ASAN_CFLAGS}
     DEFS ${ASAN_COMMON_DEFINITIONS}
     PARENT_TARGET asan)
 
   foreach(arch ${ASAN_SUPPORTED_ARCH})
-    if (UNIX)
+    if (UNIX AND COMPILER_RT_HAS_VERSION_SCRIPT)
       add_sanitizer_rt_version_list(clang_rt.asan-dynamic-${arch}
                                     LIBS clang_rt.asan-${arch} clang_rt.asan_cxx-${arch}
                                     EXTRA asan.syms.extra)
       set(VERSION_SCRIPT_FLAG
            -Wl,--version-script,${CMAKE_CURRENT_BINARY_DIR}/clang_rt.asan-dynamic-${arch}.vers)
       # The Solaris 11.4 linker supports a subset of GNU ld version scripts,
       # but requires a special option to enable it.
-      if (OS_NAME MATCHES "SunOS")
+      if (COMPILER_RT_HAS_GNU_VERSION_SCRIPT_COMPAT)
           list(APPEND VERSION_SCRIPT_FLAG -Wl,-z,gnu-version-script-compat)
       endif()
       set_property(SOURCE
         ${CMAKE_CURRENT_BINARY_DIR}/dummy.cpp
         APPEND PROPERTY
         OBJECT_DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/clang_rt.asan-dynamic-${arch}.vers)
     else()
       set(VERSION_SCRIPT_FLAG)

compiler-rt/lib/ubsan/CMakeLists.txt

if(COMPILER_RT_HAS_UBSAN)
 
     add_compiler_rt_runtime(clang_rt.ubsan_standalone_cxx
       STATIC
       ARCHS ${UBSAN_SUPPORTED_ARCH}
       OBJECT_LIBS RTUbsan_cxx
       CFLAGS ${UBSAN_CXXFLAGS}
       PARENT_TARGET ubsan)
 
-    if (FUCHSIA OR UNIX)
+    if ((FUCHSIA OR UNIX) AND COMPILER_RT_HAS_VERSION_SCRIPT)
       file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/dummy.cpp "")
       add_compiler_rt_object_libraries(RTUbsan_dynamic_version_script_dummy
         ARCHS ${UBSAN_SUPPORTED_ARCH}
         SOURCES ${CMAKE_CURRENT_BINARY_DIR}/dummy.cpp
         CFLAGS ${UBSAN_CFLAGS})
 
       foreach(arch ${UBSAN_SUPPORTED_ARCH})
         add_sanitizer_rt_version_list(clang_rt.ubsan_standalone-dynamic-${arch}
                                       LIBS clang_rt.ubsan_standalone-${arch}
                                            clang_rt.ubsan_standalone_cxx-${arch}
                                       EXTRA ubsan.syms.extra)
         set(VERSION_SCRIPT_FLAG
             -Wl,--version-script,${CMAKE_CURRENT_BINARY_DIR}/clang_rt.ubsan_standalone-dynamic-${arch}.vers)
         # The Solaris 11.4 linker supports a subset of GNU ld version scripts,
         # but requires a special option to enable it.
-        if (OS_NAME MATCHES "SunOS")
+        if (COMPILER_RT_HAS_GNU_VERSION_SCRIPT_COMPAT)
             list(APPEND VERSION_SCRIPT_FLAG -Wl,-z,gnu-version-script-compat)
         endif()
         set_property(SOURCE
           ${CMAKE_CURRENT_BINARY_DIR}/dummy.cpp
           APPEND PROPERTY
           OBJECT_DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/clang_rt.ubsan_standalone-dynamic-${arch}.vers)
 
         add_compiler_rt_runtime(clang_rt.ubsan_standalone