Don't try to run MCJIT/OrcJIT EH tests when C++ library is statically linked

[phosek]

Summary

These tests assume availability of external symbols provided by the
C++ library, but those won't be available in case when the C++ library
is statically linked because lli itself doesn't need these.

This uses llvm-readobj -needed-libs to check if C++ library is linked as
shared library and exposes that information as a feature to lit.

[beanz]

A few inline comments. Overall I like the direction.

cmake/modules/CheckCXXSharedLibrary.cmake

61

Based on our IRC conversation I ran off and read CMake's sources. Looks like CMAKE_OBJDUMP is unset on Windows, and only set elsewhere if objdump is found by CMake.

Might be worth adding an early out at the beginning of this function to mark the check as failed if CMAKE_OBJDUMP is unset. In that case you should also probably log that the check failed to the CMake status, and log why in the error log.

66

CHECK_RESULT and CHECK_ERROR are unused here, as well as LINK_RESULT, LINK_OUTPUT and LINK_ERROR.

Probably makes sense to write the value of all those variables out to log files in the event the link or objdump commands fail.

[phosek]

I have reworked this patch to use llvm-readobj relying on the -needed-libs which will be supported in ELF, COFF and Mach-O after D41529 and D41527 lands.

[beanz]

This looks good to me. Please correct me if I'm wrong, but it also looks like you've written this patch so that it will work correctly even if it is landed before the llvm-readobj changes are landed. If that is the case go ahead and land this.

[phosek]

In D41272#968768, @beanz wrote:

This looks good to me. Please correct me if I'm wrong, but it also looks like you've written this patch so that it will work correctly even if it is landed before the llvm-readobj changes are landed. If that is the case go ahead and land this.

It'd disable the MCJIT tests though because the cxx-shared-library wouldn't be available which is probably not something we want. However, D41527 is ready to land unless you have some other comments and D41529 has already landed so this could land immediately after.

cmake/modules/CheckCXXSharedLibrary.cmake

+# Check if C++ library is a shared library.
+function(check_cxx_shared_library output)
+  cmake_parse_arguments(ARG "" "" "SOURCE;FLAGS" ${ARGN})
+  if(NOT ARG_SOURCE)
+    set(ARG_SOURCE "int main() { return 0; }\n")
+  endif()
+
+  string(RANDOM TARGET_NAME)
+  set(TARGET_NAME "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/cmTC_${TARGET_NAME}.dir")
+  file(MAKE_DIRECTORY ${TARGET_NAME})
+
+  file(WRITE "${TARGET_NAME}/CheckCXXSharedLibrary.cpp" "${ARG_SOURCE}\n")
+
+  string(REGEX MATCHALL "<[A-Za-z0-9_]*>" substitutions
+         ${CMAKE_CXX_LINK_EXECUTABLE})
+
+  set(try_link_flags "${ARG_FLAGS}")
+  if(CMAKE_CXX_COMPILER_ID MATCHES Clang AND CMAKE_CXX_COMPILER_TARGET)
+    list(APPEND try_link_flags "--target=${CMAKE_CXX_COMPILER_TARGET}")
+  endif()
+  if(CMAKE_CXX_COMPILER_ID MATCHES Clang AND CMAKE_SYSROOT)
+    list(APPEND try_link_flags "--sysroot=${CMAKE_SYSROOT}")
+  endif()
+
+  string(REPLACE ";" " " extra_flags "${try_link_flags}")
+
+  set(test_link_command "${CMAKE_CXX_LINK_EXECUTABLE}")
+  foreach(substitution ${substitutions})
+    if(substitution STREQUAL "<CMAKE_CXX_COMPILER>")
+      string(REPLACE "<CMAKE_CXX_COMPILER>"
+             "${CMAKE_CXX_COMPILER}" test_link_command ${test_link_command})
+    elseif(substitution STREQUAL "<OBJECTS>")
+      string(REPLACE "<OBJECTS>" "${TARGET_NAME}/CheckCXXSharedLibrary.cpp"
+             test_link_command ${test_link_command})
+    elseif(substitution STREQUAL "<TARGET>")
+      string(REPLACE "<TARGET>" "${TARGET_NAME}/CheckCXXSharedLibrary"
+             test_link_command ${test_link_command})
+    elseif(substitution STREQUAL "<FLAGS>")
+      string(REPLACE "<FLAGS>" "${CMAKE_CXX_FLAGS}"
+             test_link_command ${test_link_command})
+    elseif(substitution STREQUAL "<LINK_FLAGS>")
+      string(REPLACE "<LINK_FLAGS>" "${CMAKE_EXE_LINKER_FLAGS} ${extra_flags}"
+             test_link_command ${test_link_command})
+    else()
+      string(REPLACE "${substitution}" "" test_link_command
+             ${test_link_command})
+    endif()
+  endforeach()
+
+  string(REPLACE " " ";" test_link_command "${test_link_command}")
+
+  execute_process(
+    COMMAND ${test_link_command}
+    RESULT_VARIABLE LINK_RESULT
+    OUTPUT_VARIABLE LINK_OUTPUT
+    ERROR_VARIABLE LINK_ERROR
+  )
+
+  execute_process(
+    COMMAND ${CMAKE_OBJDUMP} -p "${TARGET_NAME}/CheckCXXSharedLibrary"
+    RESULT_VARIABLE CHECK_RESULT
+    OUTPUT_VARIABLE CHECK_OUTPUT
+    ERROR_VARIABLE CHECK_ERROR
+  )
+
+  if(CHECK_OUTPUT MATCHES "NEEDED[ ]+lib(std)?c\\+\\+\\.so")
+    set(${output} TRUE PARENT_SCOPE)
+  else()
+    set(${output} FALSE PARENT_SCOPE)
+  endif()
+
+  file(REMOVE_RECURSE ${TARGET_NAME})
+endfunction()

test/CMakeLists.txt

+include(CheckCXXSharedLibrary)
+
+check_cxx_shared_library(HAVE_CXX_SHARED_LIBRARY)
+
 llvm_canonicalize_cmake_booleans(
   LLVM_TOOL_LTO_BUILD
   HAVE_OCAMLOPT
   HAVE_OCAML_OUNIT
   LLVM_INCLUDE_GO_TESTS
   LLVM_USE_INTEL_JITEVENTS
   HAVE_LIBZ
   HAVE_LIBXAR
   LLVM_ENABLE_DIA_SDK
   LLVM_ENABLE_FFI
   BUILD_SHARED_LIBS
   LLVM_LINK_LLVM_DYLIB
+  HAVE_CXX_SHARED_LIBRARY
   )
 
 configure_lit_site_cfg(
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.py.in
   ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg.py
   MAIN_CONFIG
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py
   )

test/ExecutionEngine/MCJIT/eh-lg-pic.ll

+; REQUIRES: cxx-shared-library
 ; RUN: %lli -relocation-model=pic -code-model=large %s
 ; XFAIL: cygwin, win32, mingw, mips-, mipsel-, i686, i386, aarch64, arm
 declare i8* @__cxa_allocate_exception(i64)
 declare void @__cxa_throw(i8*, i8*, i8*)
 declare i32 @__gxx_personality_v0(...)
 declare void @__cxa_end_catch()
 declare i8* @__cxa_begin_catch(i8*)
 

test/ExecutionEngine/MCJIT/eh.ll

+; REQUIRES: cxx-shared-library
 ; RUN: %lli %s
 ; XFAIL: arm, cygwin, win32, mingw
 declare i8* @__cxa_allocate_exception(i64)
 declare void @__cxa_throw(i8*, i8*, i8*)
 declare i32 @__gxx_personality_v0(...)
 declare void @__cxa_end_catch()
 declare i8* @__cxa_begin_catch(i8*)
 

test/ExecutionEngine/MCJIT/multi-module-eh-a.ll

+; REQUIRES: cxx-shared-library
 ; RUN: %lli -extra-module=%p/Inputs/multi-module-eh-b.ll %s
 ; XFAIL: arm, cygwin, win32, mingw
 declare i8* @__cxa_allocate_exception(i64)
 declare void @__cxa_throw(i8*, i8*, i8*)
 declare i32 @__gxx_personality_v0(...)
 declare void @__cxa_end_catch()
 declare i8* @__cxa_begin_catch(i8*)
 

test/ExecutionEngine/MCJIT/remote/eh.ll

+; REQUIRES: cxx-shared-library
 ; RUN: %lli -remote-mcjit -mcjit-remote-process=lli-child-target%exeext %s
 ; XFAIL: arm, cygwin, win32, mingw
 ; UNSUPPORTED: powerpc64-unknown-linux-gnu
 ; Remove UNSUPPORTED for powerpc64-unknown-linux-gnu if problem caused by r266663 is fixed
 declare i8* @__cxa_allocate_exception(i64)
 declare void @__cxa_throw(i8*, i8*, i8*)
 declare i32 @__gxx_personality_v0(...)
 declare void @__cxa_end_catch()

test/ExecutionEngine/OrcMCJIT/eh-lg-pic.ll

+; REQUIRES: cxx-shared-library
 ; RUN: %lli -jit-kind=orc-mcjit -relocation-model=pic -code-model=large %s
 ; XFAIL: cygwin, win32, mingw, mips-, mipsel-, i686, i386, aarch64, arm
 declare i8* @__cxa_allocate_exception(i64)
 declare void @__cxa_throw(i8*, i8*, i8*)
 declare i32 @__gxx_personality_v0(...)
 declare void @__cxa_end_catch()
 declare i8* @__cxa_begin_catch(i8*)
 

test/ExecutionEngine/OrcMCJIT/eh.ll

+; REQUIRES: cxx-shared-library
 ; RUN: %lli -jit-kind=orc-mcjit %s
 ; XFAIL: arm, cygwin, win32, mingw
 declare i8* @__cxa_allocate_exception(i64)
 declare void @__cxa_throw(i8*, i8*, i8*)
 declare i32 @__gxx_personality_v0(...)
 declare void @__cxa_end_catch()
 declare i8* @__cxa_begin_catch(i8*)
 

test/ExecutionEngine/OrcMCJIT/multi-module-eh-a.ll

+; REQUIRES: cxx-shared-library
 ; RUN: %lli -jit-kind=orc-mcjit -extra-module=%p/Inputs/multi-module-eh-b.ll %s
 ; XFAIL: arm, cygwin, win32, mingw
 declare i8* @__cxa_allocate_exception(i64)
 declare void @__cxa_throw(i8*, i8*, i8*)
 declare i32 @__gxx_personality_v0(...)
 declare void @__cxa_end_catch()
 declare i8* @__cxa_begin_catch(i8*)
 

test/ExecutionEngine/OrcMCJIT/remote/eh.ll

+; REQUIRES: cxx-shared-library
 ; RUN: %lli -remote-mcjit -mcjit-remote-process=lli-child-target%exeext %s
 ; XFAIL: arm, cygwin, win32, mingw
 ; UNSUPPORTED: powerpc64-unknown-linux-gnu
 ; Remove UNSUPPORTED for powerpc64-unknown-linux-gnu if problem caused by r266663 is fixed
 declare i8* @__cxa_allocate_exception(i64)
 declare void @__cxa_throw(i8*, i8*, i8*)
 declare i32 @__gxx_personality_v0(...)
 declare void @__cxa_end_catch()

test/lit.cfg.py

 
 if loadable_module:
     config.available_features.add('loadable_module')
 
 # Static libraries are not built if BUILD_SHARED_LIBS is ON.
 if not config.build_shared_libs and not config.link_llvm_dylib:
     config.available_features.add('static-libs')
 
+if config.have_cxx_shared_library:
+    config.available_features.add('cxx-shared-library')
+
 # Direct object generation
 if not 'hexagon' in config.target_triple:
     config.available_features.add('object-emission')
 
 # LLVM can be configured with an empty default triple
 # Some tests are "generic" and require a valid default triple
 if config.target_triple:
     config.available_features.add('default_triple')

test/lit.site.cfg.py.in

 config.have_dia_sdk = @LLVM_ENABLE_DIA_SDK@
 config.enable_ffi = @LLVM_ENABLE_FFI@
 config.build_shared_libs = @BUILD_SHARED_LIBS@
 config.link_llvm_dylib = @LLVM_LINK_LLVM_DYLIB@
 config.llvm_libxml2_enabled = "@LLVM_LIBXML2_ENABLED@"
 config.llvm_host_triple = '@LLVM_HOST_TRIPLE@'
 config.host_arch = "@HOST_ARCH@"
 config.have_opt_viewer_modules = @LLVM_HAVE_OPT_VIEWER_MODULES@
+config.have_cxx_shared_library = @HAVE_CXX_SHARED_LIBRARY@
 
 # Support substitution of the tools_dir with user parameters. This is
 # used when we can't determine the tool dir at configuration time.
 try:
     config.llvm_tools_dir = config.llvm_tools_dir % lit_config.params
     config.llvm_shlib_dir = config.llvm_shlib_dir % lit_config.params
 except KeyError:
     e = sys.exc_info()[1]
     key, = e.args
     lit_config.fatal("unable to find %r parameter, use '--param=%s=VALUE'" % (key,key))
 
 @LIT_SITE_CFG_IN_FOOTER@
 
 # Let the main config do the real work.
 lit_config.load_config(config, "@LLVM_SOURCE_DIR@/test/lit.cfg.py")