[test-suite][SPEC2000] Use -fcommon instead of -zmultidef.

[Meinersbur]

Summary

This reverts D95276 and D95506 (pass -zmultidefs to the linker) and instead pass -fcommon to the compiler. This is the same solution as already applied to non-SPEC benchmarks in D75557, and caused by a change of the defaults in gcc and clang.

(D75557 adds -fcommon to CPPFLAGS which I think is incorrect because it is not a preprocessor option)

[naromero77]

Is there any negative impact to macOS X?

[MaskRay]

LGTM. GCC 10 and Clang 11 switched to default -fno-common. The old code may be better compiling with the old behavior.

[Meinersbur]

Given that there were no issues with D75557 on MacOS, I don't expect any. -zmultidefs had a problem on MacOS because it is a GNU linker extension. While test-suite needs to work with multiple linkers, it only needs to be compatible with clang. That is, this solution should have fewer compatibility issues.

[naromero77]

LGTM

External/SPEC/CINT2000/186.crafty/CMakeLists.txt

 check_type_size("long" LONG64_TYPE_SIZE BUILTIN_TYPES_ONLY)
 if(LONG64_TYPE_SIZE EQUAL 8)
   list(APPEND CPPFLAGS -DLONG_HAS_64BITS)
 endif()
 check_type_size("long long" LONG_LONG_TYPE_SIZE BUILTIN_TYPES_ONLY)
 if(LONG_LONG_TYPE_SIZE GREATER 7)
   list(APPEND CPPFLAGS -DHAS_LONGLONG)
 endif()
-
-list(APPEND LDFLAGS ${LD_MULTIDEF_FLAG})
+list(APPEND CFLAGS -fcommon)
 
 set(SourceNames
   attacks.c
   boolean.c
   draw.c
   drawn.c
   edit.c
   enprise.c

External/SPEC/CINT2000/300.twolf/CMakeLists.txt

 list(APPEND CPPFLAGS -DHAVE_SIGNED_CHAR)
 list(APPEND LDFLAGS -lm)
-list(APPEND LDFLAGS ${LD_MULTIDEF_FLAG})
-list(APPEND CFLAGS -Wno-return-type)
+list(APPEND CFLAGS -Wno-return-type -fcommon)
 
 macro(test_input run_type)
   llvm_test_run(RUN_TYPE ${run_type}
     WORKDIR ${CMAKE_CURRENT_BINARY_DIR}/data/${run_type}/input
     ${run_type} > ${run_type}.stdout
   )
   foreach(file IN ITEMS ${run_type}.twf ${run_type}.pl2 ${run_type}.sav ${run_type}.pl1 ${run_type}.pl1 ${run_type}.pin ${run_type}.stdout ${run_type}.sv2 ${run_type}.out)
     llvm_test_verify(RUN_TYPE ${run_type} WORKDIR ${CMAKE_CURRENT_BINARY_DIR}

External/SPEC/SpecCPU2000.cmake

 include(External)
-include(CheckCSourceCompiles)
 llvm_externals_find(TEST_SUITE_SPEC2000_ROOT "speccpu2000" "SPEC CPU2000")
 if(TEST_SUITE_SPEC2000_ROOT)
   # SPEC supports three "run types": ref, train and test
   if(NOT TEST_SUITE_RUN_TYPE STREQUAL "train" AND
      NOT TEST_SUITE_RUN_TYPE STREQUAL "test" AND
      NOT TEST_SUITE_RUN_TYPE STREQUAL "ref")
     message(FATAL_ERROR
             "TEST_SUITE_RUN_TYPE must be 'train', 'test' or 'ref' for SPEC")
")
 
   function(llvm_test_data_spec target)
     llvm_test_data(${target} SOURCE_DIR ${BENCHMARK_DIR} ${ARGN})
   endfunction()
 
   function(llvm_test_data_spec_default target)
     llvm_test_data_spec(${target} data)
   endfunction()
-
-  function(check_supports_zmuldefs)
-    # Does not check whether the option has an effect.
-    # -z options are usually ignored if the particular option.
-    # Alternative option is --allow-multiple-definition
-    set(CMAKE_REQUIRED_LINK_OPTIONS "-Wl,-zmuldefs")
-    check_c_source_compiles("int main() { return 0; };" LINKER_SUPPORTS_ZMULDEFS)
-  endfunction()
-
-  check_supports_zmuldefs()
-  set(LD_MULTIDEF_FLAG)
-  if(LINKER_SUPPORTS_ZMULDEFS)
-    set(LD_MULTIDEF_FLAG "-Wl,-zmuldefs")
-  endif()
 endif()