flang: break the build on a 32bits system

[sylvestre.ledru]

Improve the wording

[PeteSteinfeld]

Aside from the message correction nit, all builds and tests correctly and looks good.

Thanks for doing this!

flang/CMakeLists.txt

59

"on on" should read "on"

[kkwli0]

flang/CMakeLists.txt

59

A compiler can have a 32-bit mode compile on a 64-bit CPU. In that case, the condition will still be false. I suggest to change "on 32 bit CPUs" to "in 32-bit mode".

flang/CMakeLists.txt

if (MSVC AND CMAKE_CXX_COMPILER_ID MATCHES Clang)
   include(HandleCompilerRT)
   find_compiler_rt_library(builtins CLANG_RT_BUILTINS_LIBRARY)
   get_filename_component(LIBDIR "${CLANG_RT_BUILTINS_LIBRARY}" DIRECTORY)
   if (IS_DIRECTORY "${LIBDIR}")
     link_libraries(${CLANG_RT_BUILTINS_LIBRARY})
   endif()
 endif()
 
+if(CMAKE_SIZEOF_VOID_P EQUAL 4)
+  message(FATAL_ERROR "flang isn't supported on 32 bit CPUs")
+endif()
+
 if (FLANG_STANDALONE_BUILD)
   set(FLANG_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
   if (NOT MSVC_IDE)
     set(LLVM_ENABLE_ASSERTIONS ${ENABLE_ASSERTIONS}
       CACHE BOOL "Enable assertions")
     # Assertions follow llvm's configuration.
     mark_as_advanced(LLVM_ENABLE_ASSERTIONS)
   endif()