[CMake][AIX] Limit tools in external project build

[daltenty]

Summary

This is a follow on to D85329 which disabled some llvm tools in the
runtimes build due to XCOFF64 limitations. This change disables them
in other external project builds as well, when no list of tools is
specified in the arguments.

[stevewan]

llvm/cmake/modules/LLVMExternalProjectUtils.cmake

63

Minor nit: While it is clear given the context, can we also be explicit in the comment that 64-bit XCOFF and big AR format is an AIX thing?

64

Let's also use STREQUAL here?

[daltenty]

• Address comments

[stevewan]

LGTM thanks. Let's give other reviewers some time to have a look.

[hubert.reinterpretcast]

llvm/cmake/modules/LLVMExternalProjectUtils.cmake

65

llvm-lipo was originally only added for Darwin.

[daltenty]

• Remove stray llvm-lipo from list

[hubert.reinterpretcast]

LGTM; thanks.

llvm/cmake/modules/LLVMExternalProjectUtils.cmake

function(llvm_ExternalProject_Add name source_dir)
 
   # If CMAKE_SYSTEM_NAME is not set explicitly in the arguments passed to us,
   # reflect CMake's own default.
   if (NOT _cmake_system_name)
     set(_cmake_system_name "${CMAKE_HOST_SYSTEM_NAME}")
   endif()
 
   if(NOT ARG_TOOLCHAIN_TOOLS)
-    set(ARG_TOOLCHAIN_TOOLS clang lld llvm-ar llvm-ranlib llvm-nm llvm-objdump)
+    set(ARG_TOOLCHAIN_TOOLS clang)
+    # AIX 64-bit XCOFF and big AR format is not yet supported in some of these tools.
+    if(NOT _cmake_system_name STREQUAL AIX)
+      list(APPEND ARG_TOOLCHAIN_TOOLS lld llvm-ar llvm-ranlib llvm-nm llvm-objdump)
       if(_cmake_system_name STREQUAL Darwin)
         list(APPEND ARG_TOOLCHAIN_TOOLS llvm-libtool-darwin llvm-lipo)
       elseif(_cmake_system_name STREQUAL Windows)
         list(APPEND ARG_TOOLCHAIN_TOOLS llvm-lib)
       else()
         # TODO: These tools don't fully support Mach-O format yet.
         list(APPEND ARG_TOOLCHAIN_TOOLS llvm-objcopy llvm-strip)
       endif()
     endif()
+  endif()
   foreach(tool ${ARG_TOOLCHAIN_TOOLS})
     if(TARGET ${tool})
       list(APPEND TOOLCHAIN_TOOLS ${tool})
 
       # $<TARGET_FILE:tgt> only works on add_executable or add_library targets
       # The below logic mirrors cmake's own implementation
       get_target_property(target_type "${tool}" TYPE)
       if(NOT target_type STREQUAL "OBJECT_LIBRARY" AND