[CMake][runtimes] Set compiler as working even for default target

[phosek]

Summary

Even when building builtins and runtimes for the default target
we shouldn't assume that the just built compiler is already useable.
When the compiler uses compiler-rt and libc++ as the default runtime
and C++ library, it won't be usable until we finish building runtimes.

[beanz]

One comment inline below.

runtimes/CMakeLists.txt

88 ↗

(On Diff #121841)

Why is this removed? Your comments don't explain this part of the change.

[phosek]

runtimes/CMakeLists.txt

88 ↗

(On Diff #121841)

This change is orthogonal to this one so I'll split it into a separate patch.

[beanz]

LGTM.

llvm/trunk/runtimes/CMakeLists.txt

else() # if this is included from LLVM's CMake
 
   function(builtin_default_target)
     llvm_ExternalProject_Add(builtins
                              ${CMAKE_CURRENT_SOURCE_DIR}/compiler-rt/lib/builtins
                              CMAKE_ARGS -DLLVM_LIBRARY_OUTPUT_INTDIR=${LLVM_LIBRARY_DIR}
                                         -DLLVM_RUNTIME_OUTPUT_INTDIR=${LLVM_TOOLS_BINARY_DIR}
                                         -DCMAKE_C_COMPILER_TARGET=${TARGET_TRIPLE}
                                         -DCMAKE_ASM_COMPILER_TARGET=${TARGET_TRIPLE}
+                                        -DCMAKE_C_COMPILER_WORKS=ON
+                                        -DCMAKE_ASM_COMPILER_WORKS=ON
                              PASSTHROUGH_PREFIXES COMPILER_RT
                              USE_TOOLCHAIN
                              ${EXTRA_ARGS})
   endfunction()
 
   function(builtin_register_target target)
     string(REPLACE "-" ";" builtin_target_list ${target})
     foreach(item ${builtin_target_list})
function(builtin_register_target target)
     endforeach()
 
     llvm_ExternalProject_Add(builtins-${target}
                              ${CMAKE_CURRENT_SOURCE_DIR}/compiler-rt/lib/builtins
                              CMAKE_ARGS -DLLVM_LIBRARY_OUTPUT_INTDIR=${LLVM_LIBRARY_DIR}
                                         -DLLVM_RUNTIME_OUTPUT_INTDIR=${LLVM_TOOLS_BINARY_DIR}
                                         -DCMAKE_C_COMPILER_TARGET=${target}
                                         -DCMAKE_ASM_COMPILER_TARGET=${target}
-                                        -DCMAKE_C_COMPILER_WORKS=On
-                                        -DCMAKE_ASM_COMPILER_WORKS=On
-                                        -DCOMPILER_RT_DEFAULT_TARGET_ONLY=On
+                                        -DCMAKE_C_COMPILER_WORKS=ON
+                                        -DCMAKE_ASM_COMPILER_WORKS=ON
+                                        -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON
                                         ${${target}_extra_args}
                              TOOLCHAIN_TOOLS clang lld llvm-ar llvm-ranlib
                              PASSTHROUGH_PREFIXES COMPILER_RT
                              USE_TOOLCHAIN
                              ${EXTRA_ARGS})
   endfunction()
 
   # If compiler-rt is present we need to build the builtin libraries first. This
function(runtime_default_target deps prefixes)
 
     llvm_ExternalProject_Add(runtimes
                              ${CMAKE_CURRENT_SOURCE_DIR}
                              DEPENDS ${deps}
                              # Builtins were built separately above
                              CMAKE_ARGS -DCOMPILER_RT_BUILD_BUILTINS=Off
                                         -DLLVM_INCLUDE_TESTS=${LLVM_INCLUDE_TESTS}
                                         -DLLVM_LIBRARY_DIR=${LLVM_LIBRARY_DIR}
+                                        -DCMAKE_C_COMPILER_WORKS=ON
+                                        -DCMAKE_CXX_COMPILER_WORKS=ON
+                                        -DCMAKE_ASM_COMPILER_WORKS=ON
                              PASSTHROUGH_PREFIXES ${prefixes}
                              EXTRA_TARGETS ${extra_targets}
                                            ${test_targets}
                                            ${SUB_COMPONENTS}
                                            ${SUB_CHECK_TARGETS}
                                            ${SUB_INSTALL_TARGETS}
                              USE_TOOLCHAIN
                              ${EXTRA_ARGS})