[CMake] Fix some breakages when using ninja multi config (llvm#65451)

When using multi-config generator to build `libLLVM.so` like `cmake -G
'Ninja Multi-Config' -Sllvm -B/tmp/out/ninja-multi
-DCMAKE_CONFIGURATION_TYPES='Debug;Release' -DLLVM_LINK_LLVM_DYLIB=on
-DLLVM_TARGETS_TO_BUILD=host && cmake --build /tmp/out/ninja-multi
--config Debug`, `lld` complains `error: cannot find version script
/tmp/out/ninja-multi/Debug/lib/tools/llvm-shlib/simple_version_script.map`.

This patch adds multi-config compatibility when configuring
`simple_version_script.map`.

Fixes llvm#63800.


When using multi-config generator, clang's headers is not copied to
proper directories, which is fixed as well.

Author: ur4t

clang/lib/Headers/CMakeLists.txt

@@ -395,12 +395,25 @@ set(riscv_generated_files)
 
 function(copy_header_to_output_dir src_dir file)
   set(src ${src_dir}/${file})
-  set(dst ${output_dir}/${file})
-  add_custom_command(OUTPUT ${dst}
-    DEPENDS ${src}
-    COMMAND ${CMAKE_COMMAND} -E copy_if_different ${src} ${dst}
-    COMMENT "Copying clang's ${file}...")
-  list(APPEND out_files ${dst})
+  if("${CMAKE_CFG_INTDIR}" STREQUAL ".")
+    set(dst ${output_dir}/${file})
+    add_custom_command(OUTPUT ${dst}
+      DEPENDS ${src}
+      COMMAND ${CMAKE_COMMAND} -E copy_if_different ${src} ${dst}
+      COMMENT "Copying clang's ${file}...")
+    list(APPEND out_files ${dst})
+  else()
+    foreach(BUILD_MODE ${CMAKE_CONFIGURATION_TYPES})
+      # Replace the special string with a per config directory.
+      string(REPLACE ${CMAKE_CFG_INTDIR} ${BUILD_MODE} per_conf_output_dir ${output_dir})
+      set(dst ${per_conf_output_dir}/${file})
+      add_custom_command(OUTPUT ${dst}
+        DEPENDS ${src}
+        COMMAND ${CMAKE_COMMAND} -E copy_if_different ${src} ${dst}
+        COMMENT "Copying clang's ${file}...")
+      list(APPEND out_files ${dst})
+    endforeach()
+  endif()
   set(out_files ${out_files} PARENT_SCOPE)
 endfunction(copy_header_to_output_dir)
 

llvm/tools/llvm-shlib/CMakeLists.txt

@@ -45,10 +45,19 @@ if(LLVM_BUILD_LLVM_DYLIB)
   if("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
     set(LIB_NAMES -Wl,-all_load ${LIB_NAMES})
   else()
-    configure_file(
-    ${CMAKE_CURRENT_SOURCE_DIR}/simple_version_script.map.in
-    ${LLVM_LIBRARY_DIR}/tools/llvm-shlib/simple_version_script.map)
-
+    if("${CMAKE_CFG_INTDIR}" STREQUAL ".")
+      configure_file(
+        ${CMAKE_CURRENT_SOURCE_DIR}/simple_version_script.map.in
+        ${LLVM_LIBRARY_DIR}/tools/llvm-shlib/simple_version_script.map)
+    else()
+      foreach(BUILD_MODE ${CMAKE_CONFIGURATION_TYPES})
+        # Replace the special string with a per config directory.
+        string(REPLACE ${CMAKE_CFG_INTDIR} ${BUILD_MODE} PER_CONF_LIBRARY_DIR ${LLVM_LIBRARY_DIR})
+        configure_file(
+          ${CMAKE_CURRENT_SOURCE_DIR}/simple_version_script.map.in
+          ${PER_CONF_LIBRARY_DIR}/tools/llvm-shlib/simple_version_script.map)
+      endforeach()
+    endif()
     if(MSVC)
       target_link_directories(LLVM PRIVATE ${LLVM_LIBRARY_DIR})
       foreach(library ${LIB_NAMES})
@@ -156,7 +165,10 @@ if(LLVM_BUILD_LLVM_C_DYLIB AND MSVC)
   # Need to separate lib names with newlines.
   string(REPLACE ";" "\n" FILE_CONTENT "${FULL_LIB_NAMES}")
 
-  if(NOT "${CMAKE_CFG_INTDIR}" STREQUAL ".")
+  if("${CMAKE_CFG_INTDIR}" STREQUAL ".")
+    # Write out the full lib names into file to be read by the python script.
+    file(WRITE ${LIBSFILE} "${FILE_CONTENT}")
+  else()
     foreach(BUILD_MODE ${CMAKE_CONFIGURATION_TYPES})
       # Replace the special string with a per config directory.
       string(REPLACE ${CMAKE_CFG_INTDIR} ${BUILD_MODE} PER_CONF_CONTENT "${FILE_CONTENT}")
@@ -166,9 +178,6 @@ if(LLVM_BUILD_LLVM_C_DYLIB AND MSVC)
       # ${CMAKE_CFG_INTDIR} correctly and select the right one.
       file(WRITE ${LLVM_BINARY_DIR}/${BUILD_MODE}/libllvm-c.args "${PER_CONF_CONTENT}")
     endforeach()
-  else()
-    # Write out the full lib names into file to be read by the python script.
-    file(WRITE ${LIBSFILE} "${FILE_CONTENT}")
   endif()
 
   # Generate the exports file dynamically.