CMake: Add the possibility to pass an arbitrary count of targets to add_cxx_pch.

* A PCH is still generated for every target which was passed to the macro
* Resolves naming conflicts when using the same PCH header from multiple projects
* Ref #15671

1 files changed, 45 insertions, 26 deletions

diff --git a/cmake/macros/FindPCHSupport.cmake b/cmake/macros/FindPCHSupport.cmake
index b068b69c26b..49d4be904d1 100644
--- a/cmake/macros/FindPCHSupport.cmake
+++ b/cmake/macros/FindPCHSupport.cmake
@@ -11,7 +11,7 @@ FUNCTION(GET_COMMON_PCH_PARAMS PCH_HEADER PCH_FE INCLUDE_PREFIX)
   SET(INCLUDE_FLAGS ${INCLUDE_FLAGS_LIST} PARENT_SCOPE)
 ENDFUNCTION(GET_COMMON_PCH_PARAMS)
 
-FUNCTION(GENERATE_CXX_PCH_COMMAND TARGET_NAME INCLUDE_FLAGS IN PCH_SRC OUT)
+FUNCTION(GENERATE_CXX_PCH_COMMAND TARGET_NAME_LIST INCLUDE_FLAGS IN PCH_SRC OUT)
   IF (CMAKE_BUILD_TYPE)
     STRING(TOUPPER _${CMAKE_BUILD_TYPE} CURRENT_BUILD_TYPE)
   ENDIF ()
@@ -55,50 +55,69 @@ FUNCTION(GENERATE_CXX_PCH_COMMAND TARGET_NAME INCLUDE_FLAGS IN PCH_SRC OUT)
     DEPENDS ${OUT}
   )
 
-  ADD_DEPENDENCIES(${TARGET_NAME} generate_${PCH_SRC_N})
+  FOREACH(TARGET_NAME ${TARGET_NAME_LIST})
+    ADD_DEPENDENCIES(${TARGET_NAME} generate_${PCH_SRC_N})
+  ENDFOREACH()
+
 ENDFUNCTION(GENERATE_CXX_PCH_COMMAND)
 
-FUNCTION(ADD_CXX_PCH_GCC TARGET_NAME PCH_HEADER PCH_SOURCE)
+FUNCTION(ADD_CXX_PCH_GCC TARGET_NAME_LIST PCH_HEADER PCH_SOURCE)
   GET_COMMON_PCH_PARAMS(${PCH_HEADER} "gch" "-I")
-  GENERATE_CXX_PCH_COMMAND(${TARGET_NAME} "${INCLUDE_FLAGS}" ${PCH_HEADER} ${PCH_SOURCE} ${PCH_HEADER_OUT})
-  SET_TARGET_PROPERTIES(
-    ${TARGET_NAME} PROPERTIES
-    COMPILE_FLAGS "-include ${CMAKE_CURRENT_BINARY_DIR}/${PCH_HEADER_NAME}"
-  )
+  GENERATE_CXX_PCH_COMMAND("${TARGET_NAME_LIST}" "${INCLUDE_FLAGS}" ${PCH_HEADER} ${PCH_SOURCE} ${PCH_HEADER_OUT})
+
+  FOREACH(TARGET_NAME ${TARGET_NAME_LIST})
+    SET_TARGET_PROPERTIES(
+      ${TARGET_NAME} PROPERTIES
+      COMPILE_FLAGS "-include ${CMAKE_CURRENT_BINARY_DIR}/${PCH_HEADER_NAME}"
+    )
+  ENDFOREACH()
 ENDFUNCTION(ADD_CXX_PCH_GCC)
 
-FUNCTION(ADD_CXX_PCH_CLANG TARGET_NAME PCH_HEADER PCH_SOURCE)
+FUNCTION(ADD_CXX_PCH_CLANG TARGET_NAME_LIST PCH_HEADER PCH_SOURCE)
   GET_COMMON_PCH_PARAMS(${PCH_HEADER} "pch" "-I")
-  GENERATE_CXX_PCH_COMMAND(${TARGET_NAME} "${INCLUDE_FLAGS}" ${PCH_HEADER} ${PCH_SOURCE} ${PCH_HEADER_OUT})
-  SET_TARGET_PROPERTIES(
-    ${TARGET_NAME} PROPERTIES
-    COMPILE_FLAGS "-include-pch ${PCH_HEADER_OUT}"
-  )
+  GENERATE_CXX_PCH_COMMAND("${TARGET_NAME_LIST}" "${INCLUDE_FLAGS}" ${PCH_HEADER} ${PCH_SOURCE} ${PCH_HEADER_OUT})
+
+  FOREACH(TARGET_NAME ${TARGET_NAME_LIST})
+    SET_TARGET_PROPERTIES(
+      ${TARGET_NAME} PROPERTIES
+      COMPILE_FLAGS "-include-pch ${PCH_HEADER_OUT}"
+    )
+  ENDFOREACH()
 ENDFUNCTION(ADD_CXX_PCH_CLANG)
 
-FUNCTION(ADD_CXX_PCH_MSVC TARGET_NAME PCH_HEADER PCH_SOURCE)
+FUNCTION(ADD_CXX_PCH_MSVC TARGET_NAME_LIST PCH_HEADER PCH_SOURCE)
   GET_COMMON_PCH_PARAMS(${PCH_HEADER} "pch" "/I")
-  SET_TARGET_PROPERTIES(
-    ${TARGET_NAME} PROPERTIES
-    COMPILE_FLAGS "/FI${PCH_HEADER_NAME} /Yu${PCH_HEADER_NAME}"
-  )
+
+  FOREACH(TARGET_NAME ${TARGET_NAME_LIST})
+    SET_TARGET_PROPERTIES(
+      ${TARGET_NAME} PROPERTIES
+      COMPILE_FLAGS "/FI${PCH_HEADER_NAME} /Yu${PCH_HEADER_NAME}"
+    )
+  ENDFOREACH()
+
   SET_SOURCE_FILES_PROPERTIES(
     ${PCH_SOURCE} PROPERTIES
     COMPILE_FLAGS "/Yc${PCH_HEADER_NAME}"
   )
 ENDFUNCTION(ADD_CXX_PCH_MSVC)
 
-FUNCTION(ADD_CXX_PCH TARGET_NAME PCH_HEADER PCH_SOURCE)
-  IF (MSVC)
-    ADD_CXX_PCH_MSVC(${TARGET_NAME} ${PCH_HEADER} ${PCH_SOURCE})
-  ELSEIF ("${CMAKE_GENERATOR}" MATCHES "Xcode")
-    SET_TARGET_PROPERTIES(${TARGET_NAME} PROPERTIES
+FUNCTION(ADD_CXX_PCH_XCODE TARGET_NAME_LIST PCH_HEADER PCH_SOURCE)
+  FOREACH(TARGET_NAME ${TARGET_NAME_LIST})
+    SET_TARGET_PROPERTIES("${TARGET_NAME}" PROPERTIES
       XCODE_ATTRIBUTE_GCC_PRECOMPILE_PREFIX_HEADER YES
       XCODE_ATTRIBUTE_GCC_PREFIX_HEADER "${CMAKE_CURRENT_SOURCE_DIR}/${PCH_HEADER}"
     )
+  ENDFOREACH()
+ENDFUNCTION(ADD_CXX_PCH_XCODE)
+
+FUNCTION(ADD_CXX_PCH TARGET_NAME_LIST PCH_HEADER PCH_SOURCE)
+  IF (MSVC)
+    ADD_CXX_PCH_MSVC("${TARGET_NAME_LIST}" ${PCH_HEADER} ${PCH_SOURCE})
+  ELSEIF ("${CMAKE_GENERATOR}" MATCHES "Xcode")
+    ADD_CXX_PCH_XCODE("${TARGET_NAME_LIST}" ${PCH_HEADER} ${PCH_SOURCE})
   ELSEIF ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
-    ADD_CXX_PCH_CLANG(${TARGET_NAME} ${PCH_HEADER} ${PCH_SOURCE})
+    ADD_CXX_PCH_CLANG("${TARGET_NAME_LIST}" ${PCH_HEADER} ${PCH_SOURCE})
   ELSEIF ("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU")
-    ADD_CXX_PCH_GCC(${TARGET_NAME} ${PCH_HEADER} ${PCH_SOURCE})
+    ADD_CXX_PCH_GCC("${TARGET_NAME_LIST}" ${PCH_HEADER} ${PCH_SOURCE})
   ENDIF ()
 ENDFUNCTION(ADD_CXX_PCH)