Modifications to save variables in parent scope

Author: kunaltyagi

cmake/Modules/UseCompilerCache.cmake

@@ -18,7 +18,7 @@
 function(pcl_ccache_compat_file_gen FILE_NAME CCACHE_PROGRAM COMPILER)
   message(STATUS "${FILE_NAME} for ${CCACHE_PROGRAM} with ${COMPILER}")
   file(WRITE "${CMAKE_BINARY_DIR}/${FILE_NAME}" ""
-       "#!/bin/sh\n"
+       "#! /usr/bin/env sh\n"
        "\n"
        "# Xcode generator doesn't include the compiler as the\n"
        "# first argument, Ninja and Makefiles do. Handle both cases.\n"
@@ -90,9 +90,10 @@ function(UseCompilerCache)
   # Indirect wrapper is needed for CCache < 3.3 or XCode
   if(NOT (${xcode_compat} OR ${ccache_compat}))
     # Support Unix Makefiles and Ninja
-    set(CMAKE_C_COMPILER_LAUNCHER    "${CCACHE_PROGRAM}")
-    set(CMAKE_CXX_COMPILER_LAUNCHER  "${CCACHE_PROGRAM}")
-    set(CMAKE_CUDA_COMPILER_LAUNCHER "${CCACHE_PROGRAM}")
+    message(STATUS "Compiler cache via cmake launcher prefix")
+    set(CMAKE_C_COMPILER_LAUNCHER    "${CCACHE_PROGRAM}" PARENT_SCOPE)
+    set(CMAKE_CXX_COMPILER_LAUNCHER  "${CCACHE_PROGRAM}" PARENT_SCOPE)
+    set(CMAKE_CUDA_COMPILER_LAUNCHER "${CCACHE_PROGRAM}" PARENT_SCOPE)
     return()
   endif()
 
@@ -105,22 +106,29 @@ function(UseCompilerCache)
                   "${CMAKE_BINARY_DIR}/launch-cxx")
 
   # Cuda support only added in CMake 3.10
+  set(cuda_supported FALSE)
   if (NOT (CMAKE_VERSION VERSION_LESS 3.10) AND CMAKE_CUDA_COMPILER)
+    set(cuda_supported TRUE)
+  endif()
+  if(${cuda_supported})
     pcl_ccache_compat_file_gen("launch-cuda" ${CCACHE_PROGRAM} ${CMAKE_CUDA_COMPILER})
     execute_process(COMMAND chmod a+rx
                     "${CMAKE_BINARY_DIR}/launch-cuda")
   endif()
 
   if(${xcode_compat})
     # Set Xcode project attributes to route compilation and linking properly
-    set(CMAKE_XCODE_ATTRIBUTE_CC         "${CMAKE_BINARY_DIR}/launch-c")
-    set(CMAKE_XCODE_ATTRIBUTE_CXX        "${CMAKE_BINARY_DIR}/launch-cxx")
-    set(CMAKE_XCODE_ATTRIBUTE_LD         "${CMAKE_BINARY_DIR}/launch-c")
-    set(CMAKE_XCODE_ATTRIBUTE_LDPLUSPLUS "${CMAKE_BINARY_DIR}/launch-cxx")
+    message(STATUS "Compiler cache via launch files to support XCode")
+    set(CMAKE_XCODE_ATTRIBUTE_CC         "${CMAKE_BINARY_DIR}/launch-c" PARENT_SCOPE)
+    set(CMAKE_XCODE_ATTRIBUTE_CXX        "${CMAKE_BINARY_DIR}/launch-cxx" PARENT_SCOPE)
+    set(CMAKE_XCODE_ATTRIBUTE_LD         "${CMAKE_BINARY_DIR}/launch-c" PARENT_SCOPE)
+    set(CMAKE_XCODE_ATTRIBUTE_LDPLUSPLUS "${CMAKE_BINARY_DIR}/launch-cxx" PARENT_SCOPE)
   else()
-    # Support Unix Makefiles and Ninja
-    set(CMAKE_C_COMPILER_LAUNCHER    "${CMAKE_BINARY_DIR}/launch-c")
-    set(CMAKE_CXX_COMPILER_LAUNCHER  "${CMAKE_BINARY_DIR}/launch-cxx")
-    set(CMAKE_CUDA_COMPILER_LAUNCHER "${CMAKE_BINARY_DIR}/launch-cuda")
+    message(STATUS "Compiler cache via launch files to support Unix Makefiles and Ninja")
+    set(CMAKE_C_COMPILER_LAUNCHER    "${CMAKE_BINARY_DIR}/launch-c" PARENT_SCOPE)
+    set(CMAKE_CXX_COMPILER_LAUNCHER  "${CMAKE_BINARY_DIR}/launch-cxx" PARENT_SCOPE)
+    if (${cuda_supported})
+        set(CMAKE_CUDA_COMPILER_LAUNCHER "${CMAKE_BINARY_DIR}/launch-cuda" PARENT_SCOPE)
+    endif()
   endif()
 endfunction()