[CMake] Simplify ROOTTEST_COMPILE_MACRO to shorten test command

  * Remove preprocessor variables that were always defined and hence
    carried no information

  * Add include path and library path via environment variables

  * Remove redundant `gROOT->SetMacroPath()` call with path to source
    directory, because the `${realfp}` variable passed to the `build.C`
    script already contains the full path

Author: guitargeek

cmake/modules/RootMacros.cmake

@@ -2314,17 +2314,14 @@ macro(ROOTTEST_COMPILE_MACRO filename)
     list(APPEND RootMacroDirDefines "-e;#define ${d}")
   endforeach()
 
-  set(RootMacroBuildDefines
-        -e "#define CMakeEnvironment"
-        -e "#define CMakeBuildDir \"${CMAKE_CURRENT_BINARY_DIR}\""
-        -e "gSystem->AddDynamicPath(\"${CMAKE_CURRENT_BINARY_DIR}\")"
-        -e "gROOT->SetMacroPath(\"${CMAKE_CURRENT_SOURCE_DIR}\")"
-        -e "gInterpreter->AddIncludePath(\"-I${CMAKE_CURRENT_BINARY_DIR}\")"
-        -e "gSystem->AddIncludePath(\"-I${CMAKE_CURRENT_BINARY_DIR}\")"
-        -e "gSystem->SetBuildDir(\"${CMAKE_CURRENT_BINARY_DIR}\", true)"
-        ${RootMacroDirDefines})
-
-  set(root_compile_macro ${ROOT_root_CMD} ${RootMacroBuildDefines} -q -l -b)
+  set(root_compile_macro ${CMAKE_COMMAND} -E env
+      ROOT_LIBRARY_PATH="${CMAKE_CURRENT_BINARY_DIR}"
+      ROOT_INCLUDE_PATH="${CMAKE_CURRENT_BINARY_DIR}"
+      ${ROOT_root_CMD}
+      -e "gSystem->SetBuildDir(\"${CMAKE_CURRENT_BINARY_DIR}\", true)"
+      ${RootMacroDirDefines}
+      -q -l -b
+  )
 
   get_filename_component(realfp ${filename} ABSOLUTE)
   if(MSVC)

roottest/scripts/build.C

@@ -75,9 +75,6 @@ void build(const char *filename, const char *lib = 0, const char *obj = 0, const
    }
    // fprintf(stderr,"from %s to %s\n",filename,fname.Data());
    int result = gSystem->CompileMacro(fname,"kc");
-#elif defined(CMakeEnvironment) && defined(CMakeBuildDir)
-   // fprintf(stderr,"CmakeBuildDir: %s filename: %s", CMakeBuildDir, filename);
-   int result = gSystem->CompileMacro(filename,"kc-", libname, CMakeBuildDir);
 #else
    int result = gSystem->CompileMacro(filename,"kc", libname);
 #endif