Fix config.h default data install path assignment during configuration.

* Remove redundant definition of KICAD_DATA_PATH since DEFAULT_INSTALL_PATH
  was already defined.
* Use DEFAULT_INSTALL_PATH as the substitution for the default environment
  variable paths.
* Add option to define DEFAULT_INSTALL_PATH during CMake configuration with
  fall back to CMAKE_INSTALL_PREFIX if not not defined.
* Developer note: this change is primarily for package builders where
  CMAKE_INSTALL_PATH is the path where the package builder temporarily
  installs the build output before creating the package.  When building
  packages, DEFAULT_INSTALL_PATH should be set to the path where the
  package will be installed by default.

CMakeLists.txt

@@ -94,7 +94,7 @@ set( KICAD_REPO_NAME "product" CACHE STRING "Name of the tree from which this bu
 set( DOWNLOAD_DIR ${PROJECT_SOURCE_DIR}/.downloads-by-cmake
     CACHE PATH "Location of KiCad downloads, suggested is a dir common to all builds, i.e. global." )
 
-#Add option to add user directories for linker, if any
+# Add option to add user directories for linker, if any
 LINK_DIRECTORIES( ${LINK_DIRECTORIES_PATH} )
 
 if( UNIX )
@@ -104,6 +104,16 @@ elseif( MINGW )
 endif()
 mark_as_advanced( KICAD_USER_CONFIG_DIR )
 
+# Set default data file path to CMAKE_INSTALL_PREFIX if it wasn't specified during the
+# CMake configuration.  The value of DEFAULT_INSTALL_PATH is expanded in config.h and
+# used in the source code to define the base path for kicad search paths and environment
+# variables.
+if( NOT DEFAULT_INSTALL_PATH )
+    set( DEFAULT_INSTALL_PATH "${CMAKE_INSTALL_PREFIX}"
+         CACHE
+         PATH
+         "Location of KiCad data files." )
+endif()
 
 #================================================
 # Set flags for GCC, or treat llvm as GCC

CMakeModules/config.h.cmake

@@ -58,17 +58,8 @@
 /// The legacy file format revision of the *.brd file created by this build
 #define LEGACY_BOARD_FILE_VERSION       2
 
-/// The install prefix defined in CMAKE_INSTALL_PREFIX.
-#define DEFAULT_INSTALL_PATH            "@CMAKE_INSTALL_PREFIX@"
-
-/// The install prefix used for KiCad's libraries.
-/// These paths are only intended to be reasonable default values that work if
-/// the user installs KiCad in the default path for a given platform.
-#if defined( __APPLE__ )
-#define KICAD_DATA_PATH                 "/Library/Application Support/kicad"
-#else
-#define KICAD_DATA_PATH                 "@CMAKE_INSTALL_PREFIX@/@KICAD_DATA@"
-#endif
+/// The install prefix defined during CMake configuration or fall back to CMAKE_INSTALL_PREFIX.
+#define DEFAULT_INSTALL_PATH            "@DEFAULT_INSTALL_PATH@"
 
 /// The wxPython version found during configuration.
 #if defined( KICAD_SCRIPTING_WXPYTHON )

common/pgm_base.cpp

@@ -423,7 +423,7 @@ bool PGM_BASE::initPgm()
         m_local_env_vars[ envVarName ] = envVarItem;
 
         wxFileName tmpFileName;
-        tmpFileName.AssignDir( wxString( wxT( KICAD_DATA_PATH ) ) );
+        tmpFileName.AssignDir( wxString( wxT( DEFAULT_INSTALL_PATH ) ) );
         tmpFileName.AppendDir( wxT( "modules" ) );
         envVarName = wxT( "KISYSMOD" );
         envVarItem.SetValue( tmpFileName.GetPath() );