cmake: strip paths in build output based on Kconfig option

Add CONFIG_BUILD_OUTPUT_STRIP_PATHS to allow keeping absolute paths
in the build output.

This can be helpful for IDEs to detect links in a console output and
jump to the code location (e.g. when running tests in native_posix
locally).

Debuggers usually have a path mapping feature to ensure the files are
still found.

Signed-off-by: Martin Jäger <martin@libre.solar>

CMakeLists.txt

@@ -442,14 +442,15 @@ zephyr_cc_option_ifdef(CONFIG_STACK_USAGE            -fstack-usage)
 # application code. This saves some memory, stops leaking user locations
 # in binaries, makes failure logs more deterministic and most
 # importantly makes builds more deterministic
-
-# If several match then the last one wins. This matters for instances
-# like tests/ and samples/: they're inside all of them! Then let's
-# strip as little as possible.
-zephyr_cc_option(-fmacro-prefix-map=${CMAKE_SOURCE_DIR}=CMAKE_SOURCE_DIR)
-zephyr_cc_option(-fmacro-prefix-map=${ZEPHYR_BASE}=ZEPHYR_BASE)
-if(WEST_TOPDIR)
-  zephyr_cc_option(-fmacro-prefix-map=${WEST_TOPDIR}=WEST_TOPDIR)
+if(CONFIG_BUILD_OUTPUT_STRIP_PATHS)
+  # If several match then the last one wins. This matters for instances
+  # like tests/ and samples/: they're inside all of them! Then let's
+  # strip as little as possible.
+  zephyr_cc_option(-fmacro-prefix-map=${CMAKE_SOURCE_DIR}=CMAKE_SOURCE_DIR)
+  zephyr_cc_option(-fmacro-prefix-map=${ZEPHYR_BASE}=ZEPHYR_BASE)
+  if(WEST_TOPDIR)
+    zephyr_cc_option(-fmacro-prefix-map=${WEST_TOPDIR}=WEST_TOPDIR)
+  endif()
 endif()
 
 # TODO: Archiver arguments

Kconfig.zephyr

@@ -684,6 +684,20 @@ config BUILD_OUTPUT_META_STATE_PROPAGATE
 	           defined when `west update` was run the last time (`manifest-rev`).
 	           The off state is only present if a west workspace is found.
 
+config BUILD_OUTPUT_STRIP_PATHS
+	bool "Strip absolute paths from binaries"
+	default y
+	help
+	  If the compiler supports it, strip the ${ZEPHYR_BASE} prefix from the
+	  __FILE__ macro used in __ASSERT*, in the
+	  .noinit."/home/joe/zephyr/fu/bar.c" section names and in any
+	  application code.
+	  This saves some memory, stops leaking user locations in binaries, makes
+	  failure logs more deterministic and most importantly makes builds more
+	  deterministic.
+	  Debuggers usually have a path mapping feature to ensure the files are
+	  still found.
+
 endmenu
 
 config DEPRECATED