fix __FILE__ base name extraction, #628 (#648)

CMakeLists.txt

@@ -46,11 +46,6 @@ if (${CMAKE_BUILD_TYPE} MATCHES "Debug")
 	include(CTest)
 endif()
 
-# fixup __FILE__ absolute paths in logging module
-# see: https://cmake.org/pipermail/cmake-developers/2015-January/024202.html
-string(LENGTH "${CMAKE_SOURCE_DIR}/" CMAKE_SOURCE_DIR_LENGTH)
-add_definitions(-DCMAKE_SOURCE_DIR_LENGTH=${CMAKE_SOURCE_DIR_LENGTH})
-
 set(STLINK_HEADERS
 	include/stlink.h
 	include/stlink/usb.h

include/stlink/logging.h

@@ -20,10 +20,8 @@ enum ugly_loglevel {
 int ugly_init(int maximum_threshold);
 int ugly_log(int level, const char *tag, const char *format, ...);
 
-#ifndef CMAKE_SOURCE_DIR_LENGTH
-#define CMAKE_SOURCE_DIR_LENGTH 0
-#endif
-#define UGLY_LOG_FILE (__FILE__+CMAKE_SOURCE_DIR_LENGTH)
+#define UGLY_LOG_FILE (strstr(__FILE__, "/") != NULL ? \
+    strrchr(__FILE__, '/') + 1 : strrchr(__FILE__, '\\') + 1)
 
 /** @todo we need to write this in a more generic way, for now this should compile
  on visual studio (See http://stackoverflow.com/a/8673872/1836746) */