Add parameter in tools settings to show error/warning as Link

Per default mbed compile prints errors/warnings on output not in a link format, therefore it is not possible to click, i.e. in an IDE, on the errors/warnings and jump to the position in the file.

The settings parameter lets you decide in witch format do you want to have it.
If it is enabled then the output will look like:
[Error/Warning] [absolute\path\to\file.ext]:[line]:[column]: [msg]

with this format nearly every common known IDE can deal with this link and lets you jump to the file

tools/default_settings.py

@@ -43,3 +43,6 @@ from os.path import join, abspath, dirname
 
 # mbed.org username
 #MBED_ORG_USER = ""
+
+# Print compiler warnings and errors as link format
+#PRINT_COMPILER_OUTPUT_AS_LINK = False

tools/settings.py

@@ -54,6 +54,9 @@ BUILD_OPTIONS = []
 # mbed.org username
 MBED_ORG_USER = ""
 
+# Print compiler warnings and errors as link format
+PRINT_COMPILER_OUTPUT_AS_LINK = False
+
 CLI_COLOR_MAP = {
     "warning": "yellow",
     "error"  : "red"
@@ -74,7 +77,7 @@ except ImportError:
 # User Settings (env vars)
 ##############################################################################
 _ENV_PATHS = ['ARM_PATH', 'GCC_ARM_PATH', 'GCC_CR_PATH', 'IAR_PATH',
-              'ARMC6_PATH']
+              'ARMC6_PATH', 'PRINT_COMPILER_OUTPUT_AS_LINK']
 
 for _n in _ENV_PATHS:
     if getenv('MBED_'+_n):

tools/toolchains/__init__.py

@@ -35,7 +35,7 @@ import fnmatch
 
 from ..utils import (run_cmd, mkdir, rel_path, ToolException,
                     NotSupportedException, split_path, compile_worker)
-from ..settings import MBED_ORG_USER
+from ..settings import MBED_ORG_USER, PRINT_COMPILER_OUTPUT_AS_LINK
 from .. import hooks
 from ..memap import MemapParser
 
@@ -460,8 +460,13 @@ class mbedToolchain:
 
         elif event['type'] == 'cc':
             event['severity'] = event['severity'].title()
-            event['file'] = basename(event['file'])
-            msg = '[%(severity)s] %(file)s@%(line)s,%(col)s: %(message)s' % event
+
+            if PRINT_COMPILER_OUTPUT_AS_LINK:
+                event['file'] = getcwd() + event['file'].strip('.')
+                msg = '[%(severity)s] %(file)s:%(line)s:%(col)s: %(message)s' % event
+            else:
+                event['file'] = basename(event['file'])
+                msg = '[%(severity)s] %(file)s@%(line)s,%(col)s: %(message)s' % event
 
         elif event['type'] == 'progress':
             if 'percent' in event: