Skip cpplint if source is not changed.

Change-Id: Ia29cd3d205e401dc3d04fbaf3cba2b01f2f4f0ca

cmake/cpplint.cmake

@@ -34,7 +34,7 @@ set(IGNORE_PATTERN
 #
 # first argument: target name to attach
 # rest arguments: source list to check code style.
-# 
+#
 # NOTE: If WITH_STYLE_CHECK is OFF, then this macro just do nothing.
 macro(add_style_check_target TARGET_NAME)
     if(WITH_STYLE_CHECK)
@@ -48,13 +48,17 @@ macro(add_style_check_target TARGET_NAME)
                 if(filename MATCHES ${pattern})
                     message(STATUS "DROP LINT ${filename}")
                     set(LINT OFF)
-                endif() 
+                endif()
             endforeach()
             if(LINT MATCHES ON)
-                add_custom_command(TARGET ${TARGET_NAME}
+                get_filename_component(base_filename ${filename} NAME)
+                set(CUR_GEN ${CMAKE_CURRENT_BINARY_DIR}/${base_filename}.cpplint)
+                add_custom_command(OUTPUT ${CUR_GEN}
                     PRE_BUILD
                     COMMAND env ${py_env} "${PYTHON_EXECUTABLE}" "${PROJ_ROOT}/paddle/scripts/cpplint.py"
-                                "--filter=${STYLE_FILTER}" ${filename}
+                                "--filter=${STYLE_FILTER}"
+                                "--write-success=${CUR_GEN}" ${filename}
+                    DEPENDS ${filename}
                     WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR})
             endif()
         endforeach()

paddle/scripts/cpplint.py

@@ -58,6 +58,7 @@ _USAGE = """
 Syntax: cpplint.py [--verbose=#] [--output=vs7] [--filter=-x,+y,...]
                    [--counting=total|toplevel|detailed] [--root=subdir]
                    [--linelength=digits]
+                   [--write-success=success_status_file]
         <file> [file] ...
 
   The style guidelines this tries to follow are those in
@@ -499,6 +500,8 @@ _line_length = 80
 # This is set by --extensions flag.
 _valid_extensions = set(['cc', 'h', 'cpp', 'cu', 'cuh'])
 
+_write_success = None
+
 
 def ParseNolintSuppressions(filename, raw_line, linenum, error):
     """Updates the global list of error-suppressions.
@@ -6337,7 +6340,7 @@ def ParseArguments(args):
     try:
         (opts, filenames) = getopt.getopt(args, '', [
             'help', 'output=', 'verbose=', 'counting=', 'filter=', 'root=',
-            'linelength=', 'extensions='
+            'linelength=', 'extensions=', 'write-success='
         ])
     except getopt.GetoptError:
         PrintUsage('Invalid arguments.')
@@ -6382,6 +6385,9 @@ def ParseArguments(args):
                 _valid_extensions = set(val.split(','))
             except ValueError:
                 PrintUsage('Extensions must be comma seperated list.')
+        elif opt == '--write-success':
+            global _write_success
+            _write_success = val
 
     if not filenames:
         PrintUsage('No files were specified.')
@@ -6408,6 +6414,10 @@ def main():
         ProcessFile(filename, _cpplint_state.verbose_level)
     _cpplint_state.PrintErrorCounts()
 
+    if _cpplint_state.error_count == 0 and _write_success is not None:
+        with open(_write_success, 'a'):
+            os.utime(_write_success, None)
+
     sys.exit(_cpplint_state.error_count > 0)