Minimal change to convert_project to turn off #include updating by

default now that we've merged Microsoft's change for implicit checked
header inclusion (checkedc#998).

I filed #520
for follow-ups.

Author: mattmccutchen-cci

clang/tools/3c/utils/port_tools/convert_project.py

@@ -47,11 +47,18 @@ def parseTheArg():
 
     parser = argparse.ArgumentParser(description='Convert the provided project into Checked C.')
 
+    parser.add_argument('--updateIncludes',
+                        dest='update_includes', action='store_true',
+                        default=False,
+                        help=('Update `#include <foo.h>` to `#include <foo_checked.h>` in '
+                              'source files before running 3c. Should normally no longer '
+                              'be needed with implicit checked header inclusion.'))
     parser.add_argument('--includeDir',
                         default=checkedcHeaderDir if os.path.exists(checkedcHeaderDir) else pathBasedDir,
                         required=False,
                         dest='includeDir',
-                        help='Path to the checkedC headers, run from a checkedCclang repo')
+                        help=('Path to the checkedC headers, run from a checkedCclang repo '
+                              '(used only if --updateIncludes is on)'))
     parser.add_argument("-p", "--prog_name", dest='prog_name', type=str, default=_3c_bin,
                         help='Program name to run. i.e., path to 3c')
 
@@ -100,7 +107,7 @@ def parseTheArg():
         logging.error("Provided argument: {} is not a file.".format(args.prog_name))
         sys.exit()
 
-    if not args.includeDir or not os.path.isdir(args.includeDir):
+    if args.update_includes and (not args.includeDir or not os.path.isdir(args.includeDir)):
         logging.error("Error: --includeDir argument must be the name of a directory.")
         logging.error("Provided argument: {} is not a directory.".format(args.includeDir))
         sys.exit()
@@ -129,10 +136,11 @@ def parseTheArg():
         logging.error("Error: Build directory does not contain compile_commands.json.")
         logging.error("compile_commands.json file: {} does not exist.".format(compileCmdsJson))
         sys.exit()
-    # replace include files
-    logging.info("Updating include lines of all the source files.")
-    updateProjectIncludes(progArgs.project_path, progArgs.includeDir)
-    logging.info("Finished updating project files.")
+    if progArgs.update_includes:
+        # replace include files
+        logging.info("Updating include lines of all the source files.")
+        updateProjectIncludes(progArgs.project_path, progArgs.includeDir)
+        logging.info("Finished updating project files.")
 
     logging.info("Trying to convert all the source files to header files")
     run3C(progArgs.prog_name, progArgs.extra_3c_args,