buildman: Add a flag to force mrproper on failure

When a file is removed by a commit (e.g. include/common.h yay!) it can
cause incremental build failures since one of the dependency files from
a previous build may mention the file.

Add an option to run 'make mrproper' automatically when a build fails.
This can be used to automatically resolve the problem, without always
adding the large overhead of 'make mrproper' to every build.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/buildman/builder.py

@@ -256,14 +256,14 @@ class Builder:
     def __init__(self, toolchains, base_dir, git_dir, num_threads, num_jobs,
                  gnu_make='make', checkout=True, show_unknown=True, step=1,
                  no_subdirs=False, full_path=False, verbose_build=False,
-                 mrproper=False, per_board_out_dir=False,
-                 config_only=False, squash_config_y=False,
-                 warnings_as_errors=False, work_in_output=False,
-                 test_thread_exceptions=False, adjust_cfg=None,
-                 allow_missing=False, no_lto=False, reproducible_builds=False,
-                 force_build=False, force_build_failures=False,
-                 force_reconfig=False, in_tree=False,
-                 force_config_on_failure=False, make_func=None):
+                 mrproper=False, fallback_mrproper=False,
+                 per_board_out_dir=False, config_only=False,
+                 squash_config_y=False, warnings_as_errors=False,
+                 work_in_output=False, test_thread_exceptions=False,
+                 adjust_cfg=None, allow_missing=False, no_lto=False,
+                 reproducible_builds=False, force_build=False,
+                 force_build_failures=False, force_reconfig=False,
+                 in_tree=False, force_config_on_failure=False, make_func=None):
         """Create a new Builder object
 
         Args:
@@ -283,6 +283,7 @@ class Builder:
                 PATH
             verbose_build: Run build with V=1 and don't use 'make -s'
             mrproper: Always run 'make mrproper' when configuring
+            fallback_mrproper: Run 'make mrproper' and retry on build failure
             per_board_out_dir: Build in a separate persistent directory per
                 board rather than a thread-specific directory
             config_only: Only configure each build, don't build it
@@ -352,6 +353,7 @@ class Builder:
         self.force_reconfig = force_reconfig
         self.in_tree = in_tree
         self.force_config_on_failure = force_config_on_failure
+        self.fallback_mrproper = fallback_mrproper
 
         if not self.squash_config_y:
             self.config_filenames += EXTRA_CONFIG_FILENAMES

tools/buildman/builderthread.py

@@ -705,8 +705,10 @@ class BuilderThread(threading.Thread):
                     # with a reconfig.
                     if self.builder.force_config_on_failure:
                         result, request_config = self.run_commit(commit_upto,
-                            brd, work_dir, True, self.mrproper, False, True,
-                            False, job.work_in_output, job.adjust_cfg)
+                            brd, work_dir, True,
+                            self.mrproper or self.builder.fallback_mrproper,
+                            False, True, False, job.work_in_output,
+                            job.adjust_cfg)
                         did_config = True
                 if not self.builder.force_reconfig:
                     do_config = request_config

tools/buildman/buildman.rst

@@ -995,7 +995,8 @@ By default, buildman doesn't execute 'make mrproper' prior to building the
 first commit for each board. This reduces the amount of work 'make' does, and
 hence speeds up the build. To force use of 'make mrproper', use -the -m flag.
 This flag will slow down any buildman invocation, since it increases the amount
-of work done on any build.
+of work done on any build. An alternative is to use the --fallback-mrproper
+flag, which retries the build with 'make mrproper' only after a build failure.
 
 One possible application of buildman is as part of a continual edit, build,
 edit, build, ... cycle; repeatedly applying buildman to the same change or

tools/buildman/cmdline.py

@@ -90,7 +90,9 @@ def add_upto_m(parser):
     parser.add_argument('--list-tool-chains', action='store_true', default=False,
           help='List available tool chains (use -v to see probing detail)')
     parser.add_argument('-m', '--mrproper', action='store_true',
-          default=False, help="Run 'make mrproper before reconfiguring")
+          default=False, help="Run 'make mrproper' before reconfiguring")
+    parser.add_argument('--fallback-mrproper', action='store_true',
+          default=False, help="Run 'make mrproper' and retry on build failure")
     parser.add_argument(
           '-M', '--allow-missing', action='store_true', default=False,
           help='Tell binman to allow missing blobs and generate fake ones as needed')

tools/buildman/control.py

@@ -656,6 +656,7 @@ def do_buildman(args, toolchains=None, make_func=None, brds=None,
             no_subdirs=args.no_subdirs, full_path=args.full_path,
             verbose_build=args.verbose_build,
             mrproper=args.mrproper,
+            fallback_mrproper=args.fallback_mrproper,
             per_board_out_dir=args.per_board_out_dir,
             config_only=args.config_only,
             squash_config_y=not args.preserve_config_y,