Add option to filter gcov source errors

Add "--gcov-filter-source-errors" to apply filters to the source
files in the errors from gcov.  If all source files in the errors
are filtered, then the error is ignored so that the file will be
processed.  This enables the usecase of running on a target where
only the source tree for a binary is available, but not all of the
external source headers are.

Upstream-Status: pending

Signed-off-by: Scott Murray <scott.murray@konsulko.com>

diff --git a/gcovr/configuration.py b/gcovr/configuration.py
index 1356097..083532c 100644
--- a/gcovr/configuration.py
+++ b/gcovr/configuration.py
@@ -915,6 +915,14 @@ GCOVR_CONFIG_OPTIONS = [
              "Default: {default!s}.",
         action="store_true",
     ),
+    GcovrConfigOption(
+        "gcov_filter_source_errors", ['--gcov-filter-source-errors'],
+        group="gcov_options",
+        help="Apply filters to missing source file errors in GCOV files "
+             "instead of exiting with an error. "
+             "Default: {default!s}.",
+        action="store_true",
+    ),
     GcovrConfigOption(
         "objdir", ['--object-directory'],
         group="gcov_options",
diff --git a/gcovr/gcov.py b/gcovr/gcov.py
index de79215..171d68d 100644
--- a/gcovr/gcov.py
+++ b/gcovr/gcov.py
@@ -667,11 +667,27 @@ def run_gcov_and_process_files(
             chdir=chdir,
             tempdir=tempdir)
 
+    skip = False
     if source_re.search(err):
-        # gcov tossed errors: try the next potential_wd
-        error(err)
-        done = False
-    else:
+        ignore = False
+        if options.gcov_filter_source_errors:
+            # Check if errors are all from source that is filtered
+            ignore = True
+            for line in err.splitlines():
+                src_fname = line.split()[-1]
+                filtered, excluded = apply_filter_include_exclude(
+                    src_fname, options.filter, options.exclude)
+                if not (filtered or excluded):
+                    ignore = False
+                    break
+
+        if not ignore:
+            # gcov tossed errors: try the next potential_wd
+            error(err)
+            skip = True
+
+    done = False
+    if not skip:
         # Process *.gcov files
         for fname in active_gcov_files:
             process_gcov_data(fname, covdata, abs_filename, options)