rules-cc: Add support for include scanning

... which is configured using a new defaults field
"include_scanner", a tool (script/binary) that generates
a new include tree without unused headers. Example
implementations are provided.

1 files changed, 64 insertions, 0 deletions

diff --git a/CC/include_scan.py b/CC/include_scan.py
new file mode 100755
index 0000000..1efa528
--- /dev/null
+++ b/CC/include_scan.py
@@ -0,0 +1,64 @@
+#!/usr/bin/env python3
+# Copyright 2024 Huawei Cloud Computing Technology Co., Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+#
+# Include scanner
+#   Parse file paths from command's space-separated stdout, select those that
+#   start with "include/", and copy them to the user-defined output directory.
+#
+# Usage:
+#   include_scan OUT_DIR ARGV...
+#
+# Example:
+#   ./include_scan.py out gcc -isystem include foo.c -E -M
+#   -> Generates output directory "out/include" from gcc's output
+
+import subprocess
+import sys
+import os
+import shutil
+
+
+def include_scan(out_dir: str, cmd: list[str]):
+    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+    if not proc.stdout:
+        proc.poll()
+        exit(proc.returncode)
+
+    includes: set[str] = set()
+    for line in proc.stdout:
+        items = line.decode('utf-8').replace('\n', ' ')
+        paths = {os.path.normpath(i) for i in items.split(' ')}
+        includes |= {p for p in paths if p.startswith('include/')}
+
+    for path in includes:
+        out_path = os.path.join(out_dir, path)
+        try:
+            shutil.copyfile(path, out_path, follow_symlinks=False)
+        except:
+            try:
+                os.makedirs(os.path.dirname(out_path), exist_ok=True)
+                shutil.copyfile(path, out_path, follow_symlinks=False)
+            except Exception as e:
+                print(e, file=sys.stderr)
+                exit(1)
+
+    proc.poll()
+    if proc.returncode != 0:
+        exit(proc.returncode)
+
+
+if __name__ == '__main__':
+    include_scan(out_dir=sys.argv[1], cmd=sys.argv[2:])