1 files changed, 53 insertions, 0 deletions
diff --git a/meson/clang-tidy/clean_compdb.py b/meson/clang-tidy/clean_compdb.py
new file mode 100755
index 000000000..6736fe63a
--- /dev/null
+++ b/meson/clang-tidy/clean_compdb.py
@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+# Deletes the PCH arguments from a compilation database, to workaround nixpkgs
+# stdenv having a cc-wrapper that is impossible to use for anything except cc
+# itself, for example, clang-tidy.
+
+import json
+import shlex
+
+
+def process_compdb(compdb: list[dict]) -> list[dict]:
+
+    def munch_command(args: list[str]) -> list[str]:
+        out = []
+        eat_next = False
+        for i, arg in enumerate(args):
+            if arg == '-fpch-preprocess':
+                # as used with gcc
+                continue
+            elif arg == '-include-pch' or (arg == '-include' and args[i + 1] == 'precompiled-headers.hh'):
+                # -include-pch some-pch (clang), or -include some-pch (gcc)
+                eat_next = True
+                continue
+            if not eat_next:
+                out.append(arg)
+            eat_next = False
+        return out
+
+    def chomp(item: dict) -> dict:
+        item = item.copy()
+        item['command'] = shlex.join(munch_command(shlex.split(item['command'])))
+        return item
+
+    return [chomp(x) for x in compdb if not x['file'].endswith('precompiled-headers.hh')]
+
+
+def main():
+    import argparse
+    ap = argparse.ArgumentParser(
+        description='Delete pch arguments from compilation database')
+    ap.add_argument('input',
+                    type=argparse.FileType('r'),
+                    help='Input json file')
+    ap.add_argument('output',
+                    type=argparse.FileType('w'),
+                    help='Output json file')
+    args = ap.parse_args()
+
+    input_json = json.load(args.input)
+    json.dump(process_compdb(input_json), args.output, indent=2)
+
+
+if __name__ == '__main__':
+    main()