[llvm] [BOLT] Create marker for source changes in nfc-mode testing. (PR #142931)

[Paschalis Mpeis via llvm-commits]

================
@@ -7,6 +7,29 @@
 import sys
 import textwrap
 
+def get_relevant_bolt_changes(dir: str) -> str:
+    # Return a list of bolt source changes that are relevant to testing.
+    all_changes = subprocess.run(
+        shlex.split("git show HEAD --name-only --pretty=''"),
+        cwd=dir,
+        text=True,
+        stdout=subprocess.PIPE,
+    )
+    keep_bolt = subprocess.run(
+        shlex.split("grep '^bolt'"),
+        input=all_changes.stdout,
+        text=True,
+        stdout=subprocess.PIPE,
+    )
+    keep_relevant = subprocess.run(
+        shlex.split(
+            "grep -v -e '^bolt/docs' -e '^bolt/utils/docker' -e '^bolt/utils/dot2html'"
----------------
paschalis-mpeis wrote:

My thinking was to include the helper python scripts, like `nfc-check-setup` itself, as a trigger for re-running the in-tree tests. That way, any breakage in the nfc-setup has a better chance being caught earlier in the buildbot.

We probably won't see frequent changes in the utils folder. Alternative options would be to include it as a whole, or ignore it entirely.

I lean towards the patch, though I'm not too happy with my grep's above.
No strong opinion either way. WDYT?

https://github.com/llvm/llvm-project/pull/142931