llvm_tools: migrate nightly_revert_checker to get_llvm_hash

Yay for replacing old custom logic

BUG=b:333462347
TEST=Unittests

Change-Id: I5459942eaaa08f0b0d694dff707bf34ee8ffe8b4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/5454856
Commit-Queue: George Burgess <gbiv@chromium.org>
Tested-by: George Burgess <gbiv@chromium.org>
Reviewed-by: Bob Haarman <inglorion@chromium.org>

2 files changed, 10 insertions, 87 deletions

diff --git a/llvm_tools/nightly_revert_checker.py b/llvm_tools/nightly_revert_checker.py
index 88aac9b7..6090e614 100755
--- a/llvm_tools/nightly_revert_checker.py
+++ b/llvm_tools/nightly_revert_checker.py
@@ -11,10 +11,10 @@ fires off an email. All LLVM SHAs to monitor are autodetected.
 
 import argparse
 import dataclasses
-import io
 import json
 import logging
 import os
+from pathlib import Path
 import pprint
 import subprocess
 import sys
@@ -131,57 +131,18 @@ def _find_interesting_android_shas(
     return result
 
 
-def _parse_llvm_ebuild_for_shas(
-    ebuild_file: io.TextIOWrapper,
-) -> List[Tuple[str, str]]:
-    def parse_ebuild_assignment(line: str) -> str:
-        no_comments = line.split("#")[0]
-        no_assign = no_comments.split("=", 1)[1].strip()
-        assert no_assign.startswith('"') and no_assign.endswith('"'), no_assign
-        return no_assign[1:-1]
-
-    llvm_hash, llvm_next_hash = None, None
-    for line in ebuild_file:
-        if line.startswith("LLVM_HASH="):
-            llvm_hash = parse_ebuild_assignment(line)
-            if llvm_next_hash:
-                break
-        if line.startswith("LLVM_NEXT_HASH"):
-            llvm_next_hash = parse_ebuild_assignment(line)
-            if llvm_hash:
-                break
-    if not llvm_next_hash or not llvm_hash:
-        raise ValueError(
-            "Failed to detect SHAs for llvm/llvm_next. Got: "
-            "llvm=%s; llvm_next=%s" % (llvm_hash, llvm_next_hash)
-        )
-
-    results: List[Tuple[str, str]] = [("llvm", llvm_hash)]
-    if llvm_next_hash != llvm_hash:
-        results.append(("llvm-next", llvm_next_hash))
-    return results
-
-
 def _find_interesting_chromeos_shas(
     chromeos_base: str,
 ) -> List[Tuple[str, str]]:
-    llvm_dir = os.path.join(
-        chromeos_base, "src/third_party/chromiumos-overlay/sys-devel/llvm"
-    )
-    candidate_ebuilds = [
-        os.path.join(llvm_dir, x)
-        for x in os.listdir(llvm_dir)
-        if "_pre" in x and not os.path.islink(os.path.join(llvm_dir, x))
-    ]
-
-    if len(candidate_ebuilds) != 1:
-        raise ValueError(
-            "Expected exactly one llvm ebuild candidate; got %s"
-            % pprint.pformat(candidate_ebuilds)
-        )
-
-    with open(candidate_ebuilds[0], encoding="utf-8") as f:
-        return _parse_llvm_ebuild_for_shas(f)
+    chromeos_path = Path(chromeos_base)
+    llvm_hash = get_llvm_hash.LLVMHash()
+
+    current_llvm = llvm_hash.GetCrOSCurrentLLVMHash(chromeos_path)
+    results = [("llvm", current_llvm)]
+    next_llvm = llvm_hash.GetCrOSLLVMNextHash()
+    if current_llvm != next_llvm:
+        results.append(("llvm-next", next_llvm))
+    return results
 
 
 _Email = NamedTuple(
diff --git a/llvm_tools/nightly_revert_checker_test.py b/llvm_tools/nightly_revert_checker_test.py
index 722ad125..dbcd01dd 100755
--- a/llvm_tools/nightly_revert_checker_test.py
+++ b/llvm_tools/nightly_revert_checker_test.py
@@ -5,7 +5,6 @@
 
 """Tests for nightly_revert_checker."""
 
-import io
 import unittest
 from unittest import mock
 
@@ -138,43 +137,6 @@ class Test(unittest.TestCase):
 
         self.assertEqual(email, expected_email)
 
-    def test_llvm_ebuild_parsing_appears_to_function(self):
-        llvm_ebuild = io.StringIO(
-            "\n".join(
-                (
-                    "foo",
-                    '#LLVM_HASH="123"',
-                    'LLVM_HASH="123" # comment',
-                    'LLVM_NEXT_HASH="456"',
-                )
-            )
-        )
-
-        shas = nightly_revert_checker._parse_llvm_ebuild_for_shas(llvm_ebuild)
-        self.assertEqual(
-            shas,
-            [
-                ("llvm", "123"),
-                ("llvm-next", "456"),
-            ],
-        )
-
-    def test_llvm_ebuild_parsing_fails_if_both_hashes_arent_present(self):
-        bad_bodies = [
-            "",
-            'LLVM_HASH="123" # comment',
-            'LLVM_NEXT_HASH="123" # comment',
-            'LLVM_NEXT_HASH="123" # comment\n#LLVM_HASH="123"',
-        ]
-
-        for bad in bad_bodies:
-            with self.assertRaises(ValueError) as e:
-                nightly_revert_checker._parse_llvm_ebuild_for_shas(
-                    io.StringIO(bad)
-                )
-
-            self.assertIn("Failed to detect SHAs", str(e.exception))
-
     @mock.patch("revert_checker.find_reverts")
     @mock.patch("get_upstream_patch.get_from_upstream")
     def test_do_cherrypick_is_called(self, do_cherrypick, find_reverts):