gn build: make sync build work with git revs now that svn is gone

llvm/utils/gn/build/sync_source_lists_from_cmake.py

@@ -25,7 +25,7 @@ import sys
 
 def patch_gn_file(gn_file, add, remove):
     with open(gn_file) as f:
-      gn_contents = f.read()
+        gn_contents = f.read()
 
     srcs_tok = 'sources = ['
     tokloc = gn_contents.find(srcs_tok)
@@ -43,7 +43,7 @@ def patch_gn_file(gn_file, add, remove):
     for r in remove:
         gn_contents = gn_contents.replace('"%s",' % r, '')
     with open(gn_file, 'w') as f:
-      f.write(gn_contents)
+        f.write(gn_contents)
 
     # Run `gn format`.
     gn = os.path.join(os.path.dirname(__file__), '..', 'gn.py')
@@ -68,12 +68,6 @@ def sync_source_lists(write):
     def find_gitrev(touched_line, in_file):
         return git_out(
             ['log', '--format=%h', '-1', '-S' + touched_line, in_file]).rstrip()
-    def svnrev_from_gitrev(gitrev):
-        git_llvm = os.path.join(
-            os.path.dirname(__file__), '..', '..', 'git-svn', 'git-llvm')
-        return int(subprocess.check_output(
-            [sys.executable, git_llvm, 'svn-lookup', gitrev],
-            ).rstrip().lstrip('r'))
 
     # Collect changes to gn files, grouped by revision.
     for gn_file in gn_files:
@@ -97,16 +91,16 @@ def sync_source_lists(write):
 
         def by_rev(files, key):
             for f in files:
-                svnrev = svnrev_from_gitrev(find_gitrev(f, cmake_file))
-                changes_by_rev[svnrev][gn_file][key].append(f)
+                rev = find_gitrev(f, cmake_file)
+                changes_by_rev[rev][gn_file][key].append(f)
         by_rev(sorted(cmake_cpp - gn_cpp), 'add')
         by_rev(sorted(gn_cpp - cmake_cpp), 'remove')
 
     # Output necessary changes grouped by revision.
-    for svnrev in sorted(changes_by_rev):
-        print('gn build: Merge r{0} -- https://reviews.llvm.org/rL{0}'
-            .format(svnrev))
-        for gn_file, data in sorted(changes_by_rev[svnrev].items()):
+    for rev in sorted(changes_by_rev):
+        print('gn build: Merge {0} -- https://reviews.llvm.org/rG{0}'
+            .format(rev))
+        for gn_file, data in sorted(changes_by_rev[rev].items()):
             add = data.get('add', [])
             remove = data.get('remove', [])
             if write:
@@ -120,7 +114,7 @@ def sync_source_lists(write):
                     print('   remove:\n    ' + '\n    '.join(remove))
                 print()
         if write:
-            git(['commit', '-m', 'gn build: Merge r%d' % svnrev])
+            git(['commit', '-m', 'gn build: Merge %s' % rev])
         else:
             print()