[UTC] Don't leave dangling CHECK-SAME when removing CHECK lines (#82569)

When removing only lines that are global value CHECK lines, a related
CHECK-SAME line could be left dangling without a previous line to belong
to.

Resolves #78517

1 files changed, 13 insertions, 2 deletions

diff --git a/llvm/utils/UpdateTestChecks/common.py b/llvm/utils/UpdateTestChecks/common.py
index 4a02a92..5377752 100644
--- a/llvm/utils/UpdateTestChecks/common.py
+++ b/llvm/utils/UpdateTestChecks/common.py
@@ -388,7 +388,12 @@ def itertests(
 
 
 def should_add_line_to_output(
-    input_line, prefix_set, skip_global_checks=False, comment_marker=";"
+    input_line,
+    prefix_set,
+    *,
+    skip_global_checks=False,
+    skip_same_checks=False,
+    comment_marker=";",
 ):
     # Skip any blank comment lines in the IR.
     if not skip_global_checks and input_line.strip() == comment_marker:
@@ -402,9 +407,14 @@ def should_add_line_to_output(
     # And skip any CHECK lines. We're building our own.
     m = CHECK_RE.match(input_line)
     if m and m.group(1) in prefix_set:
+        if skip_same_checks and CHECK_SAME_RE.match(input_line):
+            # The previous CHECK line was removed, so don't leave this dangling
+            return False
         if skip_global_checks:
+            # Skip checks only if they are of global value definitions
             global_ir_value_re = re.compile(r"(\[\[|@)", flags=(re.M))
-            return not global_ir_value_re.search(input_line)
+            is_global = global_ir_value_re.search(input_line)
+            return not is_global
         return False
 
     return True
@@ -483,6 +493,7 @@ PREFIX_RE = re.compile("^[a-zA-Z0-9_-]+$")
 CHECK_RE = re.compile(
     r"^\s*(?://|[;#])\s*([^:]+?)(?:-NEXT|-NOT|-DAG|-LABEL|-SAME|-EMPTY)?:"
 )
+CHECK_SAME_RE = re.compile(r"^\s*(?://|[;#])\s*([^:]+?)(?:-SAME)?:")
 
 UTC_ARGS_KEY = "UTC_ARGS:"
 UTC_ARGS_CMD = re.compile(r".*" + UTC_ARGS_KEY + r"\s*(?P<cmd>.*)\s*$")