[mlir] Add support for broader range of input files in generate-test-checks.py

Author: GleasonK

mlir/utils/generate-test-checks.py

@@ -236,9 +236,12 @@ def process_attribute_references(line, attribute_namer):
 # Pre-process a line of input to remove any character sequences that will be
 # problematic with FileCheck.
 def preprocess_line(line):
+    # If input line has `{{` i.e. in a StrAttr with serialized proto.
+    output_line = line.replace("{{", "{{\\{\\{}}")
+
     # Replace any double brackets, '[[' with escaped replacements. '[['
     # corresponds to variable names in FileCheck.
-    output_line = line.replace("[[", "{{\\[\\[}}")
+    output_line = output_line.replace("[[", "{{\\[\\[}}")
 
     # Replace any single brackets that are followed by an SSA identifier, the
     # identifier will be replace by a variable; Creating the same situation as
@@ -327,6 +330,11 @@ def main():
         if not input_line:
             continue
 
+        # When using `--starts_from_scope=0` to capture module lines, the file
+        # split needs to be skipped, otherwise a `CHECK: // -----` is inserted.
+        if input_line.startswith("// -----"):
+            continue
+
         # Check if this is an attribute definition and process it
         process_attribute_definition(input_line, attribute_namer, output)