Gate the new change with version 7

Author: Camsyn

llvm/test/tools/UpdateTestChecks/update_test_checks/Inputs/check_empty.ll.expected

@@ -1,4 +1,4 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 7
 ; RUN: opt < %s -S | FileCheck %s
 
 ; Test whether the UTC check empty lines instead of skipping them.

llvm/test/tools/UpdateTestChecks/update_test_checks/check_empty.test

@@ -1,3 +1,3 @@
 ## test whether the UTC generates CHECK-EMPTY for blank lines
-# RUN: cp -f %S/Inputs/check_empty.ll %t.ll && %update_test_checks %t.ll
+# RUN: cp -f %S/Inputs/check_empty.ll %t.ll && %update_test_checks %t.ll --version 7
 # RUN: diff -u %t.ll %S/Inputs/check_empty.ll.expected

llvm/utils/UpdateTestChecks/common.py

@@ -29,7 +29,7 @@
    'none' and 'all'. 'smart' is the default.
 5: Basic block labels are matched by FileCheck expressions
 6: The semantics of TBAA checks has been incorporated in the check lines.
-7: Indent switch-cases correctly.
+7: Indent switch-cases correctly; CHECK-EMPTY instead of skipping blank lines.
 """
 DEFAULT_VERSION = 6
 
@@ -2292,24 +2292,47 @@ def add_checks(
                     ignore_all_comments=not check_inst_comments,
                 )
 
+                # This could be selectively enabled with an optional invocation argument.
+                # Disabled for now: better to check everything. Be safe rather than sorry.
+
+                # Handle the first line of the function body as a special case because
+                # it's often just noise (a useless asm comment or entry label).
+                # if func_body[0].startswith("#") or func_body[0].startswith("entry:"):
+                #  is_blank_line = True
+                # else:
+                #  output_lines.append('%s %s:       %s' % (comment_marker, checkprefix, func_body[0]))
+                #  is_blank_line = False
+
+                is_blank_line = False
 
                 for func_line in func_body:
                     if func_line.strip() == "":
-                        # Instead of skipping blank lines, using CHECK_EMPTY is more defensive.
-                        output_lines.append(
-                            "{} {}-EMPTY:".format(comment_marker, checkprefix)
-                        )
+                        if ginfo.get_version() >= 7:
+                            output_lines.append(
+                                "{} {}-EMPTY:".format(comment_marker, checkprefix)
+                            )
+                        else:
+                            is_blank_line = True
                         continue
                     if not check_inst_comments:
                         # Do not waste time checking IR comments unless necessary.
                         func_line = SCRUB_IR_COMMENT_RE.sub(r"", func_line)
 
-                    check_suffix = "-NEXT" if not is_filtered else ""
-                    output_lines.append(
-                        "{} {}{}:  {}".format(
-                            comment_marker, checkprefix, check_suffix, func_line
+                    # Skip blank lines instead of checking them.
+                    if is_blank_line:
+                        output_lines.append(
+                            "{} {}:       {}".format(
+                                comment_marker, checkprefix, func_line
+                            )
                         )
-                    )
+                    else:
+                        check_suffix = "-NEXT" if not is_filtered else ""
+                        output_lines.append(
+                            "{} {}{}:  {}".format(
+                                comment_marker, checkprefix, check_suffix, func_line
+                            )
+                        )
+                    is_blank_line = False
 
                 # Add space between different check prefixes and also before the first
                 # line of code in the test function.