bpo-36876: Small adjustments to the C-analyzer tool. (GH-23045)

This is a little bit of clean-up, small fixes, and additional helpers prior to building an updated & accurate list of globals to eliminate.

Tools/c-analyzer/c_common/scriptutil.py

@@ -10,6 +10,9 @@ import sys
 from . import fsutil, strutil, iterutil, logging as loggingutil
 
 
+_NOT_SET = object()
+
+
 def get_prog(spec=None, *, absolute=False, allowsuffix=True):
     if spec is None:
         _, spec = _find_script()
@@ -313,6 +316,22 @@ def _parse_files(filenames):
         yield filename.strip()
 
 
+def add_progress_cli(parser, *, threshold=VERBOSITY, **kwargs):
+    parser.add_argument('--progress', dest='track_progress', action='store_const', const=True)
+    parser.add_argument('--no-progress', dest='track_progress', action='store_false')
+    parser.set_defaults(track_progress=True)
+
+    def process_args(args):
+        if args.track_progress:
+            ns = vars(args)
+            verbosity = ns.get('verbosity', VERBOSITY)
+            if verbosity <= threshold:
+                args.track_progress = track_progress_compact
+            else:
+                args.track_progress = track_progress_flat
+    return process_args
+
+
 def add_failure_filtering_cli(parser, pool, *, default=False):
     parser.add_argument('--fail', action='append',
                         metavar=f'"{{all|{"|".join(sorted(pool))}}},..."')
@@ -551,13 +570,39 @@ def _iter_filenames(filenames, iter_files):
         raise NotImplementedError
 
 
-def iter_marks(mark='.', *, group=5, groups=2, lines=10, sep=' '):
+def track_progress_compact(items, *, groups=5, **mark_kwargs):
+    last = os.linesep
+    marks = iter_marks(groups=groups, **mark_kwargs)
+    for item in items:
+        last = next(marks)
+        print(last, end='', flush=True)
+        yield item
+    if not last.endswith(os.linesep):
+        print()
+
+
+def track_progress_flat(items, fmt='<{}>'):
+    for item in items:
+        print(fmt.format(item), flush=True)
+        yield item
+
+
+def iter_marks(mark='.', *, group=5, groups=2, lines=_NOT_SET, sep=' '):
     mark = mark or ''
+    group = group if group and group > 1 else 1
+    groups = groups if groups and groups > 1 else 1
+
     sep = f'{mark}{sep}' if sep else mark
     end = f'{mark}{os.linesep}'
     div = os.linesep
     perline = group * groups
-    perlines = perline * lines
+    if lines is _NOT_SET:
+        # By default we try to put about 100 in each line group.
+        perlines = 100 // perline * perline
+    elif not lines or lines < 0:
+        perlines = None
+    else:
+        perlines = perline * lines
 
     if perline == 1:
         yield end
@@ -568,7 +613,7 @@ def iter_marks(mark='.', *, group=5, groups=2, lines=10, sep=' '):
     while True:
         if count % perline == 0:
             yield end
-            if count % perlines == 0:
+            if perlines and count % perlines == 0:
                 yield div
         elif count % group == 0:
             yield sep