scripts: runners: Renamed a bunch of flags

Mainly to make space for some planned bench flags, while also preferring
"step" over "period" (for consistency), and "runfreq" over "freq" (to
differentiate from "simfreq" in the future).

In runners:

- -s/--step -> --step
- --trace-period -> --trace-step
- --trace-freq -> --trace-runfreq

In scripts:

- --record -> -e/--record
- --perf-period -> --perf-step
- --perf-freq -> --perf-runfreq
- --include -> -i/--include

---

One thing that makes this work is the new sys.argv regex trick, where we
try to predict what mode the script will run in by prematching known
mode-switch flags before handing things off to argparse.

Note:

- Hiding flags from argparse risks confusing help-text, so we include
  all flags if we see -h/--help in sys.argv.

  This doesn't work for the help-text printed if argparse errors, but we
  can only do so much. Maybe argparse only showing relevant flags for
  the given mode is ok?

- We use -[^-]*[hf].* for shortform flags, which should also match
  multiple shortform flags in a single arg (-fhfhfh).

- This requires the conflict_handler='ignore' hack to work, but these
  scripts already needed it anyways.

scripts/perf.py

@@ -3,7 +3,7 @@
 # Script to aggregate and report Linux perf results.
 #
 # Example:
-# ./scripts/perf.py --record -obench.perf ./runners/bench_runner
+# ./scripts/perf.py -e -obench.perf ./runners/bench_runner
 # ./scripts/perf.py bench.perf -j -Flfs.c -Flfs_util.c -Scycles
 #
 # Copyright (c) 2022, The littlefs authors.
@@ -39,7 +39,7 @@ import zipfile
 
 PERF_PATH = ['perf']
 PERF_EVENTS = 'cycles,branch-misses,branches,cache-misses,cache-references'
-PERF_FREQ = 100
+PERF_RUNFREQ = 100
 OBJDUMP_PATH = ['objdump']
 THRESHOLD = (0.5, 0.85)
 
@@ -202,8 +202,8 @@ def openio(path, mode='r', buffering=-1):
 # run perf as a subprocess, storing measurements into a zip file
 def record(command, *,
         output=None,
-        perf_freq=PERF_FREQ,
-        perf_period=None,
+        perf_step=None,
+        perf_runfreq=PERF_RUNFREQ,
         perf_events=PERF_EVENTS,
         perf_path=PERF_PATH,
         **args):
@@ -213,11 +213,11 @@ def record(command, *,
         # figure out our perf invocation
         perf = perf_path + list(filter(None, [
                 'record',
-                '-F%s' % perf_freq
-                    if perf_freq is not None
-                    and perf_period is None else None,
-                '-c%s' % perf_period
-                    if perf_period is not None else None,
+                '-c%s' % perf_step
+                    if perf_step is not None else None,
+                '-F%s' % perf_runfreq
+                    if perf_runfreq is not None
+                    and perf_step is None else None,
                 '-B',
                 '-g',
                 '--all-user',
@@ -1660,11 +1660,12 @@ def main(**args):
 if __name__ == "__main__":
     import argparse
     import sys
+    import re
 
     # bit of a hack, but parse_intermixed_args and REMAINDER are
     # incompatible, so we need to figure out what we want before running
     # argparse
-    if '--record' in sys.argv:
+    if any(re.fullmatch('-[^-]*[e].*|--record', a) for a in sys.argv):
         nargs = argparse.REMAINDER
     else:
         nargs = '*'
@@ -1900,29 +1901,30 @@ if __name__ == "__main__":
             nargs=nargs,
             help="Command to run.")
     record_parser.add_argument(
-            '--record',
+            '-e', '--record',
             action='store_true',
             help="Run a command and aggregate perf measurements.")
-    record_parser.add_argument(
-            '-o', '--output',
-            help="Output file. Uses flock to synchronize. This is stored as a "
-                "zip-file of multiple perf results.")
-    record_parser.add_argument(
-            '--perf-freq',
-            help="perf sampling frequency. This is passed directly to perf. "
-                "Defaults to %r." % PERF_FREQ)
-    record_parser.add_argument(
-            '--perf-period',
-            help="perf sampling period. This is passed directly to perf.")
-    record_parser.add_argument(
-            '--perf-events',
-            help="perf events to record. This is passed directly to perf. "
-                "Defaults to %r." % PERF_EVENTS)
-    record_parser.add_argument(
-            '--perf-path',
-            type=lambda x: x.split(),
-            help="Path to the perf executable, may include flags. "
-                "Defaults to %r." % PERF_PATH)
+    if any(re.fullmatch('-[^-]*[he].*|--help|--record', a) for a in sys.argv):
+        record_parser.add_argument(
+                '-o', '--output',
+                help="Output file. Uses flock to synchronize. This is stored "
+                    "as a zip-file of multiple perf results.")
+        record_parser.add_argument(
+                '--perf-step',
+                help="perf sampling step. This is passed directly to perf.")
+        record_parser.add_argument(
+                '--perf-runfreq',
+                help="perf sampling frequency. This is passed directly to "
+                    "perf. Defaults to %r." % PERF_RUNFREQ)
+        record_parser.add_argument(
+                '--perf-events',
+                help="perf events to record. This is passed directly to "
+                    "perf. Defaults to %r." % PERF_EVENTS)
+        record_parser.add_argument(
+                '--perf-path',
+                type=lambda x: x.split(),
+                help="Path to the perf executable, may include flags. "
+                    "Defaults to %r." % PERF_PATH)
 
     # avoid intermixed/REMAINDER conflict, see above
     if nargs == argparse.REMAINDER:
@@ -1930,7 +1932,7 @@ if __name__ == "__main__":
     else:
         args = parser.parse_intermixed_args()
 
-    # perf_paths/command overlap, so need to do some munging here
+    # perf_paths/command overlap, so need to do some munging
     args.command = args.perf_paths
     if args.record:
         if not args.command: