fix(util): use raw strings for regex patterns (W605 invalid escapes)

util/rpcid.py

@@ -141,7 +141,7 @@ def analyze_rpc(id, client_num, server_num):
     server_info = ""
 
     for line in tt.stdout:
-        match = re.match(' *([-0-9.]+) us .* \[C([0-9]+)\]', line)
+        match = re.match(r' *([-0-9.]+) us .* \[C([0-9]+)\]', line)
         if not match:
             continue
         time = float(match.group(1))
@@ -239,7 +239,7 @@ def analyze_rpc(id, client_num, server_num):
     rpcs_analyzed += 1
     print("Client (%s, id %s):" % (client, id))
     for line in tt.stdout:
-        match = re.match(' *([-0-9.]+) us .* \[C([0-9]+)\]', line)
+        match = re.match(r' *([-0-9.]+) us .* \[C([0-9]+)\]', line)
         if not match:
             continue
         time = float(match.group(1))

util/smi.py

@@ -29,7 +29,7 @@
 printed = 0
 
 for line in f:
-    match = re.match(' *([-0-9.]+) us .* \[C([0-9]+)\]', line)
+    match = re.match(r' *([-0-9.]+) us .* \[C([0-9]+)\]', line)
     if not match:
         continue
     time = float(match.group(1))

util/tests/test_trace_line.py

@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0+
+"""Regression tests for the timetrace-line regexes in util/.
+
+These document the W605 fix (invalid escape sequences in regex string
+literals -> raw strings) and pin down the behaviour that must stay
+unchanged. Run standalone:
+
+    python -W error::SyntaxWarning -m pytest util/tests/test_trace_line.py
+
+There is no new CI wiring; this file is included as executable
+documentation of the fix.
+"""
+
+import ast
+import re
+import warnings
+from pathlib import Path
+
+import pytest
+
+UTIL = Path(__file__).resolve().parent.parent
+
+# The canonical trace-line prefix regex, shared by rpcid.py / smi.py /
+# tput.py / tthoma.py after the fix.
+PREFIX = re.compile(r' *([-0-9.]+) us .* \[C([0-9]+)\]')
+
+# Table-driven cases: positive, boundary, negative, corner.
+PREFIX_CASES = [
+    {
+        "description": "positive: typical line, extracts timestamp and core",
+        "line": "  123.5 us (+ 2.0 us) [C07] homa_data_pkt invoked",
+        "expected": ("123.5", "07"),
+    },
+    {
+        "description": "boundary: negative relative timestamp is accepted",
+        "line": "  -0.5 us stuff [C00] first event",
+        "expected": ("-0.5", "00"),
+    },
+    {
+        "description": "corner: multi-digit core id",
+        "line": "0 us x [C128] y",
+        "expected": ("0", "128"),
+    },
+    {
+        "description": "negative: literal brackets required, none present",
+        "line": "  123.5 us no core marker here",
+        "expected": None,
+    },
+    {
+        "description": "negative: '[C..]' must be literal, not a char class",
+        "line": "  123.5 us .* CX",
+        "expected": None,
+    },
+]
+
+
+@pytest.mark.parametrize("case", PREFIX_CASES, ids=lambda c: c["description"])
+def test_prefix_regex(case):
+    m = PREFIX.match(case["line"])
+    if case["expected"] is None:
+        assert m is None
+    else:
+        assert m is not None
+        assert m.groups() == case["expected"]
+
+
+# Every util/*.py that carried a W605 finding must now compile without any
+# SyntaxWarning about invalid escape sequences. Compiling the source with
+# warnings promoted to errors is the pytest form of the ruff W605 gate.
+FIXED_SOURCES = [
+    "rpcid.py",
+    "smi.py",
+    "tput.py",
+    "tthoma.py",
+    "ttmerge.py",
+    "ttsyslog.py",
+]
+
+
+@pytest.mark.parametrize("name", FIXED_SOURCES)
+def test_no_invalid_escape_sequences(name):
+    src = (UTIL / name).read_text()
+    with warnings.catch_warnings():
+        warnings.simplefilter("error", SyntaxWarning)
+        # Raises SyntaxWarning (-> error) if any invalid escape remains.
+        compile(ast.parse(src, filename=name), name, "exec")

util/tput.py

@@ -37,7 +37,7 @@
 rpcs = {}
 
 for line in f:
-    match = re.match(' *([-0-9.]+) us .* \[C([0-9]+)\]', line)
+    match = re.match(r' *([-0-9.]+) us .* \[C([0-9]+)\]', line)
     if not match:
         continue
     time = float(match.group(1))

util/tthoma.py

@@ -1736,7 +1736,7 @@ def parse(self, file):
         global traces
         start_ns = time.time_ns()
         self.__build_parse_table()
-        prefix_matcher = re.compile(' *([-0-9.]+) us .* \[C([0-9]+)\] (.*)')
+        prefix_matcher = re.compile(r' *([-0-9.]+) us .* \[C([0-9]+)\] (.*)')
 
         trace = {}
         trace['file'] = file
@@ -1838,7 +1838,7 @@ def __build_parse_table(self):
         # and 'cregexp' elements of pattern entries.
         self.prefix_length = 1000
         for pattern in self.patterns:
-            meta_matcher = re.compile('[()[\].+*?\\^${}]')
+            meta_matcher = re.compile(r'[()[\].+*?\^${}]')
             pattern['parser'] = getattr(self, '_Dispatcher__' + pattern['name'])
             pattern['cregexp'] = re.compile(pattern['regexp'])
             if pattern['name'] in self.interests:
@@ -2014,7 +2014,7 @@ def __qdisc_queue_data(self, trace, time, core, match, interests):
     patterns.append({
         'name': 'qdisc_queue_data',
         'regexp': '__dev_xmit_skb queueing homa data packet for '
-                  'id ([0-9]+), offset ([0-9]+), qid ([0-9]+) \(([^)]+)\)'
+                  r'id ([0-9]+), offset ([0-9]+), qid ([0-9]+) \(([^)]+)\)'
     })
 
     def __nic_data(self, trace, time, core, match, interests):
@@ -2355,7 +2355,7 @@ def __grant_check_unlock(self, trace, time, core, match, interests):
 
     patterns.append({
         'name': 'grant_check_unlock',
-        'regexp': 'homa_grant_check_rpc released grant lock \(id ([0-9]+)\)'
+        'regexp': r'homa_grant_check_rpc released grant lock \(id ([0-9]+)\)'
     })
 
     def __rpc_incoming(self, trace, time, core, match, interests):
@@ -12401,7 +12401,7 @@ def output(self):
                 dst = tempfile.NamedTemporaryFile(dir=os.path.dirname(file),
                         mode='w', delete=False)
                 for line in src:
-                    match = re.match(' *([-0-9.]+) us (\(\+ *[-0-9.]+ us\) \[C[0-9]+\].*)',
+                    match = re.match(r' *([-0-9.]+) us (\(\+ *[-0-9.]+ us\) \[C[0-9]+\].*)',
                             line)
                     if not match:
                         print(line, file=dst)

util/ttmerge.py

@@ -50,7 +50,7 @@ def next_line(info):
             info["f"].close()
             info["f"] = None
             return
-        match = re.match(' *([0-9.]+) us \(\+ *([0-9.]+) us\) (.*)', line)
+        match = re.match(r' *([0-9.]+) us \(\+ *([0-9.]+) us\) (.*)', line)
         if not match:
             continue
         info["time"] = (float(match.group(1)) * ghz / info["ghz"]) + info["offset"]
@@ -64,9 +64,9 @@ def next_line(info):
     if not line:
         continue
     info = {"f": f}
-    match = re.match(' *([0-9.]+) us \(\+ *([0-9.]+) us\) .* '
+    match = re.match(r' *([0-9.]+) us \(\+ *([0-9.]+) us\) .* '
             'First event has timestamp ([0-9]+) '
-            '\(cpu_ghz ([0-9.]+)\)', line)
+            r'\(cpu_ghz ([0-9.]+)\)', line)
     if not match:
         continue
     info = {"name": file,

util/ttsyslog.py

@@ -59,7 +59,7 @@
     lines.append(line)
 
 for line in reversed(lines):
-    match = re.match('.* ([0-9.]+) (\[C..\] .+)', line)
+    match = re.match(r'.* ([0-9.]+) (\[C..\] .+)', line)
     if not match:
         continue
     this_time = float(match.group(1))
@@ -76,7 +76,7 @@
 
 if extra:
     for line in lines:
-        if not re.match('.* ([0-9.]+) (\[C..\] .+)', line):
+        if not re.match(r'.* ([0-9.]+) (\[C..\] .+)', line):
             extra.write(line)
             extra.write('\n')
     extra.close()