Re: [PATCH v2 5/7] tools/perf: fix Python string escapes

Adrian Hunter
2023-09-12T10:57:18Z

On 12/09/23 09:07, Benjamin Gray wrote:
> Python 3.6 introduced a DeprecationWarning for invalid escape sequences.
> This is upgraded to a SyntaxWarning in Python 3.12, and will eventually
> be a syntax error.
>
> Fix these now to get ahead of it before it's an error.
>
> Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
> ---
> tools/perf/pmu-events/jevents.py | 2 +-
> tools/perf/scripts/python/arm-cs-trace-disasm.py | 4 ++--
> tools/perf/scripts/python/compaction-times.py | 2 +-
> tools/perf/scripts/python/exported-sql-viewer.py | 4 ++--
> 4 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
> index a7e88332276d..980f080a5a2c 100755
> --- a/tools/perf/pmu-events/jevents.py
> +++ b/tools/perf/pmu-events/jevents.py
> @@ -83,7 +83,7 @@ def c_len(s: str) -> int:
> """Return the length of s a C string
>
> This doesn't handle all escape characters properly. It first assumes
> - all \ are for escaping, it then adjusts as it will have over counted
> + all \\ are for escaping, it then adjusts as it will have over counted

It looks like the whole string should be a raw string

> \\. The code uses \000 rather than \0 as a terminator as an adjacent
> number would be folded into a string of \0 (ie. "\0" + "5" doesn't
> equal a terminator followed by the number 5 but the escape of
> diff --git a/tools/perf/scripts/python/arm-cs-trace-disasm.py b/tools/perf/scripts/python/arm-cs-trace-disasm.py
> index d59ff53f1d94..de58991c78bb 100755
> --- a/tools/perf/scripts/python/arm-cs-trace-disasm.py
> +++ b/tools/perf/scripts/python/arm-cs-trace-disasm.py
> @@ -45,8 +45,8 @@ parser = OptionParser(option_list=option_list)
> # Initialize global dicts and regular expression
> disasm_cache = dict()
> cpu_data = dict()
> -disasm_re = re.compile("^\s*([0-9a-fA-F]+):")
> -disasm_func_re = re.compile("^\s*([0-9a-fA-F]+)\s.*:")
> +disasm_re = re.compile(r"^\s*([0-9a-fA-F]+):")
> +disasm_func_re = re.compile(r"^\s*([0-9a-fA-F]+)\s.*:")
> cache_size = 64*1024
>
> glb_source_file_name = None
> diff --git a/tools/perf/scripts/python/compaction-times.py b/tools/perf/scripts/python/compaction-times.py
> index 2560a042dc6f..9401f7c14747 100644
> --- a/tools/perf/scripts/python/compaction-times.py
> +++ b/tools/perf/scripts/python/compaction-times.py
> @@ -260,7 +260,7 @@ def pr_help():
>
> comm_re = None
> pid_re = None
> -pid_regex = "^(\d*)-(\d*)$|^(\d*)$"
> +pid_regex = r"^(\d*)-(\d*)$|^(\d*)$"
>
> opt_proc = popt.DISP_DFL
> opt_disp = topt.DISP_ALL
> diff --git a/tools/perf/scripts/python/exported-sql-viewer.py b/tools/perf/scripts/python/exported-sql-viewer.py
> index 13f2d8a81610..121cf61ba1b3 100755
> --- a/tools/perf/scripts/python/exported-sql-viewer.py
> +++ b/tools/perf/scripts/python/exported-sql-viewer.py
> @@ -677,8 +677,8 @@ class CallGraphModelBase(TreeModel):
> # sqlite supports GLOB (text only) which uses * and ? and is case sensitive
> if not self.glb.dbref.is_sqlite3:
> # Escape % and _
> - s = value.replace("%", "\%")
> - s = s.replace("_", "\_")
> + s = value.replace("%", "\\%")
> + s = s.replace("_", "\\_")

Raw strings seem more readable, so could be
used here too

> # Translate * and ? into SQL LIKE pattern characters % and _
> trans = string.maketrans("*?", "%_")
> match = " LIKE '" + str(s).translate(trans) + "'"