Improving output for single characters (with SmPL)?
From: Markus Elfring
Date: Wed Jul 22 2026 - 13:19:25 EST
Hello,
I would like to achieve further source code adjustments by the means of
the following script variant for the semantic patch language.
Example:
@initialize:python@
@@
input = ''
def convert(item):
mark = ["'", item, "'"]
coccinelle.text = cocci.make_expr(''.join(mark))
def common_checks(unescaped):
if input[1] == '"':
if input[2:] == '':
convert(input[0] if unescaped else '\\' + input[0])
else:
cocci.include_match(False)
else:
cocci.include_match(False)
@find_update_candidate@
constant char[] input_string;
expression input_context;
position pos;
@@
fprintf@pos(input_context, input_string);
@script:python selection@
param << find_update_candidate.input_string;
text;
@@
if param[0] == '"':
input = param[1:]
if input[0] == '\\':
input = input[1:]
if input[0] == '"':
if input[1] == '"':
if input[2:] == '':
convert('"')
else:
cocci.include_match(False)
else:
cocci.include_match(False)
else:
common_checks(False)
else:
common_checks(True)
else:
cocci.include_match(False)
@replacement@
constant char[] find_update_candidate.input_string, selection.text;
expression find_update_candidate.input_context;
position find_update_candidate.pos;
@@
(
-fprintf@pos
+putchar
(
-stdout,
-input_string
+text
)
|
-fprintf@pos
+fputc
(input_context,
-input_string
+text
)
)
Questionable test result (according to the software combination “Coccinelle 1.3.1”):
Markus_Elfring@Sonne:…/Projekte/Linux/next-analyses/tools> time /usr/bin/spatch --timeout 23 -j4 --chunksize 1 --include-headers --no-loops -dir . …/Projekte/Coccinelle/janitor/use_fputc-20260722.cocci > …/Projekte/Bau/Linux/scripts/Coccinelle/tuning1/next/20260721/use_fputc.diff
…
HANDLING: ./tracing/rtla/src/osnoise.c
An error occurred when attempting to transform some files.
real 0m34,627s
user 1m52,330s
sys 0m4,022s
Markus_Elfring@Sonne:…/Projekte/Linux/next-analyses> lsdiff …/Projekte/Bau/Linux/scripts/Coccinelle/tuning1/next/20260721/use_fputc.diff | wc -l
49
Markus_Elfring@Sonne:…/Projekte/Linux/next2-patched/tools> LANG=C git apply …/Projekte/Bau/Linux/scripts/Coccinelle/tuning1/next/20260721/use_fputc.diff
error: patch failed: tools/bpf/bpftool/netlink_dumper.h:25
error: tools/bpf/bpftool/netlink_dumper.h: patch does not apply
Which implementation details should be reconsidered here for an affected macro?
https://elixir.bootlin.com/linux/v7.2-rc4/source/tools/bpf/bpftool/netlink_dumper.h#L25
How will chances evolve to adjust more places according to remaining update candidates?
Regards,
Markus