From 5ea77a75dd2d2158401331879f3c8f47940a732c Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:35:32 +0200 Subject: Adding upstream version 2.5.13+dfsg. Signed-off-by: Daniel Baumann --- doc/devel/variadic_debug/09-merge.cocci | 147 ++++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) create mode 100644 doc/devel/variadic_debug/09-merge.cocci (limited to 'doc/devel/variadic_debug/09-merge.cocci') diff --git a/doc/devel/variadic_debug/09-merge.cocci b/doc/devel/variadic_debug/09-merge.cocci new file mode 100644 index 0000000..4b0c1b2 --- /dev/null +++ b/doc/devel/variadic_debug/09-merge.cocci @@ -0,0 +1,147 @@ +// Note that this file has not actually been used in the end, since +// 07-shortcut.cocci covers everything we needed in the project, but being +// simpler, it makes the intent of 07-shortcut.cocci clearer + + +// Splice string `s` into the format string `fmtstring` replacing the +// %-parameter at position `pos` +@initialize:python@ +@@ + +#regex from https://stackoverflow.com/questions/30011379/how-can-i-parse-a-c-format-string-in-python +import re +fmtstring = '''\ +( # start of capture group 1 +% # literal "%" +(?: # first option +(?:[-+0 #]{0,5}) # optional flags +(?:\d+|\*)? # width +(?:\.(?:\d+|\*))? # precision +(?:h|l|ll|w|I|I32|I64)? # size +[cCdiouxXeEfgGaAnpsSZ] # type +) | # OR +%%) # literal "%%" +''' + +regex = re.compile(fmtstring, re.X) + +def parse_format(f): + return tuple((m.span(), m.group()) for m in + regex.finditer(f)) + +def insert_at_pos(fmt, s, pos): + formats = parse_format(fmt) + span, format = formats[pos] + acc = fmt[:span[0]] + if s.startswith('"'): + acc += s[1:] + else: + acc += '" ' + acc += s + if acc.endswith('"'): + acc = acc[:-1] + fmt[span[1]:] + else: + acc += ' "' + acc += fmt[span[1]:] + return acc + +// Identify the redundant snprintfs (within a locked region) +@a exists@ +expression lock, E, L; +expression list args_before, args, args_after; +identifier buf; +expression format1, format2; +type T; +position p1, p2; +@@ + +{ +... +T buf; +... +ldap_pvt_thread_mutex_lock(lock); +... +snprintf@p1( buf, E, format1, args ); +... +ldap_pvt_thread_mutex_unlock(lock); +... +Debug@p2( L, format2, args_before, buf, args_after ); +... +} + +// Merge the format strings with insert_at_pos above +@script:python a_process@ +format1 << a.format1; +format2 << a.format2; +args_before << a.args_before; +merged; +@@ + +pos = len(args_before.elements) +coccinelle.merged = insert_at_pos(format2, format1, pos) + +// And merge the two together, replacing the extra buffer that's not used anymore +@a_replace@ +position a.p1, a.p2; +identifier a_process.merged; + +expression lock, E, L; +expression list args_before, args, args_after; +identifier buf; +expression format1, format2; +type T; +@@ + +{ +... +-T buf; +... +ldap_pvt_thread_mutex_lock(lock); +... +-snprintf@p1( buf, E, format1, args ); ++Debug( L, merged, args_before, args, args_after ); +... +ldap_pvt_thread_mutex_unlock(lock); +... +-Debug@p2( L, format2, args_before, buf, args_after ); +... +} + +// Once again (same as the 'a' series above, but those that remain to be sorted +// now don't need to stay within a locked region +@b exists@ +expression E, L; +expression list args_before, args, args_after; +identifier buf; +expression format1, format2; +position p1, p2; +@@ + +snprintf@p1( buf, E, format1, args ); +... +Debug@p2( L, format2, args_before, buf, args_after ); + +@script:python b_process@ +format1 << b.format1; +format2 << b.format2; +args_before << b.args_before; +merged; +@@ + +pos = len(args_before.elements) +coccinelle.merged = insert_at_pos(format2, format1, pos) + +@b_replace@ +position b.p1, b.p2; +identifier b_process.merged; + +expression E, L; +expression list args_before, args, args_after; +identifier buf; +expression format1, format2; +@@ + +-snprintf@p1( buf, E, format1, args ); ++Debug( L, merged, args_before, args, args_after ); +... +-Debug@p2( L, format2, args_before, buf, args_after ); -- cgit v1.2.3