The best way to add one strbuf to an other is via: strbuf_addbuf(&sb, &sb2); This is a bit more idiomatic and efficient than: strbuf_addstr(&sb, sb2.buf); because the size of the second strbuf is known and thus it can spare a strlen() call, and much more so than: strbuf_addf(&sb, "%s", sb2.buf); because it can spare the whole vsnprintf() formatting magic. Add new semantic patches to 'contrib/coccinelle/strbuf.cocci' to catch these undesired patterns and to suggest strbuf_addbuf() instead. Luckily, our codebase is already clean from any such undesired patterns (but one of the in-flight topics just tried to sneak in such a strbuf_addf() call). Signed-off-by: SZEDER Gábor <szeder.dev@xxxxxxxxx> --- Inspired by: https://public-inbox.org/git/20190125112203.GB6702@xxxxxxxxxx/ contrib/coccinelle/strbuf.cocci | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/contrib/coccinelle/strbuf.cocci b/contrib/coccinelle/strbuf.cocci index e34eada1ad..d9ada69b43 100644 --- a/contrib/coccinelle/strbuf.cocci +++ b/contrib/coccinelle/strbuf.cocci @@ -12,6 +12,36 @@ constant fmt !~ "%"; ) ); +@@ +expression E; +struct strbuf SB; +format F =~ "s"; +@@ +- strbuf_addf(E, "%@F@", SB.buf); ++ strbuf_addbuf(E, &SB); + +@@ +expression E; +struct strbuf *SBP; +format F =~ "s"; +@@ +- strbuf_addf(E, "%@F@", SBP->buf); ++ strbuf_addbuf(E, SBP); + +@@ +expression E; +struct strbuf SB; +@@ +- strbuf_addstr(E, SB.buf); ++ strbuf_addbuf(E, &SB); + +@@ +expression E; +struct strbuf *SBP; +@@ +- strbuf_addstr(E, SBP->buf); ++ strbuf_addbuf(E, SBP); + @@ expression E1, E2; format F =~ "s"; -- 2.20.1.642.gc55a771460
