Hello, julia and folks,
I found the following source code (deadcode.c) isn't updated by semantic
patch (deadcode.cooci) with spatch version 1.0.4.
[deadcode.c]
int deadcode(const char* c)
{
do {
if (c) {
foo(*c);
break;
}
break;
} while (0);
}
[deadcode.cocci]
@@
expression E;
@@
-foo(E)
+bar(E)
With `--debug` option, spatch shows `FLOW: deadcode detected: File
"./deadcode.c", line 3`. But, I think there is no deadcode. There is
just a redundant `break` at the end of the loop. In my opinion, although
it's a bit strange, `break` keyword is harmless like the last `break`
keyword in the last label block in a `switch` statement, e.g.
switch (*c) {
case 'x': x++; break;
case 'y': y++; break;
default:
warn("Invalid input: %c\n", *c);
break; // <-- this is harmless, not a deadcode
}
Practical issue is seen in Wine 2.7's dlls/shlwapi/url.c from line 707
to 874. I tried to replace isalnum() to isalnumW(), a WCHAR version of
isalnum(), at line 812. However, spatch missed it without warnings. You
can see https://source.winehq.org/source/dlls/shlwapi/url.c?v=wine-2.7#0707
for the source code.
I'll be happy if spatch finds out the above case and makes a patch for it.
Deadcode.{c,cocci} are available in the Github pull requests.
Thanks in advance,
Akihiro Sagawa
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