[ccan] Testing ccanlint on Cygwin (gcc 4.3.4-3)

[Rusty Russell]

On Tue, 8 Mar 2011 15:27:03 +1100, Sam Watkins <sam at nipl.net> wrote:
> >  * ctype.h functions (islower, toupper, etc.) result in array
> > subscript warnings, treated as errors, when passed chars.  What else
> > would you pass them?
> 
> > Weird.  But such warnigns are not fatal, so I don't think we should be
> > working around them in CCAN in general.
> 
> It becomes fatal when you pass them signed chars having values less than -1.
> A plain 'char' may be signed or unsigned depending on the architecture.
> 
> You must not pass a plain char directly to islower() and friends.  The
> functions take int arguments, having the value of an _unsigned_ char, or EOF
> (typically -1).

Yech... somehow I had managed to avoid this ugly truth until now.

So I did a rough audit of code sitting on my box to see who gets this right.

1) The glibc versions handle down to -128 ("for broken old programs").
2) popt: gets it wrong. (config file parsing).
3) iniparser: gets it wrong. (strlwc and strupc implementations).
4) samba: gets it right in five places!  Wrong everywhere else (many places).

So, everyone is buggy, and that's not going to change.  Hence the glibc
behaviour is the way forward.

Meanwhile, we have four options:

(1) Create ccan wrappers which warn (using __builtin_compatible_p).
(2) Create ccan wrappers which fix (using an extra test, maybe getting
    tricky with __builtin_compatible_p to optimize)
(3) Create ccan replacements, eg. cisupper etc.
(4) Fix our own code then stick our heads back in the sand.

Thoughts?
Rusty.

PS.  Our places to fix:
ccan/talloc_link/_info:66: *			*upstr = toupper(*upstr);
ccan/failtest/failtest.c:366:			if (tolower(*failpath) != info_to_arg[call->type])
ccan/failtest/failtest.c:369:			call->fail = isupper(*(failpath++));
ccan/tdb/tools/replay_trace.c:173:	c = toupper(c);
ccan/antithread/_info:45: *				else if (toupper(r[i]) < 'N')
ccan/ciniparser/ciniparser.c:73:		l[i] = tolower(s[i]);
tools/doc_extract-core.c:115:		lowertype[i] = tolower(type[i]);
tools/ccanlint/tests/headers_idempotent.c:31:			name[i] = toupper(name[i]);
tools/ccanlint/tests/examples_compile.c:154:	for (p = end; isalnum(*p) || *p == '_'; p--) {
tools/ccanlint/tests/examples_compile.c:191:		if (!line[0] || isspace(line[0]) || strstarts(line, "//"))
tools/ccanlint/tests/examples_compile.c:231:		    && ispunct(line[len+strspn(line+len, " ")])) {
tools/ccanlint/tests/examples_run.c:49:		if (toupper(input[0]) != toupper(fmt[0]))
tools/ccanlint/ccanlint.c:74:		&& toupper(reply[0]) == 'Y';