On Tue, 30 Apr 2024 at 18:39, Lucas De Marchi <lucas.demarchi@xxxxxxxxx> wrote:
>
> On Mon, Feb 12, 2024 at 05:23:10PM GMT, Emil Velikov via B4 Relay wrote:
> >From: Emil Velikov <emil.l.velikov@xxxxxxxxx>
> >
> >Since all the compression magic is always available now, we don't need
> >to loop at runtime nor use alloca - latter of which comes with a handful
> >of caveats.
> >
> >Simply throw in a few assert_cc(), which will trigger at build-time.
> >
> >Signed-off-by: Emil Velikov <emil.l.velikov@xxxxxxxxx>
> >---
> > libkmod/libkmod-file.c | 22 ++++++++--------------
> > 1 file changed, 8 insertions(+), 14 deletions(-)
> >
> >diff --git a/libkmod/libkmod-file.c b/libkmod/libkmod-file.c
> >index b69f1ef..5b88d6c 100644
> >--- a/libkmod/libkmod-file.c
> >+++ b/libkmod/libkmod-file.c
> >@@ -410,7 +410,6 @@ struct kmod_file *kmod_file_open(const struct kmod_ctx *ctx,
> > {
> > struct kmod_file *file = calloc(1, sizeof(struct kmod_file));
> > const struct comp_type *itr;
> >- size_t magic_size_max = 0;
> > int err = 0;
> >
> > if (file == NULL)
> >@@ -422,22 +421,17 @@ struct kmod_file *kmod_file_open(const struct kmod_ctx *ctx,
> > goto error;
> > }
> >
> >- for (itr = comp_types; itr->load != NULL; itr++) {
> >- if (magic_size_max < itr->magic_size)
> >- magic_size_max = itr->magic_size;
> >- }
> >-
> >- if (magic_size_max > 0) {
> >- char *buf = alloca(magic_size_max + 1);
> >+ {
> >+ char buf[7];
> > ssize_t sz;
> >
> >- if (buf == NULL) {
> >- err = -errno;
> >- goto error;
> >- }
> >- sz = read_str_safe(file->fd, buf, magic_size_max + 1);
> >+ assert_cc(sizeof(magic_zstd) < sizeof(buf));
> >+ assert_cc(sizeof(magic_xz) < sizeof(buf));
> >+ assert_cc(sizeof(magic_zlib) < sizeof(buf));
>
> ../libkmod/libkmod-file.c: In function 'kmod_file_open':
> ../shared/macro.h:25:9: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
Is there a particular use-case for explicitly forcing C90?
The configure.ac contains `AC_PROG_CC_C99`, which seems reasonable
IMHO. Plus the autogen.sh goes a step further with `-std=gnu11`
Thanks
Emil
