On Tue, 30 Apr 2024 at 19:18, Lucas De Marchi <lucas.demarchi@xxxxxxxxx> wrote:
>
> On Tue, Apr 30, 2024 at 06:54:00PM GMT, Emil Velikov wrote:
> >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?
>
> not forcing C90, but forcing -Wdeclaration-after-statement as per
> flag passed in configure.ac. I think the message given by gcc is
> misleading here.
>
Indeed thanks. Seems like I should add `export CFLAGS+=-Werror" to my dev box.
-Emil
