On 03/09, Luc Van Oostenryck wrote:
>
> On Mon, Mar 09, 2020 at 04:25:09PM +0100, Alexey Gladkov wrote:
> > sindex is the simple to use cscope-like tool based on sparse/dissect.
> > Unlike cscope it runs after pre-processor and thus it can't index the
> > code filtered out by ifdef's, but otoh it understands how the symbol
> > is used and it can track the usage of struct members.
>
> Hi,
>
> This looks pretty good.
> I just have a few non-essential remarks I've added here below.
Great, thanks!
while Alexey is working on your comments...
> > To create an index for your linux kernel configuration:
> >
> > $ make C=2 CHECK="sindex add --"
Annoyingly, this triggers a lot of sparse_error's in pre-process.c:collect_arg().
And just in case, of course this is not specific to dissect/sindex, ./sparse or
anything else will equally complain.
For example,
1011 static inline bool page_expected_state(struct page *page,
1012 unsigned long check_flags)
1013 {
1014 if (unlikely(atomic_read(&page->_mapcount) != -1))
1015 return false;
1016
1017 if (unlikely((unsigned long)page->mapping |
1018 page_ref_count(page) |
1019 #ifdef CONFIG_MEMCG
1020 (unsigned long)page->mem_cgroup |
1021 #endif
1022 (page->flags & check_flags)))
1023 return false;
1024
1025 return true;
1026 }
leads to
mm/page_alloc.c:1019:1: error: directive in macro's argument list
mm/page_alloc.c:1021:1: error: directive in macro's argument list
and it is not immediately clear why. Yes, because "unlikely" is a macro.
Can't we simply remove this sparse_error() ? "#if" inside the macro's args
is widely used in kernel, gcc doesn't complain, afaics pre-process.c handles
this case correctly.
With the patch below
$ make -s -j4 C=2 CHECK='sindex add --'
in my dev tree is really silent:
kernel/events/core.c:571:26: warning: function 'perf_pmu_name' with external linkage has definition
arch/x86/kernel/kprobes/opt.c:468:13: warning: function 'arch_unoptimize_kprobes' with external linkage has definition
and both warnings look valid.
Oleg.
--- a/pre-process.c
+++ b/pre-process.c
@@ -271,8 +271,6 @@ static struct token *collect_arg(struct token *prev, int vararg, struct position
while (!eof_token(next = scan_next(p))) {
if (next->pos.newline && match_op(next, '#')) {
if (!next->pos.noexpand) {
- sparse_error(next->pos,
- "directive in macro's argument list");
preprocessor_line(stream, p);
__free_token(next); /* Free the '#' token */
continue;
