Em Fri, Jun 01, 2018 at 05:01:02PM +0800, Jin Yao escreveu:
<SNIP>
> +static int get_symoff(struct symbol *sym, struct addr_location *al,
> + bool print_off, char *bf, int size)
> +{
> + unsigned long offset;
> +
> + if (!sym || !sym->name)
> + return scnprintf(bf, size, "%s", "[unknown]");
52 54.22 ubuntu:17.04 : FAIL gcc (Ubuntu 6.3.0-12ubuntu2)
6.3.0 20170406
CC /tmp/build/perf/util/scripting-engines/trace-event-python.o
util/scripting-engines/trace-event-python.c:534:20: error: address of array
'sym->name' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
if (!sym || !sym->name)
~~~~~~^~~~
1 error generated.
mv: cannot stat
'/tmp/build/perf/util/scripting-engines/.trace-event-python.o.tmp': No such
file or directory
/git/linux/tools/build/Makefile.build:96: recipe for target
'/tmp/build/perf/util/scripting-engines/trace-event-python.o' failed
make[5]: *** [/tmp/build/perf/util/scripting-engines/trace-event-python.o]
Error 1
Because:
struct symbol {
struct rb_node rb_node;
u64 start;
u64 end;
u16 namelen;
<SNIP>
char name[0];
};
It sym->name is not a pointer, in symbol's constructor we have:
struct symbol *symbol__new(u64 start, u64 len, u8 binding, u8 type, const char
*name)
{
size_t namelen = strlen(name) + 1;
struct symbol *sym = calloc(1, (symbol_conf.priv_size +
sizeof(*sym) + namelen));
if (sym == NULL)
return NULL;
<SNIP>
sym->namelen = namelen - 1;
memcpy(sym->name, name, namelen);
return sym;
}
So it is at least 1 char long, the test above should be:
if (!sym || !sym->name[0])
return scnprintf(bf, size, "%s", "[unknown]");
I'm fixing this up here.
- Arnaldo
