Dear Richard,
Thank you for the information. Yes, that makes sense to me.
Nevertheless, is there any chance that I can still pinpoint this special
function call? Currently I can iterate all GIMPLE call statements, but how
to exactly figure out ASAN_MARK seems quite obscure.
Thank you!
Best,
Shuai
On Tue, Jun 9, 2020 at 3:48 PM Richard Biener <richard.guent...@gmail.com>
wrote:
> On Tue, Jun 9, 2020 at 3:38 AM Shuai Wang via Gcc <gcc@gcc.gnu.org> wrote:
> >
> > Hello!
> >
> > I am writing to report a potential bug I encountered when playing with
> the
> > GIMPLE IR. I enabled the ASan and would like to print out all ASAN_MARK
> > statements for the following simple code:
> >
> > int main(int argc ,char **argv)
> > {
> > int stack_array[100];
> > stack_array[1] = 100;
> > stack_array[argc + 12]; // an ASan check, namely, ASAN_MARK, will
> > be inserted at this point
> > }
> >
> > And I am using the following code snippet (basically derived from this
> > post <
> https://stackoverflow.com/questions/29346772/print-called-function-name-using-gcc-plugin
> >)
> > to print out all function calls, including ASAN_MARK:
> >
> > if (is_gimple_call(stmt)){
> > tree current_fn_decl = gimple_call_fndecl(stmt);
> > const char* name = get_name(current_fn_decl);
> > cerr << " Function : " << name << " is called \n";
> > }
> >
> > However, I note that some internal exceptions are encountered, when I
> > use gcc version 7.4, 8.3, and also 9.3:
> >
> > test.c: In function ‘main’:
> > test.c:9:5: internal compiler error: Segmentation fault
> > 9 | int main(int argc ,char **argv)
> > | ^~~~
> > 0xab88bf crash_signal
> > ../../gcc-9.3.0/gcc/toplev.c:326
> > 0xcfc836 location_wrapper_p(tree_node const*)
> > ../../gcc-9.3.0/gcc/tree.h:3812
> > 0xcfc836 tree_nop_conversion
> > ../../gcc-9.3.0/gcc/tree.c:12850
> > 0xcfc836 tree_strip_nop_conversions(tree_node*)
> > ../../gcc-9.3.0/gcc/tree.c:12888
> > 0xcfc836 get_name(tree_node*)
> > ../../gcc-9.3.0/gcc/tree.c:12559
> > 0x7f9466d86bb7 execute
> >
> /home/shuaiw/work/sanitizer_reduction_gcc/demo/walk_gimple/walk_gimple.cc:61
> > Please submit a full bug report,
> > with preprocessed source if appropriate.
> > Please include the complete backtrace with any bug report.
> > See <https://gcc.gnu.org/bugs/> for instructions.
> > Makefile:10: recipe for target 'test' failed
> > make: *** [test] Error 1
> >
> >
> > I think the issue is due to ASAN_MARK, because when I comment out that
> > particular array access which induces the ASAN_MARK, all other function
> > calls, including ASan related functions, __builtin___asan_init
> > and __builtin___asan_version_mismatch_check_v8, and be smoothly printed
> out
> > with no issue.
> >
> > Can I interpret it as a bug or somewhat? Any suggestions are welcomed.
> > Thank you very much.
>
> ASAN_MARK is likely an internal function which does not have a function
> declaration so you feed get_name a NULL pointer.
>
> >
> > Best,
> > Shuai
>
