[prev in list] [next in list] [prev in thread] [next in thread] 

List:       gcc
Subject:    Re: Passing an string argument to a GIMPLE call
From:       Richard Biener via Gcc <gcc () gcc ! gnu ! org>
Date:       2020-06-28 18:53:31
Message-ID: 3E397E86-DEF4-4AFB-80A7-0CB98CC1F98A () gmail ! com
[Download RAW message or body]

On June 27, 2020 11:15:50 PM GMT+02:00, David Malcolm <dmalcolm@redhat.com> wrote:
>On Sat, 2020-06-27 at 21:27 +0800, Shuai Wang via Gcc wrote:
>> Dear Richard,
>> 
>> Thanks for the info. My bad, I will need to append "\0" at the end of
>> the
>> string. Also, a follow-up question which I just cannot find an
>> answer:
>> typically in the plugin entry point:
>> 
>> virtual unsigned int execute(function *fun)
>> 
>> How do I know which C files I am instrumenting? Can I somehow get the
>> name
>> of the C file? I don't find a corresponding pointer in the function
>> struct.
>
>fun->function_start_locus and fun->function_end_locus are the
>location_t for the start and end of the function; 

DECL_SOURCE_LOCATION of cfun->decl might be a more reliable source. 

Richard 

also, each gimple
>stmt has a location_t (although this isn't always set for every stmt).
>
>Given a location_t, you can use LOCATION_FILE (loc) to get the source
>file (and various other macros and accessors, see input.h)
>
>Hope this is helpful
>Dave
>
>> Best,
>> Shuai
>> 
>> On Sat, Jun 27, 2020 at 9:12 PM Richard Biener <
>> richard.guenther@gmail.com>
>> wrote:
>> 
>> > On June 27, 2020 6:21:12 AM GMT+02:00, Shuai Wang via Gcc <
>> > gcc@gcc.gnu.org>
>> > wrote:
>> > > Hello,
>> > > 
>> > > I am writing the following statement to make a GIMPLE call:
>> > > 
>> > >      tree function_fn_type =
>> > > build_function_type_list(void_type_node,
>> > > void_type_node, integer_type_node, NULL_TREE);
>> > >      tree sancov_fndecl =
>> > > build_fn_decl("my_instrumentation_function",
>> > > function_fn_type);
>> > > 
>> > >     auto gcall = gimple_build_call(sancov_fndecl, 2,
>> > > build_string_literal(3, "foo"),
>> > > build_int_cst_type(integer_type_node,
>> > > 0));
>> > > 
>> > > However, when executing the GIMPLE plugin, while inducing no
>> > > internal
>> > > crash, the following function call statement is generated:
>> > > 
>> > >  my_instrumentation_function (*&"foo"[0]*, 0);
>> > > 
>> > > The first argument seems really strange. Can I somewhat just put
>> > > a
>> > > "foo"
>> > > there instead of the current form? Thank you very much.
>> > 
>> > It looks correct. You are passing the address of the string
>> > literal.
>> > 
>> > Richard.
>> > 
>> > > Best,
>> > > Shuai

[prev in list] [next in list] [prev in thread] [next in thread]