| Message ID | 20240826183408.88577-1-iain@sandoe.co.uk |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] c++, coroutines: The frame pointer is used in the helpers [PR116482]. | expand |
On 8/26/24 2:34 PM, Iain Sandoe wrote: > Hi Jason, > >>> As the PR notes, we now have two bogus warnings that the single frame >>> pointer parameter is unused in each of the helper functions. >>> This started when we began to use start_preparsed_function/finish_function >>> to wrap the helper function code generation. I am puzzled a little about >>> why the use is not evident without marking - or perhaps it is always needed >>> to mark use in synthetic code? >>> For the destroy function, in particular, the use of the parameter is simple >>> - an indirect ref and then it is passed to the call to the actor. >>> The fix here is somewhat trivial - to mark the param as used as soon as it >>> is. > >> You also wouldn't get the warning if the param were marked DECL_ARTIFICIAL, which seems desirable anyway? > > Yes, done as attached, OK for trunk assuming that reg-testing passes? OK. > --- 8< --- > > We have a bogus warning about the coroutine state frame pointers > being apparently unused in the resume and destroy functions. Fixed > by making the parameters DECL_ARTIFICIAL. > > PR c++/116482 > > gcc/cp/ChangeLog: > > * coroutines.cc > (coro_build_actor_or_destroy_function): Make the parameter > decls DECL_ARTIFICIAL. > > gcc/testsuite/ChangeLog: > > * g++.dg/coroutines/pr116482.C: New test. > > Signed-off-by: Iain Sandoe <iain@sandoe.co.uk> > --- > gcc/cp/coroutines.cc | 1 + > gcc/testsuite/g++.dg/coroutines/pr116482.C | 30 ++++++++++++++++++++++ > 2 files changed, 31 insertions(+) > create mode 100644 gcc/testsuite/g++.dg/coroutines/pr116482.C > > diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc > index c3e08221cc9..8f899513691 100644 > --- a/gcc/cp/coroutines.cc > +++ b/gcc/cp/coroutines.cc > @@ -4058,6 +4058,7 @@ coro_build_actor_or_destroy_function (tree orig, tree fn_type, > > tree id = get_identifier ("frame_ptr"); > tree fp = build_lang_decl (PARM_DECL, id, coro_frame_ptr); > + DECL_ARTIFICIAL (fp) = true; > DECL_CONTEXT (fp) = fn; > DECL_ARG_TYPE (fp) = type_passed_as (coro_frame_ptr); > DECL_ARGUMENTS (fn) = fp; > diff --git a/gcc/testsuite/g++.dg/coroutines/pr116482.C b/gcc/testsuite/g++.dg/coroutines/pr116482.C > new file mode 100644 > index 00000000000..702d1e235bb > --- /dev/null > +++ b/gcc/testsuite/g++.dg/coroutines/pr116482.C > @@ -0,0 +1,30 @@ > +// Override default options. > +// { dg-options "-std=c++20 -fno-exceptions -Wall -Wextra" } > + > +#include <coroutine> > + > +struct SuspendNever { > + bool await_ready(); > + void await_suspend(std::coroutine_handle<>); > + void await_resume(); > +}; > + > +struct Coroutine; > + > +struct PromiseType { > + Coroutine get_return_object(); > + SuspendNever initial_suspend(); > + SuspendNever final_suspend(); > +#if __cpp_exceptions > + void unhandled_exception() { /*std::terminate();*/ }; > +#endif > + void return_void(); > +}; > + > +struct Coroutine { > + using promise_type = PromiseType; > +}; > + > +Coroutine __async_test_input_basic() { > + co_return; > +}
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc index c3e08221cc9..8f899513691 100644 --- a/gcc/cp/coroutines.cc +++ b/gcc/cp/coroutines.cc @@ -4058,6 +4058,7 @@ coro_build_actor_or_destroy_function (tree orig, tree fn_type, tree id = get_identifier ("frame_ptr"); tree fp = build_lang_decl (PARM_DECL, id, coro_frame_ptr); + DECL_ARTIFICIAL (fp) = true; DECL_CONTEXT (fp) = fn; DECL_ARG_TYPE (fp) = type_passed_as (coro_frame_ptr); DECL_ARGUMENTS (fn) = fp; diff --git a/gcc/testsuite/g++.dg/coroutines/pr116482.C b/gcc/testsuite/g++.dg/coroutines/pr116482.C new file mode 100644 index 00000000000..702d1e235bb --- /dev/null +++ b/gcc/testsuite/g++.dg/coroutines/pr116482.C @@ -0,0 +1,30 @@ +// Override default options. +// { dg-options "-std=c++20 -fno-exceptions -Wall -Wextra" } + +#include <coroutine> + +struct SuspendNever { + bool await_ready(); + void await_suspend(std::coroutine_handle<>); + void await_resume(); +}; + +struct Coroutine; + +struct PromiseType { + Coroutine get_return_object(); + SuspendNever initial_suspend(); + SuspendNever final_suspend(); +#if __cpp_exceptions + void unhandled_exception() { /*std::terminate();*/ }; +#endif + void return_void(); +}; + +struct Coroutine { + using promise_type = PromiseType; +}; + +Coroutine __async_test_input_basic() { + co_return; +}