gcc - GNU Compiler Collection (original) (raw)

author	Iain Sandoe iain@sandoe.co.uk	2025-05-29 16:50:44 +0100
committer	Iain Sandoe iain@sandoe.co.uk	2025-06-14 11:40:55 +0100
commit	4c014a9db521b24bd900eb9a6ac70988322a57da (patch)
tree	9532707f32caa59e15caa8efe82b60ecf0abef09
parent	Daily bump. (diff)

c++, coroutines: Improve diagnostics for awaiter/promise.HEAD trunk master

At present, we can issue diagnostics about missing or malformed awaiter or promise methods when we encounter their uses in the body of a user's function. We might then re-issue the same diagnostics when processing the initial or final await expressions. This change avoids such duplication, and also attempts to identify issues with the initial or final expressions specifically since diagnostics for those do not have any useful line number. gcc/cp/ChangeLog: * coroutines.cc (build_co_await): Identify diagnostics for initial and final await expressions. (cp_coroutine_transform::wrap_original_function_body): Do not handle initial and final await expressions here ... (cp_coroutine_transform::apply_transforms): ... handle them here and avoid duplicate diagnostics. * coroutines.h: Declare inital and final await expressions in the transform class. Save the function closing brace location. gcc/testsuite/ChangeLog: * g++.dg/coroutines/coro1-missing-await-method.C: Adjust for improved diagnostics. * g++.dg/coroutines/coro-missing-final-suspend.C: Likewise. * g++.dg/coroutines/pr104051.C: Move to... * g++.dg/coroutines/pr104051-0.C: ...here. * g++.dg/coroutines/pr104051-1.C: New test. Signed-off-by: Iain Sandoe iain@sandoe.co.uk

-rw-r--r--	gcc/cp/coroutines.cc	29
-rw-r--r--	gcc/cp/coroutines.h	4
-rw-r--r--	gcc/testsuite/g++.dg/coroutines/coro-missing-final-suspend.C	4
-rw-r--r--	gcc/testsuite/g++.dg/coroutines/coro1-missing-await-method.C	2
-rw-r--r--	gcc/testsuite/g++.dg/coroutines/pr104051-0.C (renamed from gcc/testsuite/g++.dg/coroutines/pr104051.C)	4
-rw-r--r--	gcc/testsuite/g++.dg/coroutines/pr104051-1.C	23

6 files changed, 55 insertions, 11 deletions

diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.ccindex 1fbdee1b4f63..4057a0762baf 100644--- a/gcc/cp/coroutines.cc+++ b/gcc/cp/coroutines.cc
@@ -1277,8 +1277,14 @@ build_co_await (location_t loc, tree a, suspend_point_kind suspend_kind,
1277	1277
1278	if (TREE_CODE (o_type) != RECORD_TYPE)	1278	if (TREE_CODE (o_type) != RECORD_TYPE)
1279	{	1279	{
1280	error_at (loc, "awaitable type %qT is not a structure",	1280	if (suspend_kind == FINAL_SUSPEND_POINT)
1281	o_type);	1281	error_at (loc, "%qs awaitable type %qT is not a structure",
1282	"final_suspend()", o_type);
1283	else if (suspend_kind == INITIAL_SUSPEND_POINT)
1284	error_at (loc, "%qs awaitable type %qT is not a structure",
1285	"initial_suspend()", o_type);
1286	else
1287	error_at (loc, "awaitable type %qT is not a structure", o_type);
1282	return error_mark_node;	1288	return error_mark_node;
1283	}	1289	}
1284	1290
@@ -4356,7 +4362,6 @@ cp_coroutine_transform::wrap_original_function_body ()
4356	/* Wrap the function body in a try {} catch (...) {} block, if exceptions	4362	/* Wrap the function body in a try {} catch (...) {} block, if exceptions
4357	are enabled. */	4363	are enabled. */
4358	tree var_list = NULL_TREE;	4364	tree var_list = NULL_TREE;
4359	tree initial_await = build_init_or_final_await (fn_start, false);
4360	4365
4361	/* [stmt.return.coroutine] / 3	4366	/* [stmt.return.coroutine] / 3
4362	If p.return_void() is a valid expression, flowing off the end of a	4367	If p.return_void() is a valid expression, flowing off the end of a
@@ -4550,7 +4555,8 @@ cp_coroutine_transform::wrap_original_function_body ()
4550	zero_resume = build2_loc (loc, MODIFY_EXPR, act_des_fn_ptr_type,	4555	zero_resume = build2_loc (loc, MODIFY_EXPR, act_des_fn_ptr_type,
4551	resume_fn_ptr, zero_resume);	4556	resume_fn_ptr, zero_resume);
4552	finish_expr_stmt (zero_resume);	4557	finish_expr_stmt (zero_resume);
4553	finish_expr_stmt (build_init_or_final_await (fn_start, true));	4558	finish_expr_stmt (final_await);
4559
4554	BIND_EXPR_BODY (update_body) = pop_stmt_list (BIND_EXPR_BODY (update_body));	4560	BIND_EXPR_BODY (update_body) = pop_stmt_list (BIND_EXPR_BODY (update_body));
4555	BIND_EXPR_VARS (update_body) = nreverse (var_list);	4561	BIND_EXPR_VARS (update_body) = nreverse (var_list);
4556	BLOCK_VARS (top_block) = BIND_EXPR_VARS (update_body);	4562	BLOCK_VARS (top_block) = BIND_EXPR_VARS (update_body);
@@ -5207,9 +5213,10 @@ cp_coroutine_transform::cp_coroutine_transform (tree _orig_fn, bool _inl)
5207	}	5213	}
5208	5214
5209	/* We don't have the locus of the opening brace - it's filled in later (and	5215	/* We don't have the locus of the opening brace - it's filled in later (and
5210	there doesn't really seem to be any easy way to get at it).	5216	there doesn't really seem to be any easy way to get at it). */
5211	The closing brace is assumed to be input_location. */
5212	fn_start = DECL_SOURCE_LOCATION (orig_fn_decl);	5217	fn_start = DECL_SOURCE_LOCATION (orig_fn_decl);
5218	/* The closing brace is assumed to be input_location. */
5219	fn_end = input_location;
5213	5220
5214	/* Build types we need. */	5221	/* Build types we need. */
5215	tree fr_name = get_fn_local_identifier (orig_fn_decl, "Frame");	5222	tree fr_name = get_fn_local_identifier (orig_fn_decl, "Frame");
@@ -5288,6 +5295,16 @@ cp_coroutine_transform::apply_transforms ()
5288	= coro_build_actor_or_destroy_function (orig_fn_decl, act_des_fn_type,	5295	= coro_build_actor_or_destroy_function (orig_fn_decl, act_des_fn_type,
5289	frame_ptr_type, false);	5296	frame_ptr_type, false);
5290	5297
5298	/* Avoid repeating diagnostics about promise or awaiter fails. */
5299	if (!seen_error ())
5300	{
5301	iloc_sentinel stable_input_loc (fn_start);
5302	initial_await = build_init_or_final_await (fn_start, false);
5303	input_location = fn_end;
5304	if (initial_await && initial_await != error_mark_node)
5305	final_await = build_init_or_final_await (fn_end, true);
5306	}
5307
5291	/* Transform the function body as per [dcl.fct.def.coroutine] / 5. */	5308	/* Transform the function body as per [dcl.fct.def.coroutine] / 5. */
5292	wrap_original_function_body ();	5309	wrap_original_function_body ();
5293	5310
diff --git a/gcc/cp/coroutines.h b/gcc/cp/coroutines.hindex 55caa6e61e36..919dc9ab06b6 100644--- a/gcc/cp/coroutines.h+++ b/gcc/cp/coroutines.h
@@ -102,6 +102,7 @@ private:
102	tree orig_fn_decl; /* The original function decl. */	102	tree orig_fn_decl; /* The original function decl. */
103	tree orig_fn_body = NULL_TREE; /* The original function body. */	103	tree orig_fn_body = NULL_TREE; /* The original function body. */
104	location_t fn_start = UNKNOWN_LOCATION;	104	location_t fn_start = UNKNOWN_LOCATION;
105	location_t fn_end = UNKNOWN_LOCATION;
105	tree resumer = error_mark_node;	106	tree resumer = error_mark_node;
106	tree destroyer = error_mark_node;	107	tree destroyer = error_mark_node;
107	tree coroutine_body = NULL_TREE;	108	tree coroutine_body = NULL_TREE;
@@ -126,6 +127,9 @@ private:
126	bool inline_p = false;	127	bool inline_p = false;
127	bool valid_coroutine = false;	128	bool valid_coroutine = false;
128	129
130	tree initial_await = error_mark_node;
131	tree final_await = error_mark_node;
132
129	void analyze_fn_parms ();	133	void analyze_fn_parms ();
130	void wrap_original_function_body ();	134	void wrap_original_function_body ();
131	bool build_ramp_function ();	135	bool build_ramp_function ();
diff --git a/gcc/testsuite/g++.dg/coroutines/coro-missing-final-suspend.C b/gcc/testsuite/g++.dg/coroutines/coro-missing-final-suspend.Cindex 6a0878c1269a..b2522311a495 100644--- a/gcc/testsuite/g++.dg/coroutines/coro-missing-final-suspend.C+++ b/gcc/testsuite/g++.dg/coroutines/coro-missing-final-suspend.C
@@ -7,10 +7,10 @@
7	#include "coro1-ret-int-yield-int.h"	7	#include "coro1-ret-int-yield-int.h"
8	8
9	coro1	9	coro1
10	my_coro () // { dg-error {no member named 'final_suspend' in} }	10	my_coro ()
11	{	11	{
12	co_return 0;	12	co_return 0;
13	}	13	} // { dg-error {no member named 'final_suspend' in} }
14	14
15	// check we have not messed up continuation of the compilation.	15	// check we have not messed up continuation of the compilation.
16	template <class... Args>	16	template <class... Args>
diff --git a/gcc/testsuite/g++.dg/coroutines/coro1-missing-await-method.C b/gcc/testsuite/g++.dg/coroutines/coro1-missing-await-method.Cindex c1869e0654c3..c6a3188ee358 100644--- a/gcc/testsuite/g++.dg/coroutines/coro1-missing-await-method.C+++ b/gcc/testsuite/g++.dg/coroutines/coro1-missing-await-method.C
@@ -7,7 +7,7 @@
7	#include "coro1-ret-int-yield-int.h"	7	#include "coro1-ret-int-yield-int.h"
8	8
9	coro1	9	coro1
10	bar0 () // { dg-error {no member named 'await_suspend' in 'coro1::suspend_always_prt'} }	10	bar0 ()
11	{	11	{
12	co_await coro1::suspend_never_prt{}; // { dg-error {no member named 'await_ready' in 'coro1::suspend_never_prt'} }	12	co_await coro1::suspend_never_prt{}; // { dg-error {no member named 'await_ready' in 'coro1::suspend_never_prt'} }
13	co_yield 5; // { dg-error {no member named 'await_suspend' in 'coro1::suspend_always_prt'} }	13	co_yield 5; // { dg-error {no member named 'await_suspend' in 'coro1::suspend_always_prt'} }
diff --git a/gcc/testsuite/g++.dg/coroutines/pr104051.C b/gcc/testsuite/g++.dg/coroutines/pr104051-0.Cindex f77a915af745..bf878b2acbb8 100644--- a/gcc/testsuite/g++.dg/coroutines/pr104051.C+++ b/gcc/testsuite/g++.dg/coroutines/pr104051-0.C
@@ -24,7 +24,7 @@ template struct task {
24	std::coroutine_handle<> await_suspend(std::coroutine_handle<>);	24	std::coroutine_handle<> await_suspend(std::coroutine_handle<>);
25	T await_resume();	25	T await_resume();
26	};	26	};
27	task<std::vector> foo() { // { dg-error {awaitable type 'bool' is not a structure} }	27	task<std::vector> foo() {
28	while ((co_await foo()).empty())	28	while ((co_await foo()).empty())
29	;	29	;
30	}	30	} // { dg-error {'final_suspend\(\)' awaitable type 'bool' is not a structure} }
diff --git a/gcc/testsuite/g++.dg/coroutines/pr104051-1.C b/gcc/testsuite/g++.dg/coroutines/pr104051-1.Cnew file mode 100644index 000000000000..35b5e2c700d3--- /dev/null+++ b/gcc/testsuite/g++.dg/coroutines/pr104051-1.C
@@ -0,0 +1,23 @@
1	// { dg-additional-options "-fsyntax-only" }
2	// { dg-skip-if "requires hosted libstdc++ for vector" { ! hostedlib } }
3	#include
4	template
5	struct promise {
6	auto get_return_object() {
7	return std::coroutine_handle::from_promise(*this);
8	}
9	auto initial_suspend() { return 42.0; }
10	auto final_suspend() noexcept { return true; }
11	void unhandled_exception();
12	void return_void ();
13	};
14	template struct task {
15	using promise_type = promise;
16	task(std::coroutine_handle<promise>);
17	bool await_ready();
18	std::coroutine_handle<> await_suspend(std::coroutine_handle<>);
19	T await_resume();
20	};
21	task foo() { // { dg-error {'initial_suspend\(\)' awaitable type 'double' is not a structure} }
22	co_return;
23	}