While looking at Pr93458, I spotted the following non-fatal, but
unhelpful diagnostic output.
If the user's coroutine return type omits the mandatory promise
type then we will currently restate that error each time we see
a coroutine keyword, which doesn't provide any new information.
This suppresses all but the first instance in each coroutine.
tested on x86_64-darwin16
OK for master?
thanks
Iain
gcc/cp/ChangeLog:
2020-01-28 Iain Sandoe
* coroutines.cc (find_promise_type): Delete unused forward
declaration.
(struct coroutine_info): Add a bool for no promise type error.
(coro_promise_type_found_p): Only emit the error for a missing
promise once in each affected coroutine.
gcc/testsuite/ChangeLog:
2020-01-28 Iain Sandoe
* g++.dg/coroutines/coro-missing-promise.C: New test.
---
gcc/cp/coroutines.cc | 7 +--
.../g++.dg/coroutines/coro-missing-promise.C | 20 +++
2 files changed, 25 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/coroutines/coro-missing-promise.C
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index 89ecea91b9a..a56bbc883ca 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -33,7 +33,6 @@ along with GCC; see the file COPYING3. If not see
#include "gcc-rich-location.h"
#include "hash-map.h"
-static tree find_promise_type (tree);
static bool coro_promise_type_found_p (tree, location_t);
/* GCC C++ coroutines implementation.
@@ -93,6 +92,7 @@ struct GTY((for_user)) coroutine_info
function into a coroutine. */
/* Flags to avoid repeated errors for per-function issues. */
bool coro_ret_type_error_emitted;
+ bool coro_promise_error_emitted;
};
struct coroutine_info_hasher : ggc_ptr_hash
@@ -447,7 +447,10 @@ coro_promise_type_found_p (tree fndecl, location_t loc)
/* If we don't find it, punt on the rest. */
if (coro_info->promise_type == NULL_TREE)
{
- error_at (loc, "unable to find the promise type for this coroutine");
+ if (!coro_info->coro_promise_error_emitted)
+ error_at (loc, "unable to find the promise type for"
+ " this coroutine");
+ coro_info->coro_promise_error_emitted = true;
return false;
}
diff --git a/gcc/testsuite/g++.dg/coroutines/coro-missing-promise.C
b/gcc/testsuite/g++.dg/coroutines/coro-missing-promise.C
new file mode 100644
index 000..3fc21a4e2ca
--- /dev/null
+++ b/gcc/testsuite/g++.dg/coroutines/coro-missing-promise.C
@@ -0,0 +1,20 @@
+// { dg-additional-options "-fsyntax-only -w" }
+
+#include "coro.h"
+
+// Diagnose completely missing promise.
+
+// { dg-error {no type named 'promise_type' in 'struct NoPromiseHere'} "" {
target *-*-* } 0 }
+
+struct NoPromiseHere {
+ coro::coroutine_handle<> handle;
+ NoPromiseHere () : handle (nullptr) {}
+ NoPromiseHere (coro::coroutine_handle<> handle) : handle (handle) {}
+};
+
+NoPromiseHere
+bar ()
+{
+ co_yield 22; // { dg-error {unable to find the promise type for this
coroutine} }
+ co_return 0;
+}
--
2.24.1
