Hi,
C++20 [expr.await] / 2
An await-expression shall appear only in a potentially-evaluated expression
within the compound-statement of a function-body outside of a handler.
tested on x86_64, powerpc64le-linux, x86_64-darwin, cppcoro and folly,
pushed to master as obvious, thanks
Iain
Signed-off-by: Iain Sandoe <i...@sandoe.co.uk>
PR c++/99710
gcc/cp/ChangeLog:
* coroutines.cc (await_statement_walker): Report an error if
an await expression is found in a handler body.
gcc/testsuite/ChangeLog:
* g++.dg/coroutines/pr99710.C: New test.
---
gcc/cp/coroutines.cc | 17 ++++++++++++++-
gcc/testsuite/g++.dg/coroutines/pr99710.C | 25 +++++++++++++++++++++++
2 files changed, 41 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/coroutines/pr99710.C
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index 1dd9abd1e1f..377b90c777f 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -3688,7 +3688,22 @@ await_statement_walker (tree *stmt, int *do_subtree,
void *d)
*do_subtree = 0;
return res;
}
- break;
+ break;
+ case HANDLER:
+ {
+ /* [expr.await] An await-expression shall appear only in a
+ potentially-evaluated expression within the compound-statement
+ of a function-body outside of a handler. */
+ tree *await_ptr;
+ hash_set<tree> visited;
+ if (!(cp_walk_tree (&HANDLER_BODY (expr), find_any_await,
+ &await_ptr, &visited)))
+ return NULL_TREE; /* All OK. */
+ location_t loc = EXPR_LOCATION (*await_ptr);
+ error_at (loc, "await expressions are not permitted in handlers");
+ return NULL_TREE; /* This is going to fail later anyway. */
+ }
+ break;
}
else if (EXPR_P (expr))
{
diff --git a/gcc/testsuite/g++.dg/coroutines/pr99710.C
b/gcc/testsuite/g++.dg/coroutines/pr99710.C
new file mode 100644
index 00000000000..e4f7116b8d7
--- /dev/null
+++ b/gcc/testsuite/g++.dg/coroutines/pr99710.C
@@ -0,0 +1,25 @@
+#include <coroutine>
+
+struct task {
+ struct promise_type {
+ std::suspend_always initial_suspend();
+ std::suspend_always final_suspend() noexcept;
+ task get_return_object();
+ void return_void();
+ void unhandled_exception();
+ };
+};
+
+task
+my_coro ()
+{
+ try
+ { }
+ catch (...)
+ {
+ // [expr.await] An await-expression shall appear only in a potentially-
+ // evaluated expression within the compound-statement of a function-body
+ // outside of a handler
+ co_await std::suspend_always{}; // { dg-error "await expressions are not
permitted in handlers" }
+ }
+}
--
2.24.3 (Apple Git-128)
