This came up in discussion and was relatively easy to 'fix' although it remains
to be seen whether it was really intended. Tested on x86_64-darwin21.
OK for trunk?
Iain
--- >8 ---
As of now the standard does not appear to forbid this, and clang accepts.
The use-cases are somewhat unclear (question placed with the designers) but
implemented here for sake of compatibility.
Signed-off-by: Iain Sandoe <i...@sandoe.co.uk>
gcc/cp/ChangeLog:
* coroutines.cc (coro_build_actor_or_destroy_function): Accept
coroutines that are 'extern "C"' and build unmangled names for
the actor and destroy functions.
gcc/testsuite/ChangeLog:
* g++.dg/coroutines/torture/extern-c-coroutine.C: New test.
---
gcc/cp/coroutines.cc | 12 +++
.../coroutines/torture/extern-c-coroutine.C | 89 +++++++++++++++++++
2 files changed, 101 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/coroutines/torture/extern-c-coroutine.C
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index 3f23317a315..c1a0d6c2283 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -32,6 +32,7 @@ along with GCC; see the file COPYING3. If not see
#include "tree.h"
#include "gcc-rich-location.h"
#include "hash-map.h"
+#include "cgraph.h"
static bool coro_promise_type_found_p (tree, location_t);
@@ -4060,6 +4061,17 @@ coro_build_actor_or_destroy_function (tree orig, tree
fn_type,
else
info->destroy_decl = fn;
}
+ /* If the function is extern "C" the mangler will not be called. */
+ if (DECL_EXTERN_C_P (orig))
+ {
+ /* clone_function_name () picks up the name from DECL_ASSEMBLER_NAME
+ which is not yet set here. */
+ SET_DECL_ASSEMBLER_NAME (fn, DECL_NAME (orig));
+ if (actor_p)
+ SET_DECL_ASSEMBLER_NAME (fn, clone_function_name (fn, "actor"));
+ else
+ SET_DECL_ASSEMBLER_NAME (fn, clone_function_name (fn, "destroy"));
+ }
return fn;
}
diff --git a/gcc/testsuite/g++.dg/coroutines/torture/extern-c-coroutine.C
b/gcc/testsuite/g++.dg/coroutines/torture/extern-c-coroutine.C
new file mode 100644
index 00000000000..c178a80ee4b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/coroutines/torture/extern-c-coroutine.C
@@ -0,0 +1,89 @@
+#include <coroutine>
+#include <cstdio>
+
+#ifndef OUTPUT
+# define PRINT(X)
+# define PRINTF(X,...)
+#else
+# define PRINT(X) puts(X)
+# define PRINTF printf
+#endif
+
+struct future {
+ struct promise_type;
+ using handle_type = std::coroutine_handle<future::promise_type>;
+ handle_type handle;
+ future () : handle(0) {}
+ future (handle_type _handle)
+ : handle(_handle) {
+ PRINT("Created future object from handle");
+ }
+ future (const future &) = delete; // no copying
+ future (future &&s) : handle(s.handle) {
+ s.handle = nullptr;
+ PRINT("future mv ctor ");
+ }
+ future &operator = (future &&s) {
+ handle = s.handle;
+ s.handle = nullptr;
+ PRINT("future op= ");
+ return *this;
+ }
+ ~future() {
+ PRINT("Destroyed future");
+ if ( handle )
+ handle.destroy();
+ }
+
+ struct promise_type {
+ void return_value (int v) {
+ PRINTF ("return_value (%d)\n", v);
+ vv = v;
+ }
+
+ std::suspend_always initial_suspend() noexcept { return {}; }
+ std::suspend_always final_suspend() noexcept { return {}; }
+ void unhandled_exception() {}
+ auto get_return_object() {return handle_type::from_promise (*this);}
+
+ int get_value () { return vv; }
+ private:
+ int vv;
+ };
+ bool await_ready() { return false; }
+ void await_suspend(std::coroutine_handle<>) {}
+ void await_resume() {}
+};
+
+extern "C" future
+test () {
+ co_return 22;
+}
+
+extern "C" future
+f () noexcept
+{
+ PRINT ("future: about to return");
+ co_return 42;
+}
+
+int main ()
+{
+ PRINT ("main: create future");
+ future x = f ();
+ PRINT ("main: got future - resuming");
+ if (x.handle.done())
+ __builtin_abort ();
+ x.handle.resume();
+ PRINT ("main: after resume");
+ int y = x.handle.promise().get_value();
+ if ( y != 42 )
+ __builtin_abort ();
+ if (!x.handle.done())
+ {
+ PRINT ("main: apparently not done...");
+ __builtin_abort ();
+ }
+ PRINT ("main: returning");
+ return 0;
+}
--
2.37.1 (Apple Git-137.1)
