c++, coroutines: Make sure our temporaries are in a bind expr [PR105287]

There are a few cases where we can generate a temporary that does not need
to be added to the coroutine frame (i.e. these are genuinely ephemeral).  The
intent was that unnamed temporaries should not be 'promoted' to coroutine
frame entries.  However there was a thinko and these were not actually ever
added to the bind expressions being generated for the expanded awaits.  This
meant that they were showing in the global namspace, leading to an empty
DECL_CONTEXT and the ICE reported.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
	PR c++/105287

gcc/cp/ChangeLog:

	* coroutines.cc (maybe_promote_temps): Ensure generated temporaries
	are added to the bind expr.
	(add_var_to_bind): Fix local var naming to use portable punctuation.
	(register_local_var_uses): Do not add synthetic names to unnamed
	temporaries.

gcc/testsuite/ChangeLog:

	* g++.dg/coroutines/pr105287.C: New test.

diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index 64f4b4412e55d13b6aeaae652d0d4ea54c69ca55..9b651b845b7ca188bde33603e357e37fc4e8042d 100644 (file)
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -3110,7 +3110,7 @@ maybe_promote_temps (tree *stmt, void *d)
         If the initializer is a conditional expression, we need to collect
         and declare any promoted variables nested within it.  DTORs for such
         variables must be run conditionally too.  */
-      if (t->var && DECL_NAME (t->var))
+      if (t->var)
        {
          tree var = t->var;
          DECL_CHAIN (var) = vlist;
@@ -3311,7 +3311,7 @@ add_var_to_bind (tree& bind, tree var_type,
   tree b_vars = BIND_EXPR_VARS (bind);
   /* Build a variable to hold the condition, this will be included in the
      frame as a local var.  */
-  char *nam = xasprintf ("%s.%d", nam_root, nam_vers);
+  char *nam = xasprintf ("__%s_%d", nam_root, nam_vers);
   tree newvar = build_lang_decl (VAR_DECL, get_identifier (nam), var_type);
   free (nam);
   DECL_CHAIN (newvar) = b_vars;
@@ -3956,7 +3956,7 @@ register_local_var_uses (tree *stmt, int *do_subtree, void *d)
             scopes with identically named locals and still be able to
             identify them in the coroutine frame.  */
          tree lvname = DECL_NAME (lvar);
-         char *buf;
+         char *buf = NULL;
 
          /* The outermost bind scope contains the artificial variables that
             we inject to implement the coro state machine.  We want to be able
@@ -3966,14 +3966,14 @@ register_local_var_uses (tree *stmt, int *do_subtree, void *d)
          else if (lvname != NULL_TREE)
            buf = xasprintf ("%s_%u_%u", IDENTIFIER_POINTER (lvname),
                             lvd->nest_depth, lvd->bind_indx);
-         else
-           buf = xasprintf ("_D%u_%u_%u", DECL_UID (lvar), lvd->nest_depth,
-                            lvd->bind_indx);
          /* TODO: Figure out if we should build a local type that has any
             excess alignment or size from the original decl.  */
-         local_var.field_id
-           = coro_make_frame_entry (lvd->field_list, buf, lvtype, lvd->loc);
-         free (buf);
+         if (buf)
+           {
+             local_var.field_id = coro_make_frame_entry (lvd->field_list, buf,
+                                                         lvtype, lvd->loc);
+             free (buf);
+           }
          /* We don't walk any of the local var sub-trees, they won't contain
             any bind exprs.  */
        }

diff --git a/gcc/testsuite/g++.dg/coroutines/pr105287.C b/gcc/testsuite/g++.dg/coroutines/pr105287.C
new file mode 100644 (file)
index 0000000..9790945
--- /dev/null
+++ b/gcc/testsuite/g++.dg/coroutines/pr105287.C
@@ -0,0 +1,48 @@
+// { dg-additional-options "-fanalyzer" }
+// { dg-excess-errors "lots of analyzer output, but no ICE" }
+namespace std {
+template <typename _Result> struct coroutine_traits : _Result {};
+template <typename = void> struct coroutine_handle {
+  operator coroutine_handle<>();
+};
+}
+struct coro1 {
+  using handle_type = std::coroutine_handle<>;
+  coro1(handle_type);
+  struct suspend_always_prt {
+    bool await_ready() noexcept;
+    void await_suspend(handle_type) noexcept;
+    void await_resume() noexcept;
+  };
+  struct promise_type {
+    std::coroutine_handle<> ch_;
+    auto get_return_object() { return ch_; }
+    auto initial_suspend() { return suspend_always_prt{}; }
+    auto final_suspend() noexcept { return suspend_always_prt{}; }
+    void unhandled_exception();
+  };
+};
+struct BoolAwaiter {
+  BoolAwaiter(bool);
+  bool await_ready();
+  void await_suspend(std::coroutine_handle<>);
+  bool await_resume();
+};
+struct IntAwaiter {
+  IntAwaiter(int);
+  bool await_ready();
+  void await_suspend(std::coroutine_handle<>);
+  int await_resume();
+};
+coro1 my_coro() {
+ int a = 1;
+ if (a == 0) {
+   int b = 5;
+   
+ }
+ {
+   int c = 10;
+ }
+ co_await BoolAwaiter(true) && co_await IntAwaiter(a); 
+ 
+ }