From: Iain Sandoe <iain@sandoe.co.uk>
Date: Mon, 27 Apr 2020 14:21:25 +0000 (+0100)
Subject: coroutines: Fix cases where proxy variables are used [PR94879]
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=b16fd5fd8afe6f95c8ae44e759971e605c31f97b;p=gcc.git

coroutines: Fix cases where proxy variables are used [PR94879]

There are several places where the handling of a variable
declaration depends on whether it corresponds to a compiler
temporary, or to some other entity.  We were testing that var
decls were artificial in determining this.  However, proxy vars
are also artificial so that this is not sufficient.  The solution
is to exclude variables with a DECL_VALUE_EXPR as well, since
the value variable will not be a temporary.

gcc/cp/ChangeLog:

2020-04-30  Iain Sandoe  <iain@sandoe.co.uk>

	PR c++/94879
	* coroutines.cc (build_co_await): Account for variables
	with DECL_VALUE_EXPRs.
	(captures_temporary): Likewise.
	(register_awaits): Likewise.

gcc/testsuite/ChangeLog:

2020-04-30  Iain Sandoe  <iain@sandoe.co.uk>

	PR c++/94879
	* g++.dg/coroutines/pr94879-folly-1.C: New test.
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index cbedbabe3a6..3172f949ee9 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,11 @@
+2020-04-30  Iain Sandoe  <iain@sandoe.co.uk>
+
+	PR c++/94879
+	* coroutines.cc (build_co_await): Account for variables
+	with DECL_VALUE_EXPRs.
+	(captures_temporary): Likewise.
+	(register_awaits): Likewise.
+
 2020-04-29  Patrick Palka  <ppalka@redhat.com>
 
 	PR c++/94830
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index 7bb3e98fe6c..e2dbeabf48b 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -748,7 +748,8 @@ build_co_await (location_t loc, tree a, suspend_point_kind suspend_kind)
   if (INDIRECT_REF_P (e_proxy))
     e_proxy = TREE_OPERAND (e_proxy, 0);
   if (TREE_CODE (e_proxy) == PARM_DECL
-      || (TREE_CODE (e_proxy) == VAR_DECL && !DECL_ARTIFICIAL (e_proxy)))
+      || (VAR_P (e_proxy) && (!DECL_ARTIFICIAL (e_proxy)
+			      || DECL_HAS_VALUE_EXPR_P (e_proxy))))
     e_proxy = o;
   else
     {
@@ -2659,7 +2660,8 @@ captures_temporary (tree *stmt, int *do_subtree, void *d)
 	}
 
       /* This isn't a temporary.  */
-      if ((TREE_CODE (parm) == VAR_DECL && !DECL_ARTIFICIAL (parm))
+      if ((VAR_P (parm)
+	   && (!DECL_ARTIFICIAL (parm) || DECL_HAS_VALUE_EXPR_P (parm)))
 	  || TREE_CODE (parm) == PARM_DECL
 	  || TREE_CODE (parm) == NON_LVALUE_EXPR)
 	continue;
@@ -2742,7 +2744,8 @@ register_awaits (tree *stmt, int *do_subtree ATTRIBUTE_UNUSED, void *d)
   if (INDIRECT_REF_P (aw))
     aw = TREE_OPERAND (aw, 0);
   if (TREE_CODE (aw) == PARM_DECL
-      || (TREE_CODE (aw) == VAR_DECL && !DECL_ARTIFICIAL (aw)))
+      || (VAR_P (aw) && (!DECL_ARTIFICIAL (aw)
+			 || DECL_HAS_VALUE_EXPR_P (aw))))
     ; /* Don't make an additional copy.  */
   else
     {
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 49f00426e06..7f39eda0277 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2020-04-30  Iain Sandoe  <iain@sandoe.co.uk>
+
+	PR c++/94879
+	* g++.dg/coroutines/pr94xxx-folly-1.C: New test.
+
 2020-04-30  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/94775
diff --git a/gcc/testsuite/g++.dg/coroutines/pr94879-folly-1.C b/gcc/testsuite/g++.dg/coroutines/pr94879-folly-1.C
new file mode 100644
index 00000000000..7d66ce004f7
--- /dev/null
+++ b/gcc/testsuite/g++.dg/coroutines/pr94879-folly-1.C
@@ -0,0 +1,49 @@
+//  { dg-additional-options  "-fpreprocessed -w" }
+
+namespace std {
+template <typename a> a b(a &&);
+template <typename c> struct d { c e; };
+template <typename f, typename> struct coroutine_traits : f {};
+template <typename = void> struct coroutine_handle;
+template <> struct coroutine_handle<> {};
+template <typename> struct coroutine_handle : coroutine_handle<> {};
+struct g {};
+} // namespace std
+
+class h {};
+class i {
+  i(i &&);
+};
+
+namespace ac {
+template <typename> class ad {
+public:
+  bool await_ready();
+  void await_resume();
+  void await_suspend(std::coroutine_handle<>);
+  i ae;
+};
+} // namespace ac
+
+template <typename ab> ac::ad<ab> operator co_await(ab);
+class j {
+  class l {};
+
+public:
+  std::g initial_suspend();
+  l final_suspend();
+};
+class m : public j {
+public:
+  void get_return_object();
+  void unhandled_exception();
+};
+class n {
+public:
+  using promise_type = m;
+};
+std::d<h> k;
+void a() {
+  auto am = k;
+  [&]() -> n { co_await std::b(am.e); };
+}