[PR c++/81574] lambda capture of function reference

https://gcc.gnu.org/ml/gcc-patches/2017-11/msg01200.html
	PR c++/81574
	* lambda.c (lambda_capture_field_type): Function references are
	always catured by reference.

	PR c++/81574
	* g++.dg/cpp1y/pr81574.C: New.

From-SVN: r254768

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 839042e..e8c882f 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2017-11-15  Nathan Sidwell  <nathan@acm.org>
+
+       PR c++/81574
+       * lambda.c (lambda_capture_field_type): Function references are
+       always catured by reference.
+
 2017-11-15  Martin Liska  <mliska@suse.cz>
 
        * decl.c (begin_destructor_body): Use cp_build_fold_indirect_ref

diff --git a/gcc/cp/lambda.c b/gcc/cp/lambda.c
index 2cbad87..4480c67 100644 (file)
--- a/gcc/cp/lambda.c
+++ b/gcc/cp/lambda.c
@@ -245,7 +245,8 @@ lambda_capture_field_type (tree expr, bool explicit_init_p,
     {
       type = non_reference (unlowered_expr_type (expr));
 
-      if (!is_this && by_reference_p)
+      if (!is_this
+         && (by_reference_p || TREE_CODE (type) == FUNCTION_TYPE))
        type = build_reference_type (type);
     }
 

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 1dada43..8478a7a 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-11-15  Nathan Sidwell  <nathan@acm.org>
+
+       PR c++/81574
+       * g++.dg/cpp1y/pr81574.C: New.
+
 2017-11-15  Richard Biener  <rguenther@suse.de>
 
        PR tree-optimization/82985

diff --git a/gcc/testsuite/g++.dg/cpp1y/pr81574.C b/gcc/testsuite/g++.dg/cpp1y/pr81574.C
new file mode 100644 (file)
index 0000000..f9949ab
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/pr81574.C
@@ -0,0 +1,13 @@
+// { dg-do compile { target c++14 } }
+// PR c++/81574 references to functions are captured by reference.
+
+// 8.1.5.2/10
+// For each entity captured by copy, ... an lvalue reference to the
+// referenced function type if the entity is a reference to a function
+
+void f (void (&b)())
+{
+  [=] {  b; } ();
+  [=, b(f)] { b; } ();
+  [=, b(b)] { b; } ();
+}