re PR c++/78896 ([C++17] Segmentation fault occurs when use variable initialized...

	PR c++/78896
	* decl.c (cp_finish_decomp): Disallow memberwise decomposition of
	lambda expressions.

	* g++.dg/cpp1z/decomp24.C: New test.

From-SVN: r244909

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index dc098b2..6144ad7 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2017-01-25  Jakub Jelinek  <jakub@redhat.com>
 
+       PR c++/78896
+       * decl.c (cp_finish_decomp): Disallow memberwise decomposition of
+       lambda expressions.
+
        PR c++/77914
        * parser.c (cp_parser_lambda_declarator_opt): Pedwarn with
        OPT_Wpedantic on lambda templates for -std=c++14 and higher.

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index af74dcd..4b64ba1 100644 (file)
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -7562,6 +7562,11 @@ cp_finish_decomp (tree decl, tree first, unsigned int count)
       error_at (loc, "cannot decompose non-array non-class type %qT", type);
       goto error_out;
     }
+  else if (LAMBDA_TYPE_P (type))
+    {
+      error_at (loc, "cannot decompose lambda closure type %qT", type);
+      goto error_out;
+    }
   else
     {
       tree btype = find_decomp_class_base (loc, type, NULL_TREE);

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e82fb4c..7c85a6b 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2017-01-25  Jakub Jelinek  <jakub@redhat.com>
 
+       PR c++/78896
+       * g++.dg/cpp1z/decomp24.C: New test.
+
        PR c++/77914
        * g++.dg/cpp1y/lambda-generic-77914.C: New test.
        * g++.dg/cpp1y/lambda-generic-dep.C: Add -pedantic to dg-options,

diff --git a/gcc/testsuite/g++.dg/cpp1z/decomp24.C b/gcc/testsuite/g++.dg/cpp1z/decomp24.C
new file mode 100644 (file)
index 0000000..0e874fa
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/decomp24.C
@@ -0,0 +1,11 @@
+// PR c++/78896
+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+int
+foo ()
+{
+  int a {10};
+  auto [b] { [&a](){} };       // { dg-error "cannot decompose lambda closure type" }
+  return b - a;                        // { dg-warning "decomposition declaration only available with" "" { target c++14_down } .-1 }
+}