From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 22 Jun 2018 21:06:41 +0000 (+0200)
Subject: backport: re PR c++/85208 (ICE with #pragma weak and structured binding)
X-Git-Tag: releases/gcc-7.4.0~341
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=75bcfc00e5346cef2e0e4738fa0fbfcef91017e6;p=thirdparty%2Fgcc.git

backport: re PR c++/85208 (ICE with #pragma weak and structured binding)

	Backported from mainline
	2018-04-05  Jakub Jelinek  <jakub@redhat.com>

	PR c++/85208
	* decl.c (start_decl): For DECL_DECOMPOSITION_P decls, don't call
	maybe_apply_pragma_weak here...
	(cp_maybe_mangle_decomp): ... but call it here instead.

	* g++.dg/cpp1z/decomp41.C: New test.

From-SVN: r261948
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index a3bec6f43140..6b08634faa20 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,6 +1,13 @@
 2018-06-22  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2018-04-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/85208
+	* decl.c (start_decl): For DECL_DECOMPOSITION_P decls, don't call
+	maybe_apply_pragma_weak here...
+	(cp_maybe_mangle_decomp): ... but call it here instead.
+
 	2018-04-04  Jakub Jelinek  <jakub@redhat.com>
 
 	PR inline-asm/85172
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 2193dd929f85..950e04a66807 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -5022,7 +5022,7 @@ start_decl (const cp_declarator *declarator,
     }
 
   /* If #pragma weak was used, mark the decl weak now.  */
-  if (!processing_template_decl)
+  if (!processing_template_decl && !DECL_DECOMPOSITION_P (decl))
     maybe_apply_pragma_weak (decl);
 
   if (TREE_CODE (decl) == FUNCTION_DECL
@@ -7422,6 +7422,7 @@ cp_maybe_mangle_decomp (tree decl, tree first, unsigned int count)
       for (unsigned int i = 0; i < count; i++, d = DECL_CHAIN (d))
 	v[count - i - 1] = d;
       SET_DECL_ASSEMBLER_NAME (decl, mangle_decomp (decl, v));
+      maybe_apply_pragma_weak (decl);
     }
 }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 25011ca786d5..669b4bed1b72 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,6 +1,11 @@
 2018-06-22  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2018-04-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/85208
+	* g++.dg/cpp1z/decomp41.C: New test.
+
 	2018-04-04  Jakub Jelinek  <jakub@redhat.com>
 
 	PR inline-asm/85172
diff --git a/gcc/testsuite/g++.dg/cpp1z/decomp41.C b/gcc/testsuite/g++.dg/cpp1z/decomp41.C
new file mode 100644
index 000000000000..1ce836bd6dd7
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/decomp41.C
@@ -0,0 +1,9 @@
+// PR c++/85208
+// { dg-do compile { target c++11 } }
+// { dg-require-weak "" }
+// { dg-options "" }
+
+#pragma weak _ZDC1d1e1fE
+struct A { int i, j, k; };
+auto [a, b, c] = A ();	// { dg-warning "decomposition declaration only available with" "" { target c++14_down } }
+auto [d, e, f] = A ();	// { dg-warning "decomposition declaration only available with" "" { target c++14_down } }