diff mbox

Fix PR c++/27100

Message ID 20160530201951.17380-1-patrick@parcs.ath.cx
State New
Headers show

Commit Message

Patrick Palka May 30, 2016, 8:19 p.m. UTC 
Here's a more straightforward version of the patch that abuses the fact
that the fields DECL_PENDING_INLINE_INFO and DECL_SAVED_FUNCTION_DATA
are a union.

Bootstrapped + regtested on x86_64-pc-linux-gnu.  Does this look OK to
commit?

gcc/cp/ChangeLog:

	PR c++/27100
	* decl.c (duplicate_decls): Copy the DECL_PENDING_INLINE_P flag.

gcc/testsuite/ChangeLog:

	PR c++/27100
	* g++.dg/other/friend6.C: New test.
---
 gcc/cp/decl.c                        | 11 +++++++++--
 gcc/testsuite/g++.dg/other/friend6.C | 15 +++++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/other/friend6.C

Comments

Jason Merrill May 31, 2016, 2:24 p.m. UTC | #1 
On Mon, May 30, 2016 at 4:19 PM, Patrick Palka <patrick@parcs.ath.cx> wrote:
> Here's a more straightforward version of the patch that abuses the fact
> that the fields DECL_PENDING_INLINE_INFO and DECL_SAVED_FUNCTION_DATA
> are a union.

That gets into undefined behavior; let's go with the first patch.

Jason
diff mbox

Patch

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 90e147c..b26e8ae 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -2351,8 +2351,15 @@  duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
 	}
       else
 	{
-	  if (DECL_PENDING_INLINE_INFO (newdecl) == 0)
-	    DECL_PENDING_INLINE_INFO (newdecl) = DECL_PENDING_INLINE_INFO (olddecl);
+	  if (DECL_PENDING_INLINE_INFO (newdecl) == NULL)
+	    {
+	      /* This also copies DECL_SAVED_FUNCTION_DATA since the two fields
+		 are a union (tagged by DECL_PENDING_INLINE_P).  */
+	      DECL_PENDING_INLINE_INFO (newdecl)
+		= DECL_PENDING_INLINE_INFO (olddecl);
+	      DECL_PENDING_INLINE_P (newdecl)
+		= DECL_PENDING_INLINE_P (olddecl);
+	    }
 
 	  DECL_DECLARED_INLINE_P (newdecl) |= DECL_DECLARED_INLINE_P (olddecl);
 
diff --git a/gcc/testsuite/g++.dg/other/friend6.C b/gcc/testsuite/g++.dg/other/friend6.C
new file mode 100644
index 0000000..5f593a1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/other/friend6.C
@@ -0,0 +1,15 @@ 
+// PR c++/27100
+// This used to fail at link time with an "undefined reference to 'foo'" error.
+// { dg-do link }
+
+struct A
+{
+  friend void foo (const A&) { }
+  friend void foo (const A&);
+};
+
+int
+main ()
+{
+  foo (A ());
+}