diff mbox

[C++] Fix ICE with bitfields (PR c++/69164)

Message ID 20160107214329.GP18720@tucnak.redhat.com
State New
Headers show

Commit Message

Jakub Jelinek Jan. 7, 2016, 9:43 p.m. UTC 
Hi!

We ICE on the following testcase during SRA, because it sees a field
with DECL_SIZE of 1 which is not DECL_BIT_FIELD.  The problem is that
layout_class_type in some cases copies fields, including DECL_SIZE, but does
not copy over DECL_BIT_FIELD flag.  The following patch copies even that
and also DECL_SIZE_UNIT and DEC_BIT_FIELD_TYPE that weren't copied either.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2016-01-07  Jakub Jelinek  <jakub@redhat.com>

	PR c++/69164
	* class.c (layout_class_type): Also copy DEC_SIZE_UNIT, DECL_BIT_FIELD
	and DEC_BIT_FIELD_TYPE.

	* g++.dg/opt/pr69164.C: New test.


	Jakub

Comments

Bernd Schmidt Jan. 8, 2016, 12:46 p.m. UTC | #1 
On 01/07/2016 10:43 PM, Jakub Jelinek wrote:
>
> 	PR c++/69164
> 	* class.c (layout_class_type): Also copy DEC_SIZE_UNIT, DECL_BIT_FIELD
> 	and DEC_BIT_FIELD_TYPE.

Any reason this isn't using copy_node?


Bernd
Jakub Jelinek Jan. 8, 2016, 12:58 p.m. UTC | #2 
On Fri, Jan 08, 2016 at 01:46:47PM +0100, Bernd Schmidt wrote:
> On 01/07/2016 10:43 PM, Jakub Jelinek wrote:
> >
> >	PR c++/69164
> >	* class.c (layout_class_type): Also copy DEC_SIZE_UNIT, DECL_BIT_FIELD
> >	and DEC_BIT_FIELD_TYPE.
> 
> Any reason this isn't using copy_node?

No idea, perhaps that would be even better.  Jason?

	Jakub
Jason Merrill Jan. 8, 2016, 2:02 p.m. UTC | #3 
On 01/08/2016 07:58 AM, Jakub Jelinek wrote:
> On Fri, Jan 08, 2016 at 01:46:47PM +0100, Bernd Schmidt wrote:
>> On 01/07/2016 10:43 PM, Jakub Jelinek wrote:
>>>
>>> 	PR c++/69164
>>> 	* class.c (layout_class_type): Also copy DEC_SIZE_UNIT, DECL_BIT_FIELD
>>> 	and DEC_BIT_FIELD_TYPE.
>>
>> Any reason this isn't using copy_node?
>
> No idea, perhaps that would be even better.  Jason?

I imagine that the code is trying to avoid copying lang-specific 
information to the artificial as-base type, but I don't see why copying 
that would be a problem.  Try copy_node and see if anything breaks?

Jason
diff mbox

Patch

--- gcc/cp/class.c.jj	2016-01-04 14:55:57.000000000 +0100
+++ gcc/cp/class.c	2016-01-07 13:59:13.895677297 +0100
@@ -6493,7 +6493,10 @@  layout_class_type (tree t, tree *virtual
 	    DECL_FIELD_BIT_OFFSET (*next_field)
 	      = DECL_FIELD_BIT_OFFSET (field);
 	    DECL_SIZE (*next_field) = DECL_SIZE (field);
+	    DECL_SIZE_UNIT (*next_field) = DECL_SIZE_UNIT (field);
 	    DECL_MODE (*next_field) = DECL_MODE (field);
+	    DECL_BIT_FIELD (*next_field) = DECL_BIT_FIELD (field);
+	    DECL_BIT_FIELD_TYPE (*next_field) = DECL_BIT_FIELD_TYPE (field);
 	    next_field = &DECL_CHAIN (*next_field);
 	  }
 
--- gcc/testsuite/g++.dg/opt/pr69164.C.jj	2016-01-07 13:56:33.013915214 +0100
+++ gcc/testsuite/g++.dg/opt/pr69164.C	2016-01-07 13:55:57.000000000 +0100
@@ -0,0 +1,30 @@ 
+// PR c++/69164
+// { dg-do compile { target c++11 } }
+// { dg-options "-O2" }
+
+struct A {
+  struct B {
+    B () {}
+    bool : 1;
+  };
+  B foo () { B r; return r; }
+};
+
+struct C {
+  struct D {
+    D (C *x) : d (x->c.foo ()) {}
+    A::B d;
+  };
+  A c;
+};
+
+struct F : C {
+  D f = this;
+  F (int, int) {}
+};
+
+void
+bar (int a, int b)
+{
+  F (b, a);
+}