[C++ PATCH]: Fix 19964

[Nathan Sidwell <nathan at codesourcery dot com>]

Hi,
this patch fixes 19964, a C++ ICE after invalid regression.  It affects the 
common code, so I need approval.

We can create FIELD_DECLs with an error_mark type, and place_field will not set 
the field offset information for them.  This leads to blow up later on.  One 
solution would be not to create such field decls, but that leads to a worse user 
experience as we can get a cascade of errors, when the user tries to use the 
field.  So I rejected that.

This patch simply sets the offsets to zero, when a field decl has an error_mark 
type.

booted & tested on i686-pc-linux-gnu, ok?

nathan

--
Nathan Sidwell    ::   http://www.codesourcery.com   ::     CodeSourcery LLC
nathan@codesourcery.com    ::     http://www.planetfall.pwp.blueyonder.co.uk

2005-10-11  Nathan Sidwell  <nathan@codesourcery.com>

	PR c++/19964
	* stor-layout.c (place_field): Set DECL_FIELD_OFFSET and
	DECL_FIELD_BIT_OFFSET of FIELD_DECLs, even if they have an invalid
	type.

	PR c++/19964
	cp/class.c (walk_subobject_offsets): Don't walk error_mark_node.

Index: stor-layout.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/stor-layout.c,v
retrieving revision 1.243
diff -c -3 -p -r1.243 stor-layout.c
*** stor-layout.c	29 Sep 2005 22:11:12 -0000	1.243
--- stor-layout.c	11 Oct 2005 15:55:13 -0000
*************** place_field (record_layout_info rli, tre
*** 800,808 ****
    /* The type of this field.  */
    tree type = TREE_TYPE (field);
  
!   if (TREE_CODE (field) == ERROR_MARK || TREE_CODE (type) == ERROR_MARK)
!       return;
  
    /* If FIELD is static, then treat it like a separate variable, not
       really like a structure field.  If it is a FUNCTION_DECL, it's a
       method.  In both cases, all we do is lay out the decl, and we do
--- 800,818 ----
    /* The type of this field.  */
    tree type = TREE_TYPE (field);
  
!   gcc_assert (TREE_CODE (field) != ERROR_MARK);
  
+   if (TREE_CODE (type) == ERROR_MARK)
+     {
+       if (TREE_CODE (field) == FIELD_DECL)
+ 	{
+ 	  DECL_FIELD_OFFSET (field) = size_int (0);
+ 	  DECL_FIELD_BIT_OFFSET (field) = bitsize_int (0);
+ 	}
+       
+       return;
+     }
+   
    /* If FIELD is static, then treat it like a separate variable, not
       really like a structure field.  If it is a FUNCTION_DECL, it's a
       method.  In both cases, all we do is lay out the decl, and we do
Index: cp/class.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/class.c,v
retrieving revision 1.733
diff -c -3 -p -r1.733 class.c
*** cp/class.c	22 Sep 2005 16:34:50 -0000	1.733
--- cp/class.c	11 Oct 2005 15:55:20 -0000
*************** walk_subobject_offsets (tree type,
*** 3101,3106 ****
--- 3101,3109 ----
    if (max_offset && INT_CST_LT (max_offset, offset))
      return 0;
  
+   if (type == error_mark_node)
+     return 0;
+   
    if (!TYPE_P (type))
      {
        if (abi_version_at_least (2))

struct A
{ // { dg-error "forward declaration" }
  A : A; // { dg-error "expected|incomplete" }
  A : B; // { dg-error "not declared|incomplete" }
  A : A(); // { dg-error "undefined type|incomplete" }
  A : B(); // { dg-error "function call|incomplete" }
  A : A[]; // { dg-error "expected|array reference|incomplete" }
  A : B[]; // { dg-error "not declared|expected|array reference|incomplete" }
};