[lto] Possible functions for writing FIELD_DECLs

[lto] Possible functions for writing FIELD_DECLs

[Jim Blandy]

Here's my, um, theory as to how one might write DWARF for FIELD_DECLs
and get a reference to them for LTO's use.  Kenny, I'm posting this in
hopes that you'll be able to add code to test it more quickly than I
could.

gcc/ChangeLog.lto:
2007-08-13  Jim Blandy  <jimb@codesourcery.com>

	* dwarf2out.c (lto_field_ref, force_field_die): New functions.
	* dwarf2out.h (lto_field_ref): New declaration.

Index: gcc/dwarf2out.c
===================================================================
--- gcc/dwarf2out.c	(revision 127370)
+++ gcc/dwarf2out.c	(working copy)
@@ -13441,6 +13441,28 @@
   return type_die;
 }
 
+/* Returns the DIE for field.  A DIE will always be returned.  */
+
+static dw_die_ref
+force_field_die (tree field)
+{
+  dw_die_ref decl_die;
+  decl_die = lookup_decl_die (field);
+  if (!decl_die)
+    {
+      tree decl_context = DECL_CONTEXT (field);
+      gcc_assert (decl_context && TYPE_P (decl_context));
+      force_type_die (decl_context);
+
+      /* Forcing a die for the containing type should always generate
+         a die for this field.  */
+      decl_die = lookup_decl_die (field);
+      gcc_assert (decl_die);
+    }
+
+  return decl_die;
+}
+
 /* Force out any required namespaces to be able to output DECL,
    and return the new context_die for it, if it's changed.  */
 
@@ -14991,6 +15013,19 @@
   lto_init_ref (ref, die, DECL_CONTEXT (fn));
 }
 
+void
+lto_field_ref (tree field,
+               lto_out_ref *ref)
+{
+  dw_die_ref die;
+
+  gcc_assert (TREE_CODE (field) == FIELD_DECL);
+  /* Generate the DIE for FIELD.  */
+  die = force_field_die (field);
+  /* Construct the reference.  */
+  lto_init_ref (ref, die, DECL_CONTEXT (field));
+}
+
 #else
 
 /* This should never be used, but its address is needed for comparisons.  */
Index: gcc/dwarf2out.h
===================================================================
--- gcc/dwarf2out.h	(revision 127370)
+++ gcc/dwarf2out.h	(working copy)
@@ -66,3 +66,7 @@
 /* Upon return, *REF contains a reference to FN, which must be a
    FUNCTION_DECL.  */
 extern void lto_fn_ref (tree fn, lto_out_ref *ref);
+
+/* Upon return, *REF contains a reference to FIELD, which must be a
+   FIELD_DECL.  */
+extern void lto_field_ref (tree fn, lto_out_ref *ref);

Re: [lto] Possible functions for writing FIELD_DECLs

[Mark Mitchell]

Jim Blandy wrote:
> Here's my, um, theory as to how one might write DWARF for FIELD_DECLs
> and get a reference to them for LTO's use.  Kenny, I'm posting this in
> hopes that you'll be able to add code to test it more quickly than I
> could.
> 
> gcc/ChangeLog.lto:
> 2007-08-13  Jim Blandy  <jimb@codesourcery.com>
> 
> 	* dwarf2out.c (lto_field_ref, force_field_die): New functions.
> 	* dwarf2out.h (lto_field_ref): New declaration.

This looks good; please check it in.  Please also do the lto/ side of
the equation; Kenny will need lto_resolve_field_ref (like
lto_resolve_fn_ref) to get the FIELD_DECL back.

Thanks,

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713

Re: [lto] Possible functions for writing FIELD_DECLs

[Jim Blandy]

Mark Mitchell <mark@codesourcery.com> writes:
> Jim Blandy wrote:
>> Here's my, um, theory as to how one might write DWARF for FIELD_DECLs
>> and get a reference to them for LTO's use.  Kenny, I'm posting this in
>> hopes that you'll be able to add code to test it more quickly than I
>> could.
>> 
>> gcc/ChangeLog.lto:
>> 2007-08-13  Jim Blandy  <jimb@codesourcery.com>
>> 
>> 	* dwarf2out.c (lto_field_ref, force_field_die): New functions.
>> 	* dwarf2out.h (lto_field_ref): New declaration.
>
> This looks good; please check it in.  Please also do the lto/ side of
> the equation; Kenny will need lto_resolve_field_ref (like
> lto_resolve_fn_ref) to get the FIELD_DECL back.

I've committed this; thanks.

I've posted the patch for the reading side.