Generate debug info for local dynamic record types

In Ada you can embed VLAs in local record types and thus end up with
dynamic offsets in record types, which are not well described in DWARF
because 1) the temporaries generated for them by the gimplifier are
naturally marked DECL_IGNORED_P and 2) when the types are referenced
in nested subprograms, the DWARF back-end does not correctly handle
the rewritten references.

gcc/
	* dwarf2out.c (loc_list_from_tree_1) <DECL>: During early DWARF, do
	not expand the VALUE_EXPR of variables put in the non-local frame.
	* gimplify.c (gimplify_type_sizes) <RECORD_TYPE>: If the type is not
	to be ignored for debug info, ensure its variable offsets are not.
gcc/testsuite/
	* gnat.dg/debug8.adb: Minor tweak.
	* gnat.dg/debug11.adb: Likewise.
	* gnat.dg/debug16.adb: Likewise.
	* gnat.dg/debug17.adb: New test.
	* gnat.dg/specs/debug1.ads: Minor tweak.

1 files changed, 14 insertions, 6 deletions

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index b65106b..e790f08 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -15141,11 +15141,15 @@ gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
 void
 gimplify_type_sizes (tree type, gimple_seq *list_p)
 {
-  tree field, t;
-
   if (type == NULL || type == error_mark_node)
     return;
 
+  const bool ignored_p
+    = TYPE_NAME (type)
+      && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
+      && DECL_IGNORED_P (TYPE_NAME (type));
+  tree t;
+
   /* We first do the main variant, then copy into any other variants.  */
   type = TYPE_MAIN_VARIANT (type);
 
@@ -15179,9 +15183,7 @@ gimplify_type_sizes (tree type, gimple_seq *list_p)
       /* Ensure VLA bounds aren't removed, for -O0 they should be variables
 	 with assigned stack slots, for -O1+ -g they should be tracked
 	 by VTA.  */
-      if (!(TYPE_NAME (type)
-	    && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
-	    && DECL_IGNORED_P (TYPE_NAME (type)))
+      if (!ignored_p
 	  && TYPE_DOMAIN (type)
 	  && INTEGRAL_TYPE_P (TYPE_DOMAIN (type)))
 	{
@@ -15197,10 +15199,16 @@ gimplify_type_sizes (tree type, gimple_seq *list_p)
     case RECORD_TYPE:
     case UNION_TYPE:
     case QUAL_UNION_TYPE:
-      for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
+      for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
 	if (TREE_CODE (field) == FIELD_DECL)
 	  {
 	    gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
+	    /* Likewise, ensure variable offsets aren't removed.  */
+	    if (!ignored_p
+		&& (t = DECL_FIELD_OFFSET (field))
+		&& VAR_P (t)
+		&& DECL_ARTIFICIAL (t))
+	      DECL_IGNORED_P (t) = 0;
 	    gimplify_one_sizepos (&DECL_SIZE (field), list_p);
 	    gimplify_one_sizepos (&DECL_SIZE_UNIT (field), list_p);
 	    gimplify_type_sizes (TREE_TYPE (field), list_p);