[patch] Fix debug info for packed array types in Ada

[Eric Botcazou]

Hi,

packed array types are sometimes represented with integer types under the hood
in Ada, but we nevertheless need to emit them as array types in the debug info
so we have the types.get_array_descr_info langhook for this purpose; but it is
not invoked from modified_type_die, which is responsible for:

FAIL: gdb.ada/arrayptr.exp: scenario=minimal: print pa_ptr.all
FAIL: gdb.ada/arrayptr.exp: scenario=minimal: print pa_ptr.all(3)

in the GDB testsuite.

Tested on x86-64/Linux, both GCC and GDB, OK for the mainline?


2021-09-03  Eric Botcazou  <ebotca...@adacore.com>

        * dwarf2out.c (modified_type_die): Deal with all array types earlier.

-- 
Eric Botcazou
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 07a479f6382..85fc24cc2b6 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -13542,6 +13542,7 @@ modified_type_die (tree type, int cv_quals, bool reverse,
   tree qualified_type;
   tree name, low, high;
   dw_die_ref mod_scope;
+  struct array_descr_info info;
   /* Only these cv-qualifiers are currently handled.  */
   const int cv_qual_mask = (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE
 			    | TYPE_QUAL_RESTRICT | TYPE_QUAL_ATOMIC | 
@@ -13786,6 +13787,13 @@ modified_type_die (tree type, int cv_quals, bool reverse,
 	    }
 	}
     }
+  else if (TREE_CODE (type) == ARRAY_TYPE
+	   || (lang_hooks.types.get_array_descr_info
+	       && lang_hooks.types.get_array_descr_info (type, &info)))
+    {
+      gen_type_die (type, context_die);
+      return lookup_type_die (type);
+    }
   else if (code == INTEGER_TYPE
 	   && TREE_TYPE (type) != NULL_TREE
 	   && subrange_type_for_debug_p (type, &low, &high))
@@ -13836,13 +13844,12 @@ modified_type_die (tree type, int cv_quals, bool reverse,
 	      return lookup_type_die (t);
 	  return lookup_type_die (type);
 	}
-      else if (TREE_CODE (type) != VECTOR_TYPE
-	       && TREE_CODE (type) != ARRAY_TYPE)
-	return lookup_type_die (type_main_variant (type));
-      else
-	/* Vectors have the debugging information in the type,
-	   not the main variant.  */
+      /* Vectors have the debugging information in the type,
+	 not the main variant.  */
+      else if (TREE_CODE (type) == VECTOR_TYPE)
 	return lookup_type_die (type);
+      else
+	return lookup_type_die (type_main_variant (type));
     }
 
   /* Builtin types don't have a DECL_ORIGINAL_TYPE.  For those,