Change is_valid_DW_AT_defaulted to a method on attribute

This changes is_valid_DW_AT_defaulted to be a method on struct attribute.
Now it correctly respects the form of the attribute.

gdb/ChangeLog
2020-09-29  Tom Tromey  <tom@tromey.com>

	* dwarf2/read.c (is_valid_DW_AT_defaulted): Move to attribute.c.
	(dwarf2_add_member_fn): Update.
	* dwarf2/attribute.h (struct attribute) <defaulted>: Declare.
	* dwarf2/attribute.c (attribute::defaulted): New method, from
	is_valid_DW_AT_defaulted.

3 files changed, 32 insertions, 21 deletions

diff --git a/gdb/dwarf2/attribute.c b/gdb/dwarf2/attribute.c
index 7783c46..1e56139 100644
--- a/gdb/dwarf2/attribute.c
+++ b/gdb/dwarf2/attribute.c
@@ -199,3 +199,26 @@ attribute::form_requires_reprocessing () const
 	  || form == DW_FORM_addrx
 	  || form == DW_FORM_GNU_addr_index);
 }
+
+/* See attribute.h.  */
+
+dwarf_defaulted_attribute
+attribute::defaulted () const
+{
+  LONGEST value = constant_value (-1);
+
+  switch (value)
+    {
+    case DW_DEFAULTED_no:
+    case DW_DEFAULTED_in_class:
+    case DW_DEFAULTED_out_of_class:
+      return (dwarf_defaulted_attribute) value;
+    }
+
+  /* If the form was not constant, we already complained in
+     constant_value, so there's no need to complain again.  */
+  if (form_is_constant ())
+    complaint (_("unrecognized DW_AT_defaulted value (%s)"),
+	       plongest (value));
+  return DW_DEFAULTED_no;
+}
diff --git a/gdb/dwarf2/attribute.h b/gdb/dwarf2/attribute.h
index c2e14ef..0e29f80 100644
--- a/gdb/dwarf2/attribute.h
+++ b/gdb/dwarf2/attribute.h
@@ -29,6 +29,7 @@
 
 #include "dwarf2.h"
 #include "gdbtypes.h"
+#include "gdbsupport/gdb_optional.h"
 
 /* Blocks are a bunch of untyped bytes.  */
 struct dwarf_block
@@ -250,6 +251,12 @@ struct attribute
     return requires_reprocessing;
   }
 
+  /* Return the value as one of the recognized enum
+     dwarf_defaulted_attribute constants according to DWARF5 spec,
+     Table 7.24.  If the value is incorrect, or if this attribute has
+     the wrong form, then a complaint is issued and DW_DEFAULTED_no is
+     returned.  */
+  dwarf_defaulted_attribute defaulted () const;
 
   ENUM_BITFIELD(dwarf_attribute) name : 15;
 
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 43c9adb..86a7918 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -15538,25 +15538,6 @@ dwarf2_is_constructor (struct die_info *die, struct dwarf2_cu *cu)
 	  && (type_name[len] == '\0' || type_name[len] == '<'));
 }
 
-/* Check if the given VALUE is a recognized enum
-   dwarf_defaulted_attribute constant according to DWARF5 spec,
-   Table 7.24.  */
-
-static bool
-is_valid_DW_AT_defaulted (ULONGEST value)
-{
-  switch (value)
-    {
-    case DW_DEFAULTED_no:
-    case DW_DEFAULTED_in_class:
-    case DW_DEFAULTED_out_of_class:
-      return true;
-    }
-
-  complaint (_("unrecognized DW_AT_defaulted value (%s)"), pulongest (value));
-  return false;
-}
-
 /* Add a member function to the proper fieldlist.  */
 
 static void
@@ -15666,8 +15647,8 @@ dwarf2_add_member_fn (struct field_info *fip, struct die_info *die,
 
   /* Check for defaulted methods.  */
   attr = dwarf2_attr (die, DW_AT_defaulted, cu);
-  if (attr != nullptr && is_valid_DW_AT_defaulted (DW_UNSND (attr)))
-    fnp->defaulted = (enum dwarf_defaulted_attribute) DW_UNSND (attr);
+  if (attr != nullptr)
+    fnp->defaulted = attr->defaulted ();
 
   /* Check for deleted methods.  */
   attr = dwarf2_attr (die, DW_AT_deleted, cu);