[binutils-gdb] Remove null sentinel from 'attributes'

[Tom Tromey <tromey@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=c3f2a3738a3603f51e3621504d8207767526add9

commit c3f2a3738a3603f51e3621504d8207767526add9
Author: Tom Tromey <tromey@adacore.com>
Date:   Tue Feb 22 11:05:41 2022 -0700

    Remove null sentinel from 'attributes'
    
    In a subsequent patch, it's handy if the 'attributes' array in
    ada-lex.l does not have a NULL sentinel at the end.  In C++, this is
    easy to avoid.

Diff:
---
 gdb/ada-lex.l | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/gdb/ada-lex.l b/gdb/ada-lex.l
index 27470a75653..a0c9816e568 100644
--- a/gdb/ada-lex.l
+++ b/gdb/ada-lex.l
@@ -655,7 +655,6 @@ attributes[] = {
   { "size", TICK_SIZE },
   { "tag", TICK_TAG },
   { "val", TICK_VAL },
-  { NULL, -1 }
 };
 
 /* Return the syntactic code corresponding to the attribute name or
@@ -664,24 +663,23 @@ attributes[] = {
 static int
 processAttribute (const char *str)
 {
-  int i, k;
+  for (const auto &item : attributes)
+    if (strcasecmp (str, item.name) == 0)
+      return item.code;
 
-  for (i = 0; attributes[i].code != -1; i += 1)
-    if (strcasecmp (str, attributes[i].name) == 0)
-      return attributes[i].code;
-
-  for (i = 0, k = -1; attributes[i].code != -1; i += 1)
-    if (subseqMatch (str, attributes[i].name))
+  gdb::optional<int> found;
+  for (const auto &item : attributes)
+    if (subseqMatch (str, item.name))
       {
-	if (k == -1)
-	  k = i;
+	if (!found.has_value ())
+	  found = item.code;
 	else
 	  error (_("ambiguous attribute name: `%s'"), str);
       }
-  if (k == -1)
+  if (!found.has_value ())
     error (_("unrecognized attribute: `%s'"), str);
 
-  return attributes[k].code;
+  return *found;
 }
 
 /* Back up lexptr by yyleng and then to the rightmost occurrence of