Handle multi-byte bracket sequences in Ada lexer

As noted in an earlier patch, the Ada lexer does not handle multi-byte
bracket sequences.  This patch adds support for these for character
literals.  gdb does not generally seem to handle the Ada wide string
types, so for the time being these continue to be excluded -- but an
explicit error is added to make this more clear.

gdb/ada-exp.y

@@ -98,7 +98,7 @@ static struct type *type_long_long (struct parser_state *);
 
 static struct type *type_long_double (struct parser_state *);
 
-static struct type *type_char (struct parser_state *);
+static struct type *type_for_char (struct parser_state *, ULONGEST);
 
 static struct type *type_boolean (struct parser_state *);
 
@@ -1727,10 +1727,18 @@ type_long_double (struct parser_state *par_state)
 }
 
 static struct type *
-type_char (struct parser_state *par_state)
+type_for_char (struct parser_state *par_state, ULONGEST value)
 {
+  if (value <= 0xff)
     return language_string_char_type (par_state->language (),
 				      par_state->gdbarch ());
+  else if (value <= 0xffff)
+    return language_lookup_primitive_type (par_state->language (),
+					   par_state->gdbarch (),
+					   "wide_character");
+  return language_lookup_primitive_type (par_state->language (),
+					 par_state->gdbarch (),
+					 "wide_wide_character");
 }
 
 static struct type *

gdb/ada-lang.c

@@ -10187,7 +10187,7 @@ ada_resolvable::replace (operation_up &&owner,
   return std::move (owner);
 }
 
-/* Convert the character literal whose ASCII value would be VAL to the
+/* Convert the character literal whose value would be VAL to the
    appropriate value of type TYPE, if there is a translation.
    Otherwise return VAL.  Hence, in an enumeration type ('A', 'B'),
    the literal 'A' (VAL == 65), returns 0.  */
@@ -10195,7 +10195,7 @@ ada_resolvable::replace (operation_up &&owner,
 static LONGEST
 convert_char_literal (struct type *type, LONGEST val)
 {
-  char name[7];
+  char name[12];
   int f;
 
   if (type == NULL)
@@ -10206,8 +10206,12 @@ convert_char_literal (struct type *type, LONGEST val)
 
   if ((val >= 'a' && val <= 'z') || (val >= '0' && val <= '9'))
     xsnprintf (name, sizeof (name), "Q%c", (int) val);
+  else if (val >= 0 && val < 256)
+    xsnprintf (name, sizeof (name), "QU%02x", (unsigned) val);
+  else if (val >= 0 && val < 0x10000)
+    xsnprintf (name, sizeof (name), "QW%04x", (unsigned) val);
   else
-    xsnprintf (name, sizeof (name), "QU%02x", (int) val);
+    xsnprintf (name, sizeof (name), "QWW%08lx", (unsigned long) val);
   size_t len = strlen (name);
   for (f = 0; f < type->num_fields (); f += 1)
     {
@@ -13005,9 +13009,11 @@ public:
     add (arch_integer_type (gdbarch, gdbarch_short_bit (gdbarch),
 			    0, "short_integer"));
     struct type *char_type = arch_character_type (gdbarch, TARGET_CHAR_BIT,
-						  0, "character");
+						  1, "character");
     lai->set_string_char_type (char_type);
     add (char_type);
+    add (arch_character_type (gdbarch, 16, 1, "wide_character"));
+    add (arch_character_type (gdbarch, 32, 1, "wide_wide_character"));
     add (arch_float_type (gdbarch, gdbarch_float_bit (gdbarch),
 			  "float", gdbarch_float_format (gdbarch)));
     add (arch_float_type (gdbarch, gdbarch_double_bit (gdbarch),

gdb/ada-lex.l

@@ -1,4 +1,4 @@
-/* FLEX lexer for Ada expressions, for GDB.
+/* FLEX lexer for Ada expressions, for GDB. -*- c++ -*-
    Copyright (C) 1994-2022 Free Software Foundation, Inc.
 
    This file is part of GDB.
@@ -150,20 +150,22 @@ static int paren_depth;
 		}
 
 <INITIAL>"'"({GRAPHIC}|\")"'" {
-		   yylval.typed_val.type = type_char (pstate);
 		   yylval.typed_val.val = yytext[1];
+		   yylval.typed_val.type = type_for_char (pstate, yytext[1]);
 		   return CHARLIT;
 		}
 
-<INITIAL>"'[\""{HEXDIG}{2}"\"]'"   {
-                   int v;
-                   yylval.typed_val.type = type_char (pstate);
-		   sscanf (yytext+3, "%2x", &v);
+<INITIAL>"'[\""{HEXDIG}{2,}"\"]'"   {
+                   ULONGEST v = strtoulst (yytext+3, nullptr, 16);
 		   yylval.typed_val.val = v;
+                   yylval.typed_val.type = type_for_char (pstate, v);
 		   return CHARLIT;
 		}
 
-\"({GRAPHIC}|"[\""({HEXDIG}{2}|\")"\"]")*\"   {
+	/* Note that we don't handle bracket sequences of more than 2
+	   digits here.  Currently there's no support for wide or
+	   wide-wide strings.  */
+\"({GRAPHIC}|"[\""({HEXDIG}{2,}|\")"\"]")*\"   {
 	           yylval.sval = processString (yytext+1, yyleng-2);
 		   return STRING;
 		}
@@ -513,10 +515,12 @@ processString (const char *text, int len)
 	     }
            else
 	     {
-               int chr;
-	       sscanf (p+2, "%2x", &chr);
+	       const char *end;
+	       ULONGEST chr = strtoulst (p + 2, &end, 16);
+	       if (chr > 0xff)
+		 error (_("wide strings are not yet supported"));
 	       *q = (char) chr;
-	       p += 5;
+	       p = end + 1;
 	     }
          }
        else

gdb/ada-valprint.c

@@ -277,7 +277,11 @@ ada_emit_char (int c, struct type *type, struct ui_file *stream,
 	fprintf_filtered (stream, "%c", c);
     }
   else
-    fprintf_filtered (stream, "[\"%0*x\"]", type_len * 2, c);
+    {
+      /* Follow GNAT's lead here and only use 6 digits for
+	 wide_wide_character.  */
+      fprintf_filtered (stream, "[\"%0*x\"]", std::min (6, type_len * 2), c);
+    }
 }
 
 /* Character #I of STRING, given that TYPE_LEN is the size in bytes

gdb/testsuite/gdb.ada/char_enum_unicode.exp

@@ -40,4 +40,13 @@ gdb_test "print Char_Y" " = 2 $y"
 gdb_test "print Char_King" " = 3 $king"
 gdb_test "print Char_Thorn" " = 4 $thorn"
 gdb_test "print Char_Enum_Type'('x')" " = 1 'x'"
+gdb_test "print Char_Enum_Type'('\[\"0178\"\]')" " = 2 $y"
+gdb_test "print Char_Enum_Type'('\[\"1fa00\"\]')" " = 3 $king"
 gdb_test "print Char_Enum_Type'('\[\"de\"\]')" " = 4 $thorn"
+
+gdb_test "print '\[\"0178\"\]'" " = 376 $y"
+gdb_test "print '\[\"01fa00\"\]'" " = 129536 $king"
+gdb_test "print '\[\"de\"\]'" " = 222 $thorn"
+
+gdb_test "print \"\[\"0178\"\]\"" "wide strings are not yet supported"
+gdb_test "print \"\[\"de\"\]\"" " = \"\\\[\"de\"\\\]\""

gdb/testsuite/gdb.ada/widewide.exp

@@ -33,9 +33,9 @@ if ![runto "foo.adb:$bp_location" ] then {
 
 gdb_test "print some_easy" "= 74 'J'"
 
-gdb_test "print some_larger" "= 48879 '\\\[\"0000beef\"\\\]'"
+gdb_test "print some_larger" "= 48879 '\\\[\"00beef\"\\\]'"
 
-gdb_test "print some_big" "= 14335727 '\\\[\"00dabeef\"\\\]'"
+gdb_test "print some_big" "= 14335727 '\\\[\"dabeef\"\\\]'"
 
 gdb_test "print my_wws" "= \" helo\""