Convert c_string_type to an enum flags type

c_string_type contains values meant to be OR'ed together (even though
some bits are mutually exclusive), so it makes sense to make it an
enum flags type.

gdb/ChangeLog:
2015-11-17  Simon Marchi  <simon.marchi@ericsson.com>

	* c-exp.y (exp): Adjust, change enum c_string_type to
	c_string_type.
	(parse_string_or_char): Likewise.
	* c-lang.c (charset_for_string_type): Likewise.
	(classify_type): Likewise.
	(c_printchar): Likewise.
	(c_printstr): Likewise.
	(evaluate_subexp_c): Likewise.  And change cast to enum
	c_string_type_values.
	* c-lang.h: Include "common/enum_flags.h".
	(enum c_string_type): Rename to...
	(enum c_string_type_values): ...this.
	(c_string_type): Define new enum flags type.

gdb/ChangeLog

@@ -1,3 +1,19 @@
+2015-11-17  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* c-exp.y (exp): Adjust, change enum c_string_type to
+	c_string_type.
+	(parse_string_or_char): Likewise.
+	* c-lang.c (charset_for_string_type): Likewise.
+	(classify_type): Likewise.
+	(c_printchar): Likewise.
+	(c_printstr): Likewise.
+	(evaluate_subexp_c): Likewise.  And change cast to enum
+	c_string_type_values.
+	* c-lang.h: Include "common/enum_flags.h".
+	(enum c_string_type): Rename to...
+	(enum c_string_type_values): ...this.
+	(c_string_type): Define new enum flags type.
+
 2015-11-17  Pedro Alves  <palves@redhat.com>
 
 	* btrace.h: Include common/enum-flags.h.

gdb/c-exp.y

@@ -864,7 +864,7 @@ string_exp:
 exp	:	string_exp
 			{
 			  int i;
-			  enum c_string_type type = C_STRING;
+			  c_string_type type = C_STRING;
 
 			  for (i = 0; i < $1.len; ++i)
 			    {
@@ -878,7 +878,7 @@ exp	:	string_exp
 				  if (type != C_STRING
 				      && type != $1.tokens[i].type)
 				    error (_("Undefined string concatenation."));
-				  type = (enum c_string_type) $1.tokens[i].type;
+				  type = (enum c_string_type_values) $1.tokens[i].type;
 				  break;
 				default:
 				  /* internal error */
@@ -2164,7 +2164,7 @@ parse_string_or_char (const char *tokptr, const char **outptr,
 		      struct typed_stoken *value, int *host_chars)
 {
   int quote;
-  enum c_string_type type;
+  c_string_type type;
   int is_objc = 0;
 
   /* Build the gdb internal form of the input string in tempbuf.  Note

gdb/c-lang.c

@@ -41,8 +41,7 @@ extern void _initialize_c_language (void);
    character set name.  */
 
 static const char *
-charset_for_string_type (enum c_string_type str_type,
+charset_for_string_type (c_string_type str_type, struct gdbarch *gdbarch)
-			 struct gdbarch *gdbarch)
 {
   switch (str_type & ~C_CHAR)
     {
@@ -72,11 +71,11 @@ charset_for_string_type (enum c_string_type str_type,
    characters of this type in target BYTE_ORDER to the host character
    set.  */
 
-static enum c_string_type
+static c_string_type
 classify_type (struct type *elttype, struct gdbarch *gdbarch,
 	       const char **encoding)
 {
-  enum c_string_type result;
+  c_string_type result;
 
   /* We loop because ELTTYPE may be a typedef, and we want to
      successively peel each typedef until we reach a type we
@@ -155,7 +154,7 @@ c_emit_char (int c, struct type *type,
 void
 c_printchar (int c, struct type *type, struct ui_file *stream)
 {
-  enum c_string_type str_type;
+  c_string_type str_type;
 
   str_type = classify_type (type, get_type_arch (type), NULL);
   switch (str_type)
@@ -191,7 +190,7 @@ c_printstr (struct ui_file *stream, struct type *type,
 	    const char *user_encoding, int force_ellipses,
 	    const struct value_print_options *options)
 {
-  enum c_string_type str_type;
+  c_string_type str_type;
   const char *type_encoding;
   const char *encoding;
 
@@ -577,7 +576,7 @@ evaluate_subexp_c (struct type *expect_type, struct expression *exp,
 	struct obstack output;
 	struct cleanup *cleanup;
 	struct value *result;
-	enum c_string_type dest_type;
+	c_string_type dest_type;
 	const char *dest_charset;
 	int satisfy_expected = 0;
 
@@ -589,8 +588,8 @@ evaluate_subexp_c (struct type *expect_type, struct expression *exp,
 
 	++*pos;
 	limit = *pos + BYTES_TO_EXP_ELEM (oplen + 1);
-	dest_type
+	dest_type = ((enum c_string_type_values)
-	  = (enum c_string_type) longest_to_int (exp->elts[*pos].longconst);
+		     longest_to_int (exp->elts[*pos].longconst));
 	switch (dest_type & ~C_CHAR)
 	  {
 	  case C_STRING:

gdb/c-lang.h

@@ -29,12 +29,13 @@ struct parser_state;
 #include "value.h"
 #include "macroexp.h"
 #include "parser-defs.h"
+#include "common/enum-flags.h"
 
 
 /* The various kinds of C string and character.  Note that these
    values are chosen so that they may be or'd together in certain
    ways.  */
-enum c_string_type
+enum c_string_type_values
   {
     /* An ordinary string: "value".  */
     C_STRING = 0,
@@ -56,6 +57,8 @@ enum c_string_type
     C_CHAR_32 = 7
   };
 
+DEF_ENUM_FLAGS_TYPE (enum c_string_type_values, c_string_type);
+
 /* Defined in c-exp.y.  */
 
 extern int c_parse (struct parser_state *);