fixits: report duplicate %yacc directives

We should use -ffixit and --update to clean files with duplicate
directives.  And we should complain only once about duplicate obsolete
directives: keep only the "duplicate" warning.  Let's start with %yacc.

For instance on:

    %fixed-output_files
    %fixed-output-files
    %yacc
    %%
    exp:

This run of bison:

    $ bison /tmp/foo.y -u
    foo.y:1.1-19: warning: deprecated directive, use '%fixed-output-files' [-Wdeprecated]
     %fixed-output_files
     ^~~~~~~~~~~~~~~~~~~
    foo.y:2.1-19: warning: duplicate directive [-Wother]
     %fixed-output-files
     ^~~~~~~~~~~~~~~~~~~
    foo.y:1.1-19: previous declaration
     %fixed-output_files
     ^~~~~~~~~~~~~~~~~~~
    foo.y:3.1-5: warning: duplicate directive [-Wother]
     %yacc
     ^~~~~
    foo.y:1.1-19: previous declaration
     %fixed-output_files
     ^~~~~~~~~~~~~~~~~~~
    bison: file 'foo.y' was updated (backup: 'foo.y~')

gives:

    %fixed-output-files
    %%
    exp:

* src/location.h, src/location.c (location_empty): New.
* src/complain.h, src/complain.c (duplicate_directive): New.

* src/getargs.h, src/getargs.c (yacc_flag): Instead of a Boolean, be
the location of the definition.
Update dependencies.

* src/scan-gram.l (%yacc, %fixed-output-files): Move the handling of
its warnings to...
* src/parse-gram.y (do_yacc): This new function.

* tests/input.at (Deprecated Directives): Adjust expectations.

src/complain.c

@@ -399,6 +399,19 @@ deprecated_directive (location const *loc, char const *old, char const *upd)
     fixits_register (loc, upd);
 }
 
+void
+duplicate_directive (char const *directive,
+                     location first, location second)
+{
+  if (feature_flag & feature_caret)
+    complain (&second, Wother, _("duplicate directive"));
+  else
+    complain (&second, Wother, _("duplicate directive: %s"), directive);
+  unsigned i = SUB_INDENT;
+  complain_indent (&first, complaint, &i, _("previous declaration"));
+  fixits_register (&second, "");
+}
+
 void
 duplicate_rule_directive (char const *directive,
                           location first, location second)

src/complain.h

@@ -126,6 +126,10 @@ void bison_directive (location const *loc, char const *directive);
 void deprecated_directive (location const *loc,
                            char const *obsolete, char const *updated);
 
+/** Report a repeated directive.  */
+void duplicate_directive (char const *directive,
+                          location first, location second);
+
 /** Report a repeated directive for a rule.  */
 void duplicate_rule_directive (char const *directive,
                                location first, location second);

src/files.c

@@ -285,7 +285,7 @@ compute_file_name_parts (void)
                       last_component (spec_file_prefix) - spec_file_prefix);
           all_but_tab_ext = xstrdup (spec_file_prefix);
         }
-      else if (yacc_flag)
+      else if (! location_empty (yacc_loc))
         {
           /* If --yacc, then the output is 'y.tab.c'.  */
           dir_prefix = xstrdup ("");
@@ -306,7 +306,7 @@ compute_file_name_parts (void)
         all_but_ext = xstrdup (all_but_tab_ext);
 
       /* Compute the extensions from the grammar file name.  */
-      if (ext && !yacc_flag)
+      if (ext && location_empty (yacc_loc))
         compute_exts_from_gf (ext);
     }
 }

src/getargs.c

@@ -41,7 +41,7 @@ bool graph_flag = false;
 bool xml_flag = false;
 bool no_lines_flag = false;
 bool token_table_flag = false;
-bool yacc_flag = false; /* for -y */
+location yacc_loc = EMPTY_LOCATION_INIT;
 bool update_flag = false; /* for -u */
 
 bool nondeterministic_parser = false;
@@ -709,7 +709,7 @@ getargs (int argc, char *argv[])
 
       case 'y':
         warning_argmatch ("error=yacc", 0, 6);
-        yacc_flag = true;
+        yacc_loc = command_line_location ();
         break;
 
       case LOCATIONS_OPTION:

src/getargs.h

@@ -39,7 +39,7 @@ extern bool graph_flag;                 /* for -g */
 extern bool xml_flag;                   /* for -x */
 extern bool no_lines_flag;              /* for -l */
 extern bool token_table_flag;           /* for -k */
-extern bool yacc_flag;                  /* for -y */
+extern location yacc_loc;               /* for -y */
 extern bool update_flag;                /* for -u */
 
 /* GLR_PARSER is true if the input file says to use the GLR

src/location.c

@@ -216,6 +216,13 @@ location_caret (location loc, FILE *out)
   }
 }
 
+bool
+location_empty (location loc)
+{
+  return !loc.start.file && !loc.start.line && !loc.start.column
+    && !loc.end.file && !loc.end.line && !loc.end.column;
+}
+
 void
 boundary_set_from_string (boundary *bound, char *loc_str)
 {

src/location.h

@@ -126,6 +126,9 @@ location_cmp (location a, location b)
   return res;
 }
 
+/* Whether this is the empty location.  */
+bool location_empty (location loc);
+
 /* LOC_STR must be formatted as 'file:line.column', it will be modified.  */
 void boundary_set_from_string (boundary *bound, char *loc_str);
 

src/output.c

@@ -665,7 +665,7 @@ prepare (void)
   MUSCLE_INSERT_BOOL ("tag_seen_flag", tag_seen);
   MUSCLE_INSERT_BOOL ("token_table_flag", token_table_flag);
   MUSCLE_INSERT_BOOL ("use_push_for_pull_flag", use_push_for_pull_flag);
-  MUSCLE_INSERT_BOOL ("yacc_flag", yacc_flag);
+  MUSCLE_INSERT_BOOL ("yacc_flag", !location_empty (yacc_loc));
 
   /* File names.  */
   if (spec_name_prefix)

src/parse-gram.y

@@ -95,6 +95,9 @@
   /* Handle a %skeleton directive.  */
   static void do_skeleton (location const *loc, char const *skel);
 
+  /* Handle a %yacc directive.  */
+  static void do_yacc (location const *loc, char const *directive);
+
   static void gram_error (location const *, char const *);
 
   /* A string that describes a char (e.g., 'a' -> "'a'").  */
@@ -201,8 +204,9 @@
 
 %type <uniqstr>
   BRACKETED_ID ID ID_COLON
-  PERCENT_ERROR_VERBOSE PERCENT_FLAG PERCENT_NAME_PREFIX TAG
+  PERCENT_ERROR_VERBOSE PERCENT_FLAG PERCENT_NAME_PREFIX
-  tag tag.opt variable
+  PERCENT_YACC
+  TAG tag tag.opt variable
 %printer { fputs ($$, yyo); } <uniqstr>
 %printer { fprintf (yyo, "[%s]", $$); } BRACKETED_ID
 %printer { fprintf (yyo, "%s:", $$); } ID_COLON
@@ -329,7 +333,7 @@ prologue_declaration:
 | "%skeleton" STRING            { do_skeleton (&@2, $2); }
 | "%token-table"                { token_table_flag = true; }
 | "%verbose"                    { report_flag |= report_states; }
-| "%yacc"                       { yacc_flag = true; }
+| "%yacc"                       { do_yacc (&@$, $1); }
 | error ";"                     { current_class = unknown_sym; yyerrok; }
 | /*FIXME: Err?  What is this horror doing here? */ ";"
 ;
@@ -956,6 +960,25 @@ do_skeleton (location const *loc, char const *skel)
   skeleton_arg (skeleton_user, grammar_prio, *loc);
 }
 
+static void
+do_yacc (location const *loc, char const *directive)
+{
+  bison_directive (loc, directive);
+  bool warned = false;
+
+  if (location_empty (yacc_loc))
+    yacc_loc = *loc;
+  else
+    {
+      duplicate_directive (directive, yacc_loc, *loc);
+      warned = true;
+    }
+
+  if (!warned
+      && STRNEQ (directive, "%fixed-output-files")
+      && STRNEQ (directive, "%yacc"))
+    deprecated_directive (loc, directive, "%fixed-output-files");
+}
 
 static void
 gram_error (location const *loc, char const *msg)

src/scan-gram.l

@@ -229,7 +229,7 @@ eqopt    ({sp}=)?
   "%expect"                         return BISON_DIRECTIVE (EXPECT);
   "%expect-rr"                      return BISON_DIRECTIVE (EXPECT_RR);
   "%file-prefix"                    return BISON_DIRECTIVE (FILE_PREFIX);
-  "%fixed-output-files"             return BISON_DIRECTIVE (YACC);
+  "%fixed-output-files"             RETURN_VALUE (PERCENT_YACC, uniqstr_new (yytext));
   "%initial-action"                 return BISON_DIRECTIVE (INITIAL_ACTION);
   "%glr-parser"                     return BISON_DIRECTIVE (GLR_PARSER);
   "%language"                       return BISON_DIRECTIVE (LANGUAGE);
@@ -259,7 +259,7 @@ eqopt    ({sp}=)?
   "%type"                           return PERCENT_TYPE;
   "%union"                          return PERCENT_UNION;
   "%verbose"                        return BISON_DIRECTIVE (VERBOSE);
-  "%yacc"                           return BISON_DIRECTIVE (YACC);
+  "%yacc"                           RETURN_VALUE (PERCENT_YACC, uniqstr_new (yytext));
 
   /* Deprecated since Bison 3.0 (2013-07-25), but the warning is
      issued only since Bison 3.3. */
@@ -274,7 +274,7 @@ eqopt    ({sp}=)?
   "%error"[-_]"verbose"             RETURN_VALUE (PERCENT_ERROR_VERBOSE, uniqstr_new (yytext));
   "%expect"[-_]"rr"                 DEPRECATED ("%expect-rr");
   "%file-prefix"{eqopt}             DEPRECATED ("%file-prefix");
-  "%fixed"[-_]"output"[-_]"files"   DEPRECATED ("%fixed-output-files");
+  "%fixed"[-_]"output"[-_]"files"   RETURN_VALUE (PERCENT_YACC, uniqstr_new (yytext));
   "%no"[-_]"default"[-_]"prec"      DEPRECATED ("%no-default-prec");
   "%no"[-_]"lines"                  DEPRECATED ("%no-lines");
   "%output"{eqopt}                  DEPRECATED ("%output");

tests/input.at

@@ -2526,8 +2526,12 @@ input.y:14.1-15.2: warning: deprecated directive: '%file-prefix\n =', use '%file
 fix-it:"input.y":{14:1-15:3}:"%file-prefix"
 input.y:17.1-19: warning: deprecated directive: '%fixed-output_files', use '%fixed-output-files' [-Wdeprecated]
 fix-it:"input.y":{17:1-17:20}:"%fixed-output-files"
-input.y:18.1-19: warning: deprecated directive: '%fixed_output-files', use '%fixed-output-files' [-Wdeprecated]
+input.y:18.1-19: warning: duplicate directive: %fixed_output-files [-Wother]
-fix-it:"input.y":{18:1-18:20}:"%fixed-output-files"
+input.y:17.1-19: previous declaration
+fix-it:"input.y":{18:1-18:20}:""
+input.y:19.1-19: warning: duplicate directive: %fixed-output-files [-Wother]
+input.y:17.1-19: previous declaration
+fix-it:"input.y":{19:1-19:20}:""
 input.y:20.1-19: warning: deprecated directive: '%name-prefix= "foo"', use '%define api.prefix {foo}' [-Wdeprecated]
 fix-it:"input.y":{20:1-20:20}:"%define api.prefix {foo}"
 input.y:21.1-16: warning: deprecated directive: '%no-default_prec', use '%no-default-prec' [-Wdeprecated]
@@ -2550,12 +2554,12 @@ fix-it:"input.y":{29:1-29:19}:"%define api.prefix {bar}"
 input.y: warning: fix-its can be applied.  Rerun with option '--update'. [-Wother]
 ]])
 
-AT_CHECK([[sed -e '/^fix-it:/d' errors-all >experr]])
-AT_BISON_CHECK([[input.y]], [[1]], [[]], [experr])
-
 AT_CHECK([cp errors-all experr])
 AT_BISON_CHECK([[-ffixit input.y]], [[1]], [[]], [experr])
 
+AT_CHECK([[sed -e '/^fix-it:/d' errors-all >experr]])
+AT_BISON_CHECK([[input.y]], [[1]], [[]], [experr])
+
 # Update the input file.
 AT_CHECK([cp input.y input.y.orig])
 AT_CHECK([sed -e '/fix-it/d' <errors-all >experr])
@@ -2583,8 +2587,6 @@ AT_CHECK([cat input.y], [],
 %file-prefix
 "bar"
 %fixed-output-files
-%fixed-output-files
-%fixed-output-files
 %define api.prefix {foo}
 %no-default-prec
 %no-default-prec
@@ -2599,10 +2601,10 @@ exp : '0'
 ]])
 
 AT_BISON_CHECK([[-fcaret input.y]], [[1]], [],
-[[input.y:27.1-24: error: %define variable 'api.prefix' redefined
+[[input.y:25.1-24: error: %define variable 'api.prefix' redefined
  %define api.prefix {bar}
  ^~~~~~~~~~~~~~~~~~~~~~~~
-input.y:19.1-24:     previous definition
+input.y:17.1-24:     previous definition
  %define api.prefix {foo}
  ^~~~~~~~~~~~~~~~~~~~~~~~
 input.y: warning: fix-its can be applied.  Rerun with option '--update'. [-Wother]