diagnostics: keep the fixits

Introduce proper support for fixits, instead of just printing them on
demand.

* bootstrap.conf: We need gnulib's xlists.
* src/fixits.h, src/fixits.c: New.
* src/complain.c (deprecated_directive): Use fixits_register.
* src/main.c (main): Use fixits_free.

src/complain.c

@@ -28,9 +28,9 @@
 
 #include "complain.h"
 #include "files.h"
+#include "fixits.h"
 #include "getargs.h"
 #include "quote.h"
-#include "quotearg.h"
 
 err_status complaint_status = status_none;
 
@@ -394,14 +394,7 @@ deprecated_directive (location const *loc, char const *old, char const *upd)
     complain (loc, Wdeprecated,
               _("deprecated directive: %s, use %s"),
               quote (old), quote_n (1, upd));
-  /* GCC and Clang follow the same pattern.
-     http://clang.llvm.org/docs/UsersManual.html#cmdoption-fdiagnostics-parseable-fixits */
-  if (feature_flag & feature_fixit_parsable)
-    fprintf (stderr, "fix-it:%s:{%d:%d-%d:%d}:%s\n",
-             quotearg_n_style (1, c_quoting_style, loc->start.file),
-             loc->start.line, loc->start.column,
-             loc->end.line, loc->end.column,
-             quotearg_n_style (2, c_quoting_style, upd));
+  fixits_register (loc, upd);
 }
 
 void

src/fixits.c

@@ -0,0 +1,95 @@
+/* Support for fixing grammar files.
+
+   Copyright (C) 2019 Free Software Foundation, Inc.
+
+   This file is part of Bison, the GNU Compiler Compiler.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+#include "fixits.h"
+
+#include "system.h"
+
+#include "getargs.h"
+#include "gl_xlist.h"
+#include "gl_array_list.h"
+#include "quotearg.h"
+
+typedef struct
+{
+  location location;
+  char *fix;
+} fixit;
+
+gl_list_t fixits = NULL;
+
+static fixit *
+fixit_new (location const *loc, char const* fix)
+{
+  fixit *res = xmalloc (sizeof *res);
+  res->location = *loc;
+  res->fix = xstrdup (fix);
+  return res;
+}
+
+
+static void
+fixit_free (fixit *f)
+{
+  free (f->fix);
+  free (f);
+}
+
+
+/* GCC and Clang follow the same pattern.
+   https://gcc.gnu.org/onlinedocs/gcc/Diagnostic-Message-Formatting-Options.html
+   http://clang.llvm.org/docs/UsersManual.html#cmdoption-fdiagnostics-parseable-fixits */
+static void
+fixit_print (fixit const *f, FILE *out)
+{
+  fprintf (out, "fix-it:%s:{%d:%d-%d:%d}:%s\n",
+           quotearg_n_style (1, c_quoting_style, f->location.start.file),
+           f->location.start.line, f->location.start.column,
+           f->location.end.line, f->location.end.column,
+           quotearg_n_style (2, c_quoting_style, f->fix));
+}
+
+
+void
+fixits_register (location const *loc, char const* fix)
+{
+  if (!fixits)
+    fixits = gl_list_create_empty (GL_ARRAY_LIST,
+                                   /* equals */ NULL,
+                                   /* hashcode */ NULL,
+                                   (gl_listelement_dispose_fn) fixit_free,
+                                   true);
+  fixit *f = fixit_new (loc, fix);
+  gl_list_add_last (fixits, f);
+  if (feature_flag & feature_fixit_parsable)
+    fixit_print (f, stderr);
+}
+
+
+/* Free the registered fixits.  */
+void fixits_free (void)
+{
+  if (fixits)
+    {
+      gl_list_free (fixits);
+      fixits = NULL;
+    }
+}

src/fixits.h

@@ -0,0 +1,29 @@
+/* Support for fixing grammar files.
+
+   Copyright (C) 2019 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef FIXITS_H_
+# define FIXITS_H_ 1
+
+# include "location.h"
+
+/* Declare a fix to apply.  */
+void fixits_register (location const *loc, char const* update);
+
+/* Free the registered fixits.  */
+void fixits_free (void);
+
+#endif /* !FIXITS_H_ */

src/local.mk

@@ -46,6 +46,8 @@ src_bison_SOURCES =                             \
   src/derives.h                                 \
   src/files.c                                   \
   src/files.h                                   \
+  src/fixits.c                                  \
+  src/fixits.h                                  \
   src/flex-scanner.h                            \
   src/getargs.c                                 \
   src/getargs.h                                 \

src/main.c

@@ -35,6 +35,7 @@
 #include "conflicts.h"
 #include "derives.h"
 #include "files.h"
+#include "fixits.h"
 #include "getargs.h"
 #include "gram.h"
 #include "lalr.h"
@@ -205,6 +206,7 @@ main (int argc, char *argv[])
   conflicts_free ();
   grammar_free ();
   output_file_names_free ();
+  fixits_free ();
 
   /* The scanner memory cannot be released right after parsing, as it
      contains things such as user actions, prologue, epilogue etc.  */