diagnostics: update the grammar file

Let's use the fixits to actually update the grammar files.

* src/getargs.h, src/getargs.c (update_flag): New.
* src/fixits.h, src/fixits.c (fixits_run): New.
* src/main.c (main): Invoke fixits_run when --update is passed.
* tests/input.at (Deprecated directives): Check --update.

src/files.h

@@ -55,7 +55,7 @@ extern char *dir_prefix;
    and therefore GCC warns about a name clash. */
 extern uniqstr grammar_file;
 
-/* The current file name.  Might change with %include, or with #line.  */
+/* The current file name.  Might change with #line.  */
 extern uniqstr current_file;
 
 /* The computed base for output file names.  */

src/fixits.c

@@ -23,10 +23,17 @@
 
 #include "system.h"
 
+#include "error.h"
+#include "get-errno.h"
 #include "getargs.h"
-#include "gl_xlist.h"
 #include "gl_array_list.h"
+#include "gl_xlist.h"
+#include "progname.h"
+#include "quote.h"
 #include "quotearg.h"
+#include "vasnprintf.h"
+
+#include "files.h"
 
 typedef struct
 {
@@ -84,6 +91,94 @@ fixits_register (location const *loc, char const* fix)
 }
 
 
+void
+fixits_run (void)
+{
+  if (!fixits)
+    return;
+
+  /* This is not unlike what is done in location_caret.  */
+  uniqstr input = ((fixit *) gl_list_get_at (fixits, 0))->location.start.file;
+  /* Backup the file. */
+  char buf[256];
+  size_t len = sizeof (buf);
+  char *backup = asnprintf (buf, &len, "%s~", input);
+  if (!backup)
+    xalloc_die ();
+  if (rename (input, backup))
+    error (EXIT_FAILURE, get_errno (),
+           _("%s: cannot backup"), quotearg_colon (input));
+  FILE *in = xfopen (backup, "r");
+  FILE *out = xfopen (input, "w");
+  size_t line = 1;
+  size_t offset = 1;
+  fixit const *f = NULL;
+  gl_list_iterator_t iter = gl_list_iterator (fixits);
+  while (gl_list_iterator_next (&iter, (const void**) &f, NULL))
+    {
+      /* Look for the correct line. */
+      while (line < f->location.start.line)
+        {
+          int c = getc (in);
+          if (c == EOF)
+            break;
+          if (c == '\n')
+            {
+              ++line;
+              offset = 1;
+            }
+          putc (c, out);
+        }
+      /* Look for the right offset. */
+      while (offset < f->location.start.column)
+        {
+          int c = getc (in);
+          if (c == EOF)
+            break;
+          ++offset;
+          putc (c, out);
+        }
+
+      /* Paste the fix instead. */
+      fputs (f->fix, out);
+
+      /* Skip the bad input. */
+      while (line < f->location.end.line)
+        {
+          int c = getc (in);
+          if (c == EOF)
+            break;
+          if (c == '\n')
+            {
+              ++line;
+              offset = 1;
+            }
+        }
+      while (offset < f->location.end.column)
+        {
+          int c = getc (in);
+          if (c == EOF)
+            break;
+          ++offset;
+        }
+    }
+  /* Paste the rest of the file.  */
+  {
+    int c;
+    while ((c = getc (in)) != EOF)
+      putc (c, out);
+  }
+
+  gl_list_iterator_free (&iter);
+  xfclose (out);
+  xfclose (in);
+  fprintf (stderr, "%s: file %s was updated (backup: %s)\n",
+           program_name, quote_n (0, input), quote_n (1, backup));
+  if (backup != buf)
+    free (backup);
+}
+
+
 /* Free the registered fixits.  */
 void fixits_free (void)
 {

src/fixits.h

@@ -23,6 +23,9 @@
 /* Declare a fix to apply.  */
 void fixits_register (location const *loc, char const* update);
 
+/* Apply the fixits: update the source file.  */
+void fixits_run (void);
+
 /* Free the registered fixits.  */
 void fixits_free (void);
 

src/getargs.c

@@ -36,12 +36,13 @@
 #include "quote.h"
 #include "uniqstr.h"
 
-bool defines_flag;
-bool graph_flag;
-bool xml_flag;
-bool no_lines_flag;
-bool token_table_flag;
-bool yacc_flag; /* for -y */
+bool defines_flag = false;
+bool graph_flag = false;
+bool xml_flag = false;
+bool no_lines_flag = false;
+bool token_table_flag = false;
+bool yacc_flag = false; /* for -y */
+bool update_flag = false; /* for -u */
 
 bool nondeterministic_parser = false;
 bool glr_parser = false;
@@ -283,7 +284,10 @@ Operation modes:\n\
   -h, --help                 display this help and exit\n\
   -V, --version              output version information and exit\n\
       --print-localedir      output directory containing locale-dependent data\n\
+                             and exit\n\
       --print-datadir        output directory containing skeletons and XSLT\n\
+                             and exit\n\
+  -u, --update               apply fixes to the source grammar file\n\
   -y, --yacc                 emulate POSIX Yacc\n\
   -W, --warnings[=CATEGORY]  report the warnings falling in CATEGORY\n\
   -f, --feature[=FEATURE]    activate miscellaneous features\n\
@@ -478,6 +482,7 @@ static char const short_options[] =
   "p:"
   "r:"
   "t"
+  "u"   /* --update */
   "v"
   "x::"
   "y"
@@ -499,6 +504,7 @@ static struct option const long_options[] =
   { "version",         no_argument,       0,   'V' },
   { "print-localedir", no_argument,       0,   PRINT_LOCALEDIR_OPTION },
   { "print-datadir",   no_argument,       0,   PRINT_DATADIR_OPTION   },
+  { "update",          no_argument,       0,   'u' },
   { "warnings",        optional_argument, 0,   'W' },
 
   /* Parser. */
@@ -684,6 +690,10 @@ getargs (int argc, char *argv[])
                                       MUSCLE_PERCENT_DEFINE_D);
         break;
 
+      case 'u':
+        update_flag = true;
+        break;
+
       case 'v':
         report_flag |= report_states;
         break;

src/getargs.h

@@ -40,7 +40,7 @@ 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 bool update_flag;                /* for -u */
 
 /* GLR_PARSER is true if the input file says to use the GLR
    (Generalized LR) parser, and to output some additional information

src/main.c

@@ -103,6 +103,12 @@ main (int argc, char *argv[])
   reader ();
   timevar_pop (tv_reader);
 
+  /* Fix input file now, even if there are errors: that's less
+     warnings in the following runs.  */
+  if (update_flag)
+    fixits_run ();
+  fixits_free ();
+
   if (complaint_status == status_complaint)
     goto finish;
 
@@ -206,7 +212,6 @@ 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.  */