Merge remote-tracking branch 'origin/maint'

* origin/maint:
  misc: pacify the Tiny C Compiler
  cpp: make the check of Flex version portable
  misc: require getline
  c++: support wide strings for file names
  doc: document carets
  tests: enhance existing tests with carets
  errors: show carets
  getargs: add support for --flags/-f

Conflicts:
	doc/bison.texi
	m4/.gitignore
	src/complain.c
	src/flex-scanner.h
	src/getargs.c
	src/getargs.h
	src/gram.c
	src/main.c
	tests/headers.at

src/complain.c

@@ -110,12 +110,15 @@ error_message (const location *loc, warnings flags, const char *prefix,
   warnings_print_categories (flags);
   {
     size_t l = strlen (message);
-    if (l < 2 || message[l-2] != ':' || message[l-1] != ' ')
+    if (l < 2 || message[l - 2] != ':' || message[l - 1] != ' ')
       {
         putc ('\n', stderr);
         fflush (stderr);
+        if (loc && feature_flag & feature_caret)
+          location_caret (stderr, *loc);
       }
   }
+  fflush (stderr);
 }
 
 /** Raise a complaint. That can be a fatal error, a complaint or just a

src/flex-scanner.h

@@ -23,18 +23,18 @@
 
 /* Whether this version of Flex is (strictly) greater than
    Major.Minor.Subminor.  */
-#define FLEX_VERSION_GT(Major, Minor, Subminor)                         \
-  (defined YY_FLEX_MAJOR_VERSION                                        \
-   && (Major < YY_FLEX_MAJOR_VERSION                                    \
-       || (Major == YY_FLEX_MAJOR_VERSION                               \
-           && (defined YY_FLEX_MINOR_VERSION                            \
-               && (Minor < YY_FLEX_MINOR_VERSION                        \
-                   || (Minor == YY_FLEX_MINOR_VERSION                   \
-                       && defined YY_FLEX_SUBMINOR_VERSION              \
-                       && Subminor < YY_FLEX_SUBMINOR_VERSION))))))
-
+#ifdef YY_FLEX_SUBMINOR_VERSION
+# define FLEX_VERSION               \
+  (YY_FLEX_MAJOR_VERSION) * 1000000 \
++ (YY_FLEX_MINOR_VERSION) * 1000    \
++ (YY_FLEX_SUBMINOR_VERSION)
+#else
+# define FLEX_VERSION               \
+  (YY_FLEX_MAJOR_VERSION) * 1000000 \
++ (YY_FLEX_MINOR_VERSION) * 1000
+#endif
 /* Pacify "gcc -Wmissing-prototypes" when flex 2.5.31 is used.  */
-#if ! FLEX_VERSION_GT (2, 5, 31)
+# if FLEX_VERSION <= 2005031
 int   FLEX_PREFIX (get_lineno) (void);
 FILE *FLEX_PREFIX (get_in) (void);
 FILE *FLEX_PREFIX (get_out) (void);
@@ -65,7 +65,7 @@ int   FLEX_PREFIX (lex_destroy) (void);
    versions according to the Flex manual) leak memory if yylex_destroy is not
    invoked.  However, yylex_destroy is not defined before Flex 2.5.9, so give
    an implementation here that at least appears to work with Flex 2.5.4.  */
-#if ! FLEX_VERSION_GT (2, 5, 9)
+#if FLEX_VERSION <= 2005009
 # define yylex_destroy() yy_delete_buffer (YY_CURRENT_BUFFER)
 #endif
 

src/getargs.c

@@ -46,6 +46,7 @@ bool yacc_flag; /* for -y */
 bool nondeterministic_parser = false;
 bool glr_parser = false;
 
+int feature_flag = feature_none;
 int report_flag = report_none;
 int trace_flag = trace_none;
 
@@ -272,6 +273,27 @@ static const int warnings_types[] =
 
 ARGMATCH_VERIFY (warnings_args, warnings_types);
 
+/*-----------------------.
+| --feature's handling.  |
+`-----------------------*/
+
+static const char * const feature_args[] =
+{
+  "none",
+  "caret", "diagnostics-show-caret",
+  "all",
+  0
+};
+
+static const int feature_types[] =
+{
+  feature_none,
+  feature_caret, feature_caret,
+  feature_all
+};
+
+ARGMATCH_VERIFY (feature_args, feature_types);
+
 /*-------------------------------------------.
 | Display the help message and exit STATUS.  |
 `-------------------------------------------*/
@@ -315,6 +337,7 @@ Operation modes:\n\
       --print-datadir        output directory containing skeletons and XSLT\n\
   -y, --yacc                 emulate POSIX Yacc\n\
   -W, --warnings[=CATEGORY]  report the warnings falling in CATEGORY\n\
+  -f, --feature[=FEATURE]    activate miscellaneous features\n\
 \n\
 "), stdout);
 
@@ -331,8 +354,8 @@ Parser:\n\
                                    deprecated by '-Dapi.prefix=PREFIX'\n\
   -l, --no-lines                   don't generate '#line' directives\n\
   -k, --token-table                include a table of token names\n\
-\n\
 "), stdout);
+      putc ('\n', stdout);
 
       /* Keep -d and --defines separate so that ../build-aux/cross-options.pl
        * won't assume that -d also takes an argument.  */
@@ -348,8 +371,8 @@ Output:\n\
   -g, --graph[=FILE]         also output a graph of the automaton\n\
   -x, --xml[=FILE]           also output an XML report of the automaton\n\
                              (the XML schema is experimental)\n\
-\n\
 "), stdout);
+      putc ('\n', stdout);
 
       fputs (_("\
 Warning categories include:\n\
@@ -375,6 +398,14 @@ THINGS is a list of comma separated words that can include:\n\
   `all'          include all the above information\n\
   `none'         disable the report\n\
 "), stdout);
+      putc ('\n', stdout);
+
+      fputs (_("\
+FEATURE is a list of comma separated words that can include:\n\
+  `caret'        show errors with carets\n\
+  `all'          all of the above\n\
+  `none'         disable all of the above\n\
+  "), stdout);
 
       putc ('\n', stdout);
       printf (_("Report bugs to <%s>.\n"), PACKAGE_BUGREPORT);
@@ -485,6 +516,7 @@ static char const short_options[] =
   "W::"
   "b:"
   "d"
+  "f::"
   "e"
   "g::"
   "h"
@@ -537,6 +569,7 @@ static struct option const long_options[] =
 
   /* Output.  */
   { "defines",     optional_argument,   0,   'd' },
+  { "feature",     optional_argument,   0,   'f' },
 
   /* Operation modes.  */
   { "fixed-output-files", no_argument,  0,   'y' },
@@ -629,6 +662,10 @@ getargs (int argc, char *argv[])
         version ();
         exit (EXIT_SUCCESS);
 
+      case 'f':
+        FLAGS_ARGMATCH (feature, optarg, feature_all);
+        break;
+
       case 'W':
         FLAGS_ARGMATCH (warnings, optarg, Wall);
         break;

src/getargs.h

@@ -108,6 +108,18 @@ enum trace
 /** What debug items bison displays during its run.  */
 extern int trace_flag;
 
+/*-------------.
+| --features.  |
+`-------------*/
+
+enum feature
+  {
+    feature_none  = 0,         /**< No additional feature.  */
+    feature_caret = 1 << 0,    /**< Enhance the output of errors with carets.  */
+    feature_all   = ~0         /**< All above features.  */
+  };
+/** What additional features to use.  */
+extern int feature_flag;
 
 /** Process the command line arguments.
  *

src/gram.c

@@ -312,10 +312,15 @@ grammar_rules_useless_report (const char *message)
       for (r = 0; r < nrules ; ++r)
         if (!rules[r].useful)
           {
-            complain (&rules[r].location, w | silent, "%s: ", message);
-            rule_print (&rules[r], stderr);
-            warnings_print_categories (w);
-            fprintf (stderr, "\n");
+            if (feature_flag & feature_caret)
+              complain (&rules[r].location, w, "%s", message);
+            else
+              {
+                complain (&rules[r].location, w | silent, "%s: ", message);
+                rule_print (&rules[r], stderr);
+                warnings_print_categories (w);
+                fprintf (stderr, "\n");
+              }
           }
     }
 }

src/graphviz.c

@@ -103,7 +103,7 @@ conclude_red (struct obstack *out, int source, rule_number ruleno,
   /* If no lookahead tokens were valid transitions, this reduction is
      actually hidden, so cancel everything. */
   if (first)
-    return (void) obstack_finish0 (out);
+    (void) obstack_finish0 (out);
   else
     {
       char const *ed = enabled ? "" : "d";

src/location.c

@@ -138,6 +138,89 @@ location_print (FILE *out, location loc)
   return res;
 }
 
+
+/* Persistant data used by location_caret to avoid reopening and rereading the
+   same file all over for each error.  */
+struct caret_info
+{
+  FILE* source;
+  size_t line;
+  size_t offset;
+};
+
+static struct caret_info caret_info = { NULL, 1, 0 };
+
+/* Free any allocated ressources and close any open file handles that are
+   left-over by the usage of location_caret.  */
+void
+cleanup_caret ()
+{
+  if (caret_info.source)
+    fclose (caret_info.source);
+}
+
+/* Output to OUT the line and caret corresponding to location LOC.  */
+void
+location_caret (FILE *out, location loc)
+{
+  /* FIXME: find a way to support X-file locations, and only open once each
+     file. That would make the procedure future-proof.  */
+  if (! (caret_info.source
+         || (caret_info.source = fopen (loc.start.file, "r")))
+      || loc.start.column == -1 || loc.start.line == -1)
+    return;
+
+  /* If the line we want to quote is seekable (the same line as the previous
+     location), just seek it. If it was before, we lost track of it, so
+     return to the start of file.  */
+  if (caret_info.line <= loc.start.line)
+    fseek (caret_info.source, caret_info.offset, SEEK_SET);
+  else
+    {
+      caret_info.line = 1;
+      caret_info.offset = 0;
+      fseek (caret_info.source, caret_info.offset, SEEK_SET);
+    }
+
+  /* Advance to the line's position, keeping track of the offset.  */
+  {
+    int i;
+    for (i = caret_info.line; i < loc.start.line; caret_info.offset++)
+      if (fgetc (caret_info.source) == '\n')
+        ++i;
+  }
+  caret_info.line = loc.start.line;
+
+  /* Read the actual line.  Don't update the offset, so that we keep a pointer
+     to the start of the line.  */
+  {
+    ssize_t len = 0;
+    char *buf = NULL;
+    if ((len = getline (&buf, (size_t*) &len, caret_info.source)) != -1)
+      {
+        /* The caret of a multiline location ends with the first line.  */
+        int end = loc.start.line != loc.end.line ? len : loc.end.column;
+
+        if (len)
+          {
+            int i = loc.start.column;
+            /* Quote the file, indent by a single column.  */
+            fputc (' ', out);
+            fwrite (buf, 1, len, out);
+
+            /* Print the caret, with the same indent as above.  */
+            fputc (' ', out);
+            fprintf (out, "%*s", loc.start.column - 1, "");
+            do {
+              fputc ('^', out);
+            } while (++i < end);
+          }
+        fputc ('\n', out);
+        free (buf);
+      }
+  }
+}
+
 void
 boundary_set_from_string (boundary *bound, char *loc_str)
 {

src/location.h

@@ -102,6 +102,13 @@ void location_compute (location *loc,
    characters.  */
 unsigned location_print (FILE *out, location loc);
 
+/* Free any allocated ressources and close any open file handles that are
+   left-over by the usage of location_caret.  */
+void cleanup_caret (void);
+
+/* Output to OUT the line and caret corresponding to location LOC.  */
+void location_caret (FILE *out, location loc);
+
 /* Return -1, 0, 1, depending whether a is before, equal, or
    after b.  */
 static inline int

src/main.c

@@ -215,5 +215,7 @@ main (int argc, char *argv[])
   timevar_stop (TV_TOTAL);
   timevar_print (stderr);
 
+  cleanup_caret ();
+
   return complaint_status ? EXIT_FAILURE : EXIT_SUCCESS;
 }