cppinit.c (cpp_reader_init): Initialise col_adjust and default tab stop size.

	* cppinit.c (cpp_reader_init): Initialise col_adjust and
	default tab stop size.
	(no_num, OPT_ftabstop): New.
	(handle_option): Handle "ftabstop=" command-line option.
	(print_help): Document it.
	* cpplex.c (COLUMN): Remove.
	(handle_newline): Reset col_adjust.
	(skip_whitespace): Update col_adjust as tabs encountered.
	(_cpp_lex_line): Update to use col_adjust.  Call
	skip_whitespace for all whitespace.
	* cpplib.h (struct cpp_options): New member tabstop.
	(struct cpp_reader): New member col_adjust.
	(CPP_BUF_COL): Update.
	(CPP_BUF_COLUMN): New.
	* cpp.texi: Document "-ftabstop=" command line option.

From-SVN: r33982

gcc/ChangeLog

+2000-05-18  Neil Booth  <NeilB@earthling.net>
+
+	* cppinit.c (cpp_reader_init): Initialise col_adjust and
+	default tab stop size.
+	(no_num, OPT_ftabstop): New.
+	(handle_option): Handle "ftabstop=" command-line option.
+	(print_help): Document it.
+	* cpplex.c (COLUMN): Remove.
+	(handle_newline): Reset col_adjust.
+	(skip_whitespace): Update col_adjust as tabs encountered.
+	(_cpp_lex_line): Update to use col_adjust.  Call
+	skip_whitespace for all whitespace.
+	* cpplib.h (struct cpp_options): New member tabstop.
+	(struct cpp_reader): New member col_adjust.
+	(CPP_BUF_COL): Update.
+	(CPP_BUF_COLUMN): New.
+	* cpp.texi: Document "-ftabstop=" command line option.
+
 Wed May 17 18:19:41 2000  Philippe De Muyter  <phdm@macqel.be>
 
 	* configure.in (NO_MINUS_C_MINUS_O): Macro made availabe for AC_OUTPUT

gcc/cpp.texi

@@ -3155,6 +3155,13 @@ Because of the clash with @samp{-l}, you must use the awkward syntax
 above.  In a future release, this option will be replaced by
 @samp{-flint} or @samp{-Wlint}; we are not sure which yet.
 
+@item -ftabstop=NUMBER
+@findex -ftabstop
+Indicates the distance between tabstops.  This helps the preprocessor
+report correct column numbers in warnings or errors, even if tabs appear
+on the line.  Values less than 1 or greater than 100 are ignored.  The
+default is 8.
+
 @item -$
 @findex -$
 Forbid the use of @samp{$} in identifiers.  The C standard does not

gcc/cppinit.c

@@ -545,6 +545,7 @@ cpp_reader_init (pfile)
   CPP_OPTION (pfile, warn_import) = 1;
   CPP_OPTION (pfile, discard_comments) = 1;
   CPP_OPTION (pfile, show_column) = 1;
+  CPP_OPTION (pfile, tabstop) = 8;
 
   CPP_OPTION (pfile, pending) =
     (struct cpp_pending *) xcalloc (1, sizeof (struct cpp_pending));
@@ -1079,6 +1080,7 @@ new_pending_directive (pend, text, handler)
 #define no_fil N_("File name missing after %s")
 #define no_mac N_("Macro name missing after %s")
 #define no_pth N_("Path name missing after %s")
+#define no_num N_("Number missing after %s")
 
 /* This is the list of all command line options, with the leading
    "-" removed.  It must be sorted in ASCII collating order.  */
@@ -1108,6 +1110,7 @@ new_pending_directive (pend, text, handler)
   DEF_OPT("fno-show-column",          0,      OPT_fno_show_column)            \
   DEF_OPT("fpreprocessed",            0,      OPT_fpreprocessed)              \
   DEF_OPT("fshow-column",             0,      OPT_fshow_column)               \
+  DEF_OPT("ftabstop=",                no_num, OPT_ftabstop)                   \
   DEF_OPT("g",                        no_arg, OPT_g)  /* arg optional */      \
   DEF_OPT("h",                        0,      OPT_h)                          \
   DEF_OPT("idirafter",                no_dir, OPT_idirafter)                  \
@@ -1312,6 +1315,16 @@ handle_option (pfile, argc, argv)
 	case OPT_fno_show_column:
 	  CPP_OPTION (pfile, show_column) = 0;
 	  break;
+	case OPT_ftabstop:
+	  /* Silently ignore empty string, non-longs and silly values.  */
+	  if (arg[0] != '\0')
+	    {
+	      char *endptr;
+	      long tabstop = strtol (arg, &endptr, 10);
+	      if (*endptr == '\0' && tabstop >= 1 && tabstop <= 100)
+		CPP_OPTION (pfile, tabstop) = tabstop;
+	    }
+	  break;
 	case OPT_w:
 	  CPP_OPTION (pfile, inhibit_warnings) = 1;
 	  break;
@@ -1833,6 +1846,7 @@ Switches:\n\
   -dD                       Preserve macro definitions in output\n\
   -dN                       As -dD except that only the names are preserved\n\
   -dI                       Include #include directives in the output\n\
+  -ftabstop=<number>        Distance between tab stops for column reporting\n\
   -P                        Do not generate #line directives\n\
   -$                        Do not allow '$' in identifiers\n\
   -remap                    Remap file names when including files.\n\

gcc/cpplex.c

@@ -96,7 +96,6 @@ typedef unsigned int (* speller) PARAMS ((unsigned char *, cpp_toklist *,
       (name).text = (list)->namebuf + (list)->name_used;} while (0)
 
 #define IS_DIRECTIVE(list) (TOK_TYPE (list, 0) == CPP_HASH)
-#define COLUMN(cur) ((cur) - buffer->line_base)
 
 /* Maybe put these in the ISTABLE eventually.  */
 #define IS_HSPACE(c) ((c) == ' ' || (c) == '\t')
@@ -109,6 +108,7 @@ typedef unsigned int (* speller) PARAMS ((unsigned char *, cpp_toklist *,
   if ((cur) < (limit) && *(cur) == '\r' + '\n' - c) \
     (cur)++; \
   CPP_BUMP_LINE_CUR (pfile, (cur)); \
+  pfile->col_adjust = 0; \
   } while (0)
 
 #define IMMED_TOKEN() (!(cur_token->flags & PREV_WHITESPACE))
@@ -2506,7 +2506,9 @@ skip_line_comment2 (pfile)
   return multiline;
 }
 
-/* Skips whitespace, stopping at next non-whitespace character.  */
+/* Skips whitespace, stopping at next non-whitespace character.
+   Adjusts pfile->col_adjust to account for tabs.  This enables tokens
+   to be assigned the correct column.  */
 static void
 skip_whitespace (pfile, in_directive)
      cpp_reader *pfile;
@@ -2520,6 +2522,12 @@ skip_whitespace (pfile, in_directive)
     {
       unsigned char c = *cur++;
 
+      if (c == '\t')
+	{
+	  unsigned int col = CPP_BUF_COLUMN (buffer, cur - 1);
+	  pfile->col_adjust += (CPP_OPTION (pfile, tabstop) - 1
+				- col % CPP_OPTION(pfile, tabstop));
+	}
       if (IS_HSPACE(c))		/* FIXME: Fix ISTABLE.  */
 	continue;
       if (!is_space(c) || IS_NEWLINE (c)) /* Main loop handles newlines.  */
@@ -2847,6 +2855,7 @@ _cpp_lex_line (pfile, list)
   register const unsigned char *cur = buffer->cur;
   unsigned char flags = 0;
 
+  pfile->col_adjust = 0;
  expanded:
   token_limit = list->tokens + list->tokens_cap;
   cur_token = list->tokens + list->tokens_used;
@@ -2855,17 +2864,16 @@ _cpp_lex_line (pfile, list)
     {
       unsigned char c = *cur++;
 
-      /* Optimize whitespace skipping, in particular the case of a
-	 single whitespace character, as every other token is probably
-	 whitespace. (' ' '\t' '\v' '\f' '\0').  */
+      /* Optimize whitespace skipping, as most tokens are probably
+	 separated by whitespace. (' ' '\t' '\v' '\f' '\0').  */
+
       if (is_hspace ((unsigned int) c))
 	{
-	  if (c == '\0' || (cur < buffer->rlimit && is_hspace (*cur)))
-	    {
-	      buffer->cur = cur - (c == '\0');	/* Get the null warning.  */
-	      skip_whitespace (pfile, IS_DIRECTIVE (list));
-	      cur = buffer->cur;
-	    }
+	  /* Step back to get the null warning and tab correction.  */
+	  buffer->cur = cur - 1;
+	  skip_whitespace (pfile, IS_DIRECTIVE (list));
+	  cur = buffer->cur;
+
 	  flags = PREV_WHITESPACE;
 	  if (cur == buffer->rlimit)
 	    break;
@@ -2873,7 +2881,7 @@ _cpp_lex_line (pfile, list)
 	}
 
       /* Initialize current token.  Its type is set in the switch.  */
-      cur_token->col = COLUMN (cur);
+      cur_token->col = CPP_BUF_COLUMN (buffer, cur);
       cur_token->flags = flags;
       flags = 0;
 
@@ -2947,7 +2955,7 @@ _cpp_lex_line (pfile, list)
 	    }
 
 	do_parse_string:
-	  /* Here c is one of ' " > or ).  */
+	  /* Here c is one of ' " or >.  */
 	  INIT_NAME (list, cur_token->val.name);
 	  buffer->cur = cur;
 	  parse_string2 (pfile, list, &cur_token->val.name, c);

gcc/cpplib.h

@@ -302,6 +302,9 @@ struct cpp_options
   const char *in_fname;
   const char *out_fname;
 
+  /* Characters between tab stops.  */
+  unsigned int tabstop;
+
   /* Pending options - -D, -U, -A, -I, -ixxx. */
   struct cpp_pending *pending;
 
@@ -510,6 +513,9 @@ struct cpp_reader
   struct if_stack *if_stack;
   const unsigned char *potential_control_macro;
 
+  /* Token column position adjustment owing to tabs in whitespace.  */
+  unsigned int col_adjust;
+
   /* Buffer of -M output.  */
   struct deps *deps;
 
@@ -586,7 +592,8 @@ struct cpp_printer
 #define CPP_OPTION(PFILE, OPTION) ((PFILE)->opts.OPTION)
 #define CPP_BUFFER(PFILE) ((PFILE)->buffer)
 #define CPP_BUF_LINE(BUF) ((BUF)->lineno)
-#define CPP_BUF_COL(BUF) ((BUF)->cur - (BUF)->line_base)
+#define CPP_BUF_COLUMN(BUF, CUR) ((CUR) - (BUF)->line_base + pfile->col_adjust)
+#define CPP_BUF_COL(BUF) CPP_BUF_COLUMN(BUF, (BUF)->cur)
 
 /* Name under which this program was invoked.  */
 extern const char *progname;