Simplify the part of args() that is handling .Bl -column phrases:

Delete manual "Ta" handling because macro handling should
not be done in an argument parser but should be left to the
macro parsers, which exist anyway and work well.
No functional change, minus 40 lines of code.

Confusing and redundant code found while investigating
an old bug report from tim@.

diff --git a/usr.bin/mandoc/mdoc_argv.c b/usr.bin/mandoc/mdoc_argv.c
index 66869e0..27dc508 100644 (file)
--- a/usr.bin/mandoc/mdoc_argv.c
+++ b/usr.bin/mandoc/mdoc_argv.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: mdoc_argv.c,v 1.61 2015/10/06 18:30:44 schwarze Exp $ */
+/*     $OpenBSD: mdoc_argv.c,v 1.62 2015/10/15 22:45:07 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2012, 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -445,96 +445,51 @@ static enum margserr
 args(struct roff_man *mdoc, int line, int *pos,
                char *buf, enum argsflag fl, char **v)
 {
-       char            *p, *pp;
+       char            *p;
        int              pairs;
        enum margserr    rc;
 
-       if ('\0' == buf[*pos]) {
-               if (MDOC_PPHRASE & mdoc->flags)
-                       return ARGS_EOLN;
-               /*
-                * If we're not in a partial phrase and the flag for
-                * being a phrase literal is still set, the punctuation
-                * is unterminated.
-                */
-               if (MDOC_PHRASELIT & mdoc->flags)
+       if (buf[*pos] == '\0') {
+               if (mdoc->flags & MDOC_PHRASELIT &&
+                   ! (mdoc->flags & MDOC_PPHRASE)) {
                        mandoc_msg(MANDOCERR_ARG_QUOTE,
                            mdoc->parse, line, *pos, NULL);
-
-               mdoc->flags &= ~MDOC_PHRASELIT;
+                       mdoc->flags &= ~MDOC_PHRASELIT;
+               }
                return ARGS_EOLN;
        }
 
-       *v = &buf[*pos];
+       *v = buf + *pos;
 
-       if (ARGSFL_DELIM == fl)
-               if (args_checkpunct(buf, *pos))
-                       return ARGS_PUNCT;
+       if (fl == ARGSFL_DELIM && args_checkpunct(buf, *pos))
+               return ARGS_PUNCT;
 
        /*
-        * First handle TABSEP items, restricted to `Bl -column'.  This
-        * ignores conventional token parsing and instead uses tabs or
-        * `Ta' macros to separate phrases.  Phrases are parsed again
-        * for arguments at a later phase.
+        * Tabs in `It' lines in `Bl -column' can't be escaped.
+        * Phrases are reparsed for `Ta' and other macros later.
         */
 
-       if (ARGSFL_TABSEP == fl) {
-               /* Scan ahead to tab (can't be escaped). */
-               p = strchr(*v, '\t');
-               pp = NULL;
-
-               /* Scan ahead to unescaped `Ta'. */
-               if ( ! (MDOC_PHRASELIT & mdoc->flags))
-                       for (pp = *v; ; pp++) {
-                               if (NULL == (pp = strstr(pp, "Ta")))
-                                       break;
-                               if (pp > *v && ' ' != *(pp - 1))
-                                       continue;
-                               if (' ' == *(pp + 2) || '\0' == *(pp + 2))
-                                       break;
-                       }
-
-               /* By default, assume a phrase. */
-               rc = ARGS_PHRASE;
-
-               /*
-                * Adjust new-buffer position to be beyond delimiter
-                * mark (e.g., Ta -> end + 2).
-                */
-               if (p && pp) {
-                       *pos += pp < p ? 2 : 1;
-                       rc = pp < p ? ARGS_PHRASE : ARGS_PPHRASE;
-                       p = pp < p ? pp : p;
-               } else if (p && ! pp) {
+       if (fl == ARGSFL_TABSEP) {
+               if ((p = strchr(*v, '\t')) != NULL) {
+                       /* Skip any blank characters after the tab. */
+                       *pos += (int)(p - *v) + 1;
+                       while (buf[*pos] == ' ')
+                               (*pos)++;
                        rc = ARGS_PPHRASE;
-                       *pos += 1;
-               } else if (pp && ! p) {
-                       p = pp;
-                       *pos += 2;
                } else {
+                       p = strchr(*v, '\0');
+                       if (p[-1] == ' ')
+                               mandoc_msg(MANDOCERR_SPACE_EOL,
+                                   mdoc->parse, line, *pos, NULL);
+                       *pos += (int)(p - *v);
                        rc = ARGS_PEND;
-                       p = strchr(*v, 0);
-               }
-
-               /* Whitespace check for eoln case... */
-               if ('\0' == *p && ' ' == *(p - 1))
-                       mandoc_msg(MANDOCERR_SPACE_EOL, mdoc->parse,
-                           line, *pos, NULL);
-
-               *pos += (int)(p - *v);
-
-               /* Strip delimiter's preceding whitespace. */
-               pp = p - 1;
-               while (pp > *v && ' ' == *pp) {
-                       if (pp > *v && '\\' == *(pp - 1))
-                               break;
-                       pp--;
                }
-               *(pp + 1) = 0;
 
-               /* Strip delimiter's proceeding whitespace. */
-               for (pp = &buf[*pos]; ' ' == *pp; pp++, (*pos)++)
-                       /* Skip ahead. */ ;
+               /* Skip any trailing blank characters. */
+               while (p > *v && p[-1] == ' ' &&
+                   (p - 1 == *v || p[-2] != '\\'))
+                       p--;
+               *p = '\0';
 
                return rc;
        }