Avoid the layering violation of re-parsing for \E in roff_expand().

To that end, add another argument to roff_escape()
returning the index of the escape name.
This also makes the code in roff_escape() a bit more uniform
in so far as it no longer needs the "char esc_name" local variable
but now does everything with indices into buf[].
No functional change.

diff --git a/usr.bin/mandoc/roff.c b/usr.bin/mandoc/roff.c
index 7c5a272..724c345 100644 (file)
--- a/usr.bin/mandoc/roff.c
+++ b/usr.bin/mandoc/roff.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: roff.c,v 1.263 2022/05/31 20:21:40 schwarze Exp $ */
+/* $OpenBSD: roff.c,v 1.264 2022/06/02 11:28:16 schwarze Exp $ */
 /*
  * Copyright (c) 2010-2015, 2017-2022 Ingo Schwarze <schwarze@openbsd.org>
  * Copyright (c) 2008-2012, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
@@ -1408,8 +1408,8 @@ roff_expand(struct roff *r, struct buf *buf, int ln, int pos, char ec)
                 * it to backslashes and translate backslashes to \e.
                 */
 
-               if (roff_escape(buf->buf, ln, pos,
-                   &iesc, &iarg, &iendarg, &iend) != ESCAPE_EXPAND) {
+               if (roff_escape(buf->buf, ln, pos, &iesc, &inam,
+                   &iarg, &iendarg, &iend) != ESCAPE_EXPAND) {
                        while (pos < iend) {
                                if (buf->buf[pos] == ec) {
                                        buf->buf[pos] = '\\';
@@ -1426,15 +1426,6 @@ roff_expand(struct roff *r, struct buf *buf, int ln, int pos, char ec)
                        continue;
                }
 
-               /*
-                * Treat "\E" just like "\";
-                * it only makes a difference in copy mode.
-                */
-
-               inam = iesc + 1;
-               while (buf->buf[inam] == 'E')
-                       inam++;
-
                /* Handle expansion. */
 
                res = NULL;

diff --git a/usr.bin/mandoc/roff_escape.c b/usr.bin/mandoc/roff_escape.c
index 34a09f3..741bc02 100644 (file)
--- a/usr.bin/mandoc/roff_escape.c
+++ b/usr.bin/mandoc/roff_escape.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: roff_escape.c,v 1.6 2022/06/01 23:20:19 schwarze Exp $ */
+/* $OpenBSD: roff_escape.c,v 1.7 2022/06/02 11:28:16 schwarze Exp $ */
 /*
  * Copyright (c) 2011, 2012, 2013, 2014, 2015, 2017, 2018, 2020, 2022
  *               Ingo Schwarze <schwarze@openbsd.org>
@@ -41,7 +41,8 @@ mandoc_escape(const char **rendarg, const char **rarg, int *rargl)
         int             iarg, iendarg, iend;
         enum mandoc_esc  rval;
 
-        rval = roff_escape(--*rendarg, 0, 0, NULL, &iarg, &iendarg, &iend);
+        rval = roff_escape(--*rendarg, 0, 0,
+           NULL, NULL, &iarg, &iendarg, &iend);
         assert(rval != ESCAPE_EXPAND);
         if (rarg != NULL)
               *rarg = *rendarg + iarg;
@@ -63,20 +64,20 @@ mandoc_escape(const char **rendarg, const char **rarg, int *rargl)
  */
 enum mandoc_esc
 roff_escape(const char *buf, const int ln, const int aesc,
-    int *resc, int *rarg, int *rendarg, int *rend)
+    int *resc, int *rnam, int *rarg, int *rendarg, int *rend)
 {
        int              iesc;          /* index of leading escape char */
+       int              inam;          /* index of escape name */
        int              iarg;          /* index beginning the argument */
        int              iendarg;       /* index right after the argument */
        int              iend;          /* index right after the sequence */
-       int              sesc, sarg, sendarg, send; /* for sub-escape */
+       int              sesc, snam, sarg, sendarg, send; /* for sub-escape */
        int              maxl;          /* expected length of the argument */
        int              argl;          /* actual length of the argument */
        int              c, i;          /* for \[char...] parsing */
        int              valid_A;       /* for \A parsing */
        enum mandoc_esc  rval;          /* return value */
        enum mandocerr   err;           /* diagnostic code */
-       char             esc_name;
        char             term;          /* byte terminating the argument */
 
        /*
@@ -84,21 +85,20 @@ roff_escape(const char *buf, const int ln, const int aesc,
         * it only makes a difference in copy mode.
         */
 
-       iesc = iarg = aesc;
+       iesc = inam = aesc;
        do {
-               iarg++;
-       } while (buf[iarg] == 'E');
+               inam++;
+       } while (buf[inam] == 'E');
 
        /*
         * Sort the following cases first by syntax category,
         * then by escape sequence type, and finally by ASCII code.
         */
 
-       esc_name = buf[iarg];
-       iendarg = iend = ++iarg;
+       iarg = iendarg = iend = inam + 1;
        maxl = INT_MAX;
        term = '\0';
-       switch (esc_name) {
+       switch (buf[inam]) {
 
        /* Escape sequences taking no arguments at all. */
 
@@ -269,12 +269,12 @@ roff_escape(const char *buf, const int ln, const int aesc,
 
        if ((term == '\b' || (term == '\0' && maxl == INT_MAX)) &&
            buf[iarg] == buf[iesc] && roff_escape(buf, ln, iendarg,
-           &sesc, &sarg, &sendarg, &send) == ESCAPE_EXPAND)
+           &sesc, &snam, &sarg, &sendarg, &send) == ESCAPE_EXPAND)
                goto out_sub;
 
        if (term == '\b') {
-               if ((esc_name == 'N' && isdigit((unsigned char)buf[iarg])) ||
-                   (esc_name == 'h' && strchr(" %&()*+-./0123456789:<=>",
+               if ((buf[inam] == 'N' && isdigit((unsigned char)buf[iarg])) ||
+                   (buf[inam] == 'h' && strchr(" %&()*+-./0123456789:<=>",
                     buf[iarg]) != NULL)) {
                        iendarg = iend = iarg + 1;
                        rval = ESCAPE_ERROR;
@@ -282,7 +282,7 @@ roff_escape(const char *buf, const int ln, const int aesc,
                }
                term = buf[iarg++];
        } else if (term == '\0' && maxl == INT_MAX) {
-               if (esc_name == 'n' && (buf[iarg] == '+' || buf[iarg] == '-'))
+               if (buf[inam] == 'n' && (buf[iarg] == '+' || buf[iarg] == '-'))
                        iarg++;
                switch (buf[iarg]) {
                case '(':
@@ -310,7 +310,7 @@ roff_escape(const char *buf, const int ln, const int aesc,
        while (maxl > 0) {
                if (buf[iendarg] == '\0') {
                        /* Ignore an incomplete argument except for \w. */
-                       if (esc_name != 'w')
+                       if (buf[inam] != 'w')
                                iendarg = iarg;
                        break;
                }
@@ -318,14 +318,14 @@ roff_escape(const char *buf, const int ln, const int aesc,
                        iend = iendarg + 1;
                        break;
                }
-               if (esc_name == 'N' &&
+               if (buf[inam] == 'N' &&
                    isdigit((unsigned char)buf[iendarg]) == 0) {
                        iend = iendarg + 1;
                        break;
                }
                if (buf[iendarg] == buf[iesc]) {
                        switch (roff_escape(buf, ln, iendarg,
-                           &sesc, &sarg, &sendarg, &send)) {
+                           &sesc, &snam, &sarg, &sendarg, &send)) {
                        case ESCAPE_EXPAND:
                                goto out_sub;
                        case ESCAPE_UNDEF:
@@ -350,7 +350,7 @@ roff_escape(const char *buf, const int ln, const int aesc,
        /* Post-process depending on the content of the argument. */
 
        argl = iendarg - iarg;
-       switch (esc_name) {
+       switch (buf[inam]) {
        case '*':
                if (resc == NULL && argl == 2 &&
                    buf[iarg] == '.' && buf[iarg + 1] == 'T')
@@ -449,12 +449,15 @@ roff_escape(const char *buf, const int ln, const int aesc,
 
 out_sub:
        iesc = sesc;
+       inam = snam;
        iarg = sarg;
        iendarg = sendarg;
        iend = send;
        rval = ESCAPE_EXPAND;
 
 out:
+       if (rnam != NULL)
+               *rnam = inam;
        if (rarg != NULL)
                *rarg = iarg;
        if (rendarg != NULL)
@@ -478,7 +481,7 @@ out:
                err = MANDOCERR_ESC_UNSUPP;
                break;
        case ESCAPE_UNDEF:
-               if (esc_name == '\\')
+               if (buf[inam] == '\\')
                        return rval;
                err = MANDOCERR_ESC_UNDEF;
                break;

diff --git a/usr.bin/mandoc/roff_int.h b/usr.bin/mandoc/roff_int.h
index 7bbf4dd..67ff43a 100644 (file)
--- a/usr.bin/mandoc/roff_int.h
+++ b/usr.bin/mandoc/roff_int.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: roff_int.h,v 1.19 2022/05/19 15:17:51 schwarze Exp $      */
+/* $OpenBSD: roff_int.h,v 1.20 2022/06/02 11:28:16 schwarze Exp $      */
 /*
  * Copyright (c) 2013-2015, 2017-2022 Ingo Schwarze <schwarze@openbsd.org>
  * Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
@@ -83,7 +83,7 @@ enum roff_tok   roffhash_find(struct ohash *, const char *, size_t);
 void             roffhash_free(struct ohash *);
 
 enum mandoc_esc          roff_escape(const char *, const int, const int,
-                       int *, int *, int *, int *);
+                       int *, int *, int *, int *, int *);
 void             roff_state_reset(struct roff_man *);
 void             roff_validate(struct roff_man *);