* mdocml: Improve error handling in the eqn(7) parser.
@ 2014-10-12 19:31 schwarze
0 siblings, 0 replies; only message in thread
From: schwarze @ 2014-10-12 19:31 UTC (permalink / raw)
To: source
Log Message:
-----------
Improve error handling in the eqn(7) parser.
Get rid of the first fatal error, MANDOCERR_EQNSYNT.
In eqn(7), there is no need to be bug-compatible with groff, so there
is no need to abondon the whole equation in case of a syntax error.
In particular:
* Skip "back", "delim", "down", "fwd", "gfont", "gsize", "left",
"right", "size", and "up" without arguments.
* Skip "gsize" and "size" with a non-numeric argument.
* Skip closing delimiters that are not open.
* Skip "above" outside piles.
* For diacritic marks and binary operators without a left operand,
default to an empty box.
* Let piles and matrices take one argument rather than insisting
on a braced list. Let HTML output handle that, too.
* When rewinding, if the root box is guaranteed to match
the termination condition, no error handling is needed.
Modified Files:
--------------
mdocml:
eqn.c
eqn_html.c
mandoc.1
mandoc.h
read.c
Revision Data
-------------
Index: eqn.c
===================================================================
RCS file: /usr/vhosts/mdocml.bsd.lv/cvs/mdocml/eqn.c,v
retrieving revision 1.51
retrieving revision 1.52
diff -Leqn.c -Leqn.c -u -p -r1.51 -r1.52
--- eqn.c
+++ eqn.c
@@ -656,7 +656,7 @@ static int
eqn_parse(struct eqn_node *ep, struct eqn_box *parent)
{
char *p;
- enum eqn_tok tok;
+ enum eqn_tok tok, subtok;
enum eqn_post pos;
struct eqn_box *cur;
int rc, size;
@@ -665,9 +665,12 @@ eqn_parse(struct eqn_node *ep, struct eq
const char *start;
assert(NULL != parent);
-again:
- switch ((tok = eqn_tok_parse(ep, &p))) {
+next_tok:
+ tok = eqn_tok_parse(ep, &p);
+
+this_tok:
+ switch (tok) {
case (EQN_TOK_UNDEF):
if ((rc = eqn_undef(ep)) <= 0)
return(rc);
@@ -686,10 +689,9 @@ again:
break;
case (EQN_TOK_DELIM):
case (EQN_TOK_GFONT):
- if (NULL == eqn_nextrawtok(ep, NULL)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
+ if (eqn_nextrawtok(ep, NULL) == NULL)
+ mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
+ ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
break;
case (EQN_TOK_MARK):
case (EQN_TOK_LINEUP):
@@ -703,9 +705,12 @@ again:
case (EQN_TOK_HAT):
case (EQN_TOK_DOT):
case (EQN_TOK_DOTDOT):
- if (NULL == parent->last) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
+ if (parent->last == NULL) {
+ mandoc_msg(MANDOCERR_EQN_NOBOX, ep->parse,
+ ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+ cur = eqn_box_alloc(ep, parent);
+ cur->type = EQN_TEXT;
+ cur->text = mandoc_strdup("");
}
parent = eqn_box_makebinary(ep, EQNPOS_NONE, parent);
parent->type = EQN_LISTONE;
@@ -761,10 +766,12 @@ again:
case (EQN_TOK_BACK):
case (EQN_TOK_DOWN):
case (EQN_TOK_UP):
- tok = eqn_tok_parse(ep, NULL);
- if (EQN_TOK__MAX != tok) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
+ subtok = eqn_tok_parse(ep, NULL);
+ if (subtok != EQN_TOK__MAX) {
+ mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
+ ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+ tok = subtok;
+ goto this_tok;
}
break;
case (EQN_TOK_FAT):
@@ -772,10 +779,7 @@ again:
case (EQN_TOK_ITALIC):
case (EQN_TOK_BOLD):
while (parent->args == parent->expectargs)
- if (NULL == (parent = parent->parent)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
+ parent = parent->parent;
/*
* These values apply to the next word or sequence of
* words; thus, we mark that we'll have a child with
@@ -805,13 +809,15 @@ again:
case (EQN_TOK_GSIZE):
/* Accept two values: integral size and a single. */
if (NULL == (start = eqn_nexttok(ep, &sz))) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
+ mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
+ ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+ break;
}
size = mandoc_strntoi(start, sz, 10);
if (-1 == size) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
+ mandoc_msg(MANDOCERR_IT_NONUM, ep->parse,
+ ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+ break;
}
if (EQN_TOK_GSIZE == tok) {
ep->gsize = size;
@@ -831,9 +837,12 @@ again:
* Repivot under a positional node, open a child scope
* and keep on reading.
*/
- if (NULL == parent->last) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
+ if (parent->last == NULL) {
+ mandoc_msg(MANDOCERR_EQN_NOBOX, ep->parse,
+ ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+ cur = eqn_box_alloc(ep, parent);
+ cur->type = EQN_TEXT;
+ cur->text = mandoc_strdup("");
}
/* Handle the "subsup" and "fromto" positions. */
if (EQN_TOK_SUP == tok && parent->pos == EQNPOS_SUB) {
@@ -866,10 +875,7 @@ again:
break;
case (EQN_TOK_SQRT):
while (parent->args == parent->expectargs)
- if (NULL == (parent = parent->parent)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
+ parent = parent->parent;
/*
* Accept a left-right-associative set of arguments just
* like sub and sup and friends but without rebalancing
@@ -886,15 +892,15 @@ again:
* Close out anything that's currently open, then
* rebalance and continue reading.
*/
- if (NULL == parent->last) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
+ if (parent->last == NULL) {
+ mandoc_msg(MANDOCERR_EQN_NOBOX, ep->parse,
+ ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+ cur = eqn_box_alloc(ep, parent);
+ cur->type = EQN_TEXT;
+ cur->text = mandoc_strdup("");
}
while (EQN_SUBEXPR == parent->type)
- if (NULL == (parent = parent->parent)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
+ parent = parent->parent;
parent = eqn_box_makebinary(ep, EQNPOS_OVER, parent);
break;
case (EQN_TOK_RIGHT):
@@ -904,19 +910,23 @@ again:
* FIXME: this is a shitty sentinel: we should really
* have a native EQN_BRACE type or whatnot.
*/
- while (parent->type != EQN_LIST)
- if (NULL == (parent = parent->parent)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
+ for (cur = parent; cur != NULL; cur = cur->parent)
+ if (cur->type == EQN_LIST &&
+ (tok == EQN_TOK_BRACE_CLOSE ||
+ cur->left != NULL))
+ break;
+ if (cur == NULL) {
+ mandoc_msg(MANDOCERR_BLK_NOTOPEN, ep->parse,
+ ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+ break;
+ }
+ parent = cur;
if (EQN_TOK_RIGHT == tok) {
- if (NULL == parent->left) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
if (NULL == (start = eqn_nexttok(ep, &sz))) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
+ mandoc_msg(MANDOCERR_REQ_EMPTY,
+ ep->parse, ep->eqn.ln,
+ ep->eqn.pos, eqn_toks[tok]);
+ break;
}
/* Handling depends on right/left. */
if (STRNEQ(start, sz, "ceiling", 7)) {
@@ -928,10 +938,7 @@ again:
} else
parent->right = mandoc_strndup(start, sz);
}
- if (NULL == (parent = parent->parent)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
+ parent = parent->parent;
if (EQN_TOK_BRACE_CLOSE == tok && parent &&
(parent->type == EQN_PILE ||
parent->type == EQN_MATRIX))
@@ -939,10 +946,7 @@ again:
/* Close out any "singleton" lists. */
while (parent->type == EQN_LISTONE &&
parent->args == parent->expectargs)
- if (NULL == (parent = parent->parent)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
+ parent = parent->parent;
break;
case (EQN_TOK_BRACE_OPEN):
case (EQN_TOK_LEFT):
@@ -952,18 +956,16 @@ again:
* (just like with the text node).
*/
while (parent->args == parent->expectargs)
- if (NULL == (parent = parent->parent)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
+ parent = parent->parent;
+ if (EQN_TOK_LEFT == tok &&
+ (start = eqn_nexttok(ep, &sz)) == NULL) {
+ mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
+ ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+ break;
+ }
parent = eqn_box_alloc(ep, parent);
parent->type = EQN_LIST;
if (EQN_TOK_LEFT == tok) {
- if (NULL == (start = eqn_nexttok(ep, &sz))) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
- /* Handling depends on right/left. */
if (STRNEQ(start, sz, "ceiling", 7)) {
strlcpy(sym, "\\[lc]", sizeof(sym));
parent->left = mandoc_strdup(sym);
@@ -982,42 +984,29 @@ again:
case (EQN_TOK_LCOL):
case (EQN_TOK_RCOL):
while (parent->args == parent->expectargs)
- if (NULL == (parent = parent->parent)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
- if (EQN_TOK_BRACE_OPEN != eqn_tok_parse(ep, NULL)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
+ parent = parent->parent;
parent = eqn_box_alloc(ep, parent);
parent->type = EQN_PILE;
- parent = eqn_box_alloc(ep, parent);
- parent->type = EQN_LIST;
+ parent->expectargs = 1;
break;
case (EQN_TOK_ABOVE):
- while (parent->type != EQN_PILE)
- if (NULL == (parent = parent->parent)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
- parent = eqn_box_alloc(ep, parent);
+ for (cur = parent; cur != NULL; cur = cur->parent)
+ if (cur->type == EQN_PILE)
+ break;
+ if (cur == NULL) {
+ mandoc_msg(MANDOCERR_IT_STRAY, ep->parse,
+ ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+ break;
+ }
+ parent = eqn_box_alloc(ep, cur);
parent->type = EQN_LIST;
break;
case (EQN_TOK_MATRIX):
while (parent->args == parent->expectargs)
- if (NULL == (parent = parent->parent)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
- if (EQN_TOK_BRACE_OPEN != eqn_tok_parse(ep, NULL)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
+ parent = parent->parent;
parent = eqn_box_alloc(ep, parent);
parent->type = EQN_MATRIX;
- parent = eqn_box_alloc(ep, parent);
- parent->type = EQN_LIST;
+ parent->expectargs = 1;
break;
case (EQN_TOK_EOF):
/*
@@ -1033,11 +1022,7 @@ again:
* in an expression, then rewind til we're not any more.
*/
while (parent->args == parent->expectargs)
- if (NULL == (parent = parent->parent)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- free(p);
- return(-1);
- }
+ parent = parent->parent;
cur = eqn_box_alloc(ep, parent);
cur->type = EQN_TEXT;
for (i = 0; i < EQNSYM__MAX; i++)
@@ -1055,14 +1040,11 @@ again:
* Post-process list status.
*/
while (parent->type == EQN_LISTONE &&
- parent->args == parent->expectargs)
- if (NULL == (parent = parent->parent)) {
- EQN_MSG(MANDOCERR_EQNSYNT, ep);
- return(-1);
- }
+ parent->args == parent->expectargs)
+ parent = parent->parent;
break;
}
- goto again;
+ goto next_tok;
}
enum rofferr
Index: mandoc.1
===================================================================
RCS file: /usr/vhosts/mdocml.bsd.lv/cvs/mdocml/mandoc.1,v
retrieving revision 1.117
retrieving revision 1.118
diff -Lmandoc.1 -Lmandoc.1 -u -p -r1.117 -r1.118
--- mandoc.1
+++ mandoc.1
@@ -911,8 +911,11 @@ The previous, interrupted macro is delet
.Ss "Warnings related to missing arguments"
.Bl -ohang
.It Sy "skipping empty request"
-.Pq roff
-The macro name is missing from a macro definition request.
+.Pq roff , eqn
+The macro name is missing from a macro definition request,
+or an
+.Xr eqn 7
+control statement or operation keyword lacks its required argument.
.It Sy "conditional request controls empty scope"
.Pq roff
A conditional request is only useful if any of the following
@@ -1046,6 +1049,11 @@ The
utility assumes
.Fl std
even when it is not specified, but other implementations may not.
+.It Sy "missing eqn box, using \(dq\(dq"
+.Pq eqn
+A diacritic mark or a binary operator is found,
+but there is nothing to the left of it.
+An empty box is inserted.
.El
.Ss "Warnings related to bad macro arguments"
.Bl -ohang
@@ -1218,7 +1226,6 @@ keeps the code more readable.
.It "equation scope open on exit"
.It "overlapping equation scopes"
.It "unexpected end of equation"
-.It "equation syntax error"
.El
.Ss "Errors related to tables"
.Bl -inset -compact
@@ -1272,12 +1279,15 @@ macro.
It may be mistyped or unsupported.
The request or macro is discarded including its arguments.
.It Sy "skipping item outside list"
-.Pq mdoc
+.Pq mdoc , eqn
An
.Ic \&It
macro occurs outside any
.Ic \&Bl
-list.
+list, or an
+.Xr eqn 7
+.Ic above
+delimiter occurs outside any pile.
It is discarded including its arguments.
.It Sy "skipping column outside column list"
.Pq mdoc
@@ -1298,7 +1308,9 @@ block closing macro, a
.Ic \&RE
or
.Ic \&UE
-macro, or the end of an equation, table, or
+macro, an
+.Xr eqn 7
+right delimiter or closing brace, or the end of an equation, table, or
.Xr roff 7
conditional request is encountered but no matching block is open.
The offending request or macro is discarded.
@@ -1395,11 +1407,16 @@ An
.Ic \&St
macro has an unknown argument and is discarded.
.It Sy "skipping request without numeric argument"
-.Pq roff
+.Pq roff , eqn
An
.Ic \&it
-request has a non-numeric or negative argument or no argument at all.
-The invalid request is ignored.
+request or an
+.Xr eqn 7
+.Ic \&size
+or
+.Ic \&gsize
+statement has a non-numeric or negative argument or no argument at all.
+The invalid request or statement is ignored.
.It Sy "skipping all arguments"
.Pq mdoc , man , eqn , roff
An
Index: mandoc.h
===================================================================
RCS file: /usr/vhosts/mdocml.bsd.lv/cvs/mdocml/mandoc.h,v
retrieving revision 1.161
retrieving revision 1.162
diff -Lmandoc.h -Lmandoc.h -u -p -r1.161 -r1.162
--- mandoc.h
+++ mandoc.h
@@ -104,6 +104,7 @@ enum mandocerr {
MANDOCERR_BF_NOFONT, /* missing font type, using \fR: Bf */
MANDOCERR_BF_BADFONT, /* unknown font type, using \fR: Bf font */
MANDOCERR_ARG_STD, /* missing -std argument, adding it: macro */
+ MANDOCERR_EQN_NOBOX, /* missing eqn box, using "": op */
/* related to bad arguments */
MANDOCERR_ARG_QUOTE, /* unterminated quoted argument */
@@ -134,7 +135,6 @@ enum mandocerr {
MANDOCERR_EQNSCOPE, /* equation scope open on exit */
MANDOCERR_EQNBADSCOPE, /* overlapping equation scopes */
MANDOCERR_EQNEOF, /* unexpected end of equation */
- MANDOCERR_EQNSYNT, /* equation syntax error */
/* related to tables */
MANDOCERR_TBL, /* bad table syntax */
Index: eqn_html.c
===================================================================
RCS file: /usr/vhosts/mdocml.bsd.lv/cvs/mdocml/eqn_html.c,v
retrieving revision 1.9
retrieving revision 1.10
diff -Leqn_html.c -Leqn_html.c -u -p -r1.9 -r1.10
--- eqn_html.c
+++ eqn_html.c
@@ -47,10 +47,12 @@ eqn_box(struct html *p, const struct eqn
if (EQN_MATRIX == bp->type) {
if (NULL == bp->first)
goto out;
- assert(EQN_LIST == bp->first->type);
+ if (EQN_LIST != bp->first->type) {
+ eqn_box(p, bp->first);
+ goto out;
+ }
if (NULL == (parent = bp->first->first))
goto out;
- assert(EQN_PILE == parent->type);
/* Estimate the number of rows, first. */
if (NULL == (child = parent->first))
goto out;
@@ -126,8 +128,10 @@ eqn_box(struct html *p, const struct eqn
if (EQN_PILE == bp->type) {
assert(NULL == post);
- post = print_otag(p, TAG_MTABLE, 0, NULL);
- } else if (bp->parent && EQN_PILE == bp->parent->type) {
+ if (bp->first != NULL && bp->first->type == EQN_LIST)
+ post = print_otag(p, TAG_MTABLE, 0, NULL);
+ } else if (bp->type == EQN_LIST &&
+ bp->parent && bp->parent->type == EQN_PILE) {
assert(NULL == post);
post = print_otag(p, TAG_MTR, 0, NULL);
print_otag(p, TAG_MTD, 0, NULL);
Index: read.c
===================================================================
RCS file: /usr/vhosts/mdocml.bsd.lv/cvs/mdocml/read.c,v
retrieving revision 1.89
retrieving revision 1.90
diff -Lread.c -Lread.c -u -p -r1.89 -r1.90
--- read.c
+++ read.c
@@ -149,6 +149,7 @@ static const char * const mandocerrs[MAN
"missing font type, using \\fR",
"unknown font type, using \\fR",
"missing -std argument, adding it",
+ "missing eqn box, using \"\"",
/* related to bad macro arguments */
"unterminated quoted argument",
@@ -179,7 +180,6 @@ static const char * const mandocerrs[MAN
"equation scope open on exit",
"overlapping equation scopes",
"unexpected end of equation",
- "equation syntax error",
/* related to tables */
"bad table syntax",
--
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