* Can of worms: \h"..."
@ 2012-01-03 12:19 Kristaps Dzonsons
2012-01-04 0:54 ` Ingo Schwarze
0 siblings, 1 reply; 2+ messages in thread
From: Kristaps Dzonsons @ 2012-01-03 12:19 UTC (permalink / raw)
To: tech
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Hi,
On the verge of checking in a quick fix for the \h"..." TODO, it
occurred to me that we either don't want to accomodate for pod2man
badness OR something more subtle's at work. \h"..." is specifically
disallowed by groff(1). So I searched in the groff source. Behold!
In groff.c's input.cpp, we see several escapes (h, H, N, S, v, x)
directly condition their enclosing markers on the first character (see
get_delim_number()) while others do so indirectly. These set the end
marker on the first character given that it satisfies the
token::delimiter() method (or whatever is C++'s name for an object
function).
The delimiter() function (also in input.cpp) allows any character but a
certain ASCII subset and whitespace. groff(7) mentions the apostrophe,
but it can much much more.
Question is: do we want this behaviour? I'd say we do, but as it's
somewhat intrusive, I want some consensus before committing. Either
way, I do NOT suggest that we outwardly document this.
Note that this also fixes the situation where some non-\N escapes were
being assigned the NUMERIC identifier, which is only used for \N. I
also removed the check for \N numbers, as this is done again later.
Thoughts?
Kristaps
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Index: mandoc.c
===================================================================
RCS file: /usr/vhosts/mdocml.bsd.lv/cvs/mdocml/mandoc.c,v
retrieving revision 1.62
diff -u -p -r1.62 mandoc.c
--- mandoc.c 3 Dec 2011 16:08:51 -0000 1.62
+++ mandoc.c 3 Jan 2012 12:18:51 -0000
@@ -209,9 +209,15 @@ mandoc_escape(const char **end, const ch
break;
/*
- * These escapes are of the form \X'N', where 'X' is the trigger
- * and 'N' resolves to a numerical expression.
+ * These escapes accept most characters as enclosure marks
+ * (except for those listed in the switch).
+ * The enclosed materials are numbers, so run them through the
+ * numerical subexpression calculator after we process.
*/
+ case ('N'):
+ /* Special case: numerical representation of char. */
+ gly = ESCAPE_NUMBERED;
+ /* FALLTHROUGH */
case ('B'):
/* FALLTHROUGH */
case ('h'):
@@ -221,7 +227,6 @@ mandoc_escape(const char **end, const ch
case ('L'):
/* FALLTHROUGH */
case ('l'):
- gly = ESCAPE_NUMBERED;
/* FALLTHROUGH */
case ('S'):
/* FALLTHROUGH */
@@ -230,32 +235,62 @@ mandoc_escape(const char **end, const ch
case ('w'):
/* FALLTHROUGH */
case ('x'):
- if (ESCAPE_ERROR == gly)
+ if (ESCAPE_NUMBERED != gly)
gly = ESCAPE_IGNORE;
- if ('\'' != cp[i++])
+ numeric = term = cp[i++];
+ switch (numeric) {
+ case('0'):
+ /* FALLTHROUGH */
+ case('1'):
+ /* FALLTHROUGH */
+ case('2'):
+ /* FALLTHROUGH */
+ case('3'):
+ /* FALLTHROUGH */
+ case('4'):
+ /* FALLTHROUGH */
+ case('5'):
+ /* FALLTHROUGH */
+ case('6'):
+ /* FALLTHROUGH */
+ case('7'):
+ /* FALLTHROUGH */
+ case('8'):
+ /* FALLTHROUGH */
+ case('9'):
+ /* FALLTHROUGH */
+ case('+'):
+ /* FALLTHROUGH */
+ case('-'):
+ /* FALLTHROUGH */
+ case('/'):
+ /* FALLTHROUGH */
+ case('*'):
+ /* FALLTHROUGH */
+ case('%'):
+ /* FALLTHROUGH */
+ case('<'):
+ /* FALLTHROUGH */
+ case('>'):
+ /* FALLTHROUGH */
+ case('='):
+ /* FALLTHROUGH */
+ case('&'):
+ /* FALLTHROUGH */
+ case(':'):
+ /* FALLTHROUGH */
+ case('('):
+ /* FALLTHROUGH */
+ case(')'):
+ /* FALLTHROUGH */
+ case('.'):
return(ESCAPE_ERROR);
- term = numeric = '\'';
- break;
-
- /*
- * Special handling for the numbered character escape.
- * XXX Do any other escapes need similar handling?
- */
- case ('N'):
- if ('\0' == cp[i])
+ default:
+ break;
+ }
+ if (isspace((unsigned char)numeric))
return(ESCAPE_ERROR);
- *end = &cp[++i];
- if (isdigit((unsigned char)cp[i-1]))
- return(ESCAPE_IGNORE);
- while (isdigit((unsigned char)**end))
- (*end)++;
- if (start)
- *start = &cp[i];
- if (sz)
- *sz = *end - &cp[i];
- if ('\0' != **end)
- (*end)++;
- return(ESCAPE_NUMBERED);
+ break;
/*
* Sizes get a special category of their own.
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: Can of worms: \h"..."
2012-01-03 12:19 Can of worms: \h"..." Kristaps Dzonsons
@ 2012-01-04 0:54 ` Ingo Schwarze
0 siblings, 0 replies; 2+ messages in thread
From: Ingo Schwarze @ 2012-01-04 0:54 UTC (permalink / raw)
To: tech
Hi Kristaps,
just a very quick answer - it's getting late already and i can't
study this in due detail right now.
Kristaps Dzonsons wrote on Tue, Jan 03, 2012 at 01:19:48PM +0100:
> On the verge of checking in a quick fix for the \h"..." TODO, it
> occurred to me that we either don't want to accomodate for pod2man
> badness OR something more subtle's at work. \h"..." is specifically
> disallowed by groff(1). So I searched in the groff source. Behold!
>
> In groff.c's input.cpp, we see several escapes (h, H, N, S, v, x)
> directly condition their enclosing markers on the first character
> (see get_delim_number()) while others do so indirectly. These set
> the end marker on the first character given that it satisfies the
> token::delimiter() method (or whatever is C++'s name for an object
> function).
>
> The delimiter() function (also in input.cpp) allows any character
> but a certain ASCII subset and whitespace. groff(7) mentions the
> apostrophe, but it can much much more.
>
> Question is: do we want this behaviour? I'd say we do,
If i understand correctly, i tend to say:
Yes, we should accept the same characters as delimiters as groff.
> but as it's somewhat intrusive, I want some consensus before
> committing. Either way, I do NOT suggest that we outwardly
> document this.
Indeed, documenting the apostrophe as a delimiter is enough,
everything else does not seem particularly sane.
> Note that this also fixes the situation where some non-\N escapes
> were being assigned the NUMERIC identifier, which is only used for
> \N. I also removed the check for \N numbers, as this is done again
> later.
I didn't run it yet, but suspect that part to be wrong.
The point is: Sure, we have found an explicit delimiting character.
But any other letter will terminate the escape sequence as well, see
http://www.openbsd.org/cgi-bin/cvsweb/src/regress/usr.bin/mandoc/char/N/
Both the mdoc(7) input and groff(1) output are checked in.
See in particular the "mixed content" on line 18 of basic.in,
line 13 of basic.out_ascii.
Whatever you check in, please don't break that test. :-)
> Thoughts?
The longish switch(numeric) could probably be replaced by something like
strchr("0123456789+-/*%<>=&:().", numeric)
Yours,
Ingo
> Index: mandoc.c
> ===================================================================
> RCS file: /usr/vhosts/mdocml.bsd.lv/cvs/mdocml/mandoc.c,v
> retrieving revision 1.62
> diff -u -p -r1.62 mandoc.c
> --- mandoc.c 3 Dec 2011 16:08:51 -0000 1.62
> +++ mandoc.c 3 Jan 2012 12:18:51 -0000
> @@ -209,9 +209,15 @@ mandoc_escape(const char **end, const ch
> break;
>
> /*
> - * These escapes are of the form \X'N', where 'X' is the trigger
> - * and 'N' resolves to a numerical expression.
> + * These escapes accept most characters as enclosure marks
> + * (except for those listed in the switch).
> + * The enclosed materials are numbers, so run them through the
> + * numerical subexpression calculator after we process.
> */
> + case ('N'):
> + /* Special case: numerical representation of char. */
> + gly = ESCAPE_NUMBERED;
> + /* FALLTHROUGH */
> case ('B'):
> /* FALLTHROUGH */
> case ('h'):
> @@ -221,7 +227,6 @@ mandoc_escape(const char **end, const ch
> case ('L'):
> /* FALLTHROUGH */
> case ('l'):
> - gly = ESCAPE_NUMBERED;
> /* FALLTHROUGH */
> case ('S'):
> /* FALLTHROUGH */
> @@ -230,32 +235,62 @@ mandoc_escape(const char **end, const ch
> case ('w'):
> /* FALLTHROUGH */
> case ('x'):
> - if (ESCAPE_ERROR == gly)
> + if (ESCAPE_NUMBERED != gly)
> gly = ESCAPE_IGNORE;
> - if ('\'' != cp[i++])
> + numeric = term = cp[i++];
> + switch (numeric) {
> + case('0'):
> + /* FALLTHROUGH */
> + case('1'):
> + /* FALLTHROUGH */
> + case('2'):
> + /* FALLTHROUGH */
> + case('3'):
> + /* FALLTHROUGH */
> + case('4'):
> + /* FALLTHROUGH */
> + case('5'):
> + /* FALLTHROUGH */
> + case('6'):
> + /* FALLTHROUGH */
> + case('7'):
> + /* FALLTHROUGH */
> + case('8'):
> + /* FALLTHROUGH */
> + case('9'):
> + /* FALLTHROUGH */
> + case('+'):
> + /* FALLTHROUGH */
> + case('-'):
> + /* FALLTHROUGH */
> + case('/'):
> + /* FALLTHROUGH */
> + case('*'):
> + /* FALLTHROUGH */
> + case('%'):
> + /* FALLTHROUGH */
> + case('<'):
> + /* FALLTHROUGH */
> + case('>'):
> + /* FALLTHROUGH */
> + case('='):
> + /* FALLTHROUGH */
> + case('&'):
> + /* FALLTHROUGH */
> + case(':'):
> + /* FALLTHROUGH */
> + case('('):
> + /* FALLTHROUGH */
> + case(')'):
> + /* FALLTHROUGH */
> + case('.'):
> return(ESCAPE_ERROR);
> - term = numeric = '\'';
> - break;
> -
> - /*
> - * Special handling for the numbered character escape.
> - * XXX Do any other escapes need similar handling?
> - */
> - case ('N'):
> - if ('\0' == cp[i])
> + default:
> + break;
> + }
> + if (isspace((unsigned char)numeric))
> return(ESCAPE_ERROR);
> - *end = &cp[++i];
> - if (isdigit((unsigned char)cp[i-1]))
> - return(ESCAPE_IGNORE);
> - while (isdigit((unsigned char)**end))
> - (*end)++;
> - if (start)
> - *start = &cp[i];
> - if (sz)
> - *sz = *end - &cp[i];
> - if ('\0' != **end)
> - (*end)++;
> - return(ESCAPE_NUMBERED);
> + break;
>
> /*
> * Sizes get a special category of their own.
--
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2012-01-04 0:54 ` Ingo Schwarze
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