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Support a new experimental feature called scan substring
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Zoltan Herczeg committed Aug 26, 2024
1 parent 5bff405 commit ddebab2
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4 changes: 4 additions & 0 deletions ChangeLog
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Original file line number Diff line number Diff line change
Expand Up @@ -75,6 +75,10 @@ with JIT was correct.
12. Add a new error code (PCRE2_ERROR_JIT_UNSUPPORTED) which is yielded
for unsupported jit features.

13. Add a new experimental feature called scan substring. This feature
is a new type of assertion which matches the content of a captruing block
to a sub pattern.


Version 10.44 07-June-2024
--------------------------
Expand Down
185 changes: 137 additions & 48 deletions src/pcre2_compile.c
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Original file line number Diff line number Diff line change
Expand Up @@ -231,63 +231,65 @@ code (meta_extra_lengths, just below) must be updated to remain in step. */
#define META_COND_RNAME 0x80130000u /* (?(R&name)... */
#define META_COND_RNUMBER 0x80140000u /* (?(Rdigits)... */
#define META_COND_VERSION 0x80150000u /* (?(VERSION<op>x.y)... */
#define META_DOLLAR 0x80160000u /* $ metacharacter */
#define META_DOT 0x80170000u /* . metacharacter */
#define META_ESCAPE 0x80180000u /* \d and friends */
#define META_KET 0x80190000u /* closing parenthesis */
#define META_NOCAPTURE 0x801a0000u /* no capture parens */
#define META_OPTIONS 0x801b0000u /* (?i) and friends */
#define META_POSIX 0x801c0000u /* POSIX class item */
#define META_POSIX_NEG 0x801d0000u /* negative POSIX class item */
#define META_RANGE_ESCAPED 0x801e0000u /* range with at least one escape */
#define META_RANGE_LITERAL 0x801f0000u /* range defined literally */
#define META_RECURSE 0x80200000u /* Recursion */
#define META_RECURSE_BYNAME 0x80210000u /* (?&name) */
#define META_SCRIPT_RUN 0x80220000u /* (*script_run:...) */
#define META_SCS_NAME 0x80160000u /* (*scs:(<name>)... */
#define META_SCS_NUMBER 0x80170000u /* (*scs:(digits)... */
#define META_DOLLAR 0x80180000u /* $ metacharacter */
#define META_DOT 0x80190000u /* . metacharacter */
#define META_ESCAPE 0x801a0000u /* \d and friends */
#define META_KET 0x801b0000u /* closing parenthesis */
#define META_NOCAPTURE 0x801c0000u /* no capture parens */
#define META_OPTIONS 0x801d0000u /* (?i) and friends */
#define META_POSIX 0x801e0000u /* POSIX class item */
#define META_POSIX_NEG 0x801f0000u /* negative POSIX class item */
#define META_RANGE_ESCAPED 0x80200000u /* range with at least one escape */
#define META_RANGE_LITERAL 0x80210000u /* range defined literally */
#define META_RECURSE 0x80220000u /* Recursion */
#define META_RECURSE_BYNAME 0x80230000u /* (?&name) */
#define META_SCRIPT_RUN 0x80240000u /* (*script_run:...) */

/* These must be kept together to make it easy to check that an assertion
is present where expected in a conditional group. */

#define META_LOOKAHEAD 0x80230000u /* (?= */
#define META_LOOKAHEADNOT 0x80240000u /* (?! */
#define META_LOOKBEHIND 0x80250000u /* (?<= */
#define META_LOOKBEHINDNOT 0x80260000u /* (?<! */
#define META_LOOKAHEAD 0x80250000u /* (?= */
#define META_LOOKAHEADNOT 0x80260000u /* (?! */
#define META_LOOKBEHIND 0x80270000u /* (?<= */
#define META_LOOKBEHINDNOT 0x80280000u /* (?<! */

/* These cannot be conditions */

#define META_LOOKAHEAD_NA 0x80270000u /* (*napla: */
#define META_LOOKBEHIND_NA 0x80280000u /* (*naplb: */
#define META_LOOKAHEAD_NA 0x80290000u /* (*napla: */
#define META_LOOKBEHIND_NA 0x802a0000u /* (*naplb: */

/* These must be kept in this order, with consecutive values, and the _ARG
versions of COMMIT, PRUNE, SKIP, and THEN immediately after their non-argument
versions. */

#define META_MARK 0x80290000u /* (*MARK) */
#define META_ACCEPT 0x802a0000u /* (*ACCEPT) */
#define META_FAIL 0x802b0000u /* (*FAIL) */
#define META_COMMIT 0x802c0000u /* These */
#define META_COMMIT_ARG 0x802d0000u /* pairs */
#define META_PRUNE 0x802e0000u /* must */
#define META_PRUNE_ARG 0x802f0000u /* be */
#define META_SKIP 0x80300000u /* kept */
#define META_SKIP_ARG 0x80310000u /* in */
#define META_THEN 0x80320000u /* this */
#define META_THEN_ARG 0x80330000u /* order */
#define META_MARK 0x802b0000u /* (*MARK) */
#define META_ACCEPT 0x802c0000u /* (*ACCEPT) */
#define META_FAIL 0x802d0000u /* (*FAIL) */
#define META_COMMIT 0x802e0000u /* These */
#define META_COMMIT_ARG 0x802f0000u /* pairs */
#define META_PRUNE 0x80300000u /* must */
#define META_PRUNE_ARG 0x80310000u /* be */
#define META_SKIP 0x80320000u /* kept */
#define META_SKIP_ARG 0x80330000u /* in */
#define META_THEN 0x80340000u /* this */
#define META_THEN_ARG 0x80350000u /* order */

/* These must be kept in groups of adjacent 3 values, and all together. */

#define META_ASTERISK 0x80340000u /* * */
#define META_ASTERISK_PLUS 0x80350000u /* *+ */
#define META_ASTERISK_QUERY 0x80360000u /* *? */
#define META_PLUS 0x80370000u /* + */
#define META_PLUS_PLUS 0x80380000u /* ++ */
#define META_PLUS_QUERY 0x80390000u /* +? */
#define META_QUERY 0x803a0000u /* ? */
#define META_QUERY_PLUS 0x803b0000u /* ?+ */
#define META_QUERY_QUERY 0x803c0000u /* ?? */
#define META_MINMAX 0x803d0000u /* {n,m} repeat */
#define META_MINMAX_PLUS 0x803e0000u /* {n,m}+ repeat */
#define META_MINMAX_QUERY 0x803f0000u /* {n,m}? repeat */
#define META_ASTERISK 0x80360000u /* * */
#define META_ASTERISK_PLUS 0x80370000u /* *+ */
#define META_ASTERISK_QUERY 0x80380000u /* *? */
#define META_PLUS 0x80390000u /* + */
#define META_PLUS_PLUS 0x803a0000u /* ++ */
#define META_PLUS_QUERY 0x803b0000u /* +? */
#define META_QUERY 0x803c0000u /* ? */
#define META_QUERY_PLUS 0x803d0000u /* ?+ */
#define META_QUERY_QUERY 0x803e0000u /* ?? */
#define META_MINMAX 0x803f0000u /* {n,m} repeat */
#define META_MINMAX_PLUS 0x80400000u /* {n,m}+ repeat */
#define META_MINMAX_QUERY 0x80410000u /* {n,m}? repeat */

#define META_FIRST_QUANTIFIER META_ASTERISK
#define META_LAST_QUANTIFIER META_MINMAX_QUERY
Expand Down Expand Up @@ -326,6 +328,8 @@ static unsigned char meta_extra_lengths[] = {
1+SIZEOFFSET, /* META_COND_RNAME */
1+SIZEOFFSET, /* META_COND_RNUMBER */
3, /* META_COND_VERSION */
1+SIZEOFFSET, /* META_SCS_NAME */
1+SIZEOFFSET, /* META_SCS_NUMBER */
0, /* META_DOLLAR */
0, /* META_DOT */
0, /* META_ESCAPE - one more for ESC_P and ESC_p */
Expand Down Expand Up @@ -656,6 +660,8 @@ static const char alasnames[] =
STRING_non_atomic_positive_lookbehind0
STRING_negative_lookahead0
STRING_negative_lookbehind0
STRING_scs0
STRING_scan_substring0
STRING_atomic0
STRING_sr0
STRING_asr0
Expand All @@ -675,6 +681,8 @@ static const alasitem alasmeta[] = {
{ 30, META_LOOKBEHIND_NA },
{ 18, META_LOOKAHEADNOT },
{ 19, META_LOOKBEHINDNOT },
{ 3, META_SCS_NUMBER }, /* placeholder, updated later */
{ 14, META_SCS_NUMBER }, /* placeholder, updated later */
{ 6, META_ATOMIC },
{ 2, META_SCRIPT_RUN }, /* sr = script run */
{ 3, META_ATOMIC_SCRIPT_RUN }, /* asr = atomic script run */
Expand Down Expand Up @@ -1152,6 +1160,19 @@ for (;;)
fprintf(stderr, "%zd", offset);
break;

case META_SCS_NAME:
fprintf(stderr, "META (*scan_substring:(<name>) length=%d offset=", *pptr++);
GETOFFSET(offset, pptr);
fprintf(stderr, "%zd", offset);
break;

case META_SCS_NUMBER:
fprintf(stderr, "META_SCS_NUMBER %d offset=", pptr[SIZEOFFSET]);
GETOFFSET(offset, pptr);
fprintf(stderr, "%zd", offset);
pptr++;
break;

case META_MARK:
fprintf(stderr, "META (*MARK:");
goto SHOWARG;
Expand Down Expand Up @@ -4053,6 +4074,67 @@ while (ptr < ptrend)
case META_LOOKAHEADNOT:
goto NEGATIVE_LOOK_AHEAD;

case META_SCS_NUMBER:
nest_depth++;

if (++ptr >= ptrend) goto UNCLOSED_PARENTHESIS;

if (*ptr != CHAR_LEFT_PARENTHESIS)
{
errorcode = ERR15;
goto FAILED;
}

ptr++;

/* Handle (scan_substring:([+-]number)... */
if (read_number(&ptr, ptrend, cb->bracount, MAX_GROUP_NUMBER, ERR61,
&i, &errorcode))
{
if (i <= 0)
{
errorcode = ERR15;
goto FAILED;
}
*parsed_pattern++ = META_SCS_NUMBER;
offset = (PCRE2_SIZE)(ptr - cb->start_pattern - 2);
PUTOFFSET(offset, parsed_pattern);
*parsed_pattern++ = i;
}
else if (errorcode != 0) goto FAILED; /* Number too big */
else
{
if (ptr >= ptrend) goto UNCLOSED_PARENTHESIS;

/* Handle (*scan_substring:('name') or (*scan_substring:(<name>) */
if (*ptr == CHAR_LESS_THAN_SIGN)
terminator = CHAR_GREATER_THAN_SIGN;
else if (*ptr == CHAR_APOSTROPHE)
terminator = CHAR_APOSTROPHE;
else
{
errorcode = ERR15;
goto FAILED;
}

if (!read_name(&ptr, ptrend, utf, terminator, &offset, &name,
&namelen, &errorcode, cb)) goto FAILED;

*parsed_pattern++ = META_SCS_NAME;
*parsed_pattern++ = namelen;
PUTOFFSET(offset, parsed_pattern);
}

if (++ptr >= ptrend) goto UNCLOSED_PARENTHESIS;

if (*ptr != CHAR_RIGHT_PARENTHESIS)
{
errorcode = ERR24;
break;
}
ptr++;
break;

case META_LOOKBEHIND:
case META_LOOKBEHINDNOT:
case META_LOOKBEHIND_NA:
Expand Down Expand Up @@ -6642,7 +6724,8 @@ for (;; pptr++)
case META_COND_RNUMBER: /* (?(Rdigits) */
case META_COND_NAME: /* (?(name) or (?'name') or ?(<name>) */
case META_COND_RNAME: /* (?(R&name) - test for recursion */
bravalue = OP_COND;
case META_SCS_NAME: /* (*scan_substring:'name') or (*scan_substring:(<name>)) */
bravalue = meta == META_SCS_NAME ? OP_ASSERT_SCS : OP_COND;
{
int count, index;
unsigned int i;
Expand Down Expand Up @@ -6736,7 +6819,9 @@ for (;; pptr++)
PUT2(code, 2+LINK_SIZE, index);
PUT2(code, 2+LINK_SIZE+IMM2_SIZE, count);
}
goto GROUP_PROCESS_NOTE_EMPTY;
if (meta != META_SCS_NAME) goto GROUP_PROCESS_NOTE_EMPTY;
cb->assert_depth += 1;
goto GROUP_PROCESS;

/* The DEFINE condition is always false. Its internal groups may never
be called, so matched_char must remain false, hence the jump to
Expand All @@ -6752,7 +6837,8 @@ for (;; pptr++)
/* Conditional test of a group's being set. */

case META_COND_NUMBER:
bravalue = OP_COND;
case META_SCS_NUMBER:
bravalue = meta == META_SCS_NUMBER ? OP_ASSERT_SCS : OP_COND;
GETPLUSOFFSET(offset, pptr);
groupnumber = *(++pptr);
if (groupnumber > cb->bracount)
Expand All @@ -6762,11 +6848,14 @@ for (;; pptr++)
return 0;
}
if (groupnumber > cb->top_backref) cb->top_backref = groupnumber;
offset -= 2; /* Point at initial ( for too many branches error */
/* Point at initial ( for too many branches error */
if (meta != META_SCS_NUMBER) offset -= 2;
code[1+LINK_SIZE] = OP_CREF;
skipunits = 1+IMM2_SIZE;
PUT2(code, 2+LINK_SIZE, groupnumber);
goto GROUP_PROCESS_NOTE_EMPTY;
if (meta != META_SCS_NUMBER) goto GROUP_PROCESS_NOTE_EMPTY;
cb->assert_depth += 1;
goto GROUP_PROCESS;

/* Test for the PCRE2 version. */

Expand Down Expand Up @@ -6900,7 +6989,7 @@ for (;; pptr++)

/* If we've just compiled an assertion, pop the assert depth. */

if (bravalue >= OP_ASSERT && bravalue <= OP_ASSERTBACK_NA)
if (bravalue >= OP_ASSERT && bravalue <= OP_ASSERT_SCS)
cb->assert_depth -= 1;

/* At the end of compiling, code is still pointing to the start of the
Expand Down
2 changes: 2 additions & 0 deletions src/pcre2_dfa_match.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -175,6 +175,7 @@ static const uint8_t coptable[] = {
0, /* Assert behind not */
0, /* NA assert */
0, /* NA assert behind */
0, /* Assert scan substring */
0, /* ONCE */
0, /* SCRIPT_RUN */
0, 0, 0, 0, 0, /* BRA, BRAPOS, CBRA, CBRAPOS, COND */
Expand Down Expand Up @@ -253,6 +254,7 @@ static const uint8_t poptable[] = {
0, /* Assert behind not */
0, /* NA assert */
0, /* NA assert behind */
0, /* Assert scan substring */
0, /* ONCE */
0, /* SCRIPT_RUN */
0, 0, 0, 0, 0, /* BRA, BRAPOS, CBRA, CBRAPOS, COND */
Expand Down
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