Skip to content

Commit

Permalink
Various code improvements for eclasses (#546)
Browse files Browse the repository at this point in the history 
Co-authored-by: Zoltan Herczeg <hzmester@freemail.hu>
  • Loading branch information
@zherczeg
zherczeg and Zoltan Herczeg authored Nov 5, 2024
1 parent 16d7edb commit c192b8c
Show file tree
Hide file tree
Showing 4 changed files with 206 additions and 240 deletions.
80 changes: 54 additions & 26 deletions src/pcre2_compile.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2859,6 +2859,7 @@ uint32_t delimiter;
uint32_t namelen;
uint32_t class_range_state;
uint32_t class_op_state;
uint32_t *class_start;
uint32_t *verblengthptr = NULL; /* Value avoids compiler warning */
uint32_t *verbstartptr = NULL;
uint32_t *previous_callout = NULL;
Expand All @@ -2869,9 +2870,8 @@ uint32_t *prev_parsed_item = NULL;
uint32_t meta_quantifier = 0;
uint32_t add_after_mark = 0;
uint16_t nest_depth = 0;
uint16_t class_depth = 0;
uint16_t class_maxdepth = 0;
uint8_t class_op_used[ECLASS_NEST_LIMIT];
int16_t class_depth_m1 = -1; /* The m1 means minus 1. */
int16_t class_maxdepth_m1 = -1;
int after_manual_callout = 0;
int expect_cond_assert = 0;
int errorcode = 0;
Expand Down Expand Up @@ -3650,10 +3650,11 @@ while (ptr < ptrend)

/* c is still set to '[' so the loop will handle the start of the class. */

class_depth = 0;
class_maxdepth = 0;
class_depth_m1 = -1;
class_maxdepth_m1 = -1;
class_range_state = RANGE_NO;
class_op_state = CLASS_OP_NONE;
class_start = NULL;

for (;;)
{
Expand Down Expand Up @@ -3684,7 +3685,7 @@ while (ptr < ptrend)
[.ch.] and [=ch=] ("collating elements") and fault them, as Perl
5.6 and 5.8 do. */

if (class_depth > 0 &&
if (class_depth_m1 >= 0 &&
c == CHAR_LEFT_SQUARE_BRACKET &&
ptrend - ptr >= 3 &&
(*ptr == CHAR_COLON || *ptr == CHAR_DOT ||
Expand Down Expand Up @@ -3792,7 +3793,7 @@ while (ptr < ptrend)
/* Check for the start of the outermost class, or the start of a nested class. */

else if (c == CHAR_LEFT_SQUARE_BRACKET &&
(class_depth == 0 || (options & PCRE2_ALT_EXTENDED_CLASS) != 0))
(class_depth_m1 < 0 || (options & PCRE2_ALT_EXTENDED_CLASS) != 0))
{
/* Tidy up the other class before starting the nested class. */
/* -[ beginning a nested class is a literal '-' */
Expand All @@ -3801,7 +3802,7 @@ while (ptr < ptrend)
parsed_pattern[-1] = CHAR_MINUS;

/* Validate nesting depth */
if (class_depth >= ECLASS_NEST_LIMIT)
if (class_depth_m1 >= ECLASS_NEST_LIMIT - 1)
{
errorcode = ERR107;
goto FAILED; /* Classes too deeply nested */
Expand Down Expand Up @@ -3845,11 +3846,19 @@ while (ptr < ptrend)
if (c == CHAR_RIGHT_SQUARE_BRACKET &&
(cb->external_options & PCRE2_ALLOW_EMPTY_CLASS) != 0)
{
if (class_start != NULL)
{
PCRE2_ASSERT(class_depth_m1 >= 0);
/* Represents that the class is an extended class. */
*class_start |= CLASS_IS_ECLASS;
class_start = NULL;
}

*parsed_pattern++ = negate_class? META_CLASS_EMPTY_NOT : META_CLASS_EMPTY;

/* Leave nesting depth unchanged; but check for zero depth to handle the
very first (top-level) class being empty. */
if (class_depth == 0) break;
if (class_depth_m1 < 0) break;

class_range_state = RANGE_NO; /* for processing the containing class */
class_op_state = CLASS_OP_OPERAND;
Expand All @@ -3858,12 +3867,23 @@ while (ptr < ptrend)

/* Enter a non-empty class. */

if (class_start != NULL)
{
PCRE2_ASSERT(class_depth_m1 >= 0);
/* Represents that the class is an extended class. */
*class_start |= CLASS_IS_ECLASS;
class_start = NULL;
}

class_start = parsed_pattern;
*parsed_pattern++ = negate_class? META_CLASS_NOT : META_CLASS;
class_range_state = RANGE_NO;
class_op_state = CLASS_OP_NONE;
++class_depth;
class_maxdepth = class_depth > class_maxdepth ?class_depth :class_maxdepth;
class_op_used[class_depth-1] = 0; /* reset; no op seen yet at new depth */
++class_depth_m1;
if (class_maxdepth_m1 < class_depth_m1)
class_maxdepth_m1 = class_depth_m1;
/* Reset; no op seen yet at new depth. */
cb->class_op_used[class_depth_m1] = 0;

/* Implement the special start-of-class literal meaning of ']'. */
if (c == CHAR_RIGHT_SQUARE_BRACKET)
Expand Down Expand Up @@ -3894,10 +3914,13 @@ while (ptr < ptrend)

*parsed_pattern++ = META_CLASS_END;

if (--class_depth == 0) break;
if (--class_depth_m1 < 0) break;

class_range_state = RANGE_NO; /* for processing the containing class */
class_op_state = CLASS_OP_OPERAND;
/* The extended class flag has already
been set for the parent class. */
class_start = NULL;
}

/* Handle a set operator */
Expand All @@ -3924,13 +3947,21 @@ while (ptr < ptrend)
}

/* Check for mixed precedence. Forbid [A--B&&C]. */
if (class_op_used[class_depth-1] != 0 &&
class_op_used[class_depth-1] != (uint8_t)c)
if (cb->class_op_used[class_depth_m1] != 0 &&
cb->class_op_used[class_depth_m1] != (uint8_t)c)
{
errorcode = ERR111;
goto FAILED;
}

if (class_start != NULL)
{
PCRE2_ASSERT(class_depth_m1 >= 0);
/* Represents that the class is an extended class. */
*class_start |= CLASS_IS_ECLASS;
class_start = NULL;
}

/* Dangling '-' before an operator is a literal */
if (class_range_state == RANGE_STARTED)
parsed_pattern[-1] = CHAR_MINUS;
Expand All @@ -3940,7 +3971,7 @@ while (ptr < ptrend)
META_ECLASS_AND;
class_range_state = RANGE_NO;
class_op_state = CLASS_OP_OPERATOR;
class_op_used[class_depth-1] = (uint8_t)c;
cb->class_op_used[class_depth_m1] = (uint8_t)c;
}

/* Handle potential start of range */
Expand Down Expand Up @@ -4133,7 +4164,7 @@ while (ptr < ptrend)
if (ptr >= ptrend)
{
if ((options & PCRE2_ALT_EXTENDED_CLASS) != 0 &&
class_depth == 1 && class_maxdepth == 2)
class_depth_m1 == 0 && class_maxdepth_m1 == 1)
errorcode = ERR112; /* Missing terminating ']', but we saw '[ [ ]...' */
else
errorcode = ERR6; /* Missing terminating ']' */
Expand Down Expand Up @@ -5614,7 +5645,6 @@ for (;; pptr++)
uint32_t groupnumber;
uint32_t verbarglen, verbculen;
uint32_t subreqcuflags, subfirstcuflags;
uint32_t *end_ptr;
open_capitem *oc;
PCRE2_UCHAR mcbuffer[8];

Expand Down Expand Up @@ -5781,7 +5811,7 @@ for (;; pptr++)

/* Check for complex extended classes and handle them separately. */

if (!PRIV(check_class_not_nested)(pptr + 1, &end_ptr))
if ((*pptr & CLASS_IS_ECLASS) != 0)
{
previous = code;
*code++ = OP_ECLASS;
Expand Down Expand Up @@ -5920,13 +5950,11 @@ for (;; pptr++)

/* Now emit the OP_CLASS/OP_NCLASS/OP_XCLASS/OP_ALLANY opcode. */

if (!PRIV(compile_class_not_nested)(options, xoptions, pptr + 1, end_ptr,
&code, meta == META_CLASS_NOT,
errorcodeptr, cb, lengthptr))
return 0;

PCRE2_ASSERT(*end_ptr == META_CLASS_END);
pptr = end_ptr;
pptr = PRIV(compile_class_not_nested)(options, xoptions, pptr + 1,
&code, meta == META_CLASS_NOT,
errorcodeptr, cb, lengthptr);
if (pptr == NULL) return 0;
PCRE2_ASSERT(*pptr == META_CLASS_END);

/* If this class is the first thing in the branch, there can be no first
char setting, whatever the repeat count. Any reqcu setting must remain
Expand Down
18 changes: 7 additions & 11 deletions src/pcre2_compile.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -182,6 +182,10 @@ therefore no need for it to have a length entry, so use a high value. */
#define META_DATA(x) (x & 0x0000ffffu)
#define META_DIFF(x,y) ((x-y)>>16)

/* Extended class management flags. */

#define CLASS_IS_ECLASS 0x1

/* Macro for the highest character value. */

#if PCRE2_CODE_UNIT_WIDTH == 8
Expand Down Expand Up @@ -213,7 +217,6 @@ therefore no need for it to have a length entry, so use a high value. */
/* Macros for the definitions below, to prevent name collisions. */

#define _pcre2_posix_class_maps PCRE2_SUFFIX(_pcre2_posix_class_maps)
#define _pcre2_optimize_class PCRE2_SUFFIX(_pcre2_optimize_class_)
#define _pcre2_update_classbits PCRE2_SUFFIX(_pcre2_update_classbits_)
#define _pcre2_check_class_not_nested PCRE2_SUFFIX(_pcre2_check_class_not_nested_)
#define _pcre2_compile_class_nested PCRE2_SUFFIX(_pcre2_compile_class_nested_)
Expand All @@ -232,12 +235,6 @@ posix_class_maps, and posix_substitutes. They must be kept in sync. */
extern const int PRIV(posix_class_maps)[];


/* Merge intersecting ranges of classes. */

class_ranges *PRIV(optimize_class)(uint32_t *start_ptr,
const uint32_t *end_ptr, uint32_t options, uint32_t xoptions,
compile_block *cb);

/* Set bits in classbits according to the property type */

void PRIV(update_classbits)(uint32_t ptype, uint32_t pdata, BOOL negated,
Expand All @@ -261,10 +258,9 @@ BOOL PRIV(compile_class_nested)(uint32_t options, uint32_t xoptions,
/* Compile the META codes from start_ptr...end_ptr, writing a single OP_CLASS
OP_CLASS, OP_NCLASS, OP_XCLASS, or OP_ALLANY into pcode. */

BOOL PRIV(compile_class_not_nested)(uint32_t options, uint32_t xoptions,
uint32_t *start_ptr, const uint32_t *end_ptr, PCRE2_UCHAR **pcode,
BOOL negate_class, int *errorcodeptr, compile_block *cb,
PCRE2_SIZE *lengthptr);
uint32_t *PRIV(compile_class_not_nested)(uint32_t options, uint32_t xoptions,
uint32_t *start_ptr, PCRE2_UCHAR **pcode, BOOL negate_class,
int *errorcodeptr, compile_block *cb, PCRE2_SIZE *lengthptr);

#endif /* PCRE2_COMPILE_H_IDEMPOTENT_GUARD */

Expand Down
Loading

0 comments on commit c192b8c

Please sign in to comment.