src/pcre2_context.c

/*************************************************
*      Perl-Compatible Regular Expressions       *
*************************************************/

/* PCRE is a library of functions to support regular expressions whose syntax
and semantics are as close as possible to those of the Perl 5 language.

                       Written by Philip Hazel
     Original API code Copyright (c) 1997-2012 University of Cambridge
          New API code Copyright (c) 2016-2024 University of Cambridge

-----------------------------------------------------------------------------
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.

    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.

    * Neither the name of the University of Cambridge nor the names of its
      contributors may be used to endorse or promote products derived from
      this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
-----------------------------------------------------------------------------
*/


#include "pcre2_internal.h"



/*************************************************
*          Default malloc/free functions         *
*************************************************/

/* Ignore the "user data" argument in each case. */

static void *default_malloc(size_t size, void *data)
{
(void)data;
return malloc(size);
}


static void default_free(void *block, void *data)
{
(void)data;
free(block);
}



/*************************************************
*        Get a block and save memory control     *
*************************************************/

/* This internal function is called to get a block of memory in which the
memory control data is to be stored at the start for future use.

Arguments:
  size        amount of memory required
  memctl      pointer to a memctl block or NULL

Returns:      pointer to memory or NULL on failure
*/

extern void *
PRIV(memctl_malloc)(size_t size, pcre2_memctl *memctl)
{
pcre2_memctl *newmemctl;
void *yield = (memctl == NULL)? malloc(size) :
  memctl->malloc(size, memctl->memory_data);
if (yield == NULL) return NULL;
newmemctl = (pcre2_memctl *)yield;
if (memctl == NULL)
  {
  newmemctl->malloc = default_malloc;
  newmemctl->free = default_free;
  newmemctl->memory_data = NULL;
  }
else *newmemctl = *memctl;
return yield;
}



/*************************************************
*          Create and initialize contexts        *
*************************************************/

/* Initializing for compile and match contexts is done in separate, private
functions so that these can be called from functions such as pcre2_compile()
when an external context is not supplied. The initializing functions have an
option to set up default memory management. */

PCRE2_EXP_DEFN pcre2_general_context * PCRE2_CALL_CONVENTION
pcre2_general_context_create(void *(*private_malloc)(size_t, void *),
  void (*private_free)(void *, void *), void *memory_data)
{
pcre2_general_context *gcontext;
if (private_malloc == NULL) private_malloc = default_malloc;
if (private_free == NULL) private_free = default_free;
gcontext = private_malloc(sizeof(pcre2_real_general_context), memory_data);
if (gcontext == NULL) return NULL;
gcontext->memctl.malloc = private_malloc;
gcontext->memctl.free = private_free;
gcontext->memctl.memory_data = memory_data;
return gcontext;
}


/* A default compile context is set up to save having to initialize at run time
when no context is supplied to the compile function. */

pcre2_compile_context PRIV(default_compile_context) = {
  { default_malloc, default_free, NULL },    /* Default memory handling */
  NULL,                                      /* Stack guard */
  NULL,                                      /* Stack guard data */
  PRIV(default_tables),                      /* Character tables */
  PCRE2_UNSET,                               /* Max pattern length */
  PCRE2_UNSET,                               /* Max pattern compiled length */
  BSR_DEFAULT,                               /* Backslash R default */
  NEWLINE_DEFAULT,                           /* Newline convention */
  PARENS_NEST_LIMIT,                         /* As it says */
  0,                                         /* Extra options */
  MAX_VARLOOKBEHIND,                         /* As it says */
  PCRE2_OPTIMIZATION_ALL                     /* All optimizations enabled */
  };

/* The create function copies the default into the new memory, but must
override the default memory handling functions if a gcontext was provided. */

PCRE2_EXP_DEFN pcre2_compile_context * PCRE2_CALL_CONVENTION
pcre2_compile_context_create(pcre2_general_context *gcontext)
{
pcre2_compile_context *ccontext = PRIV(memctl_malloc)(
  sizeof(pcre2_real_compile_context), (pcre2_memctl *)gcontext);
if (ccontext == NULL) return NULL;
*ccontext = PRIV(default_compile_context);
if (gcontext != NULL)
  *((pcre2_memctl *)ccontext) = *((pcre2_memctl *)gcontext);
return ccontext;
}


/* A default match context is set up to save having to initialize at run time
when no context is supplied to a match function. */

pcre2_match_context PRIV(default_match_context) = {
  { default_malloc, default_free, NULL },
#ifdef SUPPORT_JIT
  NULL,          /* JIT callback */
  NULL,          /* JIT callback data */
#endif
  NULL,          /* Callout function */
  NULL,          /* Callout data */
  NULL,          /* Substitute callout function */
  NULL,          /* Substitute callout data */
  NULL,          /* Substitute case callout function */
  NULL,          /* Substitute case callout data */
  PCRE2_UNSET,   /* Offset limit */
  HEAP_LIMIT,
  MATCH_LIMIT,
  MATCH_LIMIT_DEPTH };

/* The create function copies the default into the new memory, but must
override the default memory handling functions if a gcontext was provided. */

PCRE2_EXP_DEFN pcre2_match_context * PCRE2_CALL_CONVENTION
pcre2_match_context_create(pcre2_general_context *gcontext)
{
pcre2_match_context *mcontext = PRIV(memctl_malloc)(
  sizeof(pcre2_real_match_context), (pcre2_memctl *)gcontext);
if (mcontext == NULL) return NULL;
*mcontext = PRIV(default_match_context);
if (gcontext != NULL)
  *((pcre2_memctl *)mcontext) = *((pcre2_memctl *)gcontext);
return mcontext;
}


/* A default convert context is set up to save having to initialize at run time
when no context is supplied to the convert function. */

pcre2_convert_context PRIV(default_convert_context) = {
  { default_malloc, default_free, NULL },    /* Default memory handling */
#ifdef _WIN32
  CHAR_BACKSLASH,                            /* Default path separator */
  CHAR_GRAVE_ACCENT                          /* Default escape character */
#else  /* Not Windows */
  CHAR_SLASH,                                /* Default path separator */
  CHAR_BACKSLASH                             /* Default escape character */
#endif
  };

/* The create function copies the default into the new memory, but must
override the default memory handling functions if a gcontext was provided. */

PCRE2_EXP_DEFN pcre2_convert_context * PCRE2_CALL_CONVENTION
pcre2_convert_context_create(pcre2_general_context *gcontext)
{
pcre2_convert_context *ccontext = PRIV(memctl_malloc)(
  sizeof(pcre2_real_convert_context), (pcre2_memctl *)gcontext);
if (ccontext == NULL) return NULL;
*ccontext = PRIV(default_convert_context);
if (gcontext != NULL)
  *((pcre2_memctl *)ccontext) = *((pcre2_memctl *)gcontext);
return ccontext;
}


/*************************************************
*              Context copy functions            *
*************************************************/

PCRE2_EXP_DEFN pcre2_general_context * PCRE2_CALL_CONVENTION
pcre2_general_context_copy(pcre2_general_context *gcontext)
{
pcre2_general_context *newcontext =
  gcontext->memctl.malloc(sizeof(pcre2_real_general_context),
  gcontext->memctl.memory_data);
if (newcontext == NULL) return NULL;
memcpy(newcontext, gcontext, sizeof(pcre2_real_general_context));
return newcontext;
}


PCRE2_EXP_DEFN pcre2_compile_context * PCRE2_CALL_CONVENTION
pcre2_compile_context_copy(pcre2_compile_context *ccontext)
{
pcre2_compile_context *newcontext =
  ccontext->memctl.malloc(sizeof(pcre2_real_compile_context),
  ccontext->memctl.memory_data);
if (newcontext == NULL) return NULL;
memcpy(newcontext, ccontext, sizeof(pcre2_real_compile_context));
return newcontext;
}


PCRE2_EXP_DEFN pcre2_match_context * PCRE2_CALL_CONVENTION
pcre2_match_context_copy(pcre2_match_context *mcontext)
{
pcre2_match_context *newcontext =
  mcontext->memctl.malloc(sizeof(pcre2_real_match_context),
  mcontext->memctl.memory_data);
if (newcontext == NULL) return NULL;
memcpy(newcontext, mcontext, sizeof(pcre2_real_match_context));
return newcontext;
}


PCRE2_EXP_DEFN pcre2_convert_context * PCRE2_CALL_CONVENTION
pcre2_convert_context_copy(pcre2_convert_context *ccontext)
{
pcre2_convert_context *newcontext =
  ccontext->memctl.malloc(sizeof(pcre2_real_convert_context),
  ccontext->memctl.memory_data);
if (newcontext == NULL) return NULL;
memcpy(newcontext, ccontext, sizeof(pcre2_real_convert_context));
return newcontext;
}


/*************************************************
*              Context free functions            *
*************************************************/

PCRE2_EXP_DEFN void PCRE2_CALL_CONVENTION
pcre2_general_context_free(pcre2_general_context *gcontext)
{
if (gcontext != NULL)
  gcontext->memctl.free(gcontext, gcontext->memctl.memory_data);
}


PCRE2_EXP_DEFN void PCRE2_CALL_CONVENTION
pcre2_compile_context_free(pcre2_compile_context *ccontext)
{
if (ccontext != NULL)
  ccontext->memctl.free(ccontext, ccontext->memctl.memory_data);
}


PCRE2_EXP_DEFN void PCRE2_CALL_CONVENTION
pcre2_match_context_free(pcre2_match_context *mcontext)
{
if (mcontext != NULL)
  mcontext->memctl.free(mcontext, mcontext->memctl.memory_data);
}


PCRE2_EXP_DEFN void PCRE2_CALL_CONVENTION
pcre2_convert_context_free(pcre2_convert_context *ccontext)
{
if (ccontext != NULL)
  ccontext->memctl.free(ccontext, ccontext->memctl.memory_data);
}


/*************************************************
*             Set values in contexts             *
*************************************************/

/* All these functions return 0 for success or PCRE2_ERROR_BADDATA if invalid
data is given. Only some of the functions are able to test the validity of the
data. */


/* ------------ Compile context ------------ */

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_character_tables(pcre2_compile_context *ccontext,
  const uint8_t *tables)
{
ccontext->tables = tables;
return 0;
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_bsr(pcre2_compile_context *ccontext, uint32_t value)
{
switch(value)
  {
  case PCRE2_BSR_ANYCRLF:
  case PCRE2_BSR_UNICODE:
  ccontext->bsr_convention = value;
  return 0;

  default:
  return PCRE2_ERROR_BADDATA;
  }
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_max_pattern_length(pcre2_compile_context *ccontext, PCRE2_SIZE length)
{
ccontext->max_pattern_length = length;
return 0;
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_max_pattern_compiled_length(pcre2_compile_context *ccontext, PCRE2_SIZE length)
{
ccontext->max_pattern_compiled_length = length;
return 0;
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_newline(pcre2_compile_context *ccontext, uint32_t newline)
{
switch(newline)
  {
  case PCRE2_NEWLINE_CR:
  case PCRE2_NEWLINE_LF:
  case PCRE2_NEWLINE_CRLF:
  case PCRE2_NEWLINE_ANY:
  case PCRE2_NEWLINE_ANYCRLF:
  case PCRE2_NEWLINE_NUL:
  ccontext->newline_convention = newline;
  return 0;

  default:
  return PCRE2_ERROR_BADDATA;
  }
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_max_varlookbehind(pcre2_compile_context *ccontext, uint32_t limit)
{
ccontext->max_varlookbehind = limit;
return 0;
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_parens_nest_limit(pcre2_compile_context *ccontext, uint32_t limit)
{
ccontext->parens_nest_limit = limit;
return 0;
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_compile_extra_options(pcre2_compile_context *ccontext, uint32_t options)
{
ccontext->extra_options = options;
return 0;
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_compile_recursion_guard(pcre2_compile_context *ccontext,
  int (*guard)(uint32_t, void *), void *user_data)
{
ccontext->stack_guard = guard;
ccontext->stack_guard_data = user_data;
return 0;
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_optimize(pcre2_compile_context *ccontext, uint32_t directive)
{
if (ccontext == NULL)
  return PCRE2_ERROR_NULL;

switch (directive)
  {
  case PCRE2_OPTIMIZATION_NONE:
  ccontext->optimization_flags = 0;
  break;

  case PCRE2_OPTIMIZATION_FULL:
  ccontext->optimization_flags = PCRE2_OPTIMIZATION_ALL;
  break;

  default:
  if (directive >= PCRE2_AUTO_POSSESS && directive <= PCRE2_START_OPTIMIZE_OFF)
    {
    /* Even directive numbers starting from 64 switch a bit on;
     * Odd directive numbers starting from 65 switch a bit off */
    if ((directive & 1) != 0)
      ccontext->optimization_flags &= ~(1u << ((directive >> 1) - 32));
    else
      ccontext->optimization_flags |= 1u << ((directive >> 1) - 32);
    return 0;
    }
  return PCRE2_ERROR_BADOPTION;
  }

return 0;
}

/* ------------ Match context ------------ */

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_callout(pcre2_match_context *mcontext,
  int (*callout)(pcre2_callout_block *, void *), void *callout_data)
{
mcontext->callout = callout;
mcontext->callout_data = callout_data;
return 0;
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_substitute_callout(pcre2_match_context *mcontext,
  int (*substitute_callout)(pcre2_substitute_callout_block *, void *),
  void *substitute_callout_data)
{
mcontext->substitute_callout = substitute_callout;
mcontext->substitute_callout_data = substitute_callout_data;
return 0;
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_substitute_case_callout(pcre2_match_context *mcontext,
  PCRE2_SIZE (*substitute_case_callout)(PCRE2_SPTR, PCRE2_SIZE, PCRE2_UCHAR *,
                                        PCRE2_SIZE, int, void *),
  void *substitute_case_callout_data)
{
mcontext->substitute_case_callout = substitute_case_callout;
mcontext->substitute_case_callout_data = substitute_case_callout_data;
return 0;
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_heap_limit(pcre2_match_context *mcontext, uint32_t limit)
{
mcontext->heap_limit = limit;
return 0;
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_match_limit(pcre2_match_context *mcontext, uint32_t limit)
{
mcontext->match_limit = limit;
return 0;
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_depth_limit(pcre2_match_context *mcontext, uint32_t limit)
{
mcontext->depth_limit = limit;
return 0;
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_offset_limit(pcre2_match_context *mcontext, PCRE2_SIZE limit)
{
mcontext->offset_limit = limit;
return 0;
}

/* These functions became obsolete at release 10.30. The first is kept as a
synonym for backwards compatibility. The second now does nothing. */

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_recursion_limit(pcre2_match_context *mcontext, uint32_t limit)
{
return pcre2_set_depth_limit(mcontext, limit);
}

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_recursion_memory_management(pcre2_match_context *mcontext,
  void *(*mymalloc)(size_t, void *), void (*myfree)(void *, void *),
  void *mydata)
{
(void)mcontext;
(void)mymalloc;
(void)myfree;
(void)mydata;
return 0;
}


/* ------------ Convert context ------------ */

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_glob_separator(pcre2_convert_context *ccontext, uint32_t separator)
{
if (separator != CHAR_SLASH && separator != CHAR_BACKSLASH &&
    separator != CHAR_DOT) return PCRE2_ERROR_BADDATA;
ccontext->glob_separator = separator;
return 0;
}

static const char *globpunct =
  STR_EXCLAMATION_MARK STR_QUOTATION_MARK STR_NUMBER_SIGN STR_DOLLAR_SIGN
  STR_PERCENT_SIGN STR_AMPERSAND STR_APOSTROPHE STR_LEFT_PARENTHESIS
  STR_RIGHT_PARENTHESIS STR_ASTERISK STR_PLUS STR_COMMA STR_MINUS STR_DOT
  STR_SLASH STR_COLON STR_SEMICOLON STR_LESS_THAN_SIGN STR_EQUALS_SIGN
  STR_GREATER_THAN_SIGN STR_QUESTION_MARK STR_COMMERCIAL_AT
  STR_LEFT_SQUARE_BRACKET STR_BACKSLASH STR_RIGHT_SQUARE_BRACKET
  STR_CIRCUMFLEX_ACCENT STR_UNDERSCORE STR_GRAVE_ACCENT STR_LEFT_CURLY_BRACKET
  STR_VERTICAL_LINE STR_RIGHT_CURLY_BRACKET STR_TILDE;

PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_set_glob_escape(pcre2_convert_context *ccontext, uint32_t escape)
{
if (escape > 255 || (escape != 0 && strchr(globpunct, escape) == NULL))
  return PCRE2_ERROR_BADDATA;
ccontext->glob_escape = escape;
return 0;
}

/* End of pcre2_context.c */