fixing existing and adding new byte-order related functions

git-svn-id: svn://vcs.exim.org/pcre/code/branches/pcre16@809 2f5784b3-3f2a-0410-8824-cb99058d5e15

21 files changed, 409 insertions, 217 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 784657d..956c09d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -333,7 +333,8 @@ ENDIF(PCRE_REBUILD_CHARTABLES)
 SET(PCRE_HEADERS ${PROJECT_BINARY_DIR}/pcre.h)
 
 SET(PCRE_SOURCES
-  ${PROJECT_BINARY_DIR}/pcre_chartables.c
+  ${PROJECT_BINARY_DIR}/pcre_byte_order.c
+  pcre_chartables.c
   pcre_compile.c
   pcre_config.c
   pcre_dfa_exec.c
@@ -349,7 +350,6 @@ SET(PCRE_SOURCES
   pcre_refcount.c
   pcre_study.c
   pcre_tables.c
-  pcre_try_flipped.c
   pcre_ucd.c
   pcre_valid_utf8.c
   pcre_version.c
diff --git a/Makefile.am b/Makefile.am
index cc7d6e6..100825d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -176,6 +176,7 @@ endif # WITH_REBUILD_CHARTABLES
 if WITH_PCRE8
 lib_LTLIBRARIES += libpcre.la
 libpcre_la_SOURCES = \
+  pcre_byte_order.c \
   pcre_compile.c \
   pcre_config.c \
   pcre_dfa_exec.c \
@@ -193,7 +194,6 @@ libpcre_la_SOURCES = \
   pcre_string_utils.c \
   pcre_study.c \
   pcre_tables.c \
-  pcre_try_flipped.c \
   pcre_ucd.c \
   pcre_valid_utf8.c \
   pcre_version.c \
@@ -210,6 +210,7 @@ endif # WITH_PCRE8
 if WITH_PCRE16
 lib_LTLIBRARIES += libpcre16.la
 libpcre16_la_SOURCES = \
+  pcre16_byte_order.c \
   pcre16_chartables.c \
   pcre16_compile.c \
   pcre16_config.c \
@@ -227,7 +228,6 @@ libpcre16_la_SOURCES = \
   pcre16_string_utils.c \
   pcre16_study.c \
   pcre16_tables.c \
-  pcre16_try_flipped.c \
   pcre16_ucd.c \
   pcre16_utf16_utils.c \
   pcre16_valid_utf16.c \
@@ -423,13 +423,12 @@ test: check ;
 # A PCRE user submitted the following addition, saying that it "will allow
 # anyone using the 'mingw32' compiler to simply type 'make pcre.dll' and get a
 # nice DLL for Windows use". (It is used by the pcre.dll target.)
-DLL_OBJS= pcre_compile.o pcre_config.o \
+DLL_OBJS= pcre_byte_order.o pcre_compile.o pcre_config.o \
 	pcre_dfa_exec.o pcre_exec.o pcre_fullinfo.o pcre_get.o \
 	pcre_globals.o pcre_info.o pcre_jit_compile.o pcre_maketables.o \
 	pcre_newline.o pcre_ord2utf8.o pcre_refcount.o \
-	pcre_study.o pcre_tables.o pcre_try_flipped.o \
-	pcre_ucd.o pcre_valid_utf8.o pcre_version.o \
-	pcre_chartables.o \
+	pcre_study.o pcre_tables.o pcre_ucd.o \
+	pcre_valid_utf8.o pcre_version.o pcre_chartables.o \
 	pcre_xclass.o
 
 # A PCRE user submitted the following addition, saying that it "will allow
diff --git a/NON-UNIX-USE b/NON-UNIX-USE
index 69443e7..a2657e6 100644
--- a/NON-UNIX-USE
+++ b/NON-UNIX-USE
@@ -97,6 +97,7 @@ hand":
      option if you have set up config.h with your configuration, or else use
      other -D settings to change the configuration as required.
 
+       pcre_byte_order.c
        pcre_chartables.c
        pcre_compile.c
        pcre_config.c
@@ -112,7 +113,6 @@ hand":
        pcre_refcount.c
        pcre_study.c
        pcre_tables.c
-       pcre_try_flipped.c
        pcre_ucd.c
        pcre_valid_utf8.c
        pcre_version.c
diff --git a/PrepareRelease b/PrepareRelease
index 7123be6..643318e 100755
--- a/PrepareRelease
+++ b/PrepareRelease
@@ -194,6 +194,7 @@ files="\
   pcreposix.h \
   pcre.h.in \
   pcre_internal.h
+  pcre_byte_order.c \
   pcre_compile.c \
   pcre_config.c \
   pcre_dfa_exec.c \
@@ -210,7 +211,6 @@ files="\
   pcre_refcount.c \
   pcre_study.c \
   pcre_tables.c \
-  pcre_try_flipped.c \
   pcre_ucp_searchfuncs.c \
   pcre_valid_utf8.c \
   pcre_version.c \
diff --git a/README b/README
index 765d5ff..9dc25d7 100644
--- a/README
+++ b/README
@@ -713,6 +713,7 @@ The distribution should contain the following files:
                             specified, by copying to pcre_chartables.c
 
   pcreposix.c             )
+  pcre_byte_order.c       )
   pcre_compile.c          )
   pcre_config.c           )
   pcre_dfa_exec.c         )
@@ -728,7 +729,6 @@ The distribution should contain the following files:
   pcre_refcount.c         )
   pcre_study.c            )
   pcre_tables.c           )
-  pcre_try_flipped.c      )
   pcre_ucd.c              )
   pcre_valid_utf8.c       )
   pcre_version.c          )
diff --git a/libpcre.a.dev b/libpcre.a.dev
index eafe9ac..33a8f0c 100644
--- a/libpcre.a.dev
+++ b/libpcre.a.dev
@@ -190,7 +190,7 @@ OverrideBuildCmd=0
 BuildCmd=
 
 [Unit17]
-FileName=pcre_try_flipped.c
+FileName=pcre_byte_order.c
 CompileCpp=0
 Folder=libpcre.a
 Compile=1
diff --git a/makevp_c.txt b/makevp_c.txt
index 931b8ab..a7cf8a0 100644
--- a/makevp_c.txt
+++ b/makevp_c.txt
@@ -1,3 +1,4 @@
+pcre_byte_order.c

 pcre_chartables.c

 pcre_compile.c

 pcre_config.c

@@ -13,7 +14,6 @@ pcre_ord2utf8.c
 pcre_refcount.c

 pcre_study.c

 pcre_tables.c

-pcre_try_flipped.c

 pcre_ucd.c

 pcre_valid_utf8.c

 pcre_version.c

diff --git a/makevp_l.txt b/makevp_l.txt
index 6de1cb4..5d3c70c 100644
--- a/makevp_l.txt
+++ b/makevp_l.txt
@@ -1,3 +1,4 @@
++pcre_byte_order.obj        &

 +pcre_chartables.obj        &

 +pcre_compile.obj           &

 +pcre_config.obj	    &

@@ -13,7 +14,6 @@
 +pcre_refcount.obj          &

 +pcre_study.obj		    &

 +pcre_tables.obj	    &

-+pcre_try_flipped.obj       &

 +pcre_ucd.obj               &

 +pcre_valid_utf8.obj        &

 +pcre_version.obj           &

diff --git a/pcre.h.in b/pcre.h.in
index 47d0e79..a2e2408 100644
--- a/pcre.h.in
+++ b/pcre.h.in
@@ -175,6 +175,7 @@ compiling). */
 #define PCRE_ERROR_RECURSELOOP    (-26)
 #define PCRE_ERROR_JIT_STACKLIMIT (-27)
 #define PCRE_ERROR_BADMODE        (-28)
+#define PCRE_ERROR_BADENDIANNESS  (-29)
 
 /* Specific error codes for UTF-8 validity checks */
 
@@ -432,9 +433,13 @@ PCRE_EXP_DECL void pcre16_free_study(pcre_extra *);
 PCRE_EXP_DECL const char *pcre_version(void);
 PCRE_EXP_DECL const char *pcre16_version(void);
 
-/* Utility functions. */
+/* Utility functions for byte order swaps. */
+PCRE_EXP_DECL int  pcre_pattern_to_host_byte_order(pcre *, pcre_extra *,
+                  const unsigned char *);
+PCRE_EXP_DECL int  pcre16_pattern_to_host_byte_order(pcre *, pcre_extra *,
+                  const unsigned char *);
 PCRE_EXP_DECL int  pcre16_utf16_to_host_byte_order(PCRE_SCHAR16 *,
-                  PCRE_SPTR16, int, int);
+                  PCRE_SPTR16, int, int *, int);
 
 /* JIT compiler related functions. */
 
diff --git a/pcre16_try_flipped.c b/pcre16_byte_order.c
index b646f28..622c0ab 100644
--- a/pcre16_try_flipped.c
+++ b/pcre16_byte_order.c
@@ -40,6 +40,6 @@ POSSIBILITY OF SUCH DAMAGE.
 /* Generate code with 16 bit character support. */
 #define COMPILE_PCRE16
 
-#include "pcre_try_flipped.c"
+#include "pcre_byte_order.c"
 
-/* End of pcre16_try_flipped.c */
+/* End of pcre16_byte_order.c */
diff --git a/pcre16_utf16_utils.c b/pcre16_utf16_utils.c
index b927458..358376f 100644
--- a/pcre16_utf16_utils.c
+++ b/pcre16_utf16_utils.c
@@ -67,6 +67,13 @@ Arguments:
   input      any UTF-16 string
   length     the number of characters in the input string
              can be less than zero for zero terminated strings
+  host_byte_order
+             A non-zero value means the input is in host byte
+             order, which can be dynamically changed by BOMs later.
+             Initially it contains the starting byte order and returns
+             with the last byte order so it can be used for stream
+             processing. It can be NULL, which set the host byte
+             order mode by default.
   keep_boms  for a non-zero value, the BOM (0xfeff) characters
              are copied as well
 
@@ -75,12 +82,13 @@ Returns:     the number of characters placed into the output buffer,
 */
 
 int
-pcre16_utf16_to_host_byte_order(PCRE_SCHAR16 *output, PCRE_SPTR16 input, int length, int keep_boms)
+pcre16_utf16_to_host_byte_order(PCRE_SCHAR16 *output, PCRE_SPTR16 input,
+  int length, int *host_byte_order, int keep_boms)
 {
 #ifdef SUPPORT_UTF
-/* This function converts any UTF-16 string to host byte order and optionally removes
-any Byte Order Marks (BOMS). Returns with the remainig length. */
-BOOL same_bo = TRUE;
+/* This function converts any UTF-16 string to host byte order and optionally
+removes any Byte Order Marks (BOMS). Returns with the remainig length. */
+int host_bo = host_byte_order != NULL ? *host_byte_order : 1;
 pcre_uchar *optr = (pcre_uchar *)output;
 const pcre_uchar *iptr = (const pcre_uchar *)input;
 const pcre_uchar *end;
@@ -98,15 +106,17 @@ while (iptr < end)
     {
     /* Detecting the byte order of the machine is unnecessary, it is
     enough to know that the UTF-16 string has the same byte order or not. */
-    same_bo = c == 0xfeff;
+    host_bo = c == 0xfeff;
     if (keep_boms != 0)
       *optr++ = 0xfeff;
     else
       length--;
     }
   else
-    *optr++ = same_bo ? c : ((c >> 8) | (c << 8)); /* Flip bytes if needed. */
+    *optr++ = host_bo ? c : ((c >> 8) | (c << 8)); /* Flip bytes if needed. */
   }
+if (host_byte_order != NULL)
+  *host_byte_order = host_bo;
 
 #else /* SUPPORT_UTF */
 (void)(output);  /* Keep picky compilers happy */
diff --git a/pcre_byte_order.c b/pcre_byte_order.c
new file mode 100644
index 0000000..286dd95
--- /dev/null
+++ b/pcre_byte_order.c
@@ -0,0 +1,286 @@
+/*************************************************
+*      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
+           Copyright (c) 1997-2009 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.
+-----------------------------------------------------------------------------
+*/
+
+
+/* This module contains an internal function that tests a compiled pattern to
+see if it was compiled with the opposite endianness. If so, it uses an
+auxiliary local function to flip the appropriate bytes. */
+
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "pcre_internal.h"
+
+
+/*************************************************
+*             Swap byte functions                *
+*************************************************/
+
+/* The following functions swap the bytes of a pcre_uint16
+and pcre_uint32 value.
+
+Arguments:
+  value        any number
+
+Returns:       the byte swapped value
+*/
+
+static pcre_uint32
+swap_uint32(pcre_uint32 value)
+{
+return ((value & 0x000000ff) << 24) |
+       ((value & 0x0000ff00) <<  8) |
+       ((value & 0x00ff0000) >>  8) |
+       (value >> 24);
+}
+
+static pcre_uint16
+swap_uint16(pcre_uint16 value)
+{
+return (value >> 8) | (value << 8);
+}
+
+
+/*************************************************
+*       Test for a byte-flipped compiled regex   *
+*************************************************/
+
+/* This function swaps the bytes of a compiled pattern usually
+loaeded form the disk. It also sets the tables pointer, which
+is likely an invalid pointer after reload.
+
+Arguments:
+  argument_re     points to the compiled expression
+  extra_data      points to extra data or is NULL
+  tables          points to the character tables or NULL
+
+Returns:          0 if the swap is successful, negative on error
+*/
+
+#ifdef COMPILE_PCRE8
+PCRE_EXP_DECL int pcre_pattern_to_host_byte_order(pcre *argument_re,
+  pcre_extra *extra_data, const unsigned char *tables)
+#else
+PCRE_EXP_DECL int pcre16_pattern_to_host_byte_order(pcre *argument_re,
+  pcre_extra *extra_data, const unsigned char *tables)
+#endif
+{
+real_pcre *re = (real_pcre *)argument_re;
+pcre_study_data *study;
+#ifndef COMPILE_PCRE8
+pcre_uchar *ptr;
+int length;
+#ifdef SUPPORT_UTF
+BOOL utf;
+BOOL utf16_char;
+#endif /* SUPPORT_UTF */
+#endif /* !COMPILE_PCRE8 */
+
+if (re == NULL) return PCRE_ERROR_NULL;
+if (re->magic_number == MAGIC_NUMBER)
+  {
+  if ((re->flags & PCRE_MODE) == 0) return PCRE_ERROR_BADMODE;
+  re->tables = tables;
+  return 0;
+  }
+
+if (re->magic_number != REVERSED_MAGIC_NUMBER) return PCRE_ERROR_BADMAGIC;
+if ((swap_uint16(re->flags)  & PCRE_MODE) == 0) return PCRE_ERROR_BADMODE;
+
+re->magic_number = MAGIC_NUMBER;
+re->size = swap_uint32(re->size);
+re->options = swap_uint32(re->options);
+re->flags = swap_uint16(re->flags);
+re->top_bracket = swap_uint16(re->top_bracket);
+re->top_backref = swap_uint16(re->top_backref);
+re->first_char = swap_uint16(re->first_char);
+re->req_char = swap_uint16(re->req_char);
+re->name_table_offset = swap_uint16(re->name_table_offset);
+re->name_entry_size = swap_uint16(re->name_entry_size);
+re->name_count = swap_uint16(re->name_count);
+re->ref_count = swap_uint16(re->ref_count);
+
+if (extra_data != NULL && (re->flags & PCRE_EXTRA_STUDY_DATA) != 0)
+  {
+  study = (pcre_study_data *)extra_data->study_data;
+  study->size = swap_uint32(study->size);
+  study->flags = swap_uint32(study->flags);
+  study->minlength = swap_uint32(study->minlength);
+  }
+
+#ifndef COMPILE_PCRE8
+ptr = (pcre_uchar *)re + re->name_table_offset;
+length = re->name_count * re->name_entry_size;
+#ifdef SUPPORT_UTF
+utf = (re->options & PCRE_UTF16) != 0;
+utf16_char = FALSE;
+#endif
+
+while(TRUE)
+  {
+  /* Swap previous characters. */
+  while (length-- > 0)
+    {
+    *ptr = swap_uint16(*ptr);
+    ptr++;
+    }
+#ifdef SUPPORT_UTF
+  if (utf16_char)
+    {
+    if (HAS_EXTRALEN(ptr[-1]))
+      {
+      /* We know that there is only one extra character in UTF-16. */
+      *ptr = swap_uint16(*ptr);
+      ptr++;
+      }
+    }
+  utf16_char = FALSE;
+#endif /* SUPPORT_UTF */
+
+  /* Get next opcode. */
+  length = 0;
+  *ptr = swap_uint16(*ptr);
+  switch (*ptr)
+    {
+    case OP_END:
+    return 0;
+
+    case OP_CHAR:
+    case OP_CHARI:
+    case OP_NOT:
+    case OP_NOTI:
+    case OP_STAR:
+    case OP_MINSTAR:
+    case OP_PLUS:
+    case OP_MINPLUS:
+    case OP_QUERY:
+    case OP_MINQUERY:
+    case OP_UPTO:
+    case OP_MINUPTO:
+    case OP_EXACT:
+    case OP_POSSTAR:
+    case OP_POSPLUS:
+    case OP_POSQUERY:
+    case OP_POSUPTO:
+    case OP_STARI:
+    case OP_MINSTARI:
+    case OP_PLUSI:
+    case OP_MINPLUSI:
+    case OP_QUERYI:
+    case OP_MINQUERYI:
+    case OP_UPTOI:
+    case OP_MINUPTOI:
+    case OP_EXACTI:
+    case OP_POSSTARI:
+    case OP_POSPLUSI:
+    case OP_POSQUERYI:
+    case OP_POSUPTOI:
+    case OP_NOTSTAR:
+    case OP_NOTMINSTAR:
+    case OP_NOTPLUS:
+    case OP_NOTMINPLUS:
+    case OP_NOTQUERY:
+    case OP_NOTMINQUERY:
+    case OP_NOTUPTO:
+    case OP_NOTMINUPTO:
+    case OP_NOTEXACT:
+    case OP_NOTPOSSTAR:
+    case OP_NOTPOSPLUS:
+    case OP_NOTPOSQUERY:
+    case OP_NOTPOSUPTO:
+    case OP_NOTSTARI:
+    case OP_NOTMINSTARI:
+    case OP_NOTPLUSI:
+    case OP_NOTMINPLUSI:
+    case OP_NOTQUERYI:
+    case OP_NOTMINQUERYI:
+    case OP_NOTUPTOI:
+    case OP_NOTMINUPTOI:
+    case OP_NOTEXACTI:
+    case OP_NOTPOSSTARI:
+    case OP_NOTPOSPLUSI:
+    case OP_NOTPOSQUERYI:
+    case OP_NOTPOSUPTOI:
+    utf16_char = TRUE;
+    length = PRIV(OP_lengths)[*ptr] - 1;
+    break;
+
+    case OP_CLASS:
+    case OP_NCLASS:
+    /* Skip the character bit map. */
+    ptr += 32/sizeof(pcre_uchar);
+    length = 0;
+    break;
+
+    case OP_XCLASS:
+    /* Reverse the size of the XCLASS instance. */
+    ptr++;
+    *ptr = swap_uint16(*ptr);
+    if (LINK_SIZE > 1)
+      {
+      /* LINK_SIZE can be 1 or 2 in 16 bit mode. */
+      ptr++;
+      *ptr = swap_uint16(*ptr);
+      }
+    ptr++;
+    length = (GET(ptr, -LINK_SIZE)) - (1 + LINK_SIZE + 1);
+    *ptr = swap_uint16(*ptr);
+    if ((*ptr & XCL_MAP) != 0)
+      {
+      /* Skip the character bit map. */
+      ptr += 32/sizeof(pcre_uchar);
+      length -= 32/sizeof(pcre_uchar);
+      }
+    break;
+
+    default:
+    length = PRIV(OP_lengths)[*ptr] - 1;
+    break;
+    }
+  ptr++;
+  }
+/* Control should never reach here in 16 bit mode. */
+#endif /* !COMPILE_PCRE8 */
+
+return 0;
+}
+
+/* End of pcre_byte_order.c */
diff --git a/pcre_dfa_exec.c b/pcre_dfa_exec.c
index a7d2037..6356e46 100644
--- a/pcre_dfa_exec.c
+++ b/pcre_dfa_exec.c
@@ -3019,9 +3019,7 @@ BOOL utf, anchored, startline, firstline;
 const pcre_uchar *current_subject, *end_subject;
 const pcre_uint8 *lcc;
 
-pcre_study_data internal_study;
 const pcre_study_data *study = NULL;
-real_pcre internal_re;
 
 const pcre_uchar *req_char_ptr;
 const pcre_uint8 *start_bits = NULL;
@@ -3065,16 +3063,13 @@ if (extra_data != NULL)
   }
 
 /* Check that the first field in the block is the magic number. If it is not,
-test for a regex that was compiled on a host of opposite endianness. If this is
-the case, flipped values are put in internal_re and internal_study if there was
-study data too. */
+return with PCRE_ERROR_BADMAGIC. However, if the magic number is equal to
+REVERSED_MAGIC_NUMBER we return with PCRE_ERROR_BADENDIANNESS, which
+means that the pattern is likely compiled with different endianness. */
 
 if (re->magic_number != MAGIC_NUMBER)
-  {
-  re = PRIV(try_flipped)(re, &internal_re, study, &internal_study);
-  if (re == NULL) return PCRE_ERROR_BADMAGIC;
-  if (study != NULL) study = &internal_study;
-  }
+  return re->magic_number == REVERSED_MAGIC_NUMBER?
+    PCRE_ERROR_BADENDIANNESS:PCRE_ERROR_BADMAGIC;
 if ((re->flags & PCRE_MODE) == 0) return PCRE_ERROR_BADMODE;
 
 /* Set some local values */
diff --git a/pcre_exec.c b/pcre_exec.c
index 3631845..d0984e6 100644
--- a/pcre_exec.c
+++ b/pcre_exec.c
@@ -6041,10 +6041,7 @@ PCRE_PUCHAR end_subject;
 PCRE_PUCHAR start_partial = NULL;
 PCRE_PUCHAR req_char_ptr = start_match - 1;
 
-pcre_study_data internal_study;
 const pcre_study_data *study;
-
-real_pcre internal_re;
 const real_pcre *external_re = (const real_pcre *)argument_re;
 const real_pcre *re = external_re;
 
@@ -6151,16 +6148,13 @@ in other programs later. */
 if (tables == NULL) tables = PRIV(default_tables);
 
 /* Check that the first field in the block is the magic number. If it is not,
-test for a regex that was compiled on a host of opposite endianness. If this is
-the case, flipped values are put in internal_re and internal_study if there was
-study data too. */
+return with PCRE_ERROR_BADMAGIC. However, if the magic number is equal to
+REVERSED_MAGIC_NUMBER we return with PCRE_ERROR_BADENDIANNESS, which
+means that the pattern is likely compiled with different endianness. */
 
 if (re->magic_number != MAGIC_NUMBER)
-  {
-  re = PRIV(try_flipped)(re, &internal_re, study, &internal_study);
-  if (re == NULL) return PCRE_ERROR_BADMAGIC;
-  if (study != NULL) study = &internal_study;
-  }
+  return re->magic_number == REVERSED_MAGIC_NUMBER?
+    PCRE_ERROR_BADENDIANNESS:PCRE_ERROR_BADMAGIC;
 if ((re->flags & PCRE_MODE) == 0) return PCRE_ERROR_BADMODE;
 
 /* Set up other data */
diff --git a/pcre_fullinfo.c b/pcre_fullinfo.c
index 39ee028..f0f6b21 100644
--- a/pcre_fullinfo.c
+++ b/pcre_fullinfo.c
@@ -75,8 +75,6 @@ pcre16_fullinfo(const pcre *argument_re, const pcre_extra *extra_data, int what,
   void *where)
 #endif
 {
-real_pcre internal_re;
-pcre_study_data internal_study;
 const real_pcre *re = (const real_pcre *)argument_re;
 const pcre_study_data *study = NULL;
 
@@ -85,12 +83,14 @@ if (re == NULL || where == NULL) return PCRE_ERROR_NULL;
 if (extra_data != NULL && (extra_data->flags & PCRE_EXTRA_STUDY_DATA) != 0)
   study = (const pcre_study_data *)extra_data->study_data;
 
+/* Check that the first field in the block is the magic number. If it is not,
+return with PCRE_ERROR_BADMAGIC. However, if the magic number is equal to
+REVERSED_MAGIC_NUMBER we return with PCRE_ERROR_BADENDIANNESS, which
+means that the pattern is likely compiled with different endianness. */
+
 if (re->magic_number != MAGIC_NUMBER)
-  {
-  re = PRIV(try_flipped)(re, &internal_re, study, &internal_study);
-  if (re == NULL) return PCRE_ERROR_BADMAGIC;
-  if (study != NULL) study = &internal_study;
-  }
+  return re->magic_number == REVERSED_MAGIC_NUMBER?
+    PCRE_ERROR_BADENDIANNESS:PCRE_ERROR_BADMAGIC;
 if ((re->flags & PCRE_MODE) == 0) return PCRE_ERROR_BADMODE;
 
 switch (what)
diff --git a/pcre_info.c b/pcre_info.c
index 52d593a..498c442 100644
--- a/pcre_info.c
+++ b/pcre_info.c
@@ -80,15 +80,19 @@ PCRE_EXP_DEFN int PCRE_CALL_CONVENTION
 pcre16_info(const pcre *argument_re, int *optptr, int *first_char)
 #endif
 {
-real_pcre internal_re;
 const real_pcre *re = (const real_pcre *)argument_re;
 if (re == NULL) return PCRE_ERROR_NULL;
+
+/* Check that the first field in the block is the magic number. If it is not,
+return with PCRE_ERROR_BADMAGIC. However, if the magic number is equal to
+REVERSED_MAGIC_NUMBER we return with PCRE_ERROR_BADENDIANNESS, which
+means that the pattern is likely compiled with different endianness. */
+
 if (re->magic_number != MAGIC_NUMBER)
-  {
-  re = PRIV(try_flipped)(re, &internal_re, NULL, NULL);
-  if (re == NULL) return PCRE_ERROR_BADMAGIC;
-  }
+  return re->magic_number == REVERSED_MAGIC_NUMBER?
+    PCRE_ERROR_BADENDIANNESS:PCRE_ERROR_BADMAGIC;
 if ((re->flags & PCRE_MODE) == 0) return PCRE_ERROR_BADMODE;
+
 if (optptr != NULL) *optptr = (int)(re->options & PUBLIC_COMPILE_OPTIONS);
 if (first_char != NULL)
   *first_char = ((re->flags & PCRE_FIRSTSET) != 0)? re->first_char :
diff --git a/pcre_internal.h b/pcre_internal.h
index 6453fbd..b437df5 100644
--- a/pcre_internal.h
+++ b/pcre_internal.h
@@ -889,11 +889,15 @@ time, run time, or study time, respectively. */
 #define PUBLIC_STUDY_OPTIONS \
    PCRE_STUDY_JIT_COMPILE
 
-/* Magic number to provide a small check against being handed junk. Also used
-to detect whether a pattern was compiled on a host of different endianness. */
+/* Magic number to provide a small check against being handed junk. */
 
 #define MAGIC_NUMBER  0x50435245UL   /* 'PCRE' */
 
+/* This variable is used to detect a loaded regular expression
+in different endianness. */
+
+#define REVERSED_MAGIC_NUMBER  0x45524350UL   /* 'ERCP' */
+
 /* Negative values for the firstchar and reqchar variables */
 
 #define REQ_UNSET (-2)
@@ -2264,8 +2268,6 @@ extern const pcre_uchar *PRIV(find_bracket)(const pcre_uchar *, BOOL, int);
 extern BOOL              PRIV(is_newline)(PCRE_PUCHAR, int, PCRE_PUCHAR,
                            int *, BOOL);
 extern int               PRIV(ord2utf)(pcre_uint32, pcre_uchar *);
-extern real_pcre        *PRIV(try_flipped)(const real_pcre *, real_pcre *,
-                           const pcre_study_data *, pcre_study_data *);
 extern int               PRIV(valid_utf)(PCRE_PUCHAR, int, int *);
 extern BOOL              PRIV(was_newline)(PCRE_PUCHAR, int, PCRE_PUCHAR,
                            int *, BOOL);
diff --git a/pcre_jit_compile.c b/pcre_jit_compile.c
index bcdbd5a..2543fef 100644
--- a/pcre_jit_compile.c
+++ b/pcre_jit_compile.c
@@ -510,7 +510,6 @@ switch(*cc)
   case OP_CHARI:
   case OP_NOT:
   case OP_NOTI:
-
   case OP_STAR:
   case OP_MINSTAR:
   case OP_PLUS:
diff --git a/pcre_try_flipped.c b/pcre_try_flipped.c
deleted file mode 100644
index d09a10f..0000000
--- a/pcre_try_flipped.c
+++ /dev/null
@@ -1,139 +0,0 @@
-/*************************************************
-*      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
-           Copyright (c) 1997-2009 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.
------------------------------------------------------------------------------
-*/
-
-
-/* This module contains an internal function that tests a compiled pattern to
-see if it was compiled with the opposite endianness. If so, it uses an
-auxiliary local function to flip the appropriate bytes. */
-
-
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#include "pcre_internal.h"
-
-
-/*************************************************
-*         Flip bytes in an integer               *
-*************************************************/
-
-/* This function is called when the magic number in a regex doesn't match, in
-order to flip its bytes to see if we are dealing with a pattern that was
-compiled on a host of different endianness. If so, this function is used to
-flip other byte values.
-
-Arguments:
-  value        the number to flip
-  n            the number of bytes to flip (assumed to be 2 or 4)
-
-Returns:       the flipped value
-*/
-
-static unsigned long int
-byteflip(unsigned long int value, int n)
-{
-if (n == 2) return ((value & 0x00ff) << 8) | ((value & 0xff00) >> 8);
-return ((value & 0x000000ff) << 24) |
-       ((value & 0x0000ff00) <<  8) |
-       ((value & 0x00ff0000) >>  8) |
-       ((value & 0xff000000) >> 24);
-}
-
-
-
-/*************************************************
-*       Test for a byte-flipped compiled regex   *
-*************************************************/
-
-/* This function is called from pcre_exec(), pcre_dfa_exec(), and also from
-pcre_fullinfo(). Its job is to test whether the regex is byte-flipped - that
-is, it was compiled on a system of opposite endianness. The function is called
-only when the native MAGIC_NUMBER test fails. If the regex is indeed flipped,
-we flip all the relevant values into a different data block, and return it.
-
-Arguments:
-  re               points to the regex
-  study            points to study data, or NULL
-  internal_re      points to a new regex block
-  internal_study   points to a new study block
-
-Returns:           the new block if is is indeed a byte-flipped regex
-                   NULL if it is not
-*/
-
-real_pcre *
-PRIV(try_flipped)(const real_pcre *re, real_pcre *internal_re,
-  const pcre_study_data *study, pcre_study_data *internal_study)
-{
-if (byteflip(re->magic_number, sizeof(re->magic_number)) != MAGIC_NUMBER)
-  return NULL;
-
-*internal_re = *re;           /* To copy other fields */
-internal_re->size = byteflip(re->size, sizeof(re->size));
-internal_re->options = byteflip(re->options, sizeof(re->options));
-internal_re->flags = (pcre_uint16)byteflip(re->flags, sizeof(re->flags));
-internal_re->top_bracket =
-  (pcre_uint16)byteflip(re->top_bracket, sizeof(re->top_bracket));
-internal_re->top_backref =
-  (pcre_uint16)byteflip(re->top_backref, sizeof(re->top_backref));
-internal_re->first_char =
-  (pcre_uint16)byteflip(re->first_char, sizeof(re->first_char));
-internal_re->req_char =
-  (pcre_uint16)byteflip(re->req_char, sizeof(re->req_char));
-internal_re->name_table_offset =
-  (pcre_uint16)byteflip(re->name_table_offset, sizeof(re->name_table_offset));
-internal_re->name_entry_size =
-  (pcre_uint16)byteflip(re->name_entry_size, sizeof(re->name_entry_size));
-internal_re->name_count =
-  (pcre_uint16)byteflip(re->name_count, sizeof(re->name_count));
-
-if (study != NULL)
-  {
-  *internal_study = *study;   /* To copy other fields */
-  internal_study->size = byteflip(study->size, sizeof(study->size));
-  internal_study->flags = byteflip(study->flags, sizeof(study->flags));
-  internal_study->minlength = byteflip(study->minlength,
-    sizeof(study->minlength));
-  }
-
-return internal_re;
-}
-
-/* End of pcre_tryflipped.c */
diff --git a/pcretest.c b/pcretest.c
index db5b817..b99ae41 100644
--- a/pcretest.c
+++ b/pcretest.c
@@ -197,7 +197,11 @@ use these in the definitions of generic macros. */
 
 #define PCRE_STUDY8(extra, re, options, error) \
   extra = pcre_study(re, options, error)
-#endif
+
+#define PCRE_FREE_STUDY8(extra) \
+  pcre_free_study(extra)
+
+#endif /* SUPPORT_PCRE8 */
 
 
 #ifdef SUPPORT_PCRE16
@@ -217,7 +221,11 @@ use these in the definitions of generic macros. */
 
 #define PCRE_STUDY16(extra, re, options, error) \
   extra = pcre16_study(re, options, error)
-#endif
+
+#define PCRE_FREE_STUDY16(extra) \
+  pcre16_free_study(extra)
+
+#endif /* SUPPORT_PCRE16 */
 
 
 /* ----- Both modes are supported; a runtime test is needed ----- */
@@ -257,23 +265,31 @@ use these in the definitions of generic macros. */
   else \
     PCRE_STUDY8(extra, re, options, error)
 
+#define PCRE_FREE_STUDY(extra) \
+  if (use_pcre16) \
+    PCRE_FREE_STUDY16(extra); \
+  else \
+    PCRE_FREE_STUDY8(extra)
+
 /* ----- Only 8-bit mode is supported ----- */
 
 #elif defined SUPPORT_PCRE8
-#define PCHARS       PCHARS8
-#define PCHARSV      PCHARSV8
-#define PCRE_COMPILE PCRE_COMPILE8
-#define PCRE_EXEC    PCRE_EXEC8
-#define PCRE_STUDY   PCRE_STUDY8
+#define PCHARS           PCHARS8
+#define PCHARSV          PCHARSV8
+#define PCRE_COMPILE     PCRE_COMPILE8
+#define PCRE_EXEC        PCRE_EXEC8
+#define PCRE_STUDY       PCRE_STUDY8
+#define PCRE_FREE_STUDY  PCRE_FREE_STUDY8
 
 /* ----- Only 16-bit mode is supported ----- */
 
 #else
-#define PCHARS       PCHARS16
-#define PCHARSV      PCHARSV16
-#define PCRE_COMPILE PCRE_COMPILE16
-#define PCRE_EXEC    PCRE_EXEC16
-#define PCRE_STUDY   PCRE_STUDY16
+#define PCHARS           PCHARS16
+#define PCHARSV          PCHARSV16
+#define PCRE_COMPILE     PCRE_COMPILE16
+#define PCRE_EXEC        PCRE_EXEC16
+#define PCRE_STUDY       PCRE_STUDY16
+#define PCRE_FREE_STUDY  PCRE_FREE_STUDY16
 #endif
 
 /* ----- End of mode-specific function call macros ----- */
@@ -1861,7 +1877,10 @@ while (!done)
         {
         FAIL_READ:
         fprintf(outfile, "Failed to read data from %s\n", p);
-        if (extra != NULL) pcre_free_study(extra);
+        if (extra != NULL)
+          {
+          PCRE_FREE_STUDY(extra);
+          }
         if (re != NULL) new_free(re);
         fclose(f);
         continue;
@@ -2192,7 +2211,10 @@ while (!done)
           PCRE_STUDY(extra, re, study_options | force_study_options, &error);
           }
         time_taken = clock() - start_time;
-        if (extra != NULL) pcre_free_study(extra);
+        if (extra != NULL)
+          {
+          PCRE_FREE_STUDY(extra);
+          }
         fprintf(outfile, "  Study time %.4f milliseconds\n",
           (((double)time_taken * 1000.0) / (double)timeit) /
             (double)CLOCKS_PER_SEC);
@@ -2270,10 +2292,16 @@ while (!done)
     if (do_debug)
       {
       fprintf(outfile, "------------------------------------------------------------------\n");
+#if defined SUPPORT_PCRE8 && defined SUPPORT_PCRE16
       if (use_pcre16)
         pcre16_printint(re, outfile, debug_lengths);
       else
         pcre_printint(re, outfile, debug_lengths);
+#elif defined SUPPORT_PCRE8
+      pcre_printint(re, outfile, debug_lengths);
+#else
+      pcre16_printint(re, outfile, debug_lengths);
+#endif
       }
 
     /* We already have the options in get_options (see above) */
@@ -2558,7 +2586,10 @@ while (!done)
         }
 
       new_free(re);
-      if (extra != NULL) pcre_free_study(extra);
+      if (extra != NULL) 
+        {
+        PCRE_FREE_STUDY(extra);
+        }
       if (locale_set)
         {
         new_free((void *)tables);
@@ -3424,7 +3455,10 @@ while (!done)
 #endif
 
   if (re != NULL) new_free(re);
-  if (extra != NULL) pcre_free_study(extra);
+  if (extra != NULL)
+    {
+    PCRE_FREE_STUDY(extra);
+    }
   if (locale_set)
     {
     new_free((void *)tables);
diff --git a/sljit/sljitExecAllocator.c b/sljit/sljitExecAllocator.c
index cdea346..f613d02 100644
--- a/sljit/sljitExecAllocator.c
+++ b/sljit/sljitExecAllocator.c
@@ -263,8 +263,11 @@ SLJIT_API_FUNC_ATTRIBUTE void sljit_free_exec(void* ptr)
 		header->prev_size = free_block->size;
 	}
 
+	/* The whole chunk is free. */
 	if (SLJIT_UNLIKELY(!free_block->header.prev_size && header->size == 1)) {
+		/* If this block is freed, we still have (allocated_size / 2) free space. */
 		if (total_size - free_block->size > (allocated_size * 3 / 2)) {
+			total_size -= free_block->size;
 			sljit_remove_free_block(free_block);
 			free_chunk(free_block, free_block->size + sizeof(struct block_header));
 		}