The Tor Browser: comparison intl/icu/source/common/unicode/utf8.h

--1:000000000000
+:d6ecd0b1aa56
+/*
+*******************************************************************************
+*
+*   Copyright (C) 1999-2013, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*
+*******************************************************************************
+*   file name:  utf8.h
+*   encoding:   US-ASCII
+*   tab size:   8 (not used)
+*   indentation:4
+*
+*   created on: 1999sep13
+*   created by: Markus W. Scherer
+*/
+/**
+* \file
+* \brief C API: 8-bit Unicode handling macros
+*
+* This file defines macros to deal with 8-bit Unicode (UTF-8) code units (bytes) and strings.
+*
+* For more information see utf.h and the ICU User Guide Strings chapter
+* (http://userguide.icu-project.org/strings).
+*
+* <em>Usage:</em>
+* ICU coding guidelines for if() statements should be followed when using these macros.
+* Compound statements (curly braces {}) must be used  for if-else-while...
+* bodies and all macro statements should be terminated with semicolon.
+*/
+#ifndef __UTF8_H__
+#define __UTF8_H__
+#include "unicode/umachine.h"
+#ifndef __UTF_H__
+#   include "unicode/utf.h"
+#endif
+/* internal definitions ----------------------------------------------------- */
+/**
+* \var utf8_countTrailBytes
+* Internal array with numbers of trail bytes for any given byte used in
+* lead byte position.
+*
+* This is internal since it is not meant to be called directly by external clients;
+* however it is called by public macros in this file and thus must remain stable,
+* and should not be hidden when other internal functions are hidden (otherwise
+* public macros would fail to compile).
+* @internal
+*/
+#ifdef U_UTF8_IMPL
+U_EXPORT const uint8_t
+#elif defined(U_STATIC_IMPLEMENTATION) || defined(U_COMMON_IMPLEMENTATION)
+U_CFUNC const uint8_t
+#else
+U_CFUNC U_IMPORT const uint8_t /* U_IMPORT2? */ /*U_IMPORT*/
+#endif
+utf8_countTrailBytes[256];
+/**
+* Counts the trail bytes for a UTF-8 lead byte.
+* Returns 0 for 0..0xbf as well as for 0xfe and 0xff.
+*
+* This is internal since it is not meant to be called directly by external clients;
+* however it is called by public macros in this file and thus must remain stable.
+*
+* Note: Beginning with ICU 50, the implementation uses a multi-condition expression
+* which was shown in 2012 (on x86-64) to compile to fast, branch-free code.
+* leadByte is evaluated multiple times.
+*
+* The pre-ICU 50 implementation used the exported array utf8_countTrailBytes:
+* #define U8_COUNT_TRAIL_BYTES(leadByte) (utf8_countTrailBytes[leadByte])
+* leadByte was evaluated exactly once.
+*
+* @param leadByte The first byte of a UTF-8 sequence. Must be 0..0xff.
+* @internal
+*/
+#define U8_COUNT_TRAIL_BYTES(leadByte) \
+((leadByte)<0xf0 ? \
+((leadByte)>=0xc0)+((leadByte)>=0xe0) : \
+(leadByte)<0xfe ? 3+((leadByte)>=0xf8)+((leadByte)>=0xfc) : 0)
+/**
+* Counts the trail bytes for a UTF-8 lead byte of a valid UTF-8 sequence.
+* The maximum supported lead byte is 0xf4 corresponding to U+10FFFF.
+* leadByte might be evaluated multiple times.
+*
+* This is internal since it is not meant to be called directly by external clients;
+* however it is called by public macros in this file and thus must remain stable.
+*
+* @param leadByte The first byte of a UTF-8 sequence. Must be 0..0xff.
+* @internal
+*/
+#define U8_COUNT_TRAIL_BYTES_UNSAFE(leadByte) \
+(((leadByte)>=0xc0)+((leadByte)>=0xe0)+((leadByte)>=0xf0))
+/**
+* Mask a UTF-8 lead byte, leave only the lower bits that form part of the code point value.
+*
+* This is internal since it is not meant to be called directly by external clients;
+* however it is called by public macros in this file and thus must remain stable.
+* @internal
+*/
+#define U8_MASK_LEAD_BYTE(leadByte, countTrailBytes) ((leadByte)&=(1<<(6-(countTrailBytes)))-1)
+/**
+* Function for handling "next code point" with error-checking.
+*
+* This is internal since it is not meant to be called directly by external clients;
+* however it is U_STABLE (not U_INTERNAL) since it is called by public macros in this
+* file and thus must remain stable, and should not be hidden when other internal
+* functions are hidden (otherwise public macros would fail to compile).
+* @internal
+*/
+U_STABLE UChar32 U_EXPORT2
+utf8_nextCharSafeBody(const uint8_t *s, int32_t *pi, int32_t length, UChar32 c, UBool strict);
+/**
+* Function for handling "append code point" with error-checking.
+*
+* This is internal since it is not meant to be called directly by external clients;
+* however it is U_STABLE (not U_INTERNAL) since it is called by public macros in this
+* file and thus must remain stable, and should not be hidden when other internal
+* functions are hidden (otherwise public macros would fail to compile).
+* @internal
+*/
+U_STABLE int32_t U_EXPORT2
+utf8_appendCharSafeBody(uint8_t *s, int32_t i, int32_t length, UChar32 c, UBool *pIsError);
+/**
+* Function for handling "previous code point" with error-checking.
+*
+* This is internal since it is not meant to be called directly by external clients;
+* however it is U_STABLE (not U_INTERNAL) since it is called by public macros in this
+* file and thus must remain stable, and should not be hidden when other internal
+* functions are hidden (otherwise public macros would fail to compile).
+* @internal
+*/
+U_STABLE UChar32 U_EXPORT2
+utf8_prevCharSafeBody(const uint8_t *s, int32_t start, int32_t *pi, UChar32 c, UBool strict);
+/**
+* Function for handling "skip backward one code point" with error-checking.
+*
+* This is internal since it is not meant to be called directly by external clients;
+* however it is U_STABLE (not U_INTERNAL) since it is called by public macros in this
+* file and thus must remain stable, and should not be hidden when other internal
+* functions are hidden (otherwise public macros would fail to compile).
+* @internal
+*/
+U_STABLE int32_t U_EXPORT2
+utf8_back1SafeBody(const uint8_t *s, int32_t start, int32_t i);
+/* single-code point definitions -------------------------------------------- */
+/**
+* Does this code unit (byte) encode a code point by itself (US-ASCII 0..0x7f)?
+* @param c 8-bit code unit (byte)
+* @return TRUE or FALSE
+* @stable ICU 2.4
+*/
+#define U8_IS_SINGLE(c) (((c)&0x80)==0)
+/**
+* Is this code unit (byte) a UTF-8 lead byte?
+* @param c 8-bit code unit (byte)
+* @return TRUE or FALSE
+* @stable ICU 2.4
+*/
+#define U8_IS_LEAD(c) ((uint8_t)((c)-0xc0)<0x3e)
+/**
+* Is this code unit (byte) a UTF-8 trail byte?
+* @param c 8-bit code unit (byte)
+* @return TRUE or FALSE
+* @stable ICU 2.4
+*/
+#define U8_IS_TRAIL(c) (((c)&0xc0)==0x80)
+/**
+* How many code units (bytes) are used for the UTF-8 encoding
+* of this Unicode code point?
+* @param c 32-bit code point
+* @return 1..4, or 0 if c is a surrogate or not a Unicode code point
+* @stable ICU 2.4
+*/
+#define U8_LENGTH(c) \
+((uint32_t)(c)<=0x7f ? 1 : \
+((uint32_t)(c)<=0x7ff ? 2 : \
+((uint32_t)(c)<=0xd7ff ? 3 : \
+((uint32_t)(c)<=0xdfff || (uint32_t)(c)>0x10ffff ? 0 : \
+((uint32_t)(c)<=0xffff ? 3 : 4)\
+) \
+) \
+) \
+)
+/**
+* The maximum number of UTF-8 code units (bytes) per Unicode code point (U+0000..U+10ffff).
+* @return 4
+* @stable ICU 2.4
+*/
+#define U8_MAX_LENGTH 4
+/**
+* Get a code point from a string at a random-access offset,
+* without changing the offset.
+* The offset may point to either the lead byte or one of the trail bytes
+* for a code point, in which case the macro will read all of the bytes
+* for the code point.
+* The result is undefined if the offset points to an illegal UTF-8
+* byte sequence.
+* Iteration through a string is more efficient with U8_NEXT_UNSAFE or U8_NEXT.
+*
+* @param s const uint8_t * string
+* @param i string offset
+* @param c output UChar32 variable
+* @see U8_GET
+* @stable ICU 2.4
+*/
+#define U8_GET_UNSAFE(s, i, c) { \
+int32_t _u8_get_unsafe_index=(int32_t)(i); \
+U8_SET_CP_START_UNSAFE(s, _u8_get_unsafe_index); \
+U8_NEXT_UNSAFE(s, _u8_get_unsafe_index, c); \
+}
+/**
+* Get a code point from a string at a random-access offset,
+* without changing the offset.
+* The offset may point to either the lead byte or one of the trail bytes
+* for a code point, in which case the macro will read all of the bytes
+* for the code point.
+*
+* The length can be negative for a NUL-terminated string.
+*
+* If the offset points to an illegal UTF-8 byte sequence, then
+* c is set to a negative value.
+* Iteration through a string is more efficient with U8_NEXT_UNSAFE or U8_NEXT.
+*
+* @param s const uint8_t * string
+* @param start int32_t starting string offset
+* @param i int32_t string offset, must be start<=i<length
+* @param length int32_t string length
+* @param c output UChar32 variable, set to <0 in case of an error
+* @see U8_GET_UNSAFE
+* @stable ICU 2.4
+*/
+#define U8_GET(s, start, i, length, c) { \
+int32_t _u8_get_index=(i); \
+U8_SET_CP_START(s, start, _u8_get_index); \
+U8_NEXT(s, _u8_get_index, length, c); \
+}
+#ifndef U_HIDE_DRAFT_API
+/**
+* Get a code point from a string at a random-access offset,
+* without changing the offset.
+* The offset may point to either the lead byte or one of the trail bytes
+* for a code point, in which case the macro will read all of the bytes
+* for the code point.
+*
+* The length can be negative for a NUL-terminated string.
+*
+* If the offset points to an illegal UTF-8 byte sequence, then
+* c is set to U+FFFD.
+* Iteration through a string is more efficient with U8_NEXT_UNSAFE or U8_NEXT_OR_FFFD.
+*
+* This macro does not distinguish between a real U+FFFD in the text
+* and U+FFFD returned for an ill-formed sequence.
+* Use U8_GET() if that distinction is important.
+*
+* @param s const uint8_t * string
+* @param start int32_t starting string offset
+* @param i int32_t string offset, must be start<=i<length
+* @param length int32_t string length
+* @param c output UChar32 variable, set to U+FFFD in case of an error
+* @see U8_GET
+* @draft ICU 51
+*/
+#define U8_GET_OR_FFFD(s, start, i, length, c) { \
+int32_t _u8_get_index=(i); \
+U8_SET_CP_START(s, start, _u8_get_index); \
+U8_NEXT_OR_FFFD(s, _u8_get_index, length, c); \
+}
+#endif /* U_HIDE_DRAFT_API */
+/* definitions with forward iteration --------------------------------------- */
+/**
+* Get a code point from a string at a code point boundary offset,
+* and advance the offset to the next code point boundary.
+* (Post-incrementing forward iteration.)
+* "Unsafe" macro, assumes well-formed UTF-8.
+*
+* The offset may point to the lead byte of a multi-byte sequence,
+* in which case the macro will read the whole sequence.
+* The result is undefined if the offset points to a trail byte
+* or an illegal UTF-8 sequence.
+*
+* @param s const uint8_t * string
+* @param i string offset
+* @param c output UChar32 variable
+* @see U8_NEXT
+* @stable ICU 2.4
+*/
+#define U8_NEXT_UNSAFE(s, i, c) { \
+(c)=(uint8_t)(s)[(i)++]; \
+if((c)>=0x80) { \
+if((c)<0xe0) { \
+(c)=(((c)&0x1f)<<6)|((s)[(i)++]&0x3f); \
+} else if((c)<0xf0) { \
+/* no need for (c&0xf) because the upper bits are truncated after <<12 in the cast to (UChar) */ \
+(c)=(UChar)(((c)<<12)|(((s)[i]&0x3f)<<6)|((s)[(i)+1]&0x3f)); \
+(i)+=2; \
+} else { \
+(c)=(((c)&7)<<18)|(((s)[i]&0x3f)<<12)|(((s)[(i)+1]&0x3f)<<6)|((s)[(i)+2]&0x3f); \
+(i)+=3; \
+} \
+} \
+}
+/**
+* Get a code point from a string at a code point boundary offset,
+* and advance the offset to the next code point boundary.
+* (Post-incrementing forward iteration.)
+* "Safe" macro, checks for illegal sequences and for string boundaries.
+*
+* The length can be negative for a NUL-terminated string.
+*
+* The offset may point to the lead byte of a multi-byte sequence,
+* in which case the macro will read the whole sequence.
+* If the offset points to a trail byte or an illegal UTF-8 sequence, then
+* c is set to a negative value.
+*
+* @param s const uint8_t * string
+* @param i int32_t string offset, must be i<length
+* @param length int32_t string length
+* @param c output UChar32 variable, set to <0 in case of an error
+* @see U8_NEXT_UNSAFE
+* @stable ICU 2.4
+*/
+#define U8_NEXT(s, i, length, c) { \
+(c)=(uint8_t)(s)[(i)++]; \
+if((c)>=0x80) { \
+uint8_t __t1, __t2; \
+if( /* handle U+1000..U+CFFF inline */ \
+(0xe0<(c) && (c)<=0xec) && \
+(((i)+1)<(length) || (length)<0) && \
+(__t1=(uint8_t)((s)[i]-0x80))<=0x3f && \
+(__t2=(uint8_t)((s)[(i)+1]-0x80))<= 0x3f \
+) { \
+/* no need for (c&0xf) because the upper bits are truncated after <<12 in the cast to (UChar) */ \
+(c)=(UChar)(((c)<<12)|(__t1<<6)|__t2); \
+(i)+=2; \
+} else if( /* handle U+0080..U+07FF inline */ \
+((c)<0xe0 && (c)>=0xc2) && \
+((i)!=(length)) && \
+(__t1=(uint8_t)((s)[i]-0x80))<=0x3f \
+) { \
+(c)=(((c)&0x1f)<<6)|__t1; \
+++(i); \
+} else { \
+/* function call for "complicated" and error cases */ \
+(c)=utf8_nextCharSafeBody((const uint8_t *)s, &(i), (length), c, -1); \
+} \
+} \
+}
+#ifndef U_HIDE_DRAFT_API
+/**
+* Get a code point from a string at a code point boundary offset,
+* and advance the offset to the next code point boundary.
+* (Post-incrementing forward iteration.)
+* "Safe" macro, checks for illegal sequences and for string boundaries.
+*
+* The length can be negative for a NUL-terminated string.
+*
+* The offset may point to the lead byte of a multi-byte sequence,
+* in which case the macro will read the whole sequence.
+* If the offset points to a trail byte or an illegal UTF-8 sequence, then
+* c is set to U+FFFD.
+*
+* This macro does not distinguish between a real U+FFFD in the text
+* and U+FFFD returned for an ill-formed sequence.
+* Use U8_NEXT() if that distinction is important.
+*
+* @param s const uint8_t * string
+* @param i int32_t string offset, must be i<length
+* @param length int32_t string length
+* @param c output UChar32 variable, set to U+FFFD in case of an error
+* @see U8_NEXT
+* @draft ICU 51
+*/
+#define U8_NEXT_OR_FFFD(s, i, length, c) { \
+(c)=(uint8_t)(s)[(i)++]; \
+if((c)>=0x80) { \
+uint8_t __t1, __t2; \
+if( /* handle U+1000..U+CFFF inline */ \
+(0xe0<(c) && (c)<=0xec) && \
+(((i)+1)<(length) || (length)<0) && \
+(__t1=(uint8_t)((s)[i]-0x80))<=0x3f && \
+(__t2=(uint8_t)((s)[(i)+1]-0x80))<= 0x3f \
+) { \
+/* no need for (c&0xf) because the upper bits are truncated after <<12 in the cast to (UChar) */ \
+(c)=(UChar)(((c)<<12)|(__t1<<6)|__t2); \
+(i)+=2; \
+} else if( /* handle U+0080..U+07FF inline */ \
+((c)<0xe0 && (c)>=0xc2) && \
+((i)!=(length)) && \
+(__t1=(uint8_t)((s)[i]-0x80))<=0x3f \
+) { \
+(c)=(((c)&0x1f)<<6)|__t1; \
+++(i); \
+} else { \
+/* function call for "complicated" and error cases */ \
+(c)=utf8_nextCharSafeBody((const uint8_t *)s, &(i), (length), c, -3); \
+} \
+} \
+}
+#endif /* U_HIDE_DRAFT_API */
+/**
+* Append a code point to a string, overwriting 1 to 4 bytes.
+* The offset points to the current end of the string contents
+* and is advanced (post-increment).
+* "Unsafe" macro, assumes a valid code point and sufficient space in the string.
+* Otherwise, the result is undefined.
+*
+* @param s const uint8_t * string buffer
+* @param i string offset
+* @param c code point to append
+* @see U8_APPEND
+* @stable ICU 2.4
+*/
+#define U8_APPEND_UNSAFE(s, i, c) { \
+if((uint32_t)(c)<=0x7f) { \
+(s)[(i)++]=(uint8_t)(c); \
+} else { \
+if((uint32_t)(c)<=0x7ff) { \
+(s)[(i)++]=(uint8_t)(((c)>>6)|0xc0); \
+} else { \
+if((uint32_t)(c)<=0xffff) { \
+(s)[(i)++]=(uint8_t)(((c)>>12)|0xe0); \
+} else { \
+(s)[(i)++]=(uint8_t)(((c)>>18)|0xf0); \
+(s)[(i)++]=(uint8_t)((((c)>>12)&0x3f)|0x80); \
+} \
+(s)[(i)++]=(uint8_t)((((c)>>6)&0x3f)|0x80); \
+} \
+(s)[(i)++]=(uint8_t)(((c)&0x3f)|0x80); \
+} \
+}
+/**
+* Append a code point to a string, overwriting 1 to 4 bytes.
+* The offset points to the current end of the string contents
+* and is advanced (post-increment).
+* "Safe" macro, checks for a valid code point.
+* If a non-ASCII code point is written, checks for sufficient space in the string.
+* If the code point is not valid or trail bytes do not fit,
+* then isError is set to TRUE.
+*
+* @param s const uint8_t * string buffer
+* @param i int32_t string offset, must be i<capacity
+* @param capacity int32_t size of the string buffer
+* @param c UChar32 code point to append
+* @param isError output UBool set to TRUE if an error occurs, otherwise not modified
+* @see U8_APPEND_UNSAFE
+* @stable ICU 2.4
+*/
+#define U8_APPEND(s, i, capacity, c, isError) { \
+if((uint32_t)(c)<=0x7f) { \
+(s)[(i)++]=(uint8_t)(c); \
+} else if((uint32_t)(c)<=0x7ff && (i)+1<(capacity)) { \
+(s)[(i)++]=(uint8_t)(((c)>>6)|0xc0); \
+(s)[(i)++]=(uint8_t)(((c)&0x3f)|0x80); \
+} else if((uint32_t)(c)<=0xd7ff && (i)+2<(capacity)) { \
+(s)[(i)++]=(uint8_t)(((c)>>12)|0xe0); \
+(s)[(i)++]=(uint8_t)((((c)>>6)&0x3f)|0x80); \
+(s)[(i)++]=(uint8_t)(((c)&0x3f)|0x80); \
+} else { \
+(i)=utf8_appendCharSafeBody(s, (i), (capacity), c, &(isError)); \
+} \
+}
+/**
+* Advance the string offset from one code point boundary to the next.
+* (Post-incrementing iteration.)
+* "Unsafe" macro, assumes well-formed UTF-8.
+*
+* @param s const uint8_t * string
+* @param i string offset
+* @see U8_FWD_1
+* @stable ICU 2.4
+*/
+#define U8_FWD_1_UNSAFE(s, i) { \
+(i)+=1+U8_COUNT_TRAIL_BYTES_UNSAFE((uint8_t)(s)[i]); \
+}
+/**
+* Advance the string offset from one code point boundary to the next.
+* (Post-incrementing iteration.)
+* "Safe" macro, checks for illegal sequences and for string boundaries.
+*
+* The length can be negative for a NUL-terminated string.
+*
+* @param s const uint8_t * string
+* @param i int32_t string offset, must be i<length
+* @param length int32_t string length
+* @see U8_FWD_1_UNSAFE
+* @stable ICU 2.4
+*/
+#define U8_FWD_1(s, i, length) { \
+uint8_t __b=(uint8_t)(s)[(i)++]; \
+if(U8_IS_LEAD(__b)) { \
+uint8_t __count=U8_COUNT_TRAIL_BYTES(__b); \
+if((i)+__count>(length) && (length)>=0) { \
+__count=(uint8_t)((length)-(i)); \
+} \
+while(__count>0 && U8_IS_TRAIL((s)[i])) { \
+++(i); \
+--__count; \
+} \
+} \
+}
+/**
+* Advance the string offset from one code point boundary to the n-th next one,
+* i.e., move forward by n code points.
+* (Post-incrementing iteration.)
+* "Unsafe" macro, assumes well-formed UTF-8.
+*
+* @param s const uint8_t * string
+* @param i string offset
+* @param n number of code points to skip
+* @see U8_FWD_N
+* @stable ICU 2.4
+*/
+#define U8_FWD_N_UNSAFE(s, i, n) { \
+int32_t __N=(n); \
+while(__N>0) { \
+U8_FWD_1_UNSAFE(s, i); \
+--__N; \
+} \
+}
+/**
+* Advance the string offset from one code point boundary to the n-th next one,
+* i.e., move forward by n code points.
+* (Post-incrementing iteration.)
+* "Safe" macro, checks for illegal sequences and for string boundaries.
+*
+* The length can be negative for a NUL-terminated string.
+*
+* @param s const uint8_t * string
+* @param i int32_t string offset, must be i<length
+* @param length int32_t string length
+* @param n number of code points to skip
+* @see U8_FWD_N_UNSAFE
+* @stable ICU 2.4
+*/
+#define U8_FWD_N(s, i, length, n) { \
+int32_t __N=(n); \
+while(__N>0 && ((i)<(length) || ((length)<0 && (s)[i]!=0))) { \
+U8_FWD_1(s, i, length); \
+--__N; \
+} \
+}
+/**
+* Adjust a random-access offset to a code point boundary
+* at the start of a code point.
+* If the offset points to a UTF-8 trail byte,
+* then the offset is moved backward to the corresponding lead byte.
+* Otherwise, it is not modified.
+* "Unsafe" macro, assumes well-formed UTF-8.
+*
+* @param s const uint8_t * string
+* @param i string offset
+* @see U8_SET_CP_START
+* @stable ICU 2.4
+*/
+#define U8_SET_CP_START_UNSAFE(s, i) { \
+while(U8_IS_TRAIL((s)[i])) { --(i); } \
+}
+/**
+* Adjust a random-access offset to a code point boundary
+* at the start of a code point.
+* If the offset points to a UTF-8 trail byte,
+* then the offset is moved backward to the corresponding lead byte.
+* Otherwise, it is not modified.
+* "Safe" macro, checks for illegal sequences and for string boundaries.
+*
+* @param s const uint8_t * string
+* @param start int32_t starting string offset (usually 0)
+* @param i int32_t string offset, must be start<=i
+* @see U8_SET_CP_START_UNSAFE
+* @stable ICU 2.4
+*/
+#define U8_SET_CP_START(s, start, i) { \
+if(U8_IS_TRAIL((s)[(i)])) { \
+(i)=utf8_back1SafeBody(s, start, (i)); \
+} \
+}
+/* definitions with backward iteration -------------------------------------- */
+/**
+* Move the string offset from one code point boundary to the previous one
+* and get the code point between them.
+* (Pre-decrementing backward iteration.)
+* "Unsafe" macro, assumes well-formed UTF-8.
+*
+* The input offset may be the same as the string length.
+* If the offset is behind a multi-byte sequence, then the macro will read
+* the whole sequence.
+* If the offset is behind a lead byte, then that itself
+* will be returned as the code point.
+* The result is undefined if the offset is behind an illegal UTF-8 sequence.
+*
+* @param s const uint8_t * string
+* @param i string offset
+* @param c output UChar32 variable
+* @see U8_PREV
+* @stable ICU 2.4
+*/
+#define U8_PREV_UNSAFE(s, i, c) { \
+(c)=(uint8_t)(s)[--(i)]; \
+if(U8_IS_TRAIL(c)) { \
+uint8_t __b, __count=1, __shift=6; \
+\
+/* c is a trail byte */ \
+(c)&=0x3f; \
+for(;;) { \
+__b=(uint8_t)(s)[--(i)]; \
+if(__b>=0xc0) { \
+U8_MASK_LEAD_BYTE(__b, __count); \
+(c)|=(UChar32)__b<<__shift; \
+break; \
+} else { \
+(c)|=(UChar32)(__b&0x3f)<<__shift; \
+++__count; \
+__shift+=6; \
+} \
+} \
+} \
+}
+/**
+* Move the string offset from one code point boundary to the previous one
+* and get the code point between them.
+* (Pre-decrementing backward iteration.)
+* "Safe" macro, checks for illegal sequences and for string boundaries.
+*
+* The input offset may be the same as the string length.
+* If the offset is behind a multi-byte sequence, then the macro will read
+* the whole sequence.
+* If the offset is behind a lead byte, then that itself
+* will be returned as the code point.
+* If the offset is behind an illegal UTF-8 sequence, then c is set to a negative value.
+*
+* @param s const uint8_t * string
+* @param start int32_t starting string offset (usually 0)
+* @param i int32_t string offset, must be start<i
+* @param c output UChar32 variable, set to <0 in case of an error
+* @see U8_PREV_UNSAFE
+* @stable ICU 2.4
+*/
+#define U8_PREV(s, start, i, c) { \
+(c)=(uint8_t)(s)[--(i)]; \
+if((c)>=0x80) { \
+(c)=utf8_prevCharSafeBody((const uint8_t *)s, start, &(i), c, -1); \
+} \
+}
+#ifndef U_HIDE_DRAFT_API
+/**
+* Move the string offset from one code point boundary to the previous one
+* and get the code point between them.
+* (Pre-decrementing backward iteration.)
+* "Safe" macro, checks for illegal sequences and for string boundaries.
+*
+* The input offset may be the same as the string length.
+* If the offset is behind a multi-byte sequence, then the macro will read
+* the whole sequence.
+* If the offset is behind a lead byte, then that itself
+* will be returned as the code point.
+* If the offset is behind an illegal UTF-8 sequence, then c is set to U+FFFD.
+*
+* This macro does not distinguish between a real U+FFFD in the text
+* and U+FFFD returned for an ill-formed sequence.
+* Use U8_PREV() if that distinction is important.
+*
+* @param s const uint8_t * string
+* @param start int32_t starting string offset (usually 0)
+* @param i int32_t string offset, must be start<i
+* @param c output UChar32 variable, set to U+FFFD in case of an error
+* @see U8_PREV
+* @draft ICU 51
+*/
+#define U8_PREV_OR_FFFD(s, start, i, c) { \
+(c)=(uint8_t)(s)[--(i)]; \
+if((c)>=0x80) { \
+(c)=utf8_prevCharSafeBody((const uint8_t *)s, start, &(i), c, -3); \
+} \
+}
+#endif /* U_HIDE_DRAFT_API */
+/**
+* Move the string offset from one code point boundary to the previous one.
+* (Pre-decrementing backward iteration.)
+* The input offset may be the same as the string length.
+* "Unsafe" macro, assumes well-formed UTF-8.
+*
+* @param s const uint8_t * string
+* @param i string offset
+* @see U8_BACK_1
+* @stable ICU 2.4
+*/
+#define U8_BACK_1_UNSAFE(s, i) { \
+while(U8_IS_TRAIL((s)[--(i)])) {} \
+}
+/**
+* Move the string offset from one code point boundary to the previous one.
+* (Pre-decrementing backward iteration.)
+* The input offset may be the same as the string length.
+* "Safe" macro, checks for illegal sequences and for string boundaries.
+*
+* @param s const uint8_t * string
+* @param start int32_t starting string offset (usually 0)
+* @param i int32_t string offset, must be start<i
+* @see U8_BACK_1_UNSAFE
+* @stable ICU 2.4
+*/
+#define U8_BACK_1(s, start, i) { \
+if(U8_IS_TRAIL((s)[--(i)])) { \
+(i)=utf8_back1SafeBody(s, start, (i)); \
+} \
+}
+/**
+* Move the string offset from one code point boundary to the n-th one before it,
+* i.e., move backward by n code points.
+* (Pre-decrementing backward iteration.)
+* The input offset may be the same as the string length.
+* "Unsafe" macro, assumes well-formed UTF-8.
+*
+* @param s const uint8_t * string
+* @param i string offset
+* @param n number of code points to skip
+* @see U8_BACK_N
+* @stable ICU 2.4
+*/
+#define U8_BACK_N_UNSAFE(s, i, n) { \
+int32_t __N=(n); \
+while(__N>0) { \
+U8_BACK_1_UNSAFE(s, i); \
+--__N; \
+} \
+}
+/**
+* Move the string offset from one code point boundary to the n-th one before it,
+* i.e., move backward by n code points.
+* (Pre-decrementing backward iteration.)
+* The input offset may be the same as the string length.
+* "Safe" macro, checks for illegal sequences and for string boundaries.
+*
+* @param s const uint8_t * string
+* @param start int32_t index of the start of the string
+* @param i int32_t string offset, must be start<i
+* @param n number of code points to skip
+* @see U8_BACK_N_UNSAFE
+* @stable ICU 2.4
+*/
+#define U8_BACK_N(s, start, i, n) { \
+int32_t __N=(n); \
+while(__N>0 && (i)>(start)) { \
+U8_BACK_1(s, start, i); \
+--__N; \
+} \
+}
+/**
+* Adjust a random-access offset to a code point boundary after a code point.
+* If the offset is behind a partial multi-byte sequence,
+* then the offset is incremented to behind the whole sequence.
+* Otherwise, it is not modified.
+* The input offset may be the same as the string length.
+* "Unsafe" macro, assumes well-formed UTF-8.
+*
+* @param s const uint8_t * string
+* @param i string offset
+* @see U8_SET_CP_LIMIT
+* @stable ICU 2.4
+*/
+#define U8_SET_CP_LIMIT_UNSAFE(s, i) { \
+U8_BACK_1_UNSAFE(s, i); \
+U8_FWD_1_UNSAFE(s, i); \
+}
+/**
+* Adjust a random-access offset to a code point boundary after a code point.
+* If the offset is behind a partial multi-byte sequence,
+* then the offset is incremented to behind the whole sequence.
+* Otherwise, it is not modified.
+* The input offset may be the same as the string length.
+* "Safe" macro, checks for illegal sequences and for string boundaries.
+*
+* The length can be negative for a NUL-terminated string.
+*
+* @param s const uint8_t * string
+* @param start int32_t starting string offset (usually 0)
+* @param i int32_t string offset, must be start<=i<=length
+* @param length int32_t string length
+* @see U8_SET_CP_LIMIT_UNSAFE
+* @stable ICU 2.4
+*/
+#define U8_SET_CP_LIMIT(s, start, i, length) { \
+if((start)<(i) && ((i)<(length) || ((length)<0 && (s)[i]!=0))) { \
+U8_BACK_1(s, start, i); \
+U8_FWD_1(s, i, length); \
+} \
+}
+#endif

The Tor Browser / file comparison

comparison: intl/icu/source/common/unicode/utf8.h

intl/icu/source/common/unicode/utf8.h