diff options
| -rw-r--r-- | generic/tclUtil.c | 124 |
1 files changed, 78 insertions, 46 deletions
diff --git a/generic/tclUtil.c b/generic/tclUtil.c index c67b6af..4fe1015 100644 --- a/generic/tclUtil.c +++ b/generic/tclUtil.c @@ -1002,12 +1002,12 @@ TclTrimRight( if (bytesLeft == 0) { /* No match; trim task done; *p is last non-trimmed char */ + p += pInc; break; } - pInc = 0; } while (p > bytes); - return numBytes - (p - bytes) - pInc; + return numBytes - (p - bytes); } /* @@ -1019,8 +1019,7 @@ TclTrimRight( * first string all characters found in the second string. * * Results: - * An integer index into the first string, pointing to the first - * character not to be trimmed. + * The number of bytes to be removed from the start of the string. * * Side effects: * None. @@ -1097,59 +1096,77 @@ TclTrimLeft( *---------------------------------------------------------------------- */ +/* The whitespace characters trimmed during [concat] operations */ +#define CONCAT_WS " \f\v\r\t\n" +#define CONCAT_WS_SIZE (int) (sizeof(CONCAT_WS "") - 1) + char * Tcl_Concat( int argc, /* Number of strings to concatenate. */ const char *const *argv) /* Array of strings to concatenate. */ { - int totalSize, i; - char *p; - char *result; + int i, needSpace = 0, bytesNeeded = 0; + char *result, *p; + + /* Dispose of the empty result corner case first to simplify later code */ + if (argc == 0) { + result = (char *) ckalloc(1); + result[0] = '\0'; + return result; + } - for (totalSize = 1, i = 0; i < argc; i++) { - totalSize += strlen(argv[i]) + 1; - if (totalSize <= 0) { + /* First allocate the result buffer at the size required */ + for (i = 0; i < argc; i++) { + bytesNeeded += strlen(argv[i]); + if (bytesNeeded < 0) { Tcl_Panic("Tcl_Concat: max size of Tcl value exceeded"); } } - result = ckalloc(totalSize); - if (argc == 0) { - *result = '\0'; - return result; + if (bytesNeeded + argc - 1 < 0) { + /* + * Panic test could be tighter, but not going to bother for + * this legacy routine. + */ + Tcl_Panic("Tcl_Concat: max size of Tcl value exceeded"); } - for (p = result, i = 0; i < argc; i++) { + /* All element bytes + (argc - 1) spaces + 1 terminating NULL */ + result = (char *) ckalloc((unsigned) (bytesNeeded + argc)); + + for (p = result, i = 0; i < argc; i++) { + int trim, elemLength; const char *element; - int length; + + element = argv[i]; + elemLength = strlen(argv[i]); + + /* Trim away the leading whitespace */ + trim = TclTrimLeft(element, elemLength, CONCAT_WS, CONCAT_WS_SIZE); + element += trim; + elemLength -= trim; /* - * Clip white space off the front and back of the string to generate a - * neater result, and ignore any empty elements. + * Trim away the trailing whitespace. Do not permit trimming + * to expose a final backslash character. */ - element = argv[i]; - while (isspace(UCHAR(*element))) { /* INTL: ISO space. */ - element++; - } - for (length = strlen(element); - (length > 0) - && (isspace(UCHAR(element[length-1]))) /* INTL: ISO space. */ - && ((length < 2) || (element[length-2] != '\\')); - length--) { - /* Null loop body. */ - } - if (length == 0) { + trim = TclTrimRight(element, elemLength, CONCAT_WS, CONCAT_WS_SIZE); + trim -= trim && (element[elemLength - trim - 1] == '\\'); + elemLength -= trim; + + /* If we're left with empty element after trimming, do nothing */ + if (elemLength == 0) { continue; } - memcpy(p, element, (size_t) length); - p += length; - *p = ' '; - p++; - } - if (p != result) { - p[-1] = 0; - } else { - *p = 0; + + /* Append to the result with space if needed */ + if (needSpace) { + *p++ = ' '; + } + memcpy(p, element, (size_t) elemLength); + p += elemLength; + needSpace = 1; } + *p = '\0'; return result; } @@ -1176,7 +1193,8 @@ Tcl_ConcatObj( int objc, /* Number of objects to concatenate. */ Tcl_Obj *const objv[]) /* Array of objects to concatenate. */ { - int i, needSpace = 0; + int i, elemLength, needSpace = 0, bytesNeeded = 0; + const char *element; Tcl_Obj *objPtr, *resPtr; /* @@ -1241,16 +1259,30 @@ Tcl_ConcatObj( * the slow way, using the string representations. */ + /* First try to pre-allocate the size required */ + for (i = 0; i < objc; i++) { + element = TclGetStringFromObj(objv[i], &elemLength); + bytesNeeded += elemLength; + if (bytesNeeded < 0) { + break; + } + } + /* + * Does not matter if this fails, will simply try later to build up + * the string with each Append reallocating as needed with the usual + * string append algorithm. When that fails it will report the error. + */ TclNewObj(resPtr); + Tcl_AttemptSetObjLength(resPtr, bytesNeeded + objc - 1); + Tcl_SetObjLength(resPtr, 0); + for (i = 0; i < objc; i++) { - int trim, elemLength; - const char *element; + int trim; - objPtr = objv[i]; - element = TclGetStringFromObj(objPtr, &elemLength); + element = TclGetStringFromObj(objv[i], &elemLength); /* Trim away the leading whitespace */ - trim = TclTrimLeft(element, elemLength, " \f\v\r\t\n", 6); + trim = TclTrimLeft(element, elemLength, CONCAT_WS, CONCAT_WS_SIZE); element += trim; elemLength -= trim; @@ -1259,7 +1291,7 @@ Tcl_ConcatObj( * to expose a final backslash character. */ - trim = TclTrimRight(element, elemLength, " \f\v\r\t\n", 6); + trim = TclTrimRight(element, elemLength, CONCAT_WS, CONCAT_WS_SIZE); trim -= trim && (element[elemLength - trim - 1] == '\\'); elemLength -= trim; |