diff options
Diffstat (limited to 'generic/tclUtil.c')
| -rw-r--r-- | generic/tclUtil.c | 116 |
1 files changed, 76 insertions, 40 deletions
diff --git a/generic/tclUtil.c b/generic/tclUtil.c index 558d77b..8e295f4 100644 --- a/generic/tclUtil.c +++ b/generic/tclUtil.c @@ -26,28 +26,71 @@ static ProcessGlobalValue executableName = { }; /* - * The following values are used in the flags returned by Tcl_ScanElement and - * used by Tcl_ConvertElement. The values TCL_DONT_USE_BRACES and - * TCL_DONT_QUOTE_HASH are defined in tcl.h; make sure neither value overlaps - * with any of the values below. - * - * TCL_DONT_USE_BRACES - 1 means the string mustn't be enclosed in - * braces (e.g. it contains unmatched braces, or - * ends in a backslash character, or user just - * doesn't want braces); handle all special - * characters by adding backslashes. - * USE_BRACES - 1 means the string contains a special - * character that can be handled simply by - * enclosing the entire argument in braces. + * The following values are used in the flags arguments of Tcl*Scan*Element and + * Tcl*Convert*Element. The values TCL_DONT_USE_BRACES and TCL_DONT_QUOTE_HASH + * are defined in tcl.h, like so: + * +#define TCL_DONT_USE_BRACES 1 +#define TCL_DONT_QUOTE_HASH 8 + * + * Those are public flag bits which callers of the public routines + * Tcl_Convert*Element() can use to indicate: + * + * TCL_DONT_USE_BRACES - 1 means the caller is insisting that brace + * quoting not be used when converting the list + * element. * TCL_DONT_QUOTE_HASH - 1 means the caller insists that a leading hash * character ('#') should *not* be quoted. This * is appropriate when the caller can guarantee * the element is not the first element of a * list, so [eval] cannot mis-parse the element * as a comment. + * + * The remaining values which can be carried by the flags of these routines + * are for internal use only. Make sure they do not overlap with the public + * values above. + * + * The Tcl*Scan*Element() routines make a determination which of 4 modes of + * conversion is most appropriate for Tcl*Convert*Element() to perform, and + * sets two bits of the flags value to indicate the mode selected. + * + * CONVERT_NONE The element needs no quoting. Its literal string + * is suitable as is. + * CONVERT_BRACE The conversion should be enclosing the literal string + * in braces. + * CONVERT_ESCAPE The conversion should be using backslashes to escape + * any characters in the string that require it. + * CONVERT_MASK A mask value used to extract the conversion mode from + * the flags argument. + * Also indicates a strange conversion mode where all + * special characters are escaped with backslashes + * *except for braces*. This is a strange and unnecessary + * case, but it's part of the historical way in which + * lists have been formatted in Tcl. To experiment with + * removing this case, set the value of COMPAT to 0. + * + * One last flag value is used only by callers of TclScanElement(). The flag + * value produced by a call to Tcl*Scan*Element() will never leave this bit + * set. + * + * CONVERT_ANY The caller of TclScanElement() declares it can make + * no promise about what public flags will be passed to + * the matching call of TclConvertElement(). As such, + * TclScanElement() has to determine the worst case + * destination buffer length over all possibilities, and + * in other cases this means an overestimate of the + * required size. + * + * For more details, see the comments on the Tcl*Scan*Element and + * Tcl*Convert*Element routines. */ -#define USE_BRACES 2 +#define COMPAT 1 +#define CONVERT_NONE 0 +#define CONVERT_BRACE 2 +#define CONVERT_ESCAPE 4 +#define CONVERT_MASK (CONVERT_BRACE | CONVERT_ESCAPE) +#define CONVERT_ANY 16 /* * The following key is used by Tcl_PrintDouble and TclPrecTraceProc to @@ -230,7 +273,7 @@ TclFindElement( */ case '\\': - Tcl_UtfBackslash(p, &numChars, NULL); + TclParseBackslash(p, limit - p, &numChars, NULL); p += (numChars - 1); break; @@ -324,14 +367,13 @@ TclFindElement( * * TclCopyAndCollapse -- * - * Copy a string and eliminate any backslashes that aren't in braces. + * Copy a string and substitute all backslash escape sequences * * Results: - * Count characters get copied from src to dst. Along the way, if - * backslash sequences are found outside braces, the backslashes are - * eliminated in the copy. After scanning count chars from source, a null - * character is placed at the end of dst. Returns the number of - * characters that got copied. + * Count bytes get copied from src to dst. Along the way, backslash + * sequences are substituted in the copy. After scanning count bytes + * from src, a null character is placed at the end of dst. Returns + * the number of bytes that got written to dst. * * Side effects: * None. @@ -341,26 +383,28 @@ TclFindElement( int TclCopyAndCollapse( - int count, /* Number of characters to copy from src. */ + int count, /* Number of byte to copy from src. */ CONST char *src, /* Copy from here... */ char *dst) /* ... to here. */ { - register char c; - int numRead; int newCount = 0; - int backslashCount; - for (c = *src; count > 0; src++, c = *src, count--) { + while (count > 0) { + char c = *src; if (c == '\\') { - backslashCount = Tcl_UtfBackslash(src, &numRead, dst); + int numRead; + int backslashCount = TclParseBackslash(src, count, &numRead, dst); + dst += backslashCount; newCount += backslashCount; - src += numRead-1; - count -= numRead-1; + src += numRead; + count -= numRead; } else { *dst = c; dst++; newCount++; + src++; + count--; } } *dst = 0; @@ -645,15 +689,6 @@ Tcl_ScanElement( *---------------------------------------------------------------------- */ -#define COMPAT 1 - -#define CONVERT_NONE 0 -#define CONVERT_BRACE 2 -#define CONVERT_ESCAPE 4 -#define CONVERT_SAFE 16 -#define CONVERT_MASK (CONVERT_BRACE | CONVERT_ESCAPE) - - int Tcl_ScanCountedElement( CONST char *string, /* String to convert to Tcl list element. */ @@ -661,7 +696,7 @@ Tcl_ScanCountedElement( int *flagPtr) /* Where to store information to guide * Tcl_ConvertElement. */ { - int flags = CONVERT_SAFE; + int flags = CONVERT_ANY; int numBytes = TclScanElement(string, length, &flags); *flagPtr = flags; @@ -792,10 +827,11 @@ TclScanElement( *flagPtr = CONVERT_ESCAPE; goto overflowCheck; } - if (*flagPtr & CONVERT_SAFE) { + if (*flagPtr & CONVERT_ANY) { if (extra < 2) { extra = 2; } + *flagPtr &= ~CONVERT_ANY; *flagPtr |= TCL_DONT_USE_BRACES; } if (forbidNone) { |