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-rw-r--r--generic/tclUtil.c116
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) {