+// HexToFP - Convert the ascii string in hexidecimal format to the floating
+// point representation of it.
+//
+static double HexToFP(const char *Buffer) {
+ uint64_t Result = 0;
+ for (; *Buffer; ++Buffer) {
+ uint64_t OldRes = Result;
+ Result *= 16;
+ char C = *Buffer;
+ if (C >= '0' && C <= '9')
+ Result += C-'0';
+ else if (C >= 'A' && C <= 'F')
+ Result += C-'A'+10;
+ else if (C >= 'a' && C <= 'f')
+ Result += C-'a'+10;
+
+ if (Result < OldRes) // Uh, oh, overflow detected!!!
+ ThrowException("constant bigger than 64 bits detected!");
+ }
+
+ assert(sizeof(double) == sizeof(Result) &&
+ "Data sizes incompatible on this target!");
+ // Behave nicely in the face of C TBAA rules... see:
+ // http://www.nullstone.com/htmls/category/aliastyp.htm
+ //
+ char *ProxyPointer = (char*)&Result;
+ return *(double*)ProxyPointer; // Cast Hex constant to double
+}
+
+
+// UnEscapeLexed - Run through the specified buffer and change \xx codes to the
+// appropriate character. If AllowNull is set to false, a \00 value will cause
+// an exception to be thrown.
+//
+// If AllowNull is set to true, the return value of the function points to the
+// last character of the string in memory.
+//
+char *UnEscapeLexed(char *Buffer, bool AllowNull) {
+ char *BOut = Buffer;
+ for (char *BIn = Buffer; *BIn; ) {
+ if (BIn[0] == '\\' && isxdigit(BIn[1]) && isxdigit(BIn[2])) {
+ char Tmp = BIn[3]; BIn[3] = 0; // Terminate string
+ *BOut = strtol(BIn+1, 0, 16); // Convert to number
+ if (!AllowNull && !*BOut)
+ ThrowException("String literal cannot accept \\00 escape!");
+
+ BIn[3] = Tmp; // Restore character
+ BIn += 3; // Skip over handled chars
+ ++BOut;
+ } else {
+ *BOut++ = *BIn++;
+ }
+ }
+
+ return BOut;
+}