StrBuf* InitLine (StrBuf* Buf)
/* Initialize Line from Buf and read CurC and NextC from the new input line.
* The function returns the old input line.
*/
{
StrBuf* OldLine = Line;
Line = Buf;
CurC = SB_LookAt (Buf, SB_GetIndex (Buf));
NextC = SB_LookAt (Buf, SB_GetIndex (Buf) + 1);
return OldLine;
}
int SB_GetNumber (StrBuf* B, long* Val)
/* Get a number from the string buffer. Accepted formats are decimal, octal,
** hex and character constants. Numeric constants may be preceeded by a
** minus or plus sign. The function returns 1 if a number was found and
** zero otherwise. Errors are only output for invalid numbers.
*/
{
int Sign;
char C;
unsigned Base;
unsigned DigitVal;
/* Initialize Val */
*Val = 0;
/* Handle character constants */
if (SB_Peek (B) == '\'') {
/* Character constant */
SB_Skip (B);
*Val = SignExtendChar (TgtTranslateChar (ParseChar (B)));
if (SB_Peek (B) != '\'') {
Error ("`\'' expected");
return 0;
} else {
/* Skip the quote */
SB_Skip (B);
return 1;
}
}
/* Check for a sign. A sign must be followed by a digit, otherwise it's
** not a number
*/
Sign = 1;
switch (SB_Peek (B)) {
case '-':
Sign = -1;
/* FALLTHROUGH */
case '+':
if (!IsDigit (SB_LookAt (B, SB_GetIndex (B) + 1))) {
return 0;
}
SB_Skip (B);
break;
}
/* We must have a digit now, otherwise its not a number */
C = SB_Peek (B);
if (!IsDigit (C)) {
return 0;
}
/* Determine the base */
if (C == '0') {
/* Hex or octal */
SB_Skip (B);
if (tolower (SB_Peek (B)) == 'x') {
SB_Skip (B);
Base = 16;
if (!IsXDigit (SB_Peek (B))) {
Error ("Invalid hexadecimal number");
return 0;
}
} else {
Base = 8;
}
} else {
Base = 10;
}
/* Read the number */
while (IsXDigit (C = SB_Peek (B)) && (DigitVal = HexVal (C)) < Base) {
*Val = (*Val * Base) + DigitVal;
SB_Skip (B);
}
/* Allow optional 'U' and 'L' modifiers */
C = SB_Peek (B);
if (C == 'u' || C == 'U') {
SB_Skip (B);
C = SB_Peek (B);
if (C == 'l' || C == 'L') {
SB_Skip (B);
}
} else if (C == 'l' || C == 'L') {
SB_Skip (B);
C = SB_Peek (B);
if (C == 'u' || C == 'U') {
SB_Skip (B);
}
}
/* Success, value read is in Val */
*Val *= Sign;
return 1;
}
