void ParseRepeat (void)
/* Parse and handle the .REPEAT statement */
{
char* Name;
TokList* List;
/* Repeat count follows */
long RepCount = ConstExpression ();
if (RepCount < 0) {
Error ("Range error");
RepCount = 0;
}
/* Optional there is a comma and a counter variable */
Name = 0;
if (Tok == TOK_COMMA) {
/* Skip the comma */
NextTok ();
/* Check for an identifier */
if (Tok != TOK_IDENT) {
ErrorSkip ("Identifier expected");
} else {
/* Remember the name and skip it */
SB_Terminate (&SVal);
Name = xstrdup (SB_GetConstBuf (&SVal));
NextTok ();
}
}
/* Separator */
ConsumeSep ();
/* Read the token list */
List = CollectRepeatTokens ();
/* If we had an error, bail out */
if (List == 0) {
xfree (Name);
return;
}
/* Update the token list for replay */
List->RepMax = (unsigned) RepCount;
List->Data = Name;
List->Check = RepeatTokenCheck;
/* If the list is empty, or repeat count zero, there is nothing
* to repeat.
*/
if (List->Count == 0 || RepCount == 0) {
FreeTokList (List);
return;
}
/* Read input from the repeat descriptor */
PushTokList (List, ".REPEAT");
}
static TokList* CollectRepeatTokens (void)
/* Collect all tokens inside the .REPEAT body in a token list and return
* this list. In case of errors, NULL is returned.
*/
{
/* Create the token list */
TokList* List = NewTokList ();
/* Read the token list */
unsigned Repeats = 0;
while (Repeats != 0 || Tok != TOK_ENDREP) {
/* Check for end of input */
if (Tok == TOK_EOF) {
Error ("Unexpected end of file");
FreeTokList (List);
return 0;
}
/* If we find a token that is equal to the repeat counter name,
* replace it by a REPCOUNTER token. This way we have to do strcmps
* only once for each identifier, and not for each expansion.
* Note: This will fail for nested repeats using the same repeat
* counter name, but
*/
/* Collect all tokens in the list */
AddCurTok (List);
/* Check for and count nested .REPEATs */
if (Tok == TOK_REPEAT) {
++Repeats;
} else if (Tok == TOK_ENDREP) {
--Repeats;
}
/* Get the next token */
NextTok ();
}
/* Eat the closing .ENDREP */
NextTok ();
/* Return the list of collected tokens */
return List;
}
void PushTokList (TokList* List, const char* Desc)
/* Push a token list to be used as input for InputFromStack. This includes
* several initializations needed in the token list structure, so don't use
* PushInput directly.
*/
{
/* If the list is empty, just delete it and bail out */
if (List->Count == 0) {
FreeTokList (List);
return;
}
/* Reset the last pointer to the first element */
List->Last = List->Root;
/* Insert the list specifying our input function */
PushInput (ReplayTokList, List, Desc);
}
static int ReplayTokList (void* List)
/* Function that gets the next token from a token list and sets it. This
* function may be used together with the PushInput function from the istack
* module.
*/
{
/* Cast the generic pointer to an actual list */
TokList* L = List;
/* Last may never be a NULL pointer, otherwise there's a bug in the code */
CHECK (L->Last != 0);
/* Set the next token from the list */
TokSet (L->Last);
/* If a check function is defined, call it, so it may look at the token
* just set and changed it as apropriate.
*/
if (L->Check) {
L->Check (L);
}
/* Set the pointer to the next token */
L->Last = L->Last->Next;
/* If this was the last token, decrement the repeat counter. If it goes
* zero, delete the list and remove the function from the stack.
*/
if (L->Last == 0) {
if (++L->RepCount >= L->RepMax) {
/* Done with this list */
FreeTokList (L);
PopInput ();
} else {
/* Replay one more time */
L->Last = L->Root;
}
}
/* We have a token */
return 1;
}
static TokList* CollectRepeatTokens (void)
/* Collect all tokens inside the .REPEAT body in a token list and return
* this list. In case of errors, NULL is returned.
*/
{
/* Create the token list */
TokList* List = NewTokList ();
/* Read the token list */
unsigned Repeats = 0;
while (Repeats != 0 || CurTok.Tok != TOK_ENDREP) {
/* Check for end of input */
if (CurTok.Tok == TOK_EOF) {
Error ("Unexpected end of file");
FreeTokList (List);
return 0;
}
/* Collect all tokens in the list */
AddCurTok (List);
/* Check for and count nested .REPEATs */
if (CurTok.Tok == TOK_REPEAT) {
++Repeats;
} else if (CurTok.Tok == TOK_ENDREP) {
--Repeats;
}
/* Get the next token */
NextTok ();
}
/* Eat the closing .ENDREP */
NextTok ();
/* Return the list of collected tokens */
return List;
}
