// Macro-expand a macro argument 'arg' to create 'expandedArg'.
// Does not replace 'arg'.
// Returns nullptr if no expanded argument is created.
TPpContext::TokenStream* TPpContext::PrescanMacroArg(TokenStream& arg, TPpToken* ppToken, bool newLineOkay)
{
// expand the argument
TokenStream* expandedArg = new TokenStream;
pushInput(new tMarkerInput(this));
pushTokenStreamInput(arg);
int token;
while ((token = scanToken(ppToken)) != tMarkerInput::marker && token != EndOfInput) {
token = tokenPaste(token, *ppToken);
if (token == tMarkerInput::marker || token == EndOfInput)
break;
if (token == PpAtomIdentifier && MacroExpand(ppToken, false, newLineOkay) != 0)
continue;
expandedArg->putToken(token, ppToken);
}
if (token == EndOfInput) {
// MacroExpand ate the marker, so had bad input, recover
delete expandedArg;
expandedArg = nullptr;
} else {
// remove the marker
popInput();
}
return expandedArg;
}
// Macro-expand a macro argument 'arg' to create 'expandedArg'.
// Does not replace 'arg'.
// Returns nullptr if no expanded argument is created.
TPpContext::TokenStream* TPpContext::PrescanMacroArg(TokenStream& arg, TPpToken* ppToken, bool newLineOkay)
{
// expand the argument
TokenStream* expandedArg = new TokenStream;
pushInput(new tMarkerInput(this));
pushTokenStreamInput(arg);
int token;
while ((token = scanToken(ppToken)) != tMarkerInput::marker && token != EndOfInput) {
token = tokenPaste(token, *ppToken);
if (token == PpAtomIdentifier) {
switch (MacroExpand(ppToken, false, newLineOkay)) {
case MacroExpandNotStarted:
break;
case MacroExpandError:
// toss the rest of the pushed-input argument by scanning until tMarkerInput
while ((token = scanToken(ppToken)) != tMarkerInput::marker && token != EndOfInput)
;
break;
case MacroExpandStarted:
case MacroExpandUndef:
continue;
}
}
if (token == tMarkerInput::marker || token == EndOfInput)
break;
expandedArg->putToken(token, ppToken);
}
if (token != tMarkerInput::marker) {
// Error, or MacroExpand ate the marker, so had bad input, recover
delete expandedArg;
expandedArg = nullptr;
}
return expandedArg;
}
//
// The main functional entry point into the preprocessor, which will
// scan the source strings to figure out and return the next processing token.
//
// Return the token, or EndOfInput when no more tokens.
//
int TPpContext::tokenize(TPpToken& ppToken)
{
for(;;) {
int token = scanToken(&ppToken);
// Handle token-pasting logic
token = tokenPaste(token, ppToken);
if (token == EndOfInput) {
missingEndifCheck();
return EndOfInput;
}
if (token == '#') {
if (previous_token == '\n') {
token = readCPPline(&ppToken);
if (token == EndOfInput) {
missingEndifCheck();
return EndOfInput;
}
continue;
} else {
_parseContext.ppError(ppToken.loc, "preprocessor directive cannot be preceded by another token", "#", "");
return EndOfInput;
}
}
previous_token = token;
if (token == '\n')
continue;
// expand macros
if (token == PpAtomIdentifier && MacroExpand(&ppToken, false, true) != 0)
continue;
switch (token) {
case PpAtomIdentifier:
case PpAtomConstInt:
case PpAtomConstUint:
case PpAtomConstFloat:
case PpAtomConstInt64:
case PpAtomConstUint64:
case PpAtomConstInt16:
case PpAtomConstUint16:
case PpAtomConstDouble:
case PpAtomConstFloat16:
if (ppToken.name[0] == '\0')
continue;
break;
case PpAtomConstString:
if (ifdepth == 0 && _parseContext.intermediate.getSource() != EShSourceHlsl) {
// HLSL allows string literals.
_parseContext.ppError(ppToken.loc, "string literals not supported", "\"\"", "");
continue;
}
break;
case '\'':
_parseContext.ppError(ppToken.loc, "character literals not supported", "\'", "");
continue;
default:
strcpy(ppToken.name, atomStrings.getString(token));
break;
}
return token;
}
}
