Method evalToToken

glslang/MachineIndependent/preprocessor/Pp.cpp:582–610

Expand macros, skipping empty expansions, to get to the first real token in those expansions.

// Expand macros, skipping empty expansions, to get to the first real token in those expansions.
int TPpContext::evalToToken(int token, bool shortCircuit, int& res, bool& err, TPpToken* ppToken)
{
    while (token == PpAtomIdentifier && strcmp("defined", ppToken->name) != 0) {
        switch (MacroExpand(ppToken, true, false)) {
        case MacroExpandNotStarted:
        case MacroExpandError:
            parseContext.ppError(ppToken->loc, "can't evaluate expression", "preprocessor evaluation", "");
            err = true;
            res = 0;
            break;
        case MacroExpandStarted:
            break;
        case MacroExpandUndef:
            if (! shortCircuit && parseContext.isEsProfile()) {
                const char* message = "undefined macro in expression not allowed in es profile";
                if (parseContext.relaxedErrors())
                    parseContext.ppWarn(ppToken->loc, message, "preprocessor evaluation", ppToken->name);
                else
                    parseContext.ppError(ppToken->loc, message, "preprocessor evaluation", ppToken->name);
            }
            break;
        }
        token = scanToken(ppToken);
        if (err)
            break;
    }

    return token;
}

// Handle #if
int TPpContext::CPPif(TPpToken* ppToken)