+ ftepp_t *ftepp;
+
+ ftepp = (ftepp_t*)mem_a(sizeof(*ftepp));
+ memset(ftepp, 0, sizeof(*ftepp));
+
+ return ftepp;
+}
+
+void ftepp_delete(ftepp_t *self)
+{
+ vec_free(self->macros);
+ vec_free(self->conditions);
+ mem_d(self);
+}
+
+ppmacro* ftepp_macro_find(ftepp_t *ftepp, const char *name)
+{
+ size_t i;
+ for (i = 0; i < vec_size(ftepp->macros); ++i) {
+ if (!strcmp(name, ftepp->macros[i]->name))
+ return ftepp->macros[i];
+ }
+ return NULL;
+}
+
+static inline int ftepp_next(ftepp_t *ftepp)
+{
+ return (ftepp->token = lex_do(ftepp->lex));
+}
+
+/* Important: this does not skip newlines! */
+static bool ftepp_skipspace(ftepp_t *ftepp)
+{
+ if (ftepp->token != TOKEN_WHITE)
+ return true;
+ while (ftepp_next(ftepp) == TOKEN_WHITE) {}
+ if (ftepp->token >= TOKEN_EOF) {
+ ftepp_error(ftepp, "unexpected end of preprocessor directive");
+ return false;
+ }
+ return true;
+}
+
+/**
+ * The huge macro parsing code...
+ */
+static bool ftepp_define(ftepp_t *ftepp)
+{
+ ppmacro *macro;
+ (void)ftepp_next(ftepp);
+ if (!ftepp_skipspace(ftepp))
+ return false;
+
+ switch (ftepp->token) {
+ case TOKEN_IDENT:
+ case TOKEN_TYPENAME:
+ case TOKEN_KEYWORD:
+ macro = ppmacro_new(ftepp_ctx(ftepp), ftepp_tokval(ftepp));
+ break;
+ default:
+ ftepp_error(ftepp, "expected macro name");
+ return false;
+ }
+
+ (void)ftepp_next(ftepp);
+ if (!ftepp_skipspace(ftepp))
+ return false;
+ if (ftepp->token != TOKEN_EOL) {
+ ftepp_error(ftepp, "stray tokens after macro");
+ return false;
+ }
+ vec_push(ftepp->macros, macro);
+ return true;
+}
+
+/**
+ * #if - the FTEQCC way:
+ * defined(FOO) => true if FOO was #defined regardless of parameters or contents
+ * <numbers> => True if the number is not 0
+ * !<factor> => True if the factor yields false
+ * <macro> => becomes the macro's FIRST token regardless of parameters
+ * <e> && <e> => True if both expressions are true
+ * <e> || <e> => True if either expression is true
+ * <string> => False
+ * <ident> => False (remember for macros the <macro> rule applies instead)
+ * Unary + and - are skipped
+ * parenthesis in expressions are allowed
+ * parameter lists on macros are errors
+ * No mathematical calculations are executed
+ */
+static bool ftepp_if_expr(ftepp_t *ftepp, bool *out)
+{
+ ppmacro *macro;
+
+ if (!ftepp_skipspace(ftepp))
+ return false;
+
+ switch (ftepp->token) {
+ case TOKEN_IDENT:
+ case TOKEN_TYPENAME:
+ case TOKEN_KEYWORD:
+ if (!strcmp(ftepp_tokval(ftepp), "defined")) {
+ ftepp_next(ftepp);
+ if (!ftepp_skipspace(ftepp))
+ return false;
+ if (ftepp->token != '(') {
+ ftepp_error(ftepp, "`defined` keyword in #if requires a macro name in parenthesis");
+ return false;
+ }
+ ftepp_next(ftepp);
+ if (!ftepp_skipspace(ftepp))
+ return false;
+ if (ftepp->token != TOKEN_IDENT &&
+ ftepp->token != TOKEN_TYPENAME &&
+ ftepp->token != TOKEN_KEYWORD)
+ {
+ ftepp_error(ftepp, "defined() used on an unexpected token type");
+ return false;
+ }
+ macro = ftepp_macro_find(ftepp, ftepp_tokval(ftepp));
+ *out = !!macro;
+ ftepp_next(ftepp);
+ if (!ftepp_skipspace(ftepp))
+ return false;
+ if (ftepp->token != ')') {
+ ftepp_error(ftepp, "expected closing paren");
+ return false;
+ }
+ break;
+ }
+
+ macro = ftepp_macro_find(ftepp, ftepp_tokval(ftepp));
+ if (!macro || !vec_size(macro->output)) {
+ *out = false;
+ } else {
+ /* This does not expand recursively! */
+ switch (macro->output[0]->token) {
+ case TOKEN_INTCONST:
+ *out = !!(macro->output[0]->constval.f);
+ break;
+ case TOKEN_FLOATCONST:
+ *out = !!(macro->output[0]->constval.f);
+ break;
+ default:
+ *out = false;
+ break;
+ }
+ }
+ break;
+ case TOKEN_STRINGCONST:
+ *out = false;
+ break;
+ case TOKEN_INTCONST:
+ *out = !!(ftepp->lex->tok.constval.i);
+ break;
+ case TOKEN_FLOATCONST:
+ *out = !!(ftepp->lex->tok.constval.f);
+ break;
+
+ case '(':
+ ftepp_next(ftepp);
+ if (!ftepp_if_expr(ftepp, out))
+ return false;
+ if (ftepp->token != ')') {
+ ftepp_error(ftepp, "expected closing paren in #if expression");
+ return false;
+ }
+ break;
+
+ default:
+ ftepp_error(ftepp, "junk in #if");
+ return false;
+ }
+
+ ftepp->lex->flags.noops = false;
+ ftepp_next(ftepp);
+ if (!ftepp_skipspace(ftepp))
+ return false;
+ ftepp->lex->flags.noops = true;
+
+ if (ftepp->token == ')')
+ return true;
+
+ if (ftepp->token != TOKEN_OPERATOR)
+ return true;
+
+ if (!strcmp(ftepp_tokval(ftepp), "&&") ||
+ !strcmp(ftepp_tokval(ftepp), "||"))
+ {
+ bool next = false;
+ char opc = ftepp_tokval(ftepp)[0];
+
+ ftepp_next(ftepp);
+ if (!ftepp_if_expr(ftepp, &next))
+ return false;
+
+ if (opc == '&')
+ *out = *out && next;
+ else
+ *out = *out || next;
+ return true;
+ }
+ else {
+ ftepp_error(ftepp, "junk after #if");
+ return false;
+ }
+}
+
+static bool ftepp_if(ftepp_t *ftepp, ppcondition *cond)
+{
+ bool result = false;
+
+ memset(cond, 0, sizeof(*cond));
+ (void)ftepp_next(ftepp);
+
+ if (!ftepp_skipspace(ftepp))
+ return false;
+ if (ftepp->token == TOKEN_EOL) {
+ ftepp_error(ftepp, "expected expression for #if-directive");
+ return false;
+ }
+
+ if (!ftepp_if_expr(ftepp, &result))
+ return false;
+
+ cond->on = result;
+ return true;
+}
+
+/**
+ * ifdef is rather simple
+ */
+static bool ftepp_ifdef(ftepp_t *ftepp, ppcondition *cond)
+{
+ ppmacro *macro;
+ memset(cond, 0, sizeof(*cond));
+ (void)ftepp_next(ftepp);
+ if (!ftepp_skipspace(ftepp))
+ return false;