parser: Add preprocessing stubs

Signed-off-by: Ian Moffett <ian@mirocom.org>

core/parser.c

@@ -22,6 +22,13 @@
 #define tokstr(tok)  \
     tokstr1((tok)->type)
 
+/* Unexpected end of file */
+#define ueof(state)                 \
+    trace_error(                    \
+        (state),                    \
+        "unexpected end of file\n"  \
+    );
+
 /*
  * Table used to convert token constants into human
  * readable strings
@@ -34,18 +41,62 @@ static const char *toktab[] = {
     [TT_SLASH]  = qtok("/")
 };
 
-int
-parser_parse(struct rifle_state *state)
+/*
+ * Parse-side token scan function
+ *
+ * @state: Compiler state
+ * @tok:   Last token
+ *
+ * Returns zero on success
+ */
+static int
+parse_scan(struct rifle_state *state, struct token *tok)
 {
-    struct token tok;
-
-    if (state == NULL) {
-        return 0;
+    if (state == NULL || tok == NULL) {
+        return -1;
     }
 
-    while (lexer_scan(state, &tok) == 0) {
-        trace_debug("got %s\n", tokstr(&tok));
+    switch (state->pass_num) {
+    case 0:
+        if (lexer_scan(state, tok) < 0) {
+            return -1;
+        }
+
+        break;
     }
 
     return 0;
 }
+
+static int
+parse_preprocess(struct rifle_state *state)
+{
+    struct token tok;
+
+    while (parse_scan(state, &tok) == 0) {
+        trace_debug("got token %s\n", tokstr(&tok));
+    }
+
+    return 0;
+}
+
+int
+parser_parse(struct rifle_state *state)
+{
+    if (state == NULL) {
+        return 0;
+    }
+
+    switch (state->pass_num) {
+    case 0:
+        /* Pre-processor */
+        if (parse_preprocess(state) < 0) {
+            return -1;
+        }
+
+        break;
+    }
+
+    ++state->pass_num;
+    return 0;
+}

inc/rifle/state.h

@@ -9,10 +9,12 @@
  *
  * @in_fd: Input file descriptor
  * @line_num: Current line number
+ * @pass_num: Current pass
  */
 struct rifle_state {
     int in_fd;
     size_t line_num;
+    size_t pass_num;
 };
 
 /*