core: lexer: Add preprocessor tokens

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

core/lexer.c

@@ -189,6 +189,45 @@ lexer_check_kw(struct cescal_state *state, struct token *res)
     }
 }
 
+/*
+ * Check if an identifier token is actually a directive
+ *
+ * @state:   Compiler state
+ * @res:     Token result is written here
+ */
+static int
+lexer_check_direc(struct cescal_state *state, struct token *res)
+{
+    if (state == NULL || res == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    switch (*res->s) {
+    case 'd':
+        if (strcmp(res->s, "define") == 0) {
+            res->type = TT_DEFINE;
+            return 0;
+        }
+
+        break;
+    case 'i':
+        if (strcmp(res->s, "ifndef") == 0) {
+            res->type = TT_IFNDEF;
+            return 0;
+        }
+
+        if (strcmp(res->s, "ifdef") == 0) {
+            res->type = TT_IFDEF;
+            return 0;
+        }
+
+        break;
+    }
+
+    return -1;
+}
+
 /*
  * Skip anything after a comment
  *
@@ -236,6 +275,19 @@ lexer_nom(struct cescal_state *state, struct token *res)
     case ',':
         res->type = TT_COMMA;
         res->c = c;
+        return 0;
+    case '#':
+        if ((c = lexer_consume_single(state, true)) == '\0') {
+            return -1;
+        }
+
+        if (lexer_scan_ident(state, c, res) == 0) {
+            if (lexer_check_direc(state, res) != 0) {
+                cc_error("bad directive '%s'\n", res->s);
+                return -1;
+            }
+        }
+
         return 0;
     case '/':
         if (lexer_consume_single(state, true) == '/') {