parser+codegen: Add support for loops

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

core/codegen.c

@@ -67,6 +67,29 @@ resolve_return(struct rifle_state *state, struct ast_node *root)
     return 0;
 }
 
+static int
+resolve_loop(struct rifle_state *state, struct ast_node *root)
+{
+    char label[32];
+
+    if (state == NULL || root == NULL) {
+        return -1;
+    }
+
+    if (root->epilogue) {
+        snprintf(label, sizeof(label), "L.%zu", state->loop_count - 1);
+        mu_gen_blab(state, label);
+
+        snprintf(label, sizeof(label), "L.%zu.1", state->loop_count - 1);
+        mu_gen_label(state, label, false);
+    } else {
+        snprintf(label, sizeof(label), "L.%zu", state->loop_count++);
+        mu_gen_label(state, label, false);
+    }
+
+    return 0;
+}
+
 int
 cg_resolve_node(struct rifle_state *state, struct ast_node *root)
 {
@@ -86,6 +109,12 @@ cg_resolve_node(struct rifle_state *state, struct ast_node *root)
             return -1;
         }
 
+        break;
+    case AST_LOOP:
+        if (resolve_loop(state, root) < 0) {
+            return -1;
+        }
+
         break;
     default:
         trace_error(state, "unknown ast node %d\n", root->type);

core/parser.c

@@ -545,6 +545,14 @@ parse_rbrace(struct rifle_state *state, struct token *tok, struct ast_node **res
             return -1;
         }
 
+        root->epilogue = 1;
+        break;
+    case TT_LOOP:
+        if (ast_alloc_node(state, AST_LOOP, &root) < 0) {
+            trace_error(state, "failed to allocate AST_LOOP\n");
+            return -1;
+        }
+
         root->epilogue = 1;
         break;
     default:
@@ -677,6 +685,45 @@ parse_return(struct rifle_state *state, struct token *tok, struct ast_node **res
     return 0;
 }
 
+/*
+ * Parse a loop statement
+ *
+ * @state: Compiler state
+ * @tok:   Last token
+ * @res:   AST result
+ *
+ * Returns zero on success
+ */
+static int
+parse_loop(struct rifle_state *state, struct token *tok, struct ast_node **res)
+{
+    struct ast_node *root;
+
+    if (state == NULL || tok == NULL) {
+        return -1;
+    }
+
+    if (res == NULL) {
+        return -1;
+    }
+
+    if (tok->type != TT_LOOP) {
+        return -1;
+    }
+
+    if (parse_lbrace(state, TT_LOOP, tok) < 0) {
+        return -1;
+    }
+
+    if (ast_alloc_node(state, AST_LOOP, &root) < 0) {
+        trace_error(state, "failed to allocate AST_LOOP\n");
+        return -1;
+    }
+
+    *res = root;
+    return 0;
+}
+
 static int
 parse_begin(struct rifle_state *state)
 {
@@ -702,6 +749,12 @@ parse_begin(struct rifle_state *state)
                 return -1;
             }
 
+            break;
+        case TT_LOOP:
+            if (parse_loop(state, &tok, &root) < 0) {
+                return -1;
+            }
+
             break;
         case TT_PUB:
             break;