Add .type directive

asm.js

@@ -97,6 +97,9 @@ const State = Object.freeze({
     DEF_VALUE:    25,
     BLOCK_NAME:   26,
     BLOCK_TYPE:   27,
+    TYPE_NAME:    28,
+    TYPE_PARAM:   29,
+    TYPE_RESULT:  30,
 });
 
 const Action = Object.freeze({
@@ -118,12 +121,14 @@ const Action = Object.freeze({
     ENTER:  16,
     EXIT:   17,
     ELSE:   18,
+    TYPE:   19,
 });
 
 const types = {
-    "void": 0x40,
-    "func": 0x60,
-    "i32":  0x7f,
+    "void":    0x40,
+    "func":    0x60,
+    "funcref": 0x70,
+    "i32":     0x7f,
 };
 
 const opcodes = {
@@ -208,6 +213,7 @@ class Parser {
             ".utf8":   State.UTF8,
             ".align":  State.ALIGN,
             ".def":    State.DEF_NAME,
+            ".type":   State.TYPE_NAME,
         };
         this.blocks = new Set(["block", "loop", "if"]);
         this.handlers = {
@@ -239,6 +245,9 @@ class Parser {
             [State.DEF_VALUE]:    (token) => this.token_def_value(token),
             [State.BLOCK_NAME]:   (token) => this.token_block_name(token),
             [State.BLOCK_TYPE]:   (token) => this.token_block_type(token),
+            [State.TYPE_NAME]:    (token) => this.token_type_name(token),
+            [State.TYPE_PARAM]:   (token) => this.token_type_param(token),
+            [State.TYPE_RESULT]:  (token) => this.token_type_result(token),
         };
 
         this.results = [];
@@ -669,6 +678,68 @@ class Parser {
         return action;
     }
 
+    token_type_name(token) {
+        if (token == LINE_END) {
+            console.error(
+                "ERROR: Unexpected end of line in .type, expected name");
+            this.state = State.TOP;
+            return;
+        }
+
+        this.type = { name: token, params: [] };
+        this.state = State.TYPE_PARAM;
+    }
+
+    token_type_param(token) {
+        if (token == LINE_END) {
+            console.error(
+                "ERROR: Unexpected end of line in .type, expected "
+                    + "parameter type");
+            this.type = undefined;
+            this.state = State.TOP;
+            return;
+        }
+
+        if (token == "result") {
+            this.type.results = [];
+            this.state = State.TYPE_RESULT;
+            return;
+        }
+
+        const type = types[token];
+        if (type == undefined) {
+            console.error(
+                `ERROR: Unexpected token ${token} in .type, expected `
+                    + "parameter type");
+            this.type = undefined;
+            this.state = State.TOP;
+            return;
+        }
+
+        this.type.params.push(type);
+    }
+
+    token_type_result(token) {
+        if (token == LINE_END) {
+            const action = { type: Action.TYPE, the_type: this.type };
+            this.type = undefined;
+            this.state = State.TOP;
+            return action;
+        }
+
+        const type = types[token];
+        if (type == undefined) {
+            console.error(
+                `ERROR: Unexpected token ${token} in .type, expected `
+                    + "result type");
+            this.type = undefined;
+            this.state = State.TOP;
+            return;
+        }
+
+        this.type.results.push(type);
+    }
+
     mem_action() {
         const action = {
             type: Action.MEM,
@@ -730,6 +801,7 @@ export class Assembler {
             [Action.ENTER]:  (action) => this.action_enter(action),
             [Action.EXIT]:   (action) => this.action_exit(action),
             [Action.ELSE]:   (action) => this.action_else(action),
+            [Action.TYPE]:   (action) => this.action_type(action),
         };
 
         this.exports = [];
@@ -742,6 +814,7 @@ export class Assembler {
         this.defs = {};
         this.blocks = [];
         this.types = [];
+        this.type_bindings = {};
 	}
 
     action_append(action) {
@@ -874,6 +947,12 @@ export class Assembler {
         this.blocks.push(undefined);
     }
 
+    action_type(action) {
+        const type = this.func_type(action.the_type);
+        const index = this.ensure_type(type);
+        this.type_bindings[action.the_type.name] = index;
+    }
+
 	push(chunk) {
 		const text = this.decoder.decode(chunk, { stream: true });
 		for (const action of this.parser.handle(text))
@@ -1066,7 +1145,9 @@ export class Assembler {
     }
 
     func_type({ params, results }) {
-        const param_types = Object.values(params);
+        const param_types = params.length == undefined
+              ? Object.values(params)
+              : params;
         return [
             types["func"],
             param_types.length,