load(libdir + "wasm-binary.js");

const v2vSig = {args:[], ret:VoidCode};
const v2vSigSection = sigSection([v2vSig]);

// 'ref.func' parses, validates and returns a non-null value
wasmFullPass(`
	(module
		(elem declare func $run)
		(func $run (result i32)
			ref.func $run
			ref.is_null
		)
		(export "run" (func $run))
	)
`, 0);

// function returning reference to itself
{
	let {f1} = wasmEvalText(`
		(module
			(elem declare func $f1)
			(func $f1 (result funcref) ref.func $f1)
			(export "f1" (func $f1))
		)
	`).exports;
	assertEq(f1(), f1);
}

// function returning reference to a different function
{
	let {f1, f2} = wasmEvalText(`
		(module
			(elem declare func $f1)
			(func $f1)
			(func $f2 (result funcref) ref.func $f1)
			(export "f1" (func $f1))
			(export "f2" (func $f2))
		)
	`).exports;
	assertEq(f2(), f1);
}

// function returning reference to function in a different module
{
	let i1 = wasmEvalText(`
		(module
			(elem declare func $f1)
			(func $f1)
			(export "f1" (func $f1))
		)
	`);
	let i2 = wasmEvalText(`
		(module
			(import "" "f1" (func $f1))
			(elem declare func $f1)
			(func $f2 (result funcref) ref.func $f1)
			(export "f1" (func $f1))
			(export "f2" (func $f2))
		)
	`, {"": i1.exports});

	let f1 = i1.exports.f1;
	let f2 = i2.exports.f2;
	assertEq(f2(), f1);
}

// function index must be valid
assertErrorMessage(() => {
	wasmEvalText(`
		(module
			(func (result funcref) ref.func 10)
		)
	`);
}, WebAssembly.CompileError, /(function index out of range)|(function index out of bounds)/);

function validFuncRefText(forwardDeclare, tbl_type) {
	return wasmEvalText(`
		(module
			(table 1 ${tbl_type})
			(func $test (result funcref) ref.func $referenced)
			(func $referenced)
			${forwardDeclare}
		)
	`);
}

// referenced function must be forward declared somehow
assertErrorMessage(() => validFuncRefText('', 'funcref'), WebAssembly.CompileError, /(function index is not declared in a section before the code section)|(undeclared function reference)/);

// referenced function can be forward declared via segments
assertEq(validFuncRefText('(elem 0 (i32.const 0) func $referenced)', 'funcref') instanceof WebAssembly.Instance, true);
assertEq(validFuncRefText('(elem func $referenced)', 'funcref') instanceof WebAssembly.Instance, true);
assertEq(validFuncRefText('(elem declare func $referenced)', 'funcref') instanceof WebAssembly.Instance, true);

// also when the segment is passive or active 'funcref'
assertEq(validFuncRefText('(elem 0 (i32.const 0) funcref (ref.func $referenced))', 'funcref') instanceof WebAssembly.Instance, true);
assertEq(validFuncRefText('(elem funcref (ref.func $referenced))', 'funcref') instanceof WebAssembly.Instance, true);

// reference function can be forward declared via globals
assertEq(validFuncRefText('(global funcref (ref.func $referenced))', 'externref') instanceof WebAssembly.Instance, true);

// reference function can be forward declared via export
assertEq(validFuncRefText('(export "referenced" (func $referenced))', 'externref') instanceof WebAssembly.Instance, true);

// reference function cannot be forward declared via start
assertErrorMessage(() => validFuncRefText('(start $referenced)', 'externref'), WebAssembly.CompileError, /(function index is not declared in a section before the code section)|(undeclared function reference)/);

// Tests not expressible in the text format.

// element segment with elemexpr can carry non-reference type, but this must be
// rejected.

assertErrorMessage(() => new WebAssembly.Module(
    moduleWithSections([generalElemSection([{ flag: PassiveElemExpr,
                                              typeCode: I32Code,
                                              elems: [] }])])),
                   WebAssembly.CompileError,
                   /bad type/);

// Test case for bug 1596026: when taking the ref.func of an imported function,
// the value obtained should not be the JS function.  This would assert (even in
// a release build), so the test is merely that the code runs.

var ins = new WebAssembly.Instance(new WebAssembly.Module(wasmTextToBinary(`
  (module
    (import "m" "f" (func $f (param i32) (result i32)))
    (elem declare func $f)
    (table 1 funcref)
    (func (export "f")
      (table.set 0 (i32.const 0) (ref.func $f))))`)),
                                   {m:{f:(x) => 37+x}});
ins.exports.f();

// Verification that we can handle encoding errors for passive element segments
// properly.

function checkPassiveElemSegment(mangle, err) {
    let bin = moduleWithSections(
        [v2vSigSection, declSection([0]), // One function
         tableSection(1),                 // One table
         { name: elemId,                  // One passive segment
           body: (function () {
               let body = [];
               body.push(1);           // 1 element segment
               body.push(0x1 | 0x4);   // Flags: Passive and uses element expression
               body.push(mangle == "type" ? BadType : AnyFuncCode); // always anyfunc
               body.push(1);           // Element count
               body.push(mangle == "ref.func" ? BadType : RefFuncCode); // always ref.func
               body.push(0);           // func index
               body.push(EndCode + (mangle == "end" ? 1 : 0));
               return body;
           })() },
         bodySection(                   // Empty function
             [funcBody(
                 {locals:[],
                  body:[]})])
        ]);
    if (err) {
        assertErrorMessage(() => new WebAssembly.Module(bin),
                           WebAssembly.CompileError,
                           err);
    } else {
        new WebAssembly.Module(bin);
    }
}

checkPassiveElemSegment("");
checkPassiveElemSegment("type", /bad type/);
checkPassiveElemSegment("ref.func", /unrecognized opcode/);
checkPassiveElemSegment("end", /unrecognized opcode/);

// Passive element segments can contain literal null values.

{
    let txt =
        `(module
           (table (export "t") 10 funcref)
           (elem (i32.const 1) $m)
           (elem (i32.const 3) $m)
           (elem (i32.const 6) $m)
           (elem (i32.const 8) $m)
           (elem funcref (ref.func $f) (ref.null func) (ref.func $g) (ref.null func) (ref.func $h))
           (func $m)
           (func $f)
           (func $g)
           (func $h)
           (func (export "doit") (param $idx i32)
             (table.init 4 (local.get $idx) (i32.const 0) (i32.const 5))))`;
    let ins = wasmEvalText(txt);
    ins.exports.doit(0);
    ins.exports.doit(5);
    assertEq(typeof ins.exports.t.get(0), "function");
    assertEq(ins.exports.t.get(1), null);
    assertEq(typeof ins.exports.t.get(2), "function");
    assertEq(ins.exports.t.get(0) == ins.exports.t.get(2), false);
    assertEq(ins.exports.t.get(3), null);
    assertEq(typeof ins.exports.t.get(4), "function");
    assertEq(typeof ins.exports.t.get(5), "function");
    assertEq(ins.exports.t.get(6), null);
    assertEq(typeof ins.exports.t.get(7), "function");
    assertEq(ins.exports.t.get(8), null);
    assertEq(typeof ins.exports.t.get(9), "function");
}

// Test ref.func in global initializer expressions

for (let mutable of [true, false]) {
  for (let imported of [true, false]) {
    for (let exported of [true, false]) {
      let globalType = mutable ? `(mut funcref)` : `funcref`;

      let imports = {};

      if (imported) {
        imports = wasmEvalText(`
          (module
            (global $g (export "g") ${globalType} (ref.func $f))
            (func $f (export "f") (result i32) i32.const 42)
          )
        `).exports;
      }

      let exports = wasmEvalText(`
        (module
          (global $g ${exported ? `(export "g")` : ``} ${imported ? `(import "" "g")` : ``} ${globalType} ${imported ? `` : `(ref.func $f)`})
          ${exported ? `` : `(func (export "get_g") (result funcref) global.get $g)`}
          (func $f (export "f") (result i32) i32.const 42)
        )
      `, { "": imports }).exports;

      let targetFunc = imported ? imports.f : exports.f;
      let globalVal = exported ? exports.g.value : exports.get_g();
      assertEq(targetFunc(), 42);
      assertEq(globalVal(), 42);
      assertEq(targetFunc, globalVal);
      if (imported && exported) {
        assertEq(imports.g, exports.g);
      }
    }
  }
}

// Test invalid ref.func indices

function testCodeRefFuncIndex(index) {
  assertErrorMessage(() => {
      new WebAssembly.Module(moduleWithSections(
        [v2vSigSection,
         declSection([0]), // One function
         bodySection(
          [funcBody(
              {locals:[],
               body:[
                 RefFuncCode,
                 ...varU32(index),
                 DropCode
                 ]})])
          ]))
    },
    WebAssembly.CompileError,
    /(function index out of range)|(function index out of bounds)/);
}

testCodeRefFuncIndex(1);
testCodeRefFuncIndex(2);
testCodeRefFuncIndex(10);
testCodeRefFuncIndex(1000);

function testGlobalRefFuncIndex(index) {
  assertErrorMessage(() => {
      new WebAssembly.Module(moduleWithSections(
        [v2vSigSection,
          globalSection([
           {
             valType: AnyFuncCode,
             flags: 0,
             initExpr: [RefFuncCode, ...varU32(index), EndCode],
           }
         ])
        ]))
    },
    WebAssembly.CompileError,
    /(function index out of range)|(function index out of bounds)/);
}

testGlobalRefFuncIndex(1);
testGlobalRefFuncIndex(2);
testGlobalRefFuncIndex(10);
testGlobalRefFuncIndex(1000);