Golang types.NewSignature函数代码示例

func (p *importer) obj(tag int) {
	switch tag {
	case constTag:
		pos := p.pos()
		pkg, name := p.qualifiedName()
		typ := p.typ(nil)
		val := p.value()
		p.declare(types.NewConst(pos, pkg, name, typ, val))

	case typeTag:
		_ = p.typ(nil)

	case varTag:
		pos := p.pos()
		pkg, name := p.qualifiedName()
		typ := p.typ(nil)
		p.declare(types.NewVar(pos, pkg, name, typ))

	case funcTag:
		pos := p.pos()
		pkg, name := p.qualifiedName()
		params, isddd := p.paramList()
		result, _ := p.paramList()
		sig := types.NewSignature(nil, params, result, isddd)
		p.declare(types.NewFunc(pos, pkg, name, sig))

	default:
		panic(fmt.Sprintf("unexpected object tag %d", tag))
	}
}

func (p *importer) signature() *types.Signature {
	var recv *types.Var
	if p.int() != 0 {
		recv = p.param()
	}
	return types.NewSignature(recv, p.tuple(), p.tuple(), p.int() != 0)
}

// makeLen returns the len builtin specialized to type func(T)int.
func makeLen(T types.Type) *Builtin {
	lenParams := types.NewTuple(anonVar(T))
	return &Builtin{
		name: "len",
		sig:  types.NewSignature(nil, lenParams, lenResults, false),
	}
}

func (p *importer) method(parent *types.Package) *types.Func {
	pos := p.pos()
	pkg, name := p.fieldName(parent)
	params, isddd := p.paramList()
	result, _ := p.paramList()
	sig := types.NewSignature(nil, params, result, isddd)
	return types.NewFunc(pos, pkg, name, sig)
}

// newMethod creates a new method of the specified name, package and receiver type.
func newMethod(pkg *ssa.Package, recvType types.Type, name string) *ssa.Function {
	// TODO(adonovan): fix: hack: currently the only part of Signature
	// that is needed is the "pointerness" of Recv.Type, and for
	// now, we'll set it to always be false since we're only
	// concerned with rtype.  Encapsulate this better.
	sig := types.NewSignature(types.NewVar(token.NoPos, nil, "recv", recvType), nil, nil, false)
	fn := pkg.Prog.NewFunction(name, sig, "fake reflect method")
	fn.Pkg = pkg
	return fn
}

func ParseFuncDecl(fnDecl *gst.FuncDecl) (*types.Func, bool) {
	var fn *types.Func
	var pkg *types.Package
	pkg = nil
	name := fnDecl.Name
	var sig *types.Signature
	sig = types.NewSignature(nil, nil, nil, false)
	var pos token.Pos
	fn = types.NewFunc(pos, pkg, name, sig)
	return fn, true
}

// FindTests returns the list of packages that define at least one Test,
// Example or Benchmark function (as defined by "go test"), and the
// lists of all such functions.
//
func FindTests(pkgs []*Package) (testpkgs []*Package, tests, benchmarks, examples []*Function) {
	if len(pkgs) == 0 {
		return
	}
	prog := pkgs[0].Prog

	// The first two of these may be nil: if the program doesn't import "testing",
	// it can't contain any tests, but it may yet contain Examples.
	var testSig *types.Signature                              // func(*testing.T)
	var benchmarkSig *types.Signature                         // func(*testing.B)
	var exampleSig = types.NewSignature(nil, nil, nil, false) // func()

	// Obtain the types from the parameters of testing.Main().
	if testingPkg := prog.ImportedPackage("testing"); testingPkg != nil {
		params := testingPkg.Func("Main").Signature.Params()
		testSig = funcField(params.At(1).Type())
		benchmarkSig = funcField(params.At(2).Type())
	}

	seen := make(map[*Package]bool)
	for _, pkg := range pkgs {
		if pkg.Prog != prog {
			panic("wrong Program")
		}

		// TODO(adonovan): use a stable order, e.g. lexical.
		for _, mem := range pkg.Members {
			if f, ok := mem.(*Function); ok &&
				ast.IsExported(f.Name()) &&
				strings.HasSuffix(prog.Fset.Position(f.Pos()).Filename, "_test.go") {

				switch {
				case testSig != nil && isTestSig(f, "Test", testSig):
					tests = append(tests, f)
				case benchmarkSig != nil && isTestSig(f, "Benchmark", benchmarkSig):
					benchmarks = append(benchmarks, f)
				case isTestSig(f, "Example", exampleSig):
					examples = append(examples, f)
				default:
					continue
				}

				if !seen[pkg] {
					seen[pkg] = true
					testpkgs = append(testpkgs, pkg)
				}
			}
		}
	}
	return
}

// FindTests returns the Test, Benchmark, and Example functions
// (as defined by "go test") defined in the specified package,
// and its TestMain function, if any.
func FindTests(pkg *Package) (tests, benchmarks, examples []*Function, main *Function) {
	prog := pkg.Prog

	// The first two of these may be nil: if the program doesn't import "testing",
	// it can't contain any tests, but it may yet contain Examples.
	var testSig *types.Signature                              // func(*testing.T)
	var benchmarkSig *types.Signature                         // func(*testing.B)
	var exampleSig = types.NewSignature(nil, nil, nil, false) // func()

	// Obtain the types from the parameters of testing.MainStart.
	if testingPkg := prog.ImportedPackage("testing"); testingPkg != nil {
		mainStart := testingPkg.Func("MainStart")
		params := mainStart.Signature.Params()
		testSig = funcField(params.At(1).Type())
		benchmarkSig = funcField(params.At(2).Type())

		// Does the package define this function?
		//   func TestMain(*testing.M)
		if f := pkg.Func("TestMain"); f != nil {
			sig := f.Type().(*types.Signature)
			starM := mainStart.Signature.Results().At(0).Type() // *testing.M
			if sig.Results().Len() == 0 &&
				sig.Params().Len() == 1 &&
				types.Identical(sig.Params().At(0).Type(), starM) {
				main = f
			}
		}
	}

	// TODO(adonovan): use a stable order, e.g. lexical.
	for _, mem := range pkg.Members {
		if f, ok := mem.(*Function); ok &&
			ast.IsExported(f.Name()) &&
			strings.HasSuffix(prog.Fset.Position(f.Pos()).Filename, "_test.go") {

			switch {
			case testSig != nil && isTestSig(f, "Test", testSig):
				tests = append(tests, f)
			case benchmarkSig != nil && isTestSig(f, "Benchmark", benchmarkSig):
				benchmarks = append(benchmarks, f)
			case isTestSig(f, "Example", exampleSig):
				examples = append(examples, f)
			default:
				continue
			}
		}
	}
	return
}

// Signature = Parameters [ Result ] .
// Result    = Type | Parameters .
//
func (p *parser) parseSignature(recv *types.Var) *types.Signature {
	params, isVariadic := p.parseParameters()

	// optional result type
	var results []*types.Var
	if p.tok == '(' {
		var variadic bool
		results, variadic = p.parseParameters()
		if variadic {
			p.error("... not permitted on result type")
		}
	}

	return types.NewSignature(recv, types.NewTuple(params...), types.NewTuple(results...), isVariadic)
}

func (p *importer) obj(tag int) {
	switch tag {
	case constTag:
		pos := p.pos()
		pkg, name := p.qualifiedName()
		typ := p.typ(nil)
		val := p.value()
		p.declare(types.NewConst(pos, pkg, name, typ, val))

	case typeTag:
		p.typ(nil)

	case varTag:
		pos := p.pos()
		pkg, name := p.qualifiedName()
		typ := p.typ(nil)
		p.declare(types.NewVar(pos, pkg, name, typ))

	case funcTag:
		pos := p.pos()
		pkg, name := p.qualifiedName()
		params, isddd := p.paramList()
		result, _ := p.paramList()
		sig := types.NewSignature(nil, params, result, isddd)
		p.declare(types.NewFunc(pos, pkg, name, sig))

	case aliasTag:
		pos := p.pos()
		name := p.string()
		var orig types.Object
		if pkg, name := p.qualifiedName(); pkg != nil {
			orig = pkg.Scope().Lookup(name)
		}
		// Alias-related code. Keep for now.
		_ = pos
		_ = name
		_ = orig
		// p.declare(types.NewAlias(pos, p.pkgList[0], name, orig))

	default:
		errorf("unexpected object tag %d", tag)
	}
}

// NamedType = TypeName Type { Method } .
// Method    = "func" "(" Param ")" Name ParamList ResultList ";" .
func (p *parser) parseNamedType(n int) types.Type {
	obj := p.parseTypeName()

	pkg := obj.Pkg()
	typ := obj.Type()
	p.typeMap[n] = typ

	nt, ok := typ.(*types.Named)
	if !ok {
		// This can happen for unsafe.Pointer, which is a TypeName holding a Basic type.
		pt := p.parseType(pkg)
		if pt != typ {
			p.error("unexpected underlying type for non-named TypeName")
		}
		return typ
	}

	underlying := p.parseType(pkg)
	if nt.Underlying() == nil {
		nt.SetUnderlying(underlying.Underlying())
	}

	for p.tok == scanner.Ident {
		// collect associated methods
		p.expectKeyword("func")
		p.expect('(')
		receiver, _ := p.parseParam(pkg)
		p.expect(')')
		name := p.parseName()
		params, isVariadic := p.parseParamList(pkg)
		results := p.parseResultList(pkg)
		p.expect(';')

		sig := types.NewSignature(receiver, params, results, isVariadic)
		nt.AddMethod(types.NewFunc(token.NoPos, pkg, name, sig))
	}

	return nt
}

// parent is the package which declared the type; parent == nil means
// the package currently imported. The parent package is needed for
// exported struct fields and interface methods which don't contain
// explicit package information in the export data.
func (p *importer) typ(parent *types.Package) types.Type {
	// if the type was seen before, i is its index (>= 0)
	i := p.tagOrIndex()
	if i >= 0 {
		return p.typList[i]
	}

	// otherwise, i is the type tag (< 0)
	switch i {
	case namedTag:
		// read type object
		name := p.string()
		parent = p.pkg()
		scope := parent.Scope()
		obj := scope.Lookup(name)

		// if the object doesn't exist yet, create and insert it
		if obj == nil {
			obj = types.NewTypeName(token.NoPos, parent, name, nil)
			scope.Insert(obj)
		}

		if _, ok := obj.(*types.TypeName); !ok {
			panic(fmt.Sprintf("pkg = %s, name = %s => %s", parent, name, obj))
		}

		// associate new named type with obj if it doesn't exist yet
		t0 := types.NewNamed(obj.(*types.TypeName), nil, nil)

		// but record the existing type, if any
		t := obj.Type().(*types.Named)
		p.record(t)

		// read underlying type
		t0.SetUnderlying(p.typ(parent))

		// interfaces don't have associated methods
		if _, ok := t0.Underlying().(*types.Interface); ok {
			return t
		}

		// read associated methods
		for i := p.int(); i > 0; i-- {
			name := p.string()
			recv, _ := p.paramList() // TODO(gri) do we need a full param list for the receiver?
			params, isddd := p.paramList()
			result, _ := p.paramList()
			p.int() // read and discard index of inlined function body
			sig := types.NewSignature(recv.At(0), params, result, isddd)
			t0.AddMethod(types.NewFunc(token.NoPos, parent, name, sig))
		}

		return t

	case arrayTag:
		t := new(types.Array)
		p.record(t)

		n := p.int64()
		*t = *types.NewArray(p.typ(parent), n)
		return t

	case sliceTag:
		t := new(types.Slice)
		p.record(t)

		*t = *types.NewSlice(p.typ(parent))
		return t

	case dddTag:
		t := new(dddSlice)
		p.record(t)

		t.elem = p.typ(parent)
		return t

	case structTag:
		t := new(types.Struct)
		p.record(t)

		n := p.int()
		fields := make([]*types.Var, n)
		tags := make([]string, n)
		for i := range fields {
			fields[i] = p.field(parent)
			tags[i] = p.string()
		}
		*t = *types.NewStruct(fields, tags)
		return t

	case pointerTag:
		t := new(types.Pointer)
		p.record(t)

		*t = *types.NewPointer(p.typ(parent))
		return t
//.........这里部分代码省略.........

func changeRecv(s *types.Signature, recv *types.Var) *types.Signature {
	return types.NewSignature(recv, s.Params(), s.Results(), s.Variadic())
}

// makeWrapper returns a synthetic method that delegates to the
// declared method denoted by meth.Obj(), first performing any
// necessary pointer indirections or field selections implied by meth.
//
// The resulting method's receiver type is meth.Recv().
//
// This function is versatile but quite subtle!  Consider the
// following axes of variation when making changes:
//   - optional receiver indirection
//   - optional implicit field selections
//   - meth.Obj() may denote a concrete or an interface method
//   - the result may be a thunk or a wrapper.
//
// EXCLUSIVE_LOCKS_REQUIRED(prog.methodsMu)
//
func makeWrapper(prog *Program, sel *types.Selection) *Function {
	obj := sel.Obj().(*types.Func)       // the declared function
	sig := sel.Type().(*types.Signature) // type of this wrapper

	var recv *types.Var // wrapper's receiver or thunk's params[0]
	name := obj.Name()
	var description string
	var start int // first regular param
	if sel.Kind() == types.MethodExpr {
		name += "$thunk"
		description = "thunk"
		recv = sig.Params().At(0)
		start = 1
	} else {
		description = "wrapper"
		recv = sig.Recv()
	}

	description = fmt.Sprintf("%s for %s", description, sel.Obj())
	if prog.mode&LogSource != 0 {
		defer logStack("make %s to (%s)", description, recv.Type())()
	}
	fn := &Function{
		name:      name,
		method:    sel,
		object:    obj,
		Signature: sig,
		Synthetic: description,
		Prog:      prog,
		pos:       obj.Pos(),
	}
	fn.startBody()
	fn.addSpilledParam(recv)
	createParams(fn, start)

	indices := sel.Index()

	var v Value = fn.Locals[0] // spilled receiver
	if isPointer(sel.Recv()) {
		v = emitLoad(fn, v)

		// For simple indirection wrappers, perform an informative nil-check:
		// "value method (T).f called using nil *T pointer"
		if len(indices) == 1 && !isPointer(recvType(obj)) {
			var c Call
			c.Call.Value = &Builtin{
				name: "ssa:wrapnilchk",
				sig: types.NewSignature(nil,
					types.NewTuple(anonVar(sel.Recv()), anonVar(tString), anonVar(tString)),
					types.NewTuple(anonVar(sel.Recv())), false),
			}
			c.Call.Args = []Value{
				v,
				stringConst(deref(sel.Recv()).String()),
				stringConst(sel.Obj().Name()),
			}
			c.setType(v.Type())
			v = fn.emit(&c)
		}
	}

	// Invariant: v is a pointer, either
	//   value of *A receiver param, or
	// address of  A spilled receiver.

	// We use pointer arithmetic (FieldAddr possibly followed by
	// Load) in preference to value extraction (Field possibly
	// preceded by Load).

	v = emitImplicitSelections(fn, v, indices[:len(indices)-1])

	// Invariant: v is a pointer, either
	//   value of implicit *C field, or
	// address of implicit  C field.

	var c Call
	if r := recvType(obj); !isInterface(r) { // concrete method
		if !isPointer(r) {
			v = emitLoad(fn, v)
		}
		c.Call.Value = prog.declaredFunc(obj)
		c.Call.Args = append(c.Call.Args, v)
	} else {
		c.Call.Method = obj
		c.Call.Value = emitLoad(fn, v)
//.........这里部分代码省略.........

func Compile(importPath string, files []*ast.File, fileSet *token.FileSet, importContext *ImportContext, minify bool) (*Archive, error) {
	typesInfo := &types.Info{
		Types:      make(map[ast.Expr]types.TypeAndValue),
		Defs:       make(map[*ast.Ident]types.Object),
		Uses:       make(map[*ast.Ident]types.Object),
		Implicits:  make(map[ast.Node]types.Object),
		Selections: make(map[*ast.SelectorExpr]*types.Selection),
		Scopes:     make(map[ast.Node]*types.Scope),
	}

	var importError error
	var errList ErrorList
	var previousErr error
	config := &types.Config{
		Importer: packageImporter{
			importContext: importContext,
			importError:   &importError,
		},
		Sizes: sizes32,
		Error: func(err error) {
			if previousErr != nil && previousErr.Error() == err.Error() {
				return
			}
			errList = append(errList, err)
			previousErr = err
		},
	}
	typesPkg, err := config.Check(importPath, fileSet, files, typesInfo)
	if importError != nil {
		return nil, importError
	}
	if errList != nil {
		if len(errList) > 10 {
			pos := token.NoPos
			if last, ok := errList[9].(types.Error); ok {
				pos = last.Pos
			}
			errList = append(errList[:10], types.Error{Fset: fileSet, Pos: pos, Msg: "too many errors"})
		}
		return nil, errList
	}
	if err != nil {
		return nil, err
	}
	importContext.Packages[importPath] = typesPkg

	exportData := importer.ExportData(typesPkg)
	encodedFileSet := bytes.NewBuffer(nil)
	if err := fileSet.Write(json.NewEncoder(encodedFileSet).Encode); err != nil {
		return nil, err
	}

	isBlocking := func(f *types.Func) bool {
		archive, err := importContext.Import(f.Pkg().Path())
		if err != nil {
			panic(err)
		}
		fullName := f.FullName()
		for _, d := range archive.Declarations {
			if string(d.FullName) == fullName {
				return d.Blocking
			}
		}
		panic(fullName)
	}
	pkgInfo := analysis.AnalyzePkg(files, fileSet, typesInfo, typesPkg, isBlocking)
	c := &funcContext{
		FuncInfo: pkgInfo.InitFuncInfo,
		p: &pkgContext{
			Info:                 pkgInfo,
			additionalSelections: make(map[*ast.SelectorExpr]selection),

			pkgVars:      make(map[string]string),
			objectNames:  make(map[types.Object]string),
			varPtrNames:  make(map[*types.Var]string),
			escapingVars: make(map[*types.Var]bool),
			indentation:  1,
			dependencies: make(map[types.Object]bool),
			minify:       minify,
			fileSet:      fileSet,
		},
		allVars:     make(map[string]int),
		flowDatas:   map[*types.Label]*flowData{nil: {}},
		caseCounter: 1,
		labelCases:  make(map[*types.Label]int),
	}
	for name := range reservedKeywords {
		c.allVars[name] = 1
	}

	// imports
	var importDecls []*Decl
	var importedPaths []string
	for _, importedPkg := range typesPkg.Imports() {
		c.p.pkgVars[importedPkg.Path()] = c.newVariableWithLevel(importedPkg.Name(), true)
		importedPaths = append(importedPaths, importedPkg.Path())
	}
	sort.Strings(importedPaths)
	for _, impPath := range importedPaths {
		id := c.newIdent(fmt.Sprintf(`%s.$init`, c.p.pkgVars[impPath]), types.NewSignature(nil, nil, nil, false))
//.........这里部分代码省略.........