| // Copyright 2021 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package vta |
| |
| import ( |
| "go/ast" |
| "go/parser" |
| "io/ioutil" |
| "strings" |
| |
| "golang.org/x/tools/go/ssa/ssautil" |
| |
| "golang.org/x/tools/go/loader" |
| "golang.org/x/tools/go/ssa" |
| ) |
| |
| // want extracts the contents of the first comment |
| // section starting with "WANT:\n". The returned |
| // content is split into lines without // prefix. |
| func want(f *ast.File) []string { |
| for _, c := range f.Comments { |
| text := strings.TrimSpace(c.Text()) |
| if t := strings.TrimPrefix(text, "WANT:\n"); t != text { |
| return strings.Split(t, "\n") |
| } |
| } |
| return nil |
| } |
| |
| // testProg returns an ssa representation of a program at |
| // `path`, assumed to define package "testdata," and the |
| // test want result as list of strings. |
| func testProg(path string) (*ssa.Program, []string, error) { |
| content, err := ioutil.ReadFile(path) |
| if err != nil { |
| return nil, nil, err |
| } |
| |
| conf := loader.Config{ |
| ParserMode: parser.ParseComments, |
| } |
| |
| f, err := conf.ParseFile(path, content) |
| if err != nil { |
| return nil, nil, err |
| } |
| |
| conf.CreateFromFiles("testdata", f) |
| iprog, err := conf.Load() |
| if err != nil { |
| return nil, nil, err |
| } |
| |
| prog := ssautil.CreateProgram(iprog, 0) |
| // Set debug mode to exercise DebugRef instructions. |
| prog.Package(iprog.Created[0].Pkg).SetDebugMode(true) |
| prog.Build() |
| return prog, want(f), nil |
| } |
| |
| func firstRegInstr(f *ssa.Function) ssa.Value { |
| for _, b := range f.Blocks { |
| for _, i := range b.Instrs { |
| if v, ok := i.(ssa.Value); ok { |
| return v |
| } |
| } |
| } |
| return nil |
| } |
| |
| // funcName returns a name of the function `f` |
| // prefixed with the name of the receiver type. |
| func funcName(f *ssa.Function) string { |
| recv := f.Signature.Recv() |
| if recv == nil { |
| return f.Name() |
| } |
| tp := recv.Type().String() |
| return tp[strings.LastIndex(tp, ".")+1:] + "." + f.Name() |
| } |