| // Copyright 2013 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. |
| |
| //go:build !android && !ios && (unix || aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || plan9 || windows) |
| // +build !android |
| // +build !ios |
| // +build unix aix darwin dragonfly freebsd linux netbsd openbsd solaris plan9 windows |
| |
| package ssa_test |
| |
| import ( |
| "fmt" |
| "go/ast" |
| "go/importer" |
| "go/parser" |
| "go/token" |
| "go/types" |
| "log" |
| "os" |
| |
| "golang.org/x/tools/go/packages" |
| "golang.org/x/tools/go/ssa" |
| "golang.org/x/tools/go/ssa/ssautil" |
| ) |
| |
| const hello = ` |
| package main |
| |
| import "fmt" |
| |
| const message = "Hello, World!" |
| |
| func main() { |
| fmt.Println(message) |
| } |
| ` |
| |
| // This program demonstrates how to run the SSA builder on a single |
| // package of one or more already-parsed files. Its dependencies are |
| // loaded from compiler export data. This is what you'd typically use |
| // for a compiler; it does not depend on golang.org/x/tools/go/loader. |
| // |
| // It shows the printed representation of packages, functions, and |
| // instructions. Within the function listing, the name of each |
| // BasicBlock such as ".0.entry" is printed left-aligned, followed by |
| // the block's Instructions. |
| // |
| // For each instruction that defines an SSA virtual register |
| // (i.e. implements Value), the type of that value is shown in the |
| // right column. |
| // |
| // Build and run the ssadump.go program if you want a standalone tool |
| // with similar functionality. It is located at |
| // golang.org/x/tools/cmd/ssadump. |
| func Example_buildPackage() { |
| // Replace interface{} with any for this test. |
| ssa.SetNormalizeAnyForTesting(true) |
| defer ssa.SetNormalizeAnyForTesting(false) |
| // Parse the source files. |
| fset := token.NewFileSet() |
| f, err := parser.ParseFile(fset, "hello.go", hello, parser.ParseComments) |
| if err != nil { |
| fmt.Print(err) // parse error |
| return |
| } |
| files := []*ast.File{f} |
| |
| // Create the type-checker's package. |
| pkg := types.NewPackage("hello", "") |
| |
| // Type-check the package, load dependencies. |
| // Create and build the SSA program. |
| hello, _, err := ssautil.BuildPackage( |
| &types.Config{Importer: importer.Default()}, fset, pkg, files, ssa.SanityCheckFunctions) |
| if err != nil { |
| fmt.Print(err) // type error in some package |
| return |
| } |
| |
| // Print out the package. |
| hello.WriteTo(os.Stdout) |
| |
| // Print out the package-level functions. |
| hello.Func("init").WriteTo(os.Stdout) |
| hello.Func("main").WriteTo(os.Stdout) |
| |
| // Output: |
| // |
| // package hello: |
| // func init func() |
| // var init$guard bool |
| // func main func() |
| // const message message = "Hello, World!":untyped string |
| // |
| // # Name: hello.init |
| // # Package: hello |
| // # Synthetic: package initializer |
| // func init(): |
| // 0: entry P:0 S:2 |
| // t0 = *init$guard bool |
| // if t0 goto 2 else 1 |
| // 1: init.start P:1 S:1 |
| // *init$guard = true:bool |
| // t1 = fmt.init() () |
| // jump 2 |
| // 2: init.done P:2 S:0 |
| // return |
| // |
| // # Name: hello.main |
| // # Package: hello |
| // # Location: hello.go:8:6 |
| // func main(): |
| // 0: entry P:0 S:0 |
| // t0 = new [1]any (varargs) *[1]any |
| // t1 = &t0[0:int] *any |
| // t2 = make any <- string ("Hello, World!":string) any |
| // *t1 = t2 |
| // t3 = slice t0[:] []any |
| // t4 = fmt.Println(t3...) (n int, err error) |
| // return |
| } |
| |
| // This example builds SSA code for a set of packages using the |
| // x/tools/go/packages API. This is what you would typically use for a |
| // analysis capable of operating on a single package. |
| func Example_loadPackages() { |
| // Load, parse, and type-check the initial packages. |
| cfg := &packages.Config{Mode: packages.LoadSyntax} |
| initial, err := packages.Load(cfg, "fmt", "net/http") |
| if err != nil { |
| log.Fatal(err) |
| } |
| |
| // Stop if any package had errors. |
| // This step is optional; without it, the next step |
| // will create SSA for only a subset of packages. |
| if packages.PrintErrors(initial) > 0 { |
| log.Fatalf("packages contain errors") |
| } |
| |
| // Create SSA packages for all well-typed packages. |
| prog, pkgs := ssautil.Packages(initial, ssa.PrintPackages) |
| _ = prog |
| |
| // Build SSA code for the well-typed initial packages. |
| for _, p := range pkgs { |
| if p != nil { |
| p.Build() |
| } |
| } |
| } |
| |
| // This example builds SSA code for a set of packages plus all their dependencies, |
| // using the x/tools/go/packages API. |
| // This is what you'd typically use for a whole-program analysis. |
| func Example_loadWholeProgram() { |
| // Load, parse, and type-check the whole program. |
| cfg := packages.Config{Mode: packages.LoadAllSyntax} |
| initial, err := packages.Load(&cfg, "fmt", "net/http") |
| if err != nil { |
| log.Fatal(err) |
| } |
| |
| // Create SSA packages for well-typed packages and their dependencies. |
| prog, pkgs := ssautil.AllPackages(initial, ssa.PrintPackages|ssa.InstantiateGenerics) |
| _ = pkgs |
| |
| // Build SSA code for the whole program. |
| prog.Build() |
| } |