--- /dev/null
+// 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.
+
+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() {
+ // 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]interface{} (varargs) *[1]interface{}
+ // t1 = &t0[0:int] *interface{}
+ // t2 = make interface{} <- string ("Hello, World!":string) interface{}
+ // *t1 = t2
+ // t3 = slice t0[:] []interface{}
+ // 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)
+ _ = pkgs
+
+ // Build SSA code for the whole program.
+ prog.Build()
+}
projects / dotfiles / .git / blobdiff