move out c/cpp/py

chore/ssadump/ssadump.go

@@ -0,0 +1,201 @@
+// 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.
+
+// ssadump: a tool for displaying and interpreting the SSA form of Go programs.
+package main // import "golang.org/x/tools/cmd/ssadump"
+
+import (
+	"flag"
+	"fmt"
+	"go/build"
+	"go/types"
+	"os"
+	"runtime"
+	"runtime/pprof"
+
+	"golang.org/x/tools/go/buildutil"
+	"golang.org/x/tools/go/packages"
+	"golang.org/x/tools/go/ssa"
+	"golang.org/x/tools/go/ssa/interp"
+	"golang.org/x/tools/go/ssa/ssautil"
+)
+
+const (
+	loadFiles   = packages.NeedName | packages.NeedFiles | packages.NeedCompiledGoFiles
+	loadImports = loadFiles | packages.NeedImports
+	loadTypes   = loadImports | packages.NeedTypes | packages.NeedTypesSizes
+	loadSyntax  = loadTypes | packages.NeedSyntax | packages.NeedTypesInfo
+)
+
+// flags
+var (
+	mode = ssa.BuilderMode(0)
+
+	testFlag = flag.Bool("test", false, "include implicit test packages and executables")
+
+	runFlag = flag.Bool("run", false, "interpret the SSA program")
+
+	interpFlag = flag.String("interp", "", `Options controlling the SSA test interpreter.
+The value is a sequence of zero or more more of these letters:
+R	disable [R]ecover() from panic; show interpreter crash instead.
+T	[T]race execution of the program.  Best for single-threaded programs!
+`)
+
+	cpuprofile = flag.String("cpuprofile", "", "write cpu profile to file")
+
+	args stringListValue
+)
+
+func init() {
+	flag.Var(&mode, "build", ssa.BuilderModeDoc)
+	flag.Var((*buildutil.TagsFlag)(&build.Default.BuildTags), "tags", buildutil.TagsFlagDoc)
+	flag.Var(&args, "arg", "add argument to interpreted program")
+}
+
+const usage = `SSA builder and interpreter.
+Usage: ssadump [-build=[DBCSNFLG]] [-test] [-run] [-interp=[TR]] [-arg=...] package...
+Use -help flag to display options.
+
+Examples:
+% ssadump -build=F hello.go              # dump SSA form of a single package
+% ssadump -build=F -test fmt             # dump SSA form of a package and its tests
+% ssadump -run -interp=T hello.go        # interpret a program, with tracing
+
+The -run flag causes ssadump to build the code in a runnable form and run the first
+package named main.
+
+Interpretation of the standard "testing" package is no longer supported.
+`
+
+func main() {
+	if err := doMain(); err != nil {
+		fmt.Fprintf(os.Stderr, "ssadump: %s\n", err)
+		os.Exit(1)
+	}
+}
+
+func doMain() error {
+	flag.Parse()
+	if len(flag.Args()) == 0 {
+		fmt.Fprint(os.Stderr, usage)
+		os.Exit(1)
+	}
+
+	cfg := &packages.Config{
+		Mode:  loadSyntax,
+		Tests: *testFlag,
+	}
+
+	// Choose types.Sizes from conf.Build.
+	// TODO(adonovan): remove this when go/packages provides a better way.
+	var wordSize int64 = 8
+	switch build.Default.GOARCH {
+	case "386", "arm":
+		wordSize = 4
+	}
+	sizes := &types.StdSizes{
+		MaxAlign: 8,
+		WordSize: wordSize,
+	}
+
+	var interpMode interp.Mode
+	for _, c := range *interpFlag {
+		switch c {
+		case 'T':
+			interpMode |= interp.EnableTracing
+		case 'R':
+			interpMode |= interp.DisableRecover
+		default:
+			return fmt.Errorf("unknown -interp option: '%c'", c)
+		}
+	}
+
+	// Profiling support.
+	if *cpuprofile != "" {
+		f, err := os.Create(*cpuprofile)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
+		pprof.StartCPUProfile(f)
+		defer pprof.StopCPUProfile()
+	}
+
+	// Load, parse and type-check the initial packages,
+	// and, if -run, their dependencies.
+	if *runFlag {
+		cfg.Mode = loadSyntax | packages.NeedDeps
+	}
+	initial, err := packages.Load(cfg, flag.Args()...)
+	if err != nil {
+		return err
+	}
+	if len(initial) == 0 {
+		return fmt.Errorf("no packages")
+	}
+	if packages.PrintErrors(initial) > 0 {
+		return fmt.Errorf("packages contain errors")
+	}
+
+	// Turn on instantiating generics during build if the program will be run.
+	if *runFlag {
+		mode |= ssa.InstantiateGenerics
+	}
+
+	// Create SSA-form program representation.
+	prog, pkgs := ssautil.AllPackages(initial, mode)
+
+	for i, p := range pkgs {
+		if p == nil {
+			return fmt.Errorf("cannot build SSA for package %s", initial[i].ID)
+		}
+	}
+
+	if !*runFlag {
+		// Build and display only the initial packages
+		// (and synthetic wrappers).
+		for _, p := range pkgs {
+			p.Build()
+		}
+
+	} else {
+		// Run the interpreter.
+		// Build SSA for all packages.
+		prog.Build()
+
+		// Earlier versions of the interpreter needed the runtime
+		// package; however, interp cannot handle unsafe constructs
+		// used during runtime's package initialization at the moment.
+		// The key construct blocking support is:
+		//    *((*T)(unsafe.Pointer(p)))
+		// Unfortunately, this means only trivial programs can be
+		// interpreted by ssadump.
+		if prog.ImportedPackage("runtime") != nil {
+			return fmt.Errorf("-run: program depends on runtime package (interpreter can run only trivial programs)")
+		}
+
+		if runtime.GOARCH != build.Default.GOARCH {
+			return fmt.Errorf("cross-interpretation is not supported (target has GOARCH %s, interpreter has %s)",
+				build.Default.GOARCH, runtime.GOARCH)
+		}
+
+		// Run first main package.
+		for _, main := range ssautil.MainPackages(pkgs) {
+			fmt.Fprintf(os.Stderr, "Running: %s\n", main.Pkg.Path())
+			os.Exit(interp.Interpret(main, interpMode, sizes, main.Pkg.Path(), args))
+		}
+		return fmt.Errorf("no main package")
+	}
+	return nil
+}
+
+// stringListValue is a flag.Value that accumulates strings.
+// e.g. --flag=one --flag=two would produce []string{"one", "two"}.
+type stringListValue []string
+
+func (ss *stringListValue) Get() interface{} { return []string(*ss) }
+
+func (ss *stringListValue) String() string { return fmt.Sprintf("%q", *ss) }
+
+func (ss *stringListValue) Set(s string) error { *ss = append(*ss, s); return nil }