1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
// 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.
// +build go1.5
// 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/loader"
"golang.org/x/tools/go/ssa"
"golang.org/x/tools/go/ssa/interp"
"golang.org/x/tools/go/ssa/ssautil"
)
// flags
var (
mode = ssa.BuilderMode(0)
testFlag = flag.Bool("test", false, "Loads test code (*_test.go) for imported packages.")
runFlag = flag.Bool("run", false, "Invokes the SSA interpreter on the 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")
)
func init() {
flag.Var(&mode, "build", ssa.BuilderModeDoc)
flag.Var((*buildutil.TagsFlag)(&build.Default.BuildTags), "tags", buildutil.TagsFlagDoc)
}
const usage = `SSA builder and interpreter.
Usage: ssadump [<flag> ...] <args> ...
Use -help flag to display options.
Examples:
% ssadump -build=F hello.go # dump SSA form of a single package
% ssadump -run -interp=T hello.go # interpret a program, with tracing
% ssadump -run -test unicode -- -test.v # interpret the unicode package's tests, verbosely
` + loader.FromArgsUsage +
`
When -run is specified, ssadump will run the program.
The entry point depends on the -test flag:
if clear, it runs the first package named main.
if set, it runs the tests of each package.
`
func main() {
if err := doMain(); err != nil {
fmt.Fprintf(os.Stderr, "ssadump: %s\n", err)
os.Exit(1)
}
}
func doMain() error {
flag.Parse()
args := flag.Args()
conf := loader.Config{Build: &build.Default}
// Choose types.Sizes from conf.Build.
var wordSize int64 = 8
switch conf.Build.GOARCH {
case "386", "arm":
wordSize = 4
}
conf.TypeChecker.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)
}
}
if len(args) == 0 {
fmt.Fprint(os.Stderr, usage)
os.Exit(1)
}
// 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()
}
// Use the initial packages from the command line.
args, err := conf.FromArgs(args, *testFlag)
if err != nil {
return err
}
// The interpreter needs the runtime package.
if *runFlag {
conf.Import("runtime")
}
// Load, parse and type-check the whole program.
lprog, err := conf.Load()
if err != nil {
return err
}
// Create and build SSA-form program representation.
prog := ssautil.CreateProgram(lprog, mode)
// Build and display only the initial packages
// (and synthetic wrappers), unless -run is specified.
var initpkgs []*ssa.Package
for _, info := range lprog.InitialPackages() {
ssapkg := prog.Package(info.Pkg)
ssapkg.Build()
if info.Pkg.Path() != "runtime" {
initpkgs = append(initpkgs, ssapkg)
}
}
// Run the interpreter.
if *runFlag {
prog.Build()
var mains []*ssa.Package
if *testFlag {
// If -test, run the tests.
for _, pkg := range initpkgs {
if main := prog.CreateTestMainPackage(pkg); main != nil {
mains = append(mains, main)
}
}
if mains == nil {
return fmt.Errorf("no tests")
}
} else {
// Otherwise, run the main packages.
mains := ssautil.MainPackages(initpkgs)
if len(mains) == 0 {
return fmt.Errorf("no main package")
}
}
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)
}
for _, main := range mains {
if len(mains) > 1 {
fmt.Fprintf(os.Stderr, "Running: %s\n", main.Pkg.Path())
}
interp.Interpret(main, interpMode, conf.TypeChecker.Sizes, main.Pkg.Path(), args)
}
}
return nil
}
|
