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// 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
// This file implements the String() methods for all Value and
// Instruction types.
import (
"bytes"
"fmt"
"go/types"
"io"
"reflect"
"sort"
"golang.org/x/tools/go/types/typeutil"
)
// relName returns the name of v relative to i.
// In most cases, this is identical to v.Name(), but references to
// Functions (including methods) and Globals use RelString and
// all types are displayed with relType, so that only cross-package
// references are package-qualified.
//
func relName(v Value, i Instruction) string {
var from *types.Package
if i != nil {
from = i.Parent().pkg()
}
switch v := v.(type) {
case Member: // *Function or *Global
return v.RelString(from)
case *Const:
return v.RelString(from)
}
return v.Name()
}
func relType(t types.Type, from *types.Package) string {
return types.TypeString(t, types.RelativeTo(from))
}
func relString(m Member, from *types.Package) string {
// NB: not all globals have an Object (e.g. init$guard),
// so use Package().Object not Object.Package().
if pkg := m.Package().Pkg; pkg != nil && pkg != from {
return fmt.Sprintf("%s.%s", pkg.Path(), m.Name())
}
return m.Name()
}
// Value.String()
//
// This method is provided only for debugging.
// It never appears in disassembly, which uses Value.Name().
func (v *Parameter) String() string {
from := v.Parent().pkg()
return fmt.Sprintf("parameter %s : %s", v.Name(), relType(v.Type(), from))
}
func (v *FreeVar) String() string {
from := v.Parent().pkg()
return fmt.Sprintf("freevar %s : %s", v.Name(), relType(v.Type(), from))
}
func (v *Builtin) String() string {
return fmt.Sprintf("builtin %s", v.Name())
}
// Instruction.String()
func (v *Alloc) String() string {
op := "local"
if v.Heap {
op = "new"
}
from := v.Parent().pkg()
return fmt.Sprintf("%s %s (%s)", op, relType(deref(v.Type()), from), v.Comment)
}
func (v *Phi) String() string {
var b bytes.Buffer
b.WriteString("phi [")
for i, edge := range v.Edges {
if i > 0 {
b.WriteString(", ")
}
// Be robust against malformed CFG.
if v.block == nil {
b.WriteString("??")
continue
}
block := -1
if i < len(v.block.Preds) {
block = v.block.Preds[i].Index
}
fmt.Fprintf(&b, "%d: ", block)
edgeVal := "<nil>" // be robust
if edge != nil {
edgeVal = relName(edge, v)
}
b.WriteString(edgeVal)
}
b.WriteString("]")
if v.Comment != "" {
b.WriteString(" #")
b.WriteString(v.Comment)
}
return b.String()
}
func printCall(v *CallCommon, prefix string, instr Instruction) string {
var b bytes.Buffer
b.WriteString(prefix)
if !v.IsInvoke() {
b.WriteString(relName(v.Value, instr))
} else {
fmt.Fprintf(&b, "invoke %s.%s", relName(v.Value, instr), v.Method.Name())
}
b.WriteString("(")
for i, arg := range v.Args {
if i > 0 {
b.WriteString(", ")
}
b.WriteString(relName(arg, instr))
}
if v.Signature().Variadic() {
b.WriteString("...")
}
b.WriteString(")")
return b.String()
}
func (c *CallCommon) String() string {
return printCall(c, "", nil)
}
func (v *Call) String() string {
return printCall(&v.Call, "", v)
}
func (v *BinOp) String() string {
return fmt.Sprintf("%s %s %s", relName(v.X, v), v.Op.String(), relName(v.Y, v))
}
func (v *UnOp) String() string {
return fmt.Sprintf("%s%s%s", v.Op, relName(v.X, v), commaOk(v.CommaOk))
}
func printConv(prefix string, v, x Value) string {
from := v.Parent().pkg()
return fmt.Sprintf("%s %s <- %s (%s)",
prefix,
relType(v.Type(), from),
relType(x.Type(), from),
relName(x, v.(Instruction)))
}
func (v *ChangeType) String() string { return printConv("changetype", v, v.X) }
func (v *Convert) String() string { return printConv("convert", v, v.X) }
func (v *ChangeInterface) String() string { return printConv("change interface", v, v.X) }
func (v *MakeInterface) String() string { return printConv("make", v, v.X) }
func (v *MakeClosure) String() string {
var b bytes.Buffer
fmt.Fprintf(&b, "make closure %s", relName(v.Fn, v))
if v.Bindings != nil {
b.WriteString(" [")
for i, c := range v.Bindings {
if i > 0 {
b.WriteString(", ")
}
b.WriteString(relName(c, v))
}
b.WriteString("]")
}
return b.String()
}
func (v *MakeSlice) String() string {
from := v.Parent().pkg()
return fmt.Sprintf("make %s %s %s",
relType(v.Type(), from),
relName(v.Len, v),
relName(v.Cap, v))
}
func (v *Slice) String() string {
var b bytes.Buffer
b.WriteString("slice ")
b.WriteString(relName(v.X, v))
b.WriteString("[")
if v.Low != nil {
b.WriteString(relName(v.Low, v))
}
b.WriteString(":")
if v.High != nil {
b.WriteString(relName(v.High, v))
}
if v.Max != nil {
b.WriteString(":")
b.WriteString(relName(v.Max, v))
}
b.WriteString("]")
return b.String()
}
func (v *MakeMap) String() string {
res := ""
if v.Reserve != nil {
res = relName(v.Reserve, v)
}
from := v.Parent().pkg()
return fmt.Sprintf("make %s %s", relType(v.Type(), from), res)
}
func (v *MakeChan) String() string {
from := v.Parent().pkg()
return fmt.Sprintf("make %s %s", relType(v.Type(), from), relName(v.Size, v))
}
func (v *FieldAddr) String() string {
st := deref(v.X.Type()).Underlying().(*types.Struct)
// Be robust against a bad index.
name := "?"
if 0 <= v.Field && v.Field < st.NumFields() {
name = st.Field(v.Field).Name()
}
return fmt.Sprintf("&%s.%s [#%d]", relName(v.X, v), name, v.Field)
}
func (v *Field) String() string {
st := v.X.Type().Underlying().(*types.Struct)
// Be robust against a bad index.
name := "?"
if 0 <= v.Field && v.Field < st.NumFields() {
name = st.Field(v.Field).Name()
}
return fmt.Sprintf("%s.%s [#%d]", relName(v.X, v), name, v.Field)
}
func (v *IndexAddr) String() string {
return fmt.Sprintf("&%s[%s]", relName(v.X, v), relName(v.Index, v))
}
func (v *Index) String() string {
return fmt.Sprintf("%s[%s]", relName(v.X, v), relName(v.Index, v))
}
func (v *Lookup) String() string {
return fmt.Sprintf("%s[%s]%s", relName(v.X, v), relName(v.Index, v), commaOk(v.CommaOk))
}
func (v *Range) String() string {
return "range " + relName(v.X, v)
}
func (v *Next) String() string {
return "next " + relName(v.Iter, v)
}
func (v *TypeAssert) String() string {
from := v.Parent().pkg()
return fmt.Sprintf("typeassert%s %s.(%s)", commaOk(v.CommaOk), relName(v.X, v), relType(v.AssertedType, from))
}
func (v *Extract) String() string {
return fmt.Sprintf("extract %s #%d", relName(v.Tuple, v), v.Index)
}
func (s *Jump) String() string {
// Be robust against malformed CFG.
block := -1
if s.block != nil && len(s.block.Succs) == 1 {
block = s.block.Succs[0].Index
}
return fmt.Sprintf("jump %d", block)
}
func (s *If) String() string {
// Be robust against malformed CFG.
tblock, fblock := -1, -1
if s.block != nil && len(s.block.Succs) == 2 {
tblock = s.block.Succs[0].Index
fblock = s.block.Succs[1].Index
}
return fmt.Sprintf("if %s goto %d else %d", relName(s.Cond, s), tblock, fblock)
}
func (s *Go) String() string {
return printCall(&s.Call, "go ", s)
}
func (s *Panic) String() string {
return "panic " + relName(s.X, s)
}
func (s *Return) String() string {
var b bytes.Buffer
b.WriteString("return")
for i, r := range s.Results {
if i == 0 {
b.WriteString(" ")
} else {
b.WriteString(", ")
}
b.WriteString(relName(r, s))
}
return b.String()
}
func (*RunDefers) String() string {
return "rundefers"
}
func (s *Send) String() string {
return fmt.Sprintf("send %s <- %s", relName(s.Chan, s), relName(s.X, s))
}
func (s *Defer) String() string {
return printCall(&s.Call, "defer ", s)
}
func (s *Select) String() string {
var b bytes.Buffer
for i, st := range s.States {
if i > 0 {
b.WriteString(", ")
}
if st.Dir == types.RecvOnly {
b.WriteString("<-")
b.WriteString(relName(st.Chan, s))
} else {
b.WriteString(relName(st.Chan, s))
b.WriteString("<-")
b.WriteString(relName(st.Send, s))
}
}
non := ""
if !s.Blocking {
non = "non"
}
return fmt.Sprintf("select %sblocking [%s]", non, b.String())
}
func (s *Store) String() string {
return fmt.Sprintf("*%s = %s", relName(s.Addr, s), relName(s.Val, s))
}
func (s *MapUpdate) String() string {
return fmt.Sprintf("%s[%s] = %s", relName(s.Map, s), relName(s.Key, s), relName(s.Value, s))
}
func (s *DebugRef) String() string {
p := s.Parent().Prog.Fset.Position(s.Pos())
var descr interface{}
if s.object != nil {
descr = s.object // e.g. "var x int"
} else {
descr = reflect.TypeOf(s.Expr) // e.g. "*ast.CallExpr"
}
var addr string
if s.IsAddr {
addr = "address of "
}
return fmt.Sprintf("; %s%s @ %d:%d is %s", addr, descr, p.Line, p.Column, s.X.Name())
}
func (p *Package) String() string {
return "package " + p.Pkg.Path()
}
var _ io.WriterTo = (*Package)(nil) // *Package implements io.Writer
func (p *Package) WriteTo(w io.Writer) (int64, error) {
var buf bytes.Buffer
WritePackage(&buf, p)
n, err := w.Write(buf.Bytes())
return int64(n), err
}
// WritePackage writes to buf a human-readable summary of p.
func WritePackage(buf *bytes.Buffer, p *Package) {
fmt.Fprintf(buf, "%s:\n", p)
var names []string
maxname := 0
for name := range p.Members {
if l := len(name); l > maxname {
maxname = l
}
names = append(names, name)
}
from := p.Pkg
sort.Strings(names)
for _, name := range names {
switch mem := p.Members[name].(type) {
case *NamedConst:
fmt.Fprintf(buf, " const %-*s %s = %s\n",
maxname, name, mem.Name(), mem.Value.RelString(from))
case *Function:
fmt.Fprintf(buf, " func %-*s %s\n",
maxname, name, relType(mem.Type(), from))
case *Type:
fmt.Fprintf(buf, " type %-*s %s\n",
maxname, name, relType(mem.Type().Underlying(), from))
for _, meth := range typeutil.IntuitiveMethodSet(mem.Type(), &p.Prog.MethodSets) {
fmt.Fprintf(buf, " %s\n", types.SelectionString(meth, types.RelativeTo(from)))
}
case *Global:
fmt.Fprintf(buf, " var %-*s %s\n",
maxname, name, relType(mem.Type().(*types.Pointer).Elem(), from))
}
}
fmt.Fprintf(buf, "\n")
}
func commaOk(x bool) string {
if x {
return ",ok"
}
return ""
}