src

print.go (11055B)

---

 // 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"
 	"strings"
 
 	"golang.org/x/tools/go/types/typeutil"
 	"golang.org/x/tools/internal/typeparams"
 )
 
 // 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().relPkg()
 	}
 	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 relTerm(term *types.Term, from *types.Package) string {
 	s := relType(term.Type(), from)
 	if term.Tilde() {
 		return "~" + s
 	}
 	return s
 }
 
 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().relPkg()
 	return fmt.Sprintf("parameter %s : %s", v.Name(), relType(v.Type(), from))
 }
 
 func (v *FreeVar) String() string {
 	from := v.Parent().relPkg()
 	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().relPkg()
 	return fmt.Sprintf("%s %s (%s)", op, relType(typeparams.MustDeref(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().relPkg()
 	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 *SliceToArrayPointer) String() string { return printConv("slice to array pointer", v, v.X) }
 func (v *MakeInterface) String() string       { return printConv("make", v, v.X) }
 
 func (v *MultiConvert) String() string {
 	from := v.Parent().relPkg()
 
 	var b strings.Builder
 	b.WriteString(printConv("multiconvert", v, v.X))
 	b.WriteString(" [")
 	for i, s := range termListOf(v.from) {
 		for j, d := range termListOf(v.to) {
 			if i != 0 || j != 0 {
 				b.WriteString(" | ")
 			}
 			fmt.Fprintf(&b, "%s <- %s", relTerm(d, from), relTerm(s, from))
 		}
 	}
 	b.WriteString("]")
 	return b.String()
 }
 
 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().relPkg()
 	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().relPkg()
 	return fmt.Sprintf("make %s %s", relType(v.Type(), from), res)
 }
 
 func (v *MakeChan) String() string {
 	from := v.Parent().relPkg()
 	return fmt.Sprintf("make %s %s", relType(v.Type(), from), relName(v.Size, v))
 }
 
 func (v *FieldAddr) String() string {
 	// Be robust against a bad index.
 	name := "?"
 	if fld := fieldOf(typeparams.MustDeref(v.X.Type()), v.Field); fld != nil {
 		name = fld.Name()
 	}
 	return fmt.Sprintf("&%s.%s [#%d]", relName(v.X, v), name, v.Field)
 }
 
 func (v *Field) String() string {
 	// Be robust against a bad index.
 	name := "?"
 	if fld := fieldOf(v.X.Type(), v.Field); fld != nil {
 		name = fld.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().relPkg()
 	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 {
 	prefix := "defer "
 	if s.DeferStack != nil {
 		prefix += "[" + relName(s.DeferStack, s) + "] "
 	}
 	c := printCall(&s.Call, prefix, s)
 	return c
 }
 
 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 any
 	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(typeparams.MustDeref(mem.Type()), from))
 		}
 	}
 
 	fmt.Fprintf(buf, "\n")
 }
 
 func commaOk(x bool) string {
 	if x {
 		return ",ok"
 	}
 	return ""
 }