go fmt 源码
golang fmt 代码
文件路径：/src/cmd/compile/internal/ir/fmt.go
// Copyright 2011 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 ir
import (
"bytes"
"fmt"
"go/constant"
"io"
"math"
"os"
"path/filepath"
"reflect"
"strings"
"unicode/utf8"
"cmd/compile/internal/base"
"cmd/compile/internal/types"
"cmd/internal/src"
)
// Op
var OpNames = []string{
OADDR: "&",
OADD: "+",
OADDSTR: "+",
OALIGNOF: "unsafe.Alignof",
OANDAND: "&&",
OANDNOT: "&^",
OAND: "&",
OAPPEND: "append",
OAS: "=",
OAS2: "=",
OBREAK: "break",
OCALL: "function call", // not actual syntax
OCAP: "cap",
OCASE: "case",
OCLOSE: "close",
OCOMPLEX: "complex",
OBITNOT: "^",
OCONTINUE: "continue",
OCOPY: "copy",
ODELETE: "delete",
ODEFER: "defer",
ODIV: "/",
OEQ: "==",
OFALL: "fallthrough",
OFOR: "for",
OFORUNTIL: "foruntil", // not actual syntax; used to avoid off-end pointer live on backedge.892
OGE: ">=",
OGOTO: "goto",
OGT: ">",
OIF: "if",
OIMAG: "imag",
OINLMARK: "inlmark",
ODEREF: "*",
OLEN: "len",
OLE: "<=",
OLSH: "<<",
OLT: "<",
OMAKE: "make",
ONEG: "-",
OMOD: "%",
OMUL: "*",
ONEW: "new",
ONE: "!=",
ONOT: "!",
OOFFSETOF: "unsafe.Offsetof",
OOROR: "||",
OOR: "|",
OPANIC: "panic",
OPLUS: "+",
OPRINTN: "println",
OPRINT: "print",
ORANGE: "range",
OREAL: "real",
ORECV: "<-",
ORECOVER: "recover",
ORETURN: "return",
ORSH: ">>",
OSELECT: "select",
OSEND: "<-",
OSIZEOF: "unsafe.Sizeof",
OSUB: "-",
OSWITCH: "switch",
OUNSAFEADD: "unsafe.Add",
OUNSAFESLICE: "unsafe.Slice",
OXOR: "^",
}
// GoString returns the Go syntax for the Op, or else its name.
func (o Op) GoString() string {
if int(o) < len(OpNames) && OpNames[o] != "" {
return OpNames[o]
}
return o.String()
}
// Format implements formatting for an Op.
// The valid formats are:
//
// %v Go syntax ("+", "<-", "print")
// %+v Debug syntax ("ADD", "RECV", "PRINT")
func (o Op) Format(s fmt.State, verb rune) {
switch verb {
default:
fmt.Fprintf(s, "%%!%c(Op=%d)", verb, int(o))
case 'v':
if s.Flag('+') {
// %+v is OMUL instead of "*"
io.WriteString(s, o.String())
return
}
io.WriteString(s, o.GoString())
}
}
// Node
// FmtNode implements formatting for a Node n.
// Every Node implementation must define a Format method that calls FmtNode.
// The valid formats are:
//
// %v Go syntax
// %L Go syntax followed by " (type T)" if type is known.
// %+v Debug syntax, as in Dump.
func fmtNode(n Node, s fmt.State, verb rune) {
// %+v prints Dump.
// Otherwise we print Go syntax.
if s.Flag('+') && verb == 'v' {
dumpNode(s, n, 1)
return
}
if verb != 'v' && verb != 'S' && verb != 'L' {
fmt.Fprintf(s, "%%!%c(*Node=%p)", verb, n)
return
}
if n == nil {
fmt.Fprint(s, "<nil>")
return
}
t := n.Type()
if verb == 'L' && t != nil {
if t.Kind() == types.TNIL {
fmt.Fprint(s, "nil")
} else if n.Op() == ONAME && n.Name().AutoTemp() {
fmt.Fprintf(s, "%v value", t)
} else {
fmt.Fprintf(s, "%v (type %v)", n, t)
}
return
}
// TODO inlining produces expressions with ninits. we can't print these yet.
if OpPrec[n.Op()] < 0 {
stmtFmt(n, s)
return
}
exprFmt(n, s, 0)
}
var OpPrec = []int{
OALIGNOF: 8,
OAPPEND: 8,
OBYTES2STR: 8,
OARRAYLIT: 8,
OSLICELIT: 8,
ORUNES2STR: 8,
OCALLFUNC: 8,
OCALLINTER: 8,
OCALLMETH: 8,
OCALL: 8,
OCAP: 8,
OCLOSE: 8,
OCOMPLIT: 8,
OCONVIFACE: 8,
OCONVIDATA: 8,
OCONVNOP: 8,
OCONV: 8,
OCOPY: 8,
ODELETE: 8,
OGETG: 8,
OLEN: 8,
OLITERAL: 8,
OMAKESLICE: 8,
OMAKESLICECOPY: 8,
OMAKE: 8,
OMAPLIT: 8,
ONAME: 8,
ONEW: 8,
ONIL: 8,
ONONAME: 8,
OOFFSETOF: 8,
OPANIC: 8,
OPAREN: 8,
OPRINTN: 8,
OPRINT: 8,
ORUNESTR: 8,
OSIZEOF: 8,
OSLICE2ARRPTR: 8,
OSTR2BYTES: 8,
OSTR2RUNES: 8,
OSTRUCTLIT: 8,
OTYPE: 8,
OUNSAFEADD: 8,
OUNSAFESLICE: 8,
OINDEXMAP: 8,
OINDEX: 8,
OSLICE: 8,
OSLICESTR: 8,
OSLICEARR: 8,
OSLICE3: 8,
OSLICE3ARR: 8,
OSLICEHEADER: 8,
ODOTINTER: 8,
ODOTMETH: 8,
ODOTPTR: 8,
ODOTTYPE2: 8,
ODOTTYPE: 8,
ODOT: 8,
OXDOT: 8,
OMETHVALUE: 8,
OMETHEXPR: 8,
OPLUS: 7,
ONOT: 7,
OBITNOT: 7,
ONEG: 7,
OADDR: 7,
ODEREF: 7,
ORECV: 7,
OMUL: 6,
ODIV: 6,
OMOD: 6,
OLSH: 6,
ORSH: 6,
OAND: 6,
OANDNOT: 6,
OADD: 5,
OSUB: 5,
OOR: 5,
OXOR: 5,
OEQ: 4,
OLT: 4,
OLE: 4,
OGE: 4,
OGT: 4,
ONE: 4,
OSEND: 3,
OANDAND: 2,
OOROR: 1,
// Statements handled by stmtfmt
OAS: -1,
OAS2: -1,
OAS2DOTTYPE: -1,
OAS2FUNC: -1,
OAS2MAPR: -1,
OAS2RECV: -1,
OASOP: -1,
OBLOCK: -1,
OBREAK: -1,
OCASE: -1,
OCONTINUE: -1,
ODCL: -1,
ODEFER: -1,
OFALL: -1,
OFOR: -1,
OFORUNTIL: -1,
OGOTO: -1,
OIF: -1,
OLABEL: -1,
OGO: -1,
ORANGE: -1,
ORETURN: -1,
OSELECT: -1,
OSWITCH: -1,
OEND: 0,
}
// StmtWithInit reports whether op is a statement with an explicit init list.
func StmtWithInit(op Op) bool {
switch op {
case OIF, OFOR, OFORUNTIL, OSWITCH:
return true
}
return false
}
func stmtFmt(n Node, s fmt.State) {
// NOTE(rsc): This code used to support the text-based
// which was more aggressive about printing full Go syntax
// (for example, an actual loop instead of "for loop").
// The code is preserved for now in case we want to expand
// any of those shortenings later. Or maybe we will delete
// the code. But for now, keep it.
const exportFormat = false
// some statements allow for an init, but at most one,
// but we may have an arbitrary number added, eg by typecheck
// and inlining. If it doesn't fit the syntax, emit an enclosing
// block starting with the init statements.
// if we can just say "for" n->ninit; ... then do so
simpleinit := len(n.Init()) == 1 && len(n.Init()[0].Init()) == 0 && StmtWithInit(n.Op())
// otherwise, print the inits as separate statements
complexinit := len(n.Init()) != 0 && !simpleinit && exportFormat
// but if it was for if/for/switch, put in an extra surrounding block to limit the scope
extrablock := complexinit && StmtWithInit(n.Op())
if extrablock {
fmt.Fprint(s, "{")
}
if complexinit {
fmt.Fprintf(s, " %v; ", n.Init())
}
switch n.Op() {
case ODCL:
n := n.(*Decl)
fmt.Fprintf(s, "var %v %v", n.X.Sym(), n.X.Type())
// Don't export "v = <N>" initializing statements, hope they're always
// preceded by the DCL which will be re-parsed and typechecked to reproduce
// the "v = <N>" again.
case OAS:
n := n.(*AssignStmt)
if n.Def && !complexinit {
fmt.Fprintf(s, "%v := %v", n.X, n.Y)
} else {
fmt.Fprintf(s, "%v = %v", n.X, n.Y)
}
case OASOP:
n := n.(*AssignOpStmt)
if n.IncDec {
if n.AsOp == OADD {
fmt.Fprintf(s, "%v++", n.X)
} else {
fmt.Fprintf(s, "%v--", n.X)
}
break
}
fmt.Fprintf(s, "%v %v= %v", n.X, n.AsOp, n.Y)
case OAS2, OAS2DOTTYPE, OAS2FUNC, OAS2MAPR, OAS2RECV:
n := n.(*AssignListStmt)
if n.Def && !complexinit {
fmt.Fprintf(s, "%.v := %.v", n.Lhs, n.Rhs)
} else {
fmt.Fprintf(s, "%.v = %.v", n.Lhs, n.Rhs)
}
case OBLOCK:
n := n.(*BlockStmt)
if len(n.List) != 0 {
fmt.Fprintf(s, "%v", n.List)
}
case ORETURN:
n := n.(*ReturnStmt)
fmt.Fprintf(s, "return %.v", n.Results)
case OTAILCALL:
n := n.(*TailCallStmt)
fmt.Fprintf(s, "tailcall %v", n.Call)
case OINLMARK:
n := n.(*InlineMarkStmt)
fmt.Fprintf(s, "inlmark %d", n.Index)
case OGO:
n := n.(*GoDeferStmt)
fmt.Fprintf(s, "go %v", n.Call)
case ODEFER:
n := n.(*GoDeferStmt)
fmt.Fprintf(s, "defer %v", n.Call)
case OIF:
n := n.(*IfStmt)
if simpleinit {
fmt.Fprintf(s, "if %v; %v { %v }", n.Init()[0], n.Cond, n.Body)
} else {
fmt.Fprintf(s, "if %v { %v }", n.Cond, n.Body)
}
if len(n.Else) != 0 {
fmt.Fprintf(s, " else { %v }", n.Else)
}
case OFOR, OFORUNTIL:
n := n.(*ForStmt)
opname := "for"
if n.Op() == OFORUNTIL {
opname = "foruntil"
}
if !exportFormat { // TODO maybe only if FmtShort, same below
fmt.Fprintf(s, "%s loop", opname)
break
}
fmt.Fprint(s, opname)
if simpleinit {
fmt.Fprintf(s, " %v;", n.Init()[0])
} else if n.Post != nil {
fmt.Fprint(s, " ;")
}
if n.Cond != nil {
fmt.Fprintf(s, " %v", n.Cond)
}
if n.Post != nil {
fmt.Fprintf(s, "; %v", n.Post)
} else if simpleinit {
fmt.Fprint(s, ";")
}
if n.Op() == OFORUNTIL && len(n.Late) != 0 {
fmt.Fprintf(s, "; %v", n.Late)
}
fmt.Fprintf(s, " { %v }", n.Body)
case ORANGE:
n := n.(*RangeStmt)
if !exportFormat {
fmt.Fprint(s, "for loop")
break
}
fmt.Fprint(s, "for")
if n.Key != nil {
fmt.Fprintf(s, " %v", n.Key)
if n.Value != nil {
fmt.Fprintf(s, ", %v", n.Value)
}
fmt.Fprint(s, " =")
}
fmt.Fprintf(s, " range %v { %v }", n.X, n.Body)
case OSELECT:
n := n.(*SelectStmt)
if !exportFormat {
fmt.Fprintf(s, "%v statement", n.Op())
break
}
fmt.Fprintf(s, "select { %v }", n.Cases)
case OSWITCH:
n := n.(*SwitchStmt)
if !exportFormat {
fmt.Fprintf(s, "%v statement", n.Op())
break
}
fmt.Fprintf(s, "switch")
if simpleinit {
fmt.Fprintf(s, " %v;", n.Init()[0])
}
if n.Tag != nil {
fmt.Fprintf(s, " %v ", n.Tag)
}
fmt.Fprintf(s, " { %v }", n.Cases)
case OCASE:
n := n.(*CaseClause)
if len(n.List) != 0 {
fmt.Fprintf(s, "case %.v", n.List)
} else {
fmt.Fprint(s, "default")
}
fmt.Fprintf(s, ": %v", n.Body)
case OBREAK, OCONTINUE, OGOTO, OFALL:
n := n.(*BranchStmt)
if n.Label != nil {
fmt.Fprintf(s, "%v %v", n.Op(), n.Label)
} else {
fmt.Fprintf(s, "%v", n.Op())
}
case OLABEL:
n := n.(*LabelStmt)
fmt.Fprintf(s, "%v: ", n.Label)
}
if extrablock {
fmt.Fprint(s, "}")
}
}
func exprFmt(n Node, s fmt.State, prec int) {
// NOTE(rsc): This code used to support the text-based
// which was more aggressive about printing full Go syntax
// (for example, an actual loop instead of "for loop").
// The code is preserved for now in case we want to expand
// any of those shortenings later. Or maybe we will delete
// the code. But for now, keep it.
const exportFormat = false
for {
if n == nil {
fmt.Fprint(s, "<nil>")
return
}
// We always want the original, if any.
if o := Orig(n); o != n {
n = o
continue
}
// Skip implicit operations introduced during typechecking.
switch nn := n; nn.Op() {
case OADDR:
nn := nn.(*AddrExpr)
if nn.Implicit() {
n = nn.X
continue
}
case ODEREF:
nn := nn.(*StarExpr)
if nn.Implicit() {
n = nn.X
continue
}
case OCONV, OCONVNOP, OCONVIFACE, OCONVIDATA:
nn := nn.(*ConvExpr)
if nn.Implicit() {
n = nn.X
continue
}
}
break
}
nprec := OpPrec[n.Op()]
if n.Op() == OTYPE && n.Type() != nil && n.Type().IsPtr() {
nprec = OpPrec[ODEREF]
}
if prec > nprec {
fmt.Fprintf(s, "(%v)", n)
return
}
if n, ok := n.(*RawOrigExpr); ok {
fmt.Fprint(s, n.Raw)
return
}
switch n.Op() {
case OPAREN:
n := n.(*ParenExpr)
fmt.Fprintf(s, "(%v)", n.X)
case ONIL:
fmt.Fprint(s, "nil")
case OLITERAL: // this is a bit of a mess
if !exportFormat && n.Sym() != nil {
fmt.Fprint(s, n.Sym())
return
}
needUnparen := false
if n.Type() != nil && !n.Type().IsUntyped() {
// Need parens when type begins with what might
// be misinterpreted as a unary operator: * or <-.
if n.Type().IsPtr() || (n.Type().IsChan() && n.Type().ChanDir() == types.Crecv) {
fmt.Fprintf(s, "(%v)(", n.Type())
} else {
fmt.Fprintf(s, "%v(", n.Type())
}
needUnparen = true
}
if n.Type() == types.UntypedRune {
switch x, ok := constant.Uint64Val(n.Val()); {
case !ok:
fallthrough
default:
fmt.Fprintf(s, "('\\x00' + %v)", n.Val())
case x < utf8.RuneSelf:
fmt.Fprintf(s, "%q", x)
case x < 1<<16:
fmt.Fprintf(s, "'\\u%04x'", x)
case x <= utf8.MaxRune:
fmt.Fprintf(s, "'\\U%08x'", x)
}
} else {
fmt.Fprint(s, types.FmtConst(n.Val(), s.Flag('#')))
}
if needUnparen {
fmt.Fprintf(s, ")")
}
case ODCLFUNC:
n := n.(*Func)
if sym := n.Sym(); sym != nil {
fmt.Fprint(s, sym)
return
}
fmt.Fprintf(s, "<unnamed Func>")
case ONAME:
n := n.(*Name)
// Special case: name used as local variable in export.
// _ becomes ~b%d internally; print as _ for export
if !exportFormat && n.Sym() != nil && n.Sym().Name[0] == '~' && n.Sym().Name[1] == 'b' {
fmt.Fprint(s, "_")
return
}
fallthrough
case ONONAME:
fmt.Fprint(s, n.Sym())
case OLINKSYMOFFSET:
n := n.(*LinksymOffsetExpr)
fmt.Fprintf(s, "(%v)(%s@%d)", n.Type(), n.Linksym.Name, n.Offset_)
case OTYPE:
if n.Type() == nil && n.Sym() != nil {
fmt.Fprint(s, n.Sym())
return
}
fmt.Fprintf(s, "%v", n.Type())
case OCLOSURE:
n := n.(*ClosureExpr)
if !exportFormat {
fmt.Fprint(s, "func literal")
return
}
fmt.Fprintf(s, "%v { %v }", n.Type(), n.Func.Body)
case OCOMPLIT:
n := n.(*CompLitExpr)
if !exportFormat {
if n.Implicit() {
fmt.Fprintf(s, "... argument")
return
}
if typ := n.Type(); typ != nil {
fmt.Fprintf(s, "%v{%s}", typ, ellipsisIf(len(n.List) != 0))
return
}
fmt.Fprint(s, "composite literal")
return
}
fmt.Fprintf(s, "(%v{ %.v })", n.Type(), n.List)
case OPTRLIT:
n := n.(*AddrExpr)
fmt.Fprintf(s, "&%v", n.X)
case OSTRUCTLIT, OARRAYLIT, OSLICELIT, OMAPLIT:
n := n.(*CompLitExpr)
if !exportFormat {
fmt.Fprintf(s, "%v{%s}", n.Type(), ellipsisIf(len(n.List) != 0))
return
}
fmt.Fprintf(s, "(%v{ %.v })", n.Type(), n.List)
case OKEY:
n := n.(*KeyExpr)
if n.Key != nil && n.Value != nil {
fmt.Fprintf(s, "%v:%v", n.Key, n.Value)
return
}
if n.Key == nil && n.Value != nil {
fmt.Fprintf(s, ":%v", n.Value)
return
}
if n.Key != nil && n.Value == nil {
fmt.Fprintf(s, "%v:", n.Key)
return
}
fmt.Fprint(s, ":")
case OSTRUCTKEY:
n := n.(*StructKeyExpr)
fmt.Fprintf(s, "%v:%v", n.Field, n.Value)
case OXDOT, ODOT, ODOTPTR, ODOTINTER, ODOTMETH, OMETHVALUE, OMETHEXPR:
n := n.(*SelectorExpr)
exprFmt(n.X, s, nprec)
if n.Sel == nil {
fmt.Fprint(s, ".<nil>")
return
}
fmt.Fprintf(s, ".%s", n.Sel.Name)
case ODOTTYPE, ODOTTYPE2:
n := n.(*TypeAssertExpr)
exprFmt(n.X, s, nprec)
fmt.Fprintf(s, ".(%v)", n.Type())
case OINDEX, OINDEXMAP:
n := n.(*IndexExpr)
exprFmt(n.X, s, nprec)
fmt.Fprintf(s, "[%v]", n.Index)
case OSLICE, OSLICESTR, OSLICEARR, OSLICE3, OSLICE3ARR:
n := n.(*SliceExpr)
exprFmt(n.X, s, nprec)
fmt.Fprint(s, "[")
if n.Low != nil {
fmt.Fprint(s, n.Low)
}
fmt.Fprint(s, ":")
if n.High != nil {
fmt.Fprint(s, n.High)
}
if n.Op().IsSlice3() {
fmt.Fprint(s, ":")
if n.Max != nil {
fmt.Fprint(s, n.Max)
}
}
fmt.Fprint(s, "]")
case OSLICEHEADER:
n := n.(*SliceHeaderExpr)
fmt.Fprintf(s, "sliceheader{%v,%v,%v}", n.Ptr, n.Len, n.Cap)
case OCOMPLEX, OCOPY, OUNSAFEADD, OUNSAFESLICE:
n := n.(*BinaryExpr)
fmt.Fprintf(s, "%v(%v, %v)", n.Op(), n.X, n.Y)
case OCONV,
OCONVIFACE,
OCONVIDATA,
OCONVNOP,
OBYTES2STR,
ORUNES2STR,
OSTR2BYTES,
OSTR2RUNES,
ORUNESTR,
OSLICE2ARRPTR:
n := n.(*ConvExpr)
if n.Type() == nil || n.Type().Sym() == nil {
fmt.Fprintf(s, "(%v)", n.Type())
} else {
fmt.Fprintf(s, "%v", n.Type())
}
fmt.Fprintf(s, "(%v)", n.X)
case OREAL,
OIMAG,
OCAP,
OCLOSE,
OLEN,
ONEW,
OPANIC,
OALIGNOF,
OOFFSETOF,
OSIZEOF:
n := n.(*UnaryExpr)
fmt.Fprintf(s, "%v(%v)", n.Op(), n.X)
case OAPPEND,
ODELETE,
OMAKE,
ORECOVER,
OPRINT,
OPRINTN:
n := n.(*CallExpr)
if n.IsDDD {
fmt.Fprintf(s, "%v(%.v...)", n.Op(), n.Args)
return
}
fmt.Fprintf(s, "%v(%.v)", n.Op(), n.Args)
case OCALL, OCALLFUNC, OCALLINTER, OCALLMETH, OGETG:
n := n.(*CallExpr)
exprFmt(n.X, s, nprec)
if n.IsDDD {
fmt.Fprintf(s, "(%.v...)", n.Args)
return
}
fmt.Fprintf(s, "(%.v)", n.Args)
case OINLCALL:
n := n.(*InlinedCallExpr)
// TODO(mdempsky): Print Init and/or Body?
if len(n.ReturnVars) == 1 {
fmt.Fprintf(s, "%v", n.ReturnVars[0])
return
}
fmt.Fprintf(s, "(.%v)", n.ReturnVars)
case OMAKEMAP, OMAKECHAN, OMAKESLICE:
n := n.(*MakeExpr)
if n.Cap != nil {
fmt.Fprintf(s, "make(%v, %v, %v)", n.Type(), n.Len, n.Cap)
return
}
if n.Len != nil && (n.Op() == OMAKESLICE || !n.Len.Type().IsUntyped()) {
fmt.Fprintf(s, "make(%v, %v)", n.Type(), n.Len)
return
}
fmt.Fprintf(s, "make(%v)", n.Type())
case OMAKESLICECOPY:
n := n.(*MakeExpr)
fmt.Fprintf(s, "makeslicecopy(%v, %v, %v)", n.Type(), n.Len, n.Cap)
case OPLUS, ONEG, OBITNOT, ONOT, ORECV:
// Unary
n := n.(*UnaryExpr)
fmt.Fprintf(s, "%v", n.Op())
if n.X != nil && n.X.Op() == n.Op() {
fmt.Fprint(s, " ")
}
exprFmt(n.X, s, nprec+1)
case OADDR:
n := n.(*AddrExpr)
fmt.Fprintf(s, "%v", n.Op())
if n.X != nil && n.X.Op() == n.Op() {
fmt.Fprint(s, " ")
}
exprFmt(n.X, s, nprec+1)
case ODEREF:
n := n.(*StarExpr)
fmt.Fprintf(s, "%v", n.Op())
exprFmt(n.X, s, nprec+1)
// Binary
case OADD,
OAND,
OANDNOT,
ODIV,
OEQ,
OGE,
OGT,
OLE,
OLT,
OLSH,
OMOD,
OMUL,
ONE,
OOR,
ORSH,
OSUB,
OXOR:
n := n.(*BinaryExpr)
exprFmt(n.X, s, nprec)
fmt.Fprintf(s, " %v ", n.Op())
exprFmt(n.Y, s, nprec+1)
case OANDAND,
OOROR:
n := n.(*LogicalExpr)
exprFmt(n.X, s, nprec)
fmt.Fprintf(s, " %v ", n.Op())
exprFmt(n.Y, s, nprec+1)
case OSEND:
n := n.(*SendStmt)
exprFmt(n.Chan, s, nprec)
fmt.Fprintf(s, " <- ")
exprFmt(n.Value, s, nprec+1)
case OADDSTR:
n := n.(*AddStringExpr)
for i, n1 := range n.List {
if i != 0 {
fmt.Fprint(s, " + ")
}
exprFmt(n1, s, nprec)
}
default:
fmt.Fprintf(s, "<node %v>", n.Op())
}
}
func ellipsisIf(b bool) string {
if b {
return "..."
}
return ""
}
// Nodes
// Format implements formatting for a Nodes.
// The valid formats are:
//
// %v Go syntax, semicolon-separated
// %.v Go syntax, comma-separated
// %+v Debug syntax, as in DumpList.
func (l Nodes) Format(s fmt.State, verb rune) {
if s.Flag('+') && verb == 'v' {
// %+v is DumpList output
dumpNodes(s, l, 1)
return
}
if verb != 'v' {
fmt.Fprintf(s, "%%!%c(Nodes)", verb)
return
}
sep := "; "
if _, ok := s.Precision(); ok { // %.v is expr list
sep = ", "
}
for i, n := range l {
fmt.Fprint(s, n)
if i+1 < len(l) {
fmt.Fprint(s, sep)
}
}
}
// Dump
// Dump prints the message s followed by a debug dump of n.
func Dump(s string, n Node) {
fmt.Printf("%s%+v\n", s, n)
}
// DumpList prints the message s followed by a debug dump of each node in the list.
func DumpList(s string, list Nodes) {
var buf bytes.Buffer
FDumpList(&buf, s, list)
os.Stdout.Write(buf.Bytes())
}
// FDumpList prints to w the message s followed by a debug dump of each node in the list.
func FDumpList(w io.Writer, s string, list Nodes) {
io.WriteString(w, s)
dumpNodes(w, list, 1)
io.WriteString(w, "\n")
}
// indent prints indentation to w.
func indent(w io.Writer, depth int) {
fmt.Fprint(w, "\n")
for i := 0; i < depth; i++ {
fmt.Fprint(w, ". ")
}
}
// EscFmt is set by the escape analysis code to add escape analysis details to the node print.
var EscFmt func(n Node) string
// dumpNodeHeader prints the debug-format node header line to w.
func dumpNodeHeader(w io.Writer, n Node) {
// Useful to see which nodes in an AST printout are actually identical
if base.Debug.DumpPtrs != 0 {
fmt.Fprintf(w, " p(%p)", n)
}
if base.Debug.DumpPtrs != 0 && n.Name() != nil && n.Name().Defn != nil {
// Useful to see where Defn is set and what node it points to
fmt.Fprintf(w, " defn(%p)", n.Name().Defn)
}
if base.Debug.DumpPtrs != 0 && n.Name() != nil && n.Name().Curfn != nil {
// Useful to see where Defn is set and what node it points to
fmt.Fprintf(w, " curfn(%p)", n.Name().Curfn)
}
if base.Debug.DumpPtrs != 0 && n.Name() != nil && n.Name().Outer != nil {
// Useful to see where Defn is set and what node it points to
fmt.Fprintf(w, " outer(%p)", n.Name().Outer)
}
if EscFmt != nil {
if esc := EscFmt(n); esc != "" {
fmt.Fprintf(w, " %s", esc)
}
}
if n.Sym() != nil && n.Op() != ONAME && n.Op() != ONONAME && n.Op() != OTYPE {
fmt.Fprintf(w, " %+v", n.Sym())
}
// Print Node-specific fields of basic type in header line.
v := reflect.ValueOf(n).Elem()
t := v.Type()
nf := t.NumField()
for i := 0; i < nf; i++ {
tf := t.Field(i)
if tf.PkgPath != "" {
// skip unexported field - Interface will fail
continue
}
k := tf.Type.Kind()
if reflect.Bool <= k && k <= reflect.Complex128 {
name := strings.TrimSuffix(tf.Name, "_")
vf := v.Field(i)
vfi := vf.Interface()
if name == "Offset" && vfi == types.BADWIDTH || name != "Offset" && isZero(vf) {
continue
}
if vfi == true {
fmt.Fprintf(w, " %s", name)
} else {
fmt.Fprintf(w, " %s:%+v", name, vf.Interface())
}
}
}
// Print Node-specific booleans by looking for methods.
// Different v, t from above - want *Struct not Struct, for methods.
v = reflect.ValueOf(n)
t = v.Type()
nm := t.NumMethod()
for i := 0; i < nm; i++ {
tm := t.Method(i)
if tm.PkgPath != "" {
// skip unexported method - call will fail
continue
}
m := v.Method(i)
mt := m.Type()
if mt.NumIn() == 0 && mt.NumOut() == 1 && mt.Out(0).Kind() == reflect.Bool {
// TODO(rsc): Remove the func/defer/recover wrapping,
// which is guarding against panics in miniExpr,
// once we get down to the simpler state in which
// nodes have no getter methods that aren't allowed to be called.
func() {
defer func() { recover() }()
if m.Call(nil)[0].Bool() {
name := strings.TrimSuffix(tm.Name, "_")
fmt.Fprintf(w, " %s", name)
}
}()
}
}
if n.Op() == OCLOSURE {
n := n.(*ClosureExpr)
if fn := n.Func; fn != nil && fn.Nname.Sym() != nil {
fmt.Fprintf(w, " fnName(%+v)", fn.Nname.Sym())
}
}
if n.Type() != nil {
if n.Op() == OTYPE {
fmt.Fprintf(w, " type")
}
fmt.Fprintf(w, " %+v", n.Type())
}
if n.Typecheck() != 0 {
fmt.Fprintf(w, " tc(%d)", n.Typecheck())
}
if n.Pos().IsKnown() {
fmt.Fprint(w, " # ")
switch n.Pos().IsStmt() {
case src.PosNotStmt:
fmt.Fprint(w, "_") // "-" would be confusing
case src.PosIsStmt:
fmt.Fprint(w, "+")
}
for i, pos := range base.Ctxt.AllPos(n.Pos(), nil) {
if i > 0 {
fmt.Fprint(w, ",")
}
// TODO(mdempsky): Print line pragma details too.
file := filepath.Base(pos.Filename())
// Note: this output will be parsed by ssa/html.go:(*HTMLWriter).WriteAST. Keep in sync.
fmt.Fprintf(w, "%s:%d:%d", file, pos.Line(), pos.Col())
}
}
}
func dumpNode(w io.Writer, n Node, depth int) {
indent(w, depth)
if depth > 40 {
fmt.Fprint(w, "...")
return
}
if n == nil {
fmt.Fprint(w, "NilIrNode")
return
}
if len(n.Init()) != 0 {
fmt.Fprintf(w, "%+v-init", n.Op())
dumpNodes(w, n.Init(), depth+1)
indent(w, depth)
}
switch n.Op() {
default:
fmt.Fprintf(w, "%+v", n.Op())
dumpNodeHeader(w, n)
case OLITERAL:
fmt.Fprintf(w, "%+v-%v", n.Op(), n.Val())
dumpNodeHeader(w, n)
return
case ONAME, ONONAME:
if n.Sym() != nil {
fmt.Fprintf(w, "%+v-%+v", n.Op(), n.Sym())
} else {
fmt.Fprintf(w, "%+v", n.Op())
}
dumpNodeHeader(w, n)
return
case OASOP:
n := n.(*AssignOpStmt)
fmt.Fprintf(w, "%+v-%+v", n.Op(), n.AsOp)
dumpNodeHeader(w, n)
case OTYPE:
fmt.Fprintf(w, "%+v %+v", n.Op(), n.Sym())
dumpNodeHeader(w, n)
return
case OCLOSURE:
fmt.Fprintf(w, "%+v", n.Op())
dumpNodeHeader(w, n)
case ODCLFUNC:
// Func has many fields we don't want to print.
// Bypass reflection and just print what we want.
n := n.(*Func)
fmt.Fprintf(w, "%+v", n.Op())
dumpNodeHeader(w, n)
fn := n
if len(fn.Dcl) > 0 {
indent(w, depth)
fmt.Fprintf(w, "%+v-Dcl", n.Op())
for _, dcl := range n.Dcl {
dumpNode(w, dcl, depth+1)
}
}
if len(fn.ClosureVars) > 0 {
indent(w, depth)
fmt.Fprintf(w, "%+v-ClosureVars", n.Op())
for _, cv := range fn.ClosureVars {
dumpNode(w, cv, depth+1)
}
}
if len(fn.Enter) > 0 {
indent(w, depth)
fmt.Fprintf(w, "%+v-Enter", n.Op())
dumpNodes(w, fn.Enter, depth+1)
}
if len(fn.Body) > 0 {
indent(w, depth)
fmt.Fprintf(w, "%+v-body", n.Op())
dumpNodes(w, fn.Body, depth+1)
}
return
}
v := reflect.ValueOf(n).Elem()
t := reflect.TypeOf(n).Elem()
nf := t.NumField()
for i := 0; i < nf; i++ {
tf := t.Field(i)
vf := v.Field(i)
if tf.PkgPath != "" {
// skip unexported field - Interface will fail
continue
}
switch tf.Type.Kind() {
case reflect.Interface, reflect.Ptr, reflect.Slice:
if vf.IsNil() {
continue
}
}
name := strings.TrimSuffix(tf.Name, "_")
// Do not bother with field name header lines for the
// most common positional arguments: unary, binary expr,
// index expr, send stmt, go and defer call expression.
switch name {
case "X", "Y", "Index", "Chan", "Value", "Call":
name = ""
}
switch val := vf.Interface().(type) {
case Node:
if name != "" {
indent(w, depth)
fmt.Fprintf(w, "%+v-%s", n.Op(), name)
}
dumpNode(w, val, depth+1)
case Nodes:
if len(val) == 0 {
continue
}
if name != "" {
indent(w, depth)
fmt.Fprintf(w, "%+v-%s", n.Op(), name)
}
dumpNodes(w, val, depth+1)
default:
if vf.Kind() == reflect.Slice && vf.Type().Elem().Implements(nodeType) {
if vf.Len() == 0 {
continue
}
if name != "" {
indent(w, depth)
fmt.Fprintf(w, "%+v-%s", n.Op(), name)
}
for i, n := 0, vf.Len(); i < n; i++ {
dumpNode(w, vf.Index(i).Interface().(Node), depth+1)
}
}
}
}
}
var nodeType = reflect.TypeOf((*Node)(nil)).Elem()
func dumpNodes(w io.Writer, list Nodes, depth int) {
if len(list) == 0 {
fmt.Fprintf(w, " <nil>")
return
}
for _, n := range list {
dumpNode(w, n, depth)
}
}
// reflect.IsZero is not available in Go 1.4 (added in Go 1.13), so we use this copy instead.
func isZero(v reflect.Value) bool {
switch v.Kind() {
case reflect.Bool:
return !v.Bool()
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return v.Int() == 0
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
return v.Uint() == 0
case reflect.Float32, reflect.Float64:
return math.Float64bits(v.Float()) == 0
case reflect.Complex64, reflect.Complex128:
c := v.Complex()
return math.Float64bits(real(c)) == 0 && math.Float64bits(imag(c)) == 0
case reflect.Array:
for i := 0; i < v.Len(); i++ {
if !isZero(v.Index(i)) {
return false
}
}
return true
case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice, reflect.UnsafePointer:
return v.IsNil()
case reflect.String:
return v.Len() == 0
case reflect.Struct:
for i := 0; i < v.NumField(); i++ {
if !isZero(v.Field(i)) {
return false
}
}
return true
default:
return false
}
}
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