Adding upstream version 1.18.10.upstream/1.18.10upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1359 insertions, 0 deletions

diff --git a/src/cmd/compile/internal/ir/fmt.go b/src/cmd/compile/internal/ir/fmt.go
new file mode 100644
index 0000000..0331885
--- /dev/null
+++ b/src/cmd/compile/internal/ir/fmt.go
@@ -0,0 +1,1359 @@
+// 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,
+	OPACK:          8,
+	OPANIC:         8,
+	OPAREN:         8,
+	OPRINTN:        8,
+	OPRINT:         8,
+	ORUNESTR:       8,
+	OSIZEOF:        8,
+	OSLICE2ARRPTR:  8,
+	OSTR2BYTES:     8,
+	OSTR2RUNES:     8,
+	OSTRUCTLIT:     8,
+	OTARRAY:        8,
+	OTSLICE:        8,
+	OTCHAN:         8,
+	OTFUNC:         8,
+	OTINTER:        8,
+	OTMAP:          8,
+	OTSTRUCT:       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 OPACK, 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 OTSLICE:
+		n := n.(*SliceType)
+		if n.DDD {
+			fmt.Fprintf(s, "...%v", n.Elem)
+		} else {
+			fmt.Fprintf(s, "[]%v", n.Elem) // happens before typecheck
+		}
+
+	case OTARRAY:
+		n := n.(*ArrayType)
+		if n.Len == nil {
+			fmt.Fprintf(s, "[...]%v", n.Elem)
+		} else {
+			fmt.Fprintf(s, "[%v]%v", n.Len, n.Elem)
+		}
+
+	case OTMAP:
+		n := n.(*MapType)
+		fmt.Fprintf(s, "map[%v]%v", n.Key, n.Elem)
+
+	case OTCHAN:
+		n := n.(*ChanType)
+		switch n.Dir {
+		case types.Crecv:
+			fmt.Fprintf(s, "<-chan %v", n.Elem)
+
+		case types.Csend:
+			fmt.Fprintf(s, "chan<- %v", n.Elem)
+
+		default:
+			if n.Elem != nil && n.Elem.Op() == OTCHAN && n.Elem.(*ChanType).Dir == types.Crecv {
+				fmt.Fprintf(s, "chan (%v)", n.Elem)
+			} else {
+				fmt.Fprintf(s, "chan %v", n.Elem)
+			}
+		}
+
+	case OTSTRUCT:
+		fmt.Fprint(s, "<struct>")
+
+	case OTINTER:
+		fmt.Fprint(s, "<inter>")
+
+	case OTFUNC:
+		fmt.Fprint(s, "<func>")
+
+	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
+			}
+			if n.Ntype != nil {
+				fmt.Fprintf(s, "%v{%s}", n.Ntype, ellipsisIf(len(n.List) != 0))
+				return
+			}
+
+			fmt.Fprint(s, "composite literal")
+			return
+		}
+		fmt.Fprintf(s, "(%v{ %.v })", n.Ntype, 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)
+		if n.Ntype != nil {
+			fmt.Fprintf(s, ".(%v)", n.Ntype)
+			return
+		}
+		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)
+		if n.Type() == nil && n.Name() != nil && n.Name().Ntype != nil {
+			indent(w, depth)
+			fmt.Fprintf(w, "%+v-ntype", n.Op())
+			dumpNode(w, n.Name().Ntype, depth+1)
+		}
+		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)
+		if n.Type() == nil && n.Name() != nil && n.Name().Ntype != nil {
+			indent(w, depth)
+			fmt.Fprintf(w, "%+v-ntype", n.Op())
+			dumpNode(w, n.Name().Ntype, depth+1)
+		}
+		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
+	}
+}