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-rw-r--r--src/cmd/compile/internal/gc/noder.go1756
1 files changed, 1756 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/gc/noder.go b/src/cmd/compile/internal/gc/noder.go
new file mode 100644
index 0000000..7494c3e
--- /dev/null
+++ b/src/cmd/compile/internal/gc/noder.go
@@ -0,0 +1,1756 @@
+// Copyright 2016 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 gc
+
+import (
+ "fmt"
+ "os"
+ "path/filepath"
+ "runtime"
+ "strconv"
+ "strings"
+ "unicode"
+ "unicode/utf8"
+
+ "cmd/compile/internal/syntax"
+ "cmd/compile/internal/types"
+ "cmd/internal/obj"
+ "cmd/internal/objabi"
+ "cmd/internal/src"
+)
+
+// parseFiles concurrently parses files into *syntax.File structures.
+// Each declaration in every *syntax.File is converted to a syntax tree
+// and its root represented by *Node is appended to xtop.
+// Returns the total count of parsed lines.
+func parseFiles(filenames []string) uint {
+ noders := make([]*noder, 0, len(filenames))
+ // Limit the number of simultaneously open files.
+ sem := make(chan struct{}, runtime.GOMAXPROCS(0)+10)
+
+ for _, filename := range filenames {
+ p := &noder{
+ basemap: make(map[*syntax.PosBase]*src.PosBase),
+ err: make(chan syntax.Error),
+ }
+ noders = append(noders, p)
+
+ go func(filename string) {
+ sem <- struct{}{}
+ defer func() { <-sem }()
+ defer close(p.err)
+ base := syntax.NewFileBase(filename)
+
+ f, err := os.Open(filename)
+ if err != nil {
+ p.error(syntax.Error{Msg: err.Error()})
+ return
+ }
+ defer f.Close()
+
+ p.file, _ = syntax.Parse(base, f, p.error, p.pragma, syntax.CheckBranches) // errors are tracked via p.error
+ }(filename)
+ }
+
+ var lines uint
+ for _, p := range noders {
+ for e := range p.err {
+ p.yyerrorpos(e.Pos, "%s", e.Msg)
+ }
+
+ p.node()
+ lines += p.file.Lines
+ p.file = nil // release memory
+
+ if nsyntaxerrors != 0 {
+ errorexit()
+ }
+ // Always run testdclstack here, even when debug_dclstack is not set, as a sanity measure.
+ testdclstack()
+ }
+
+ localpkg.Height = myheight
+
+ return lines
+}
+
+// makeSrcPosBase translates from a *syntax.PosBase to a *src.PosBase.
+func (p *noder) makeSrcPosBase(b0 *syntax.PosBase) *src.PosBase {
+ // fast path: most likely PosBase hasn't changed
+ if p.basecache.last == b0 {
+ return p.basecache.base
+ }
+
+ b1, ok := p.basemap[b0]
+ if !ok {
+ fn := b0.Filename()
+ if b0.IsFileBase() {
+ b1 = src.NewFileBase(fn, absFilename(fn))
+ } else {
+ // line directive base
+ p0 := b0.Pos()
+ p0b := p0.Base()
+ if p0b == b0 {
+ panic("infinite recursion in makeSrcPosBase")
+ }
+ p1 := src.MakePos(p.makeSrcPosBase(p0b), p0.Line(), p0.Col())
+ b1 = src.NewLinePragmaBase(p1, fn, fileh(fn), b0.Line(), b0.Col())
+ }
+ p.basemap[b0] = b1
+ }
+
+ // update cache
+ p.basecache.last = b0
+ p.basecache.base = b1
+
+ return b1
+}
+
+func (p *noder) makeXPos(pos syntax.Pos) (_ src.XPos) {
+ return Ctxt.PosTable.XPos(src.MakePos(p.makeSrcPosBase(pos.Base()), pos.Line(), pos.Col()))
+}
+
+func (p *noder) yyerrorpos(pos syntax.Pos, format string, args ...interface{}) {
+ yyerrorl(p.makeXPos(pos), format, args...)
+}
+
+var pathPrefix string
+
+// TODO(gri) Can we eliminate fileh in favor of absFilename?
+func fileh(name string) string {
+ return objabi.AbsFile("", name, pathPrefix)
+}
+
+func absFilename(name string) string {
+ return objabi.AbsFile(Ctxt.Pathname, name, pathPrefix)
+}
+
+// noder transforms package syntax's AST into a Node tree.
+type noder struct {
+ basemap map[*syntax.PosBase]*src.PosBase
+ basecache struct {
+ last *syntax.PosBase
+ base *src.PosBase
+ }
+
+ file *syntax.File
+ linknames []linkname
+ pragcgobuf [][]string
+ err chan syntax.Error
+ scope ScopeID
+ importedUnsafe bool
+ importedEmbed bool
+
+ // scopeVars is a stack tracking the number of variables declared in the
+ // current function at the moment each open scope was opened.
+ scopeVars []int
+
+ lastCloseScopePos syntax.Pos
+}
+
+func (p *noder) funcBody(fn *Node, block *syntax.BlockStmt) {
+ oldScope := p.scope
+ p.scope = 0
+ funchdr(fn)
+
+ if block != nil {
+ body := p.stmts(block.List)
+ if body == nil {
+ body = []*Node{nod(OEMPTY, nil, nil)}
+ }
+ fn.Nbody.Set(body)
+
+ lineno = p.makeXPos(block.Rbrace)
+ fn.Func.Endlineno = lineno
+ }
+
+ funcbody()
+ p.scope = oldScope
+}
+
+func (p *noder) openScope(pos syntax.Pos) {
+ types.Markdcl()
+
+ if trackScopes {
+ Curfn.Func.Parents = append(Curfn.Func.Parents, p.scope)
+ p.scopeVars = append(p.scopeVars, len(Curfn.Func.Dcl))
+ p.scope = ScopeID(len(Curfn.Func.Parents))
+
+ p.markScope(pos)
+ }
+}
+
+func (p *noder) closeScope(pos syntax.Pos) {
+ p.lastCloseScopePos = pos
+ types.Popdcl()
+
+ if trackScopes {
+ scopeVars := p.scopeVars[len(p.scopeVars)-1]
+ p.scopeVars = p.scopeVars[:len(p.scopeVars)-1]
+ if scopeVars == len(Curfn.Func.Dcl) {
+ // no variables were declared in this scope, so we can retract it.
+
+ if int(p.scope) != len(Curfn.Func.Parents) {
+ Fatalf("scope tracking inconsistency, no variables declared but scopes were not retracted")
+ }
+
+ p.scope = Curfn.Func.Parents[p.scope-1]
+ Curfn.Func.Parents = Curfn.Func.Parents[:len(Curfn.Func.Parents)-1]
+
+ nmarks := len(Curfn.Func.Marks)
+ Curfn.Func.Marks[nmarks-1].Scope = p.scope
+ prevScope := ScopeID(0)
+ if nmarks >= 2 {
+ prevScope = Curfn.Func.Marks[nmarks-2].Scope
+ }
+ if Curfn.Func.Marks[nmarks-1].Scope == prevScope {
+ Curfn.Func.Marks = Curfn.Func.Marks[:nmarks-1]
+ }
+ return
+ }
+
+ p.scope = Curfn.Func.Parents[p.scope-1]
+
+ p.markScope(pos)
+ }
+}
+
+func (p *noder) markScope(pos syntax.Pos) {
+ xpos := p.makeXPos(pos)
+ if i := len(Curfn.Func.Marks); i > 0 && Curfn.Func.Marks[i-1].Pos == xpos {
+ Curfn.Func.Marks[i-1].Scope = p.scope
+ } else {
+ Curfn.Func.Marks = append(Curfn.Func.Marks, Mark{xpos, p.scope})
+ }
+}
+
+// closeAnotherScope is like closeScope, but it reuses the same mark
+// position as the last closeScope call. This is useful for "for" and
+// "if" statements, as their implicit blocks always end at the same
+// position as an explicit block.
+func (p *noder) closeAnotherScope() {
+ p.closeScope(p.lastCloseScopePos)
+}
+
+// linkname records a //go:linkname directive.
+type linkname struct {
+ pos syntax.Pos
+ local string
+ remote string
+}
+
+func (p *noder) node() {
+ types.Block = 1
+ p.importedUnsafe = false
+ p.importedEmbed = false
+
+ p.setlineno(p.file.PkgName)
+ mkpackage(p.file.PkgName.Value)
+
+ if pragma, ok := p.file.Pragma.(*Pragma); ok {
+ pragma.Flag &^= GoBuildPragma
+ p.checkUnused(pragma)
+ }
+
+ xtop = append(xtop, p.decls(p.file.DeclList)...)
+
+ for _, n := range p.linknames {
+ if !p.importedUnsafe {
+ p.yyerrorpos(n.pos, "//go:linkname only allowed in Go files that import \"unsafe\"")
+ continue
+ }
+ s := lookup(n.local)
+ if n.remote != "" {
+ s.Linkname = n.remote
+ } else {
+ // Use the default object symbol name if the
+ // user didn't provide one.
+ if myimportpath == "" {
+ p.yyerrorpos(n.pos, "//go:linkname requires linkname argument or -p compiler flag")
+ } else {
+ s.Linkname = objabi.PathToPrefix(myimportpath) + "." + n.local
+ }
+ }
+ }
+
+ // The linker expects an ABI0 wrapper for all cgo-exported
+ // functions.
+ for _, prag := range p.pragcgobuf {
+ switch prag[0] {
+ case "cgo_export_static", "cgo_export_dynamic":
+ if symabiRefs == nil {
+ symabiRefs = make(map[string]obj.ABI)
+ }
+ symabiRefs[prag[1]] = obj.ABI0
+ }
+ }
+
+ pragcgobuf = append(pragcgobuf, p.pragcgobuf...)
+ lineno = src.NoXPos
+ clearImports()
+}
+
+func (p *noder) decls(decls []syntax.Decl) (l []*Node) {
+ var cs constState
+
+ for _, decl := range decls {
+ p.setlineno(decl)
+ switch decl := decl.(type) {
+ case *syntax.ImportDecl:
+ p.importDecl(decl)
+
+ case *syntax.VarDecl:
+ l = append(l, p.varDecl(decl)...)
+
+ case *syntax.ConstDecl:
+ l = append(l, p.constDecl(decl, &cs)...)
+
+ case *syntax.TypeDecl:
+ l = append(l, p.typeDecl(decl))
+
+ case *syntax.FuncDecl:
+ l = append(l, p.funcDecl(decl))
+
+ default:
+ panic("unhandled Decl")
+ }
+ }
+
+ return
+}
+
+func (p *noder) importDecl(imp *syntax.ImportDecl) {
+ if imp.Path.Bad {
+ return // avoid follow-on errors if there was a syntax error
+ }
+
+ if pragma, ok := imp.Pragma.(*Pragma); ok {
+ p.checkUnused(pragma)
+ }
+
+ val := p.basicLit(imp.Path)
+ ipkg := importfile(&val)
+ if ipkg == nil {
+ if nerrors == 0 {
+ Fatalf("phase error in import")
+ }
+ return
+ }
+
+ if ipkg == unsafepkg {
+ p.importedUnsafe = true
+ }
+ if ipkg.Path == "embed" {
+ p.importedEmbed = true
+ }
+
+ ipkg.Direct = true
+
+ var my *types.Sym
+ if imp.LocalPkgName != nil {
+ my = p.name(imp.LocalPkgName)
+ } else {
+ my = lookup(ipkg.Name)
+ }
+
+ pack := p.nod(imp, OPACK, nil, nil)
+ pack.Sym = my
+ pack.Name.Pkg = ipkg
+
+ switch my.Name {
+ case ".":
+ importdot(ipkg, pack)
+ return
+ case "init":
+ yyerrorl(pack.Pos, "cannot import package as init - init must be a func")
+ return
+ case "_":
+ return
+ }
+ if my.Def != nil {
+ redeclare(pack.Pos, my, "as imported package name")
+ }
+ my.Def = asTypesNode(pack)
+ my.Lastlineno = pack.Pos
+ my.Block = 1 // at top level
+}
+
+func (p *noder) varDecl(decl *syntax.VarDecl) []*Node {
+ names := p.declNames(decl.NameList)
+ typ := p.typeExprOrNil(decl.Type)
+
+ var exprs []*Node
+ if decl.Values != nil {
+ exprs = p.exprList(decl.Values)
+ }
+
+ if pragma, ok := decl.Pragma.(*Pragma); ok {
+ if len(pragma.Embeds) > 0 {
+ if !p.importedEmbed {
+ // This check can't be done when building the list pragma.Embeds
+ // because that list is created before the noder starts walking over the file,
+ // so at that point it hasn't seen the imports.
+ // We're left to check now, just before applying the //go:embed lines.
+ for _, e := range pragma.Embeds {
+ p.yyerrorpos(e.Pos, "//go:embed only allowed in Go files that import \"embed\"")
+ }
+ } else {
+ varEmbed(p, names, typ, exprs, pragma.Embeds)
+ }
+ pragma.Embeds = nil
+ }
+ p.checkUnused(pragma)
+ }
+
+ p.setlineno(decl)
+ return variter(names, typ, exprs)
+}
+
+// constState tracks state between constant specifiers within a
+// declaration group. This state is kept separate from noder so nested
+// constant declarations are handled correctly (e.g., issue 15550).
+type constState struct {
+ group *syntax.Group
+ typ *Node
+ values []*Node
+ iota int64
+}
+
+func (p *noder) constDecl(decl *syntax.ConstDecl, cs *constState) []*Node {
+ if decl.Group == nil || decl.Group != cs.group {
+ *cs = constState{
+ group: decl.Group,
+ }
+ }
+
+ if pragma, ok := decl.Pragma.(*Pragma); ok {
+ p.checkUnused(pragma)
+ }
+
+ names := p.declNames(decl.NameList)
+ typ := p.typeExprOrNil(decl.Type)
+
+ var values []*Node
+ if decl.Values != nil {
+ values = p.exprList(decl.Values)
+ cs.typ, cs.values = typ, values
+ } else {
+ if typ != nil {
+ yyerror("const declaration cannot have type without expression")
+ }
+ typ, values = cs.typ, cs.values
+ }
+
+ nn := make([]*Node, 0, len(names))
+ for i, n := range names {
+ if i >= len(values) {
+ yyerror("missing value in const declaration")
+ break
+ }
+ v := values[i]
+ if decl.Values == nil {
+ v = treecopy(v, n.Pos)
+ }
+
+ n.Op = OLITERAL
+ declare(n, dclcontext)
+
+ n.Name.Param.Ntype = typ
+ n.Name.Defn = v
+ n.SetIota(cs.iota)
+
+ nn = append(nn, p.nod(decl, ODCLCONST, n, nil))
+ }
+
+ if len(values) > len(names) {
+ yyerror("extra expression in const declaration")
+ }
+
+ cs.iota++
+
+ return nn
+}
+
+func (p *noder) typeDecl(decl *syntax.TypeDecl) *Node {
+ n := p.declName(decl.Name)
+ n.Op = OTYPE
+ declare(n, dclcontext)
+
+ // decl.Type may be nil but in that case we got a syntax error during parsing
+ typ := p.typeExprOrNil(decl.Type)
+
+ param := n.Name.Param
+ param.Ntype = typ
+ param.SetAlias(decl.Alias)
+ if pragma, ok := decl.Pragma.(*Pragma); ok {
+ if !decl.Alias {
+ param.SetPragma(pragma.Flag & TypePragmas)
+ pragma.Flag &^= TypePragmas
+ }
+ p.checkUnused(pragma)
+ }
+
+ nod := p.nod(decl, ODCLTYPE, n, nil)
+ if param.Alias() && !langSupported(1, 9, localpkg) {
+ yyerrorl(nod.Pos, "type aliases only supported as of -lang=go1.9")
+ }
+ return nod
+}
+
+func (p *noder) declNames(names []*syntax.Name) []*Node {
+ nodes := make([]*Node, 0, len(names))
+ for _, name := range names {
+ nodes = append(nodes, p.declName(name))
+ }
+ return nodes
+}
+
+func (p *noder) declName(name *syntax.Name) *Node {
+ n := dclname(p.name(name))
+ n.Pos = p.pos(name)
+ return n
+}
+
+func (p *noder) funcDecl(fun *syntax.FuncDecl) *Node {
+ name := p.name(fun.Name)
+ t := p.signature(fun.Recv, fun.Type)
+ f := p.nod(fun, ODCLFUNC, nil, nil)
+
+ if fun.Recv == nil {
+ if name.Name == "init" {
+ name = renameinit()
+ if t.List.Len() > 0 || t.Rlist.Len() > 0 {
+ yyerrorl(f.Pos, "func init must have no arguments and no return values")
+ }
+ }
+
+ if localpkg.Name == "main" && name.Name == "main" {
+ if t.List.Len() > 0 || t.Rlist.Len() > 0 {
+ yyerrorl(f.Pos, "func main must have no arguments and no return values")
+ }
+ }
+ } else {
+ f.Func.Shortname = name
+ name = nblank.Sym // filled in by typecheckfunc
+ }
+
+ f.Func.Nname = newfuncnamel(p.pos(fun.Name), name)
+ f.Func.Nname.Name.Defn = f
+ f.Func.Nname.Name.Param.Ntype = t
+
+ if pragma, ok := fun.Pragma.(*Pragma); ok {
+ f.Func.Pragma = pragma.Flag & FuncPragmas
+ if pragma.Flag&Systemstack != 0 && pragma.Flag&Nosplit != 0 {
+ yyerrorl(f.Pos, "go:nosplit and go:systemstack cannot be combined")
+ }
+ pragma.Flag &^= FuncPragmas
+ p.checkUnused(pragma)
+ }
+
+ if fun.Recv == nil {
+ declare(f.Func.Nname, PFUNC)
+ }
+
+ p.funcBody(f, fun.Body)
+
+ if fun.Body != nil {
+ if f.Func.Pragma&Noescape != 0 {
+ yyerrorl(f.Pos, "can only use //go:noescape with external func implementations")
+ }
+ } else {
+ if pure_go || strings.HasPrefix(f.funcname(), "init.") {
+ // Linknamed functions are allowed to have no body. Hopefully
+ // the linkname target has a body. See issue 23311.
+ isLinknamed := false
+ for _, n := range p.linknames {
+ if f.funcname() == n.local {
+ isLinknamed = true
+ break
+ }
+ }
+ if !isLinknamed {
+ yyerrorl(f.Pos, "missing function body")
+ }
+ }
+ }
+
+ return f
+}
+
+func (p *noder) signature(recv *syntax.Field, typ *syntax.FuncType) *Node {
+ n := p.nod(typ, OTFUNC, nil, nil)
+ if recv != nil {
+ n.Left = p.param(recv, false, false)
+ }
+ n.List.Set(p.params(typ.ParamList, true))
+ n.Rlist.Set(p.params(typ.ResultList, false))
+ return n
+}
+
+func (p *noder) params(params []*syntax.Field, dddOk bool) []*Node {
+ nodes := make([]*Node, 0, len(params))
+ for i, param := range params {
+ p.setlineno(param)
+ nodes = append(nodes, p.param(param, dddOk, i+1 == len(params)))
+ }
+ return nodes
+}
+
+func (p *noder) param(param *syntax.Field, dddOk, final bool) *Node {
+ var name *types.Sym
+ if param.Name != nil {
+ name = p.name(param.Name)
+ }
+
+ typ := p.typeExpr(param.Type)
+ n := p.nodSym(param, ODCLFIELD, typ, name)
+
+ // rewrite ...T parameter
+ if typ.Op == ODDD {
+ if !dddOk {
+ // We mark these as syntax errors to get automatic elimination
+ // of multiple such errors per line (see yyerrorl in subr.go).
+ yyerror("syntax error: cannot use ... in receiver or result parameter list")
+ } else if !final {
+ if param.Name == nil {
+ yyerror("syntax error: cannot use ... with non-final parameter")
+ } else {
+ p.yyerrorpos(param.Name.Pos(), "syntax error: cannot use ... with non-final parameter %s", param.Name.Value)
+ }
+ }
+ typ.Op = OTARRAY
+ typ.Right = typ.Left
+ typ.Left = nil
+ n.SetIsDDD(true)
+ if n.Left != nil {
+ n.Left.SetIsDDD(true)
+ }
+ }
+
+ return n
+}
+
+func (p *noder) exprList(expr syntax.Expr) []*Node {
+ if list, ok := expr.(*syntax.ListExpr); ok {
+ return p.exprs(list.ElemList)
+ }
+ return []*Node{p.expr(expr)}
+}
+
+func (p *noder) exprs(exprs []syntax.Expr) []*Node {
+ nodes := make([]*Node, 0, len(exprs))
+ for _, expr := range exprs {
+ nodes = append(nodes, p.expr(expr))
+ }
+ return nodes
+}
+
+func (p *noder) expr(expr syntax.Expr) *Node {
+ p.setlineno(expr)
+ switch expr := expr.(type) {
+ case nil, *syntax.BadExpr:
+ return nil
+ case *syntax.Name:
+ return p.mkname(expr)
+ case *syntax.BasicLit:
+ n := nodlit(p.basicLit(expr))
+ n.SetDiag(expr.Bad) // avoid follow-on errors if there was a syntax error
+ return n
+ case *syntax.CompositeLit:
+ n := p.nod(expr, OCOMPLIT, nil, nil)
+ if expr.Type != nil {
+ n.Right = p.expr(expr.Type)
+ }
+ l := p.exprs(expr.ElemList)
+ for i, e := range l {
+ l[i] = p.wrapname(expr.ElemList[i], e)
+ }
+ n.List.Set(l)
+ lineno = p.makeXPos(expr.Rbrace)
+ return n
+ case *syntax.KeyValueExpr:
+ // use position of expr.Key rather than of expr (which has position of ':')
+ return p.nod(expr.Key, OKEY, p.expr(expr.Key), p.wrapname(expr.Value, p.expr(expr.Value)))
+ case *syntax.FuncLit:
+ return p.funcLit(expr)
+ case *syntax.ParenExpr:
+ return p.nod(expr, OPAREN, p.expr(expr.X), nil)
+ case *syntax.SelectorExpr:
+ // parser.new_dotname
+ obj := p.expr(expr.X)
+ if obj.Op == OPACK {
+ obj.Name.SetUsed(true)
+ return importName(obj.Name.Pkg.Lookup(expr.Sel.Value))
+ }
+ n := nodSym(OXDOT, obj, p.name(expr.Sel))
+ n.Pos = p.pos(expr) // lineno may have been changed by p.expr(expr.X)
+ return n
+ case *syntax.IndexExpr:
+ return p.nod(expr, OINDEX, p.expr(expr.X), p.expr(expr.Index))
+ case *syntax.SliceExpr:
+ op := OSLICE
+ if expr.Full {
+ op = OSLICE3
+ }
+ n := p.nod(expr, op, p.expr(expr.X), nil)
+ var index [3]*Node
+ for i, x := range &expr.Index {
+ if x != nil {
+ index[i] = p.expr(x)
+ }
+ }
+ n.SetSliceBounds(index[0], index[1], index[2])
+ return n
+ case *syntax.AssertExpr:
+ return p.nod(expr, ODOTTYPE, p.expr(expr.X), p.typeExpr(expr.Type))
+ case *syntax.Operation:
+ if expr.Op == syntax.Add && expr.Y != nil {
+ return p.sum(expr)
+ }
+ x := p.expr(expr.X)
+ if expr.Y == nil {
+ return p.nod(expr, p.unOp(expr.Op), x, nil)
+ }
+ return p.nod(expr, p.binOp(expr.Op), x, p.expr(expr.Y))
+ case *syntax.CallExpr:
+ n := p.nod(expr, OCALL, p.expr(expr.Fun), nil)
+ n.List.Set(p.exprs(expr.ArgList))
+ n.SetIsDDD(expr.HasDots)
+ return n
+
+ case *syntax.ArrayType:
+ var len *Node
+ if expr.Len != nil {
+ len = p.expr(expr.Len)
+ } else {
+ len = p.nod(expr, ODDD, nil, nil)
+ }
+ return p.nod(expr, OTARRAY, len, p.typeExpr(expr.Elem))
+ case *syntax.SliceType:
+ return p.nod(expr, OTARRAY, nil, p.typeExpr(expr.Elem))
+ case *syntax.DotsType:
+ return p.nod(expr, ODDD, p.typeExpr(expr.Elem), nil)
+ case *syntax.StructType:
+ return p.structType(expr)
+ case *syntax.InterfaceType:
+ return p.interfaceType(expr)
+ case *syntax.FuncType:
+ return p.signature(nil, expr)
+ case *syntax.MapType:
+ return p.nod(expr, OTMAP, p.typeExpr(expr.Key), p.typeExpr(expr.Value))
+ case *syntax.ChanType:
+ n := p.nod(expr, OTCHAN, p.typeExpr(expr.Elem), nil)
+ n.SetTChanDir(p.chanDir(expr.Dir))
+ return n
+
+ case *syntax.TypeSwitchGuard:
+ n := p.nod(expr, OTYPESW, nil, p.expr(expr.X))
+ if expr.Lhs != nil {
+ n.Left = p.declName(expr.Lhs)
+ if n.Left.isBlank() {
+ yyerror("invalid variable name %v in type switch", n.Left)
+ }
+ }
+ return n
+ }
+ panic("unhandled Expr")
+}
+
+// sum efficiently handles very large summation expressions (such as
+// in issue #16394). In particular, it avoids left recursion and
+// collapses string literals.
+func (p *noder) sum(x syntax.Expr) *Node {
+ // While we need to handle long sums with asymptotic
+ // efficiency, the vast majority of sums are very small: ~95%
+ // have only 2 or 3 operands, and ~99% of string literals are
+ // never concatenated.
+
+ adds := make([]*syntax.Operation, 0, 2)
+ for {
+ add, ok := x.(*syntax.Operation)
+ if !ok || add.Op != syntax.Add || add.Y == nil {
+ break
+ }
+ adds = append(adds, add)
+ x = add.X
+ }
+
+ // nstr is the current rightmost string literal in the
+ // summation (if any), and chunks holds its accumulated
+ // substrings.
+ //
+ // Consider the expression x + "a" + "b" + "c" + y. When we
+ // reach the string literal "a", we assign nstr to point to
+ // its corresponding Node and initialize chunks to {"a"}.
+ // Visiting the subsequent string literals "b" and "c", we
+ // simply append their values to chunks. Finally, when we
+ // reach the non-constant operand y, we'll join chunks to form
+ // "abc" and reassign the "a" string literal's value.
+ //
+ // N.B., we need to be careful about named string constants
+ // (indicated by Sym != nil) because 1) we can't modify their
+ // value, as doing so would affect other uses of the string
+ // constant, and 2) they may have types, which we need to
+ // handle correctly. For now, we avoid these problems by
+ // treating named string constants the same as non-constant
+ // operands.
+ var nstr *Node
+ chunks := make([]string, 0, 1)
+
+ n := p.expr(x)
+ if Isconst(n, CTSTR) && n.Sym == nil {
+ nstr = n
+ chunks = append(chunks, nstr.StringVal())
+ }
+
+ for i := len(adds) - 1; i >= 0; i-- {
+ add := adds[i]
+
+ r := p.expr(add.Y)
+ if Isconst(r, CTSTR) && r.Sym == nil {
+ if nstr != nil {
+ // Collapse r into nstr instead of adding to n.
+ chunks = append(chunks, r.StringVal())
+ continue
+ }
+
+ nstr = r
+ chunks = append(chunks, nstr.StringVal())
+ } else {
+ if len(chunks) > 1 {
+ nstr.SetVal(Val{U: strings.Join(chunks, "")})
+ }
+ nstr = nil
+ chunks = chunks[:0]
+ }
+ n = p.nod(add, OADD, n, r)
+ }
+ if len(chunks) > 1 {
+ nstr.SetVal(Val{U: strings.Join(chunks, "")})
+ }
+
+ return n
+}
+
+func (p *noder) typeExpr(typ syntax.Expr) *Node {
+ // TODO(mdempsky): Be stricter? typecheck should handle errors anyway.
+ return p.expr(typ)
+}
+
+func (p *noder) typeExprOrNil(typ syntax.Expr) *Node {
+ if typ != nil {
+ return p.expr(typ)
+ }
+ return nil
+}
+
+func (p *noder) chanDir(dir syntax.ChanDir) types.ChanDir {
+ switch dir {
+ case 0:
+ return types.Cboth
+ case syntax.SendOnly:
+ return types.Csend
+ case syntax.RecvOnly:
+ return types.Crecv
+ }
+ panic("unhandled ChanDir")
+}
+
+func (p *noder) structType(expr *syntax.StructType) *Node {
+ l := make([]*Node, 0, len(expr.FieldList))
+ for i, field := range expr.FieldList {
+ p.setlineno(field)
+ var n *Node
+ if field.Name == nil {
+ n = p.embedded(field.Type)
+ } else {
+ n = p.nodSym(field, ODCLFIELD, p.typeExpr(field.Type), p.name(field.Name))
+ }
+ if i < len(expr.TagList) && expr.TagList[i] != nil {
+ n.SetVal(p.basicLit(expr.TagList[i]))
+ }
+ l = append(l, n)
+ }
+
+ p.setlineno(expr)
+ n := p.nod(expr, OTSTRUCT, nil, nil)
+ n.List.Set(l)
+ return n
+}
+
+func (p *noder) interfaceType(expr *syntax.InterfaceType) *Node {
+ l := make([]*Node, 0, len(expr.MethodList))
+ for _, method := range expr.MethodList {
+ p.setlineno(method)
+ var n *Node
+ if method.Name == nil {
+ n = p.nodSym(method, ODCLFIELD, importName(p.packname(method.Type)), nil)
+ } else {
+ mname := p.name(method.Name)
+ sig := p.typeExpr(method.Type)
+ sig.Left = fakeRecv()
+ n = p.nodSym(method, ODCLFIELD, sig, mname)
+ ifacedcl(n)
+ }
+ l = append(l, n)
+ }
+
+ n := p.nod(expr, OTINTER, nil, nil)
+ n.List.Set(l)
+ return n
+}
+
+func (p *noder) packname(expr syntax.Expr) *types.Sym {
+ switch expr := expr.(type) {
+ case *syntax.Name:
+ name := p.name(expr)
+ if n := oldname(name); n.Name != nil && n.Name.Pack != nil {
+ n.Name.Pack.Name.SetUsed(true)
+ }
+ return name
+ case *syntax.SelectorExpr:
+ name := p.name(expr.X.(*syntax.Name))
+ def := asNode(name.Def)
+ if def == nil {
+ yyerror("undefined: %v", name)
+ return name
+ }
+ var pkg *types.Pkg
+ if def.Op != OPACK {
+ yyerror("%v is not a package", name)
+ pkg = localpkg
+ } else {
+ def.Name.SetUsed(true)
+ pkg = def.Name.Pkg
+ }
+ return pkg.Lookup(expr.Sel.Value)
+ }
+ panic(fmt.Sprintf("unexpected packname: %#v", expr))
+}
+
+func (p *noder) embedded(typ syntax.Expr) *Node {
+ op, isStar := typ.(*syntax.Operation)
+ if isStar {
+ if op.Op != syntax.Mul || op.Y != nil {
+ panic("unexpected Operation")
+ }
+ typ = op.X
+ }
+
+ sym := p.packname(typ)
+ n := p.nodSym(typ, ODCLFIELD, importName(sym), lookup(sym.Name))
+ n.SetEmbedded(true)
+
+ if isStar {
+ n.Left = p.nod(op, ODEREF, n.Left, nil)
+ }
+ return n
+}
+
+func (p *noder) stmts(stmts []syntax.Stmt) []*Node {
+ return p.stmtsFall(stmts, false)
+}
+
+func (p *noder) stmtsFall(stmts []syntax.Stmt, fallOK bool) []*Node {
+ var nodes []*Node
+ for i, stmt := range stmts {
+ s := p.stmtFall(stmt, fallOK && i+1 == len(stmts))
+ if s == nil {
+ } else if s.Op == OBLOCK && s.Ninit.Len() == 0 {
+ nodes = append(nodes, s.List.Slice()...)
+ } else {
+ nodes = append(nodes, s)
+ }
+ }
+ return nodes
+}
+
+func (p *noder) stmt(stmt syntax.Stmt) *Node {
+ return p.stmtFall(stmt, false)
+}
+
+func (p *noder) stmtFall(stmt syntax.Stmt, fallOK bool) *Node {
+ p.setlineno(stmt)
+ switch stmt := stmt.(type) {
+ case *syntax.EmptyStmt:
+ return nil
+ case *syntax.LabeledStmt:
+ return p.labeledStmt(stmt, fallOK)
+ case *syntax.BlockStmt:
+ l := p.blockStmt(stmt)
+ if len(l) == 0 {
+ // TODO(mdempsky): Line number?
+ return nod(OEMPTY, nil, nil)
+ }
+ return liststmt(l)
+ case *syntax.ExprStmt:
+ return p.wrapname(stmt, p.expr(stmt.X))
+ case *syntax.SendStmt:
+ return p.nod(stmt, OSEND, p.expr(stmt.Chan), p.expr(stmt.Value))
+ case *syntax.DeclStmt:
+ return liststmt(p.decls(stmt.DeclList))
+ case *syntax.AssignStmt:
+ if stmt.Op != 0 && stmt.Op != syntax.Def {
+ n := p.nod(stmt, OASOP, p.expr(stmt.Lhs), p.expr(stmt.Rhs))
+ n.SetImplicit(stmt.Rhs == syntax.ImplicitOne)
+ n.SetSubOp(p.binOp(stmt.Op))
+ return n
+ }
+
+ n := p.nod(stmt, OAS, nil, nil) // assume common case
+
+ rhs := p.exprList(stmt.Rhs)
+ lhs := p.assignList(stmt.Lhs, n, stmt.Op == syntax.Def)
+
+ if len(lhs) == 1 && len(rhs) == 1 {
+ // common case
+ n.Left = lhs[0]
+ n.Right = rhs[0]
+ } else {
+ n.Op = OAS2
+ n.List.Set(lhs)
+ n.Rlist.Set(rhs)
+ }
+ return n
+
+ case *syntax.BranchStmt:
+ var op Op
+ switch stmt.Tok {
+ case syntax.Break:
+ op = OBREAK
+ case syntax.Continue:
+ op = OCONTINUE
+ case syntax.Fallthrough:
+ if !fallOK {
+ yyerror("fallthrough statement out of place")
+ }
+ op = OFALL
+ case syntax.Goto:
+ op = OGOTO
+ default:
+ panic("unhandled BranchStmt")
+ }
+ n := p.nod(stmt, op, nil, nil)
+ if stmt.Label != nil {
+ n.Sym = p.name(stmt.Label)
+ }
+ return n
+ case *syntax.CallStmt:
+ var op Op
+ switch stmt.Tok {
+ case syntax.Defer:
+ op = ODEFER
+ case syntax.Go:
+ op = OGO
+ default:
+ panic("unhandled CallStmt")
+ }
+ return p.nod(stmt, op, p.expr(stmt.Call), nil)
+ case *syntax.ReturnStmt:
+ var results []*Node
+ if stmt.Results != nil {
+ results = p.exprList(stmt.Results)
+ }
+ n := p.nod(stmt, ORETURN, nil, nil)
+ n.List.Set(results)
+ if n.List.Len() == 0 && Curfn != nil {
+ for _, ln := range Curfn.Func.Dcl {
+ if ln.Class() == PPARAM {
+ continue
+ }
+ if ln.Class() != PPARAMOUT {
+ break
+ }
+ if asNode(ln.Sym.Def) != ln {
+ yyerror("%s is shadowed during return", ln.Sym.Name)
+ }
+ }
+ }
+ return n
+ case *syntax.IfStmt:
+ return p.ifStmt(stmt)
+ case *syntax.ForStmt:
+ return p.forStmt(stmt)
+ case *syntax.SwitchStmt:
+ return p.switchStmt(stmt)
+ case *syntax.SelectStmt:
+ return p.selectStmt(stmt)
+ }
+ panic("unhandled Stmt")
+}
+
+func (p *noder) assignList(expr syntax.Expr, defn *Node, colas bool) []*Node {
+ if !colas {
+ return p.exprList(expr)
+ }
+
+ defn.SetColas(true)
+
+ var exprs []syntax.Expr
+ if list, ok := expr.(*syntax.ListExpr); ok {
+ exprs = list.ElemList
+ } else {
+ exprs = []syntax.Expr{expr}
+ }
+
+ res := make([]*Node, len(exprs))
+ seen := make(map[*types.Sym]bool, len(exprs))
+
+ newOrErr := false
+ for i, expr := range exprs {
+ p.setlineno(expr)
+ res[i] = nblank
+
+ name, ok := expr.(*syntax.Name)
+ if !ok {
+ p.yyerrorpos(expr.Pos(), "non-name %v on left side of :=", p.expr(expr))
+ newOrErr = true
+ continue
+ }
+
+ sym := p.name(name)
+ if sym.IsBlank() {
+ continue
+ }
+
+ if seen[sym] {
+ p.yyerrorpos(expr.Pos(), "%v repeated on left side of :=", sym)
+ newOrErr = true
+ continue
+ }
+ seen[sym] = true
+
+ if sym.Block == types.Block {
+ res[i] = oldname(sym)
+ continue
+ }
+
+ newOrErr = true
+ n := newname(sym)
+ declare(n, dclcontext)
+ n.Name.Defn = defn
+ defn.Ninit.Append(nod(ODCL, n, nil))
+ res[i] = n
+ }
+
+ if !newOrErr {
+ yyerrorl(defn.Pos, "no new variables on left side of :=")
+ }
+ return res
+}
+
+func (p *noder) blockStmt(stmt *syntax.BlockStmt) []*Node {
+ p.openScope(stmt.Pos())
+ nodes := p.stmts(stmt.List)
+ p.closeScope(stmt.Rbrace)
+ return nodes
+}
+
+func (p *noder) ifStmt(stmt *syntax.IfStmt) *Node {
+ p.openScope(stmt.Pos())
+ n := p.nod(stmt, OIF, nil, nil)
+ if stmt.Init != nil {
+ n.Ninit.Set1(p.stmt(stmt.Init))
+ }
+ if stmt.Cond != nil {
+ n.Left = p.expr(stmt.Cond)
+ }
+ n.Nbody.Set(p.blockStmt(stmt.Then))
+ if stmt.Else != nil {
+ e := p.stmt(stmt.Else)
+ if e.Op == OBLOCK && e.Ninit.Len() == 0 {
+ n.Rlist.Set(e.List.Slice())
+ } else {
+ n.Rlist.Set1(e)
+ }
+ }
+ p.closeAnotherScope()
+ return n
+}
+
+func (p *noder) forStmt(stmt *syntax.ForStmt) *Node {
+ p.openScope(stmt.Pos())
+ var n *Node
+ if r, ok := stmt.Init.(*syntax.RangeClause); ok {
+ if stmt.Cond != nil || stmt.Post != nil {
+ panic("unexpected RangeClause")
+ }
+
+ n = p.nod(r, ORANGE, nil, p.expr(r.X))
+ if r.Lhs != nil {
+ n.List.Set(p.assignList(r.Lhs, n, r.Def))
+ }
+ } else {
+ n = p.nod(stmt, OFOR, nil, nil)
+ if stmt.Init != nil {
+ n.Ninit.Set1(p.stmt(stmt.Init))
+ }
+ if stmt.Cond != nil {
+ n.Left = p.expr(stmt.Cond)
+ }
+ if stmt.Post != nil {
+ n.Right = p.stmt(stmt.Post)
+ }
+ }
+ n.Nbody.Set(p.blockStmt(stmt.Body))
+ p.closeAnotherScope()
+ return n
+}
+
+func (p *noder) switchStmt(stmt *syntax.SwitchStmt) *Node {
+ p.openScope(stmt.Pos())
+ n := p.nod(stmt, OSWITCH, nil, nil)
+ if stmt.Init != nil {
+ n.Ninit.Set1(p.stmt(stmt.Init))
+ }
+ if stmt.Tag != nil {
+ n.Left = p.expr(stmt.Tag)
+ }
+
+ tswitch := n.Left
+ if tswitch != nil && tswitch.Op != OTYPESW {
+ tswitch = nil
+ }
+ n.List.Set(p.caseClauses(stmt.Body, tswitch, stmt.Rbrace))
+
+ p.closeScope(stmt.Rbrace)
+ return n
+}
+
+func (p *noder) caseClauses(clauses []*syntax.CaseClause, tswitch *Node, rbrace syntax.Pos) []*Node {
+ nodes := make([]*Node, 0, len(clauses))
+ for i, clause := range clauses {
+ p.setlineno(clause)
+ if i > 0 {
+ p.closeScope(clause.Pos())
+ }
+ p.openScope(clause.Pos())
+
+ n := p.nod(clause, OCASE, nil, nil)
+ if clause.Cases != nil {
+ n.List.Set(p.exprList(clause.Cases))
+ }
+ if tswitch != nil && tswitch.Left != nil {
+ nn := newname(tswitch.Left.Sym)
+ declare(nn, dclcontext)
+ n.Rlist.Set1(nn)
+ // keep track of the instances for reporting unused
+ nn.Name.Defn = tswitch
+ }
+
+ // Trim trailing empty statements. We omit them from
+ // the Node AST anyway, and it's easier to identify
+ // out-of-place fallthrough statements without them.
+ body := clause.Body
+ for len(body) > 0 {
+ if _, ok := body[len(body)-1].(*syntax.EmptyStmt); !ok {
+ break
+ }
+ body = body[:len(body)-1]
+ }
+
+ n.Nbody.Set(p.stmtsFall(body, true))
+ if l := n.Nbody.Len(); l > 0 && n.Nbody.Index(l-1).Op == OFALL {
+ if tswitch != nil {
+ yyerror("cannot fallthrough in type switch")
+ }
+ if i+1 == len(clauses) {
+ yyerror("cannot fallthrough final case in switch")
+ }
+ }
+
+ nodes = append(nodes, n)
+ }
+ if len(clauses) > 0 {
+ p.closeScope(rbrace)
+ }
+ return nodes
+}
+
+func (p *noder) selectStmt(stmt *syntax.SelectStmt) *Node {
+ n := p.nod(stmt, OSELECT, nil, nil)
+ n.List.Set(p.commClauses(stmt.Body, stmt.Rbrace))
+ return n
+}
+
+func (p *noder) commClauses(clauses []*syntax.CommClause, rbrace syntax.Pos) []*Node {
+ nodes := make([]*Node, 0, len(clauses))
+ for i, clause := range clauses {
+ p.setlineno(clause)
+ if i > 0 {
+ p.closeScope(clause.Pos())
+ }
+ p.openScope(clause.Pos())
+
+ n := p.nod(clause, OCASE, nil, nil)
+ if clause.Comm != nil {
+ n.List.Set1(p.stmt(clause.Comm))
+ }
+ n.Nbody.Set(p.stmts(clause.Body))
+ nodes = append(nodes, n)
+ }
+ if len(clauses) > 0 {
+ p.closeScope(rbrace)
+ }
+ return nodes
+}
+
+func (p *noder) labeledStmt(label *syntax.LabeledStmt, fallOK bool) *Node {
+ lhs := p.nodSym(label, OLABEL, nil, p.name(label.Label))
+
+ var ls *Node
+ if label.Stmt != nil { // TODO(mdempsky): Should always be present.
+ ls = p.stmtFall(label.Stmt, fallOK)
+ }
+
+ lhs.Name.Defn = ls
+ l := []*Node{lhs}
+ if ls != nil {
+ if ls.Op == OBLOCK && ls.Ninit.Len() == 0 {
+ l = append(l, ls.List.Slice()...)
+ } else {
+ l = append(l, ls)
+ }
+ }
+ return liststmt(l)
+}
+
+var unOps = [...]Op{
+ syntax.Recv: ORECV,
+ syntax.Mul: ODEREF,
+ syntax.And: OADDR,
+
+ syntax.Not: ONOT,
+ syntax.Xor: OBITNOT,
+ syntax.Add: OPLUS,
+ syntax.Sub: ONEG,
+}
+
+func (p *noder) unOp(op syntax.Operator) Op {
+ if uint64(op) >= uint64(len(unOps)) || unOps[op] == 0 {
+ panic("invalid Operator")
+ }
+ return unOps[op]
+}
+
+var binOps = [...]Op{
+ syntax.OrOr: OOROR,
+ syntax.AndAnd: OANDAND,
+
+ syntax.Eql: OEQ,
+ syntax.Neq: ONE,
+ syntax.Lss: OLT,
+ syntax.Leq: OLE,
+ syntax.Gtr: OGT,
+ syntax.Geq: OGE,
+
+ syntax.Add: OADD,
+ syntax.Sub: OSUB,
+ syntax.Or: OOR,
+ syntax.Xor: OXOR,
+
+ syntax.Mul: OMUL,
+ syntax.Div: ODIV,
+ syntax.Rem: OMOD,
+ syntax.And: OAND,
+ syntax.AndNot: OANDNOT,
+ syntax.Shl: OLSH,
+ syntax.Shr: ORSH,
+}
+
+func (p *noder) binOp(op syntax.Operator) Op {
+ if uint64(op) >= uint64(len(binOps)) || binOps[op] == 0 {
+ panic("invalid Operator")
+ }
+ return binOps[op]
+}
+
+// checkLangCompat reports an error if the representation of a numeric
+// literal is not compatible with the current language version.
+func checkLangCompat(lit *syntax.BasicLit) {
+ s := lit.Value
+ if len(s) <= 2 || langSupported(1, 13, localpkg) {
+ return
+ }
+ // len(s) > 2
+ if strings.Contains(s, "_") {
+ yyerrorv("go1.13", "underscores in numeric literals")
+ return
+ }
+ if s[0] != '0' {
+ return
+ }
+ base := s[1]
+ if base == 'b' || base == 'B' {
+ yyerrorv("go1.13", "binary literals")
+ return
+ }
+ if base == 'o' || base == 'O' {
+ yyerrorv("go1.13", "0o/0O-style octal literals")
+ return
+ }
+ if lit.Kind != syntax.IntLit && (base == 'x' || base == 'X') {
+ yyerrorv("go1.13", "hexadecimal floating-point literals")
+ }
+}
+
+func (p *noder) basicLit(lit *syntax.BasicLit) Val {
+ // We don't use the errors of the conversion routines to determine
+ // if a literal string is valid because the conversion routines may
+ // accept a wider syntax than the language permits. Rely on lit.Bad
+ // instead.
+ switch s := lit.Value; lit.Kind {
+ case syntax.IntLit:
+ checkLangCompat(lit)
+ x := new(Mpint)
+ if !lit.Bad {
+ x.SetString(s)
+ }
+ return Val{U: x}
+
+ case syntax.FloatLit:
+ checkLangCompat(lit)
+ x := newMpflt()
+ if !lit.Bad {
+ x.SetString(s)
+ }
+ return Val{U: x}
+
+ case syntax.ImagLit:
+ checkLangCompat(lit)
+ x := newMpcmplx()
+ if !lit.Bad {
+ x.Imag.SetString(strings.TrimSuffix(s, "i"))
+ }
+ return Val{U: x}
+
+ case syntax.RuneLit:
+ x := new(Mpint)
+ x.Rune = true
+ if !lit.Bad {
+ u, _ := strconv.Unquote(s)
+ var r rune
+ if len(u) == 1 {
+ r = rune(u[0])
+ } else {
+ r, _ = utf8.DecodeRuneInString(u)
+ }
+ x.SetInt64(int64(r))
+ }
+ return Val{U: x}
+
+ case syntax.StringLit:
+ var x string
+ if !lit.Bad {
+ if len(s) > 0 && s[0] == '`' {
+ // strip carriage returns from raw string
+ s = strings.Replace(s, "\r", "", -1)
+ }
+ x, _ = strconv.Unquote(s)
+ }
+ return Val{U: x}
+
+ default:
+ panic("unhandled BasicLit kind")
+ }
+}
+
+func (p *noder) name(name *syntax.Name) *types.Sym {
+ return lookup(name.Value)
+}
+
+func (p *noder) mkname(name *syntax.Name) *Node {
+ // TODO(mdempsky): Set line number?
+ return mkname(p.name(name))
+}
+
+func (p *noder) wrapname(n syntax.Node, x *Node) *Node {
+ // These nodes do not carry line numbers.
+ // Introduce a wrapper node to give them the correct line.
+ switch x.Op {
+ case OTYPE, OLITERAL:
+ if x.Sym == nil {
+ break
+ }
+ fallthrough
+ case ONAME, ONONAME, OPACK:
+ x = p.nod(n, OPAREN, x, nil)
+ x.SetImplicit(true)
+ }
+ return x
+}
+
+func (p *noder) nod(orig syntax.Node, op Op, left, right *Node) *Node {
+ return nodl(p.pos(orig), op, left, right)
+}
+
+func (p *noder) nodSym(orig syntax.Node, op Op, left *Node, sym *types.Sym) *Node {
+ n := nodSym(op, left, sym)
+ n.Pos = p.pos(orig)
+ return n
+}
+
+func (p *noder) pos(n syntax.Node) src.XPos {
+ // TODO(gri): orig.Pos() should always be known - fix package syntax
+ xpos := lineno
+ if pos := n.Pos(); pos.IsKnown() {
+ xpos = p.makeXPos(pos)
+ }
+ return xpos
+}
+
+func (p *noder) setlineno(n syntax.Node) {
+ if n != nil {
+ lineno = p.pos(n)
+ }
+}
+
+// error is called concurrently if files are parsed concurrently.
+func (p *noder) error(err error) {
+ p.err <- err.(syntax.Error)
+}
+
+// pragmas that are allowed in the std lib, but don't have
+// a syntax.Pragma value (see lex.go) associated with them.
+var allowedStdPragmas = map[string]bool{
+ "go:cgo_export_static": true,
+ "go:cgo_export_dynamic": true,
+ "go:cgo_import_static": true,
+ "go:cgo_import_dynamic": true,
+ "go:cgo_ldflag": true,
+ "go:cgo_dynamic_linker": true,
+ "go:embed": true,
+ "go:generate": true,
+}
+
+// *Pragma is the value stored in a syntax.Pragma during parsing.
+type Pragma struct {
+ Flag PragmaFlag // collected bits
+ Pos []PragmaPos // position of each individual flag
+ Embeds []PragmaEmbed
+}
+
+type PragmaPos struct {
+ Flag PragmaFlag
+ Pos syntax.Pos
+}
+
+type PragmaEmbed struct {
+ Pos syntax.Pos
+ Patterns []string
+}
+
+func (p *noder) checkUnused(pragma *Pragma) {
+ for _, pos := range pragma.Pos {
+ if pos.Flag&pragma.Flag != 0 {
+ p.yyerrorpos(pos.Pos, "misplaced compiler directive")
+ }
+ }
+ if len(pragma.Embeds) > 0 {
+ for _, e := range pragma.Embeds {
+ p.yyerrorpos(e.Pos, "misplaced go:embed directive")
+ }
+ }
+}
+
+func (p *noder) checkUnusedDuringParse(pragma *Pragma) {
+ for _, pos := range pragma.Pos {
+ if pos.Flag&pragma.Flag != 0 {
+ p.error(syntax.Error{Pos: pos.Pos, Msg: "misplaced compiler directive"})
+ }
+ }
+ if len(pragma.Embeds) > 0 {
+ for _, e := range pragma.Embeds {
+ p.error(syntax.Error{Pos: e.Pos, Msg: "misplaced go:embed directive"})
+ }
+ }
+}
+
+// pragma is called concurrently if files are parsed concurrently.
+func (p *noder) pragma(pos syntax.Pos, blankLine bool, text string, old syntax.Pragma) syntax.Pragma {
+ pragma, _ := old.(*Pragma)
+ if pragma == nil {
+ pragma = new(Pragma)
+ }
+
+ if text == "" {
+ // unused pragma; only called with old != nil.
+ p.checkUnusedDuringParse(pragma)
+ return nil
+ }
+
+ if strings.HasPrefix(text, "line ") {
+ // line directives are handled by syntax package
+ panic("unreachable")
+ }
+
+ if !blankLine {
+ // directive must be on line by itself
+ p.error(syntax.Error{Pos: pos, Msg: "misplaced compiler directive"})
+ return pragma
+ }
+
+ switch {
+ case strings.HasPrefix(text, "go:linkname "):
+ f := strings.Fields(text)
+ if !(2 <= len(f) && len(f) <= 3) {
+ p.error(syntax.Error{Pos: pos, Msg: "usage: //go:linkname localname [linkname]"})
+ break
+ }
+ // The second argument is optional. If omitted, we use
+ // the default object symbol name for this and
+ // linkname only serves to mark this symbol as
+ // something that may be referenced via the object
+ // symbol name from another package.
+ var target string
+ if len(f) == 3 {
+ target = f[2]
+ }
+ p.linknames = append(p.linknames, linkname{pos, f[1], target})
+
+ case text == "go:embed", strings.HasPrefix(text, "go:embed "):
+ args, err := parseGoEmbed(text[len("go:embed"):])
+ if err != nil {
+ p.error(syntax.Error{Pos: pos, Msg: err.Error()})
+ }
+ if len(args) == 0 {
+ p.error(syntax.Error{Pos: pos, Msg: "usage: //go:embed pattern..."})
+ break
+ }
+ pragma.Embeds = append(pragma.Embeds, PragmaEmbed{pos, args})
+
+ case strings.HasPrefix(text, "go:cgo_import_dynamic "):
+ // This is permitted for general use because Solaris
+ // code relies on it in golang.org/x/sys/unix and others.
+ fields := pragmaFields(text)
+ if len(fields) >= 4 {
+ lib := strings.Trim(fields[3], `"`)
+ if lib != "" && !safeArg(lib) && !isCgoGeneratedFile(pos) {
+ p.error(syntax.Error{Pos: pos, Msg: fmt.Sprintf("invalid library name %q in cgo_import_dynamic directive", lib)})
+ }
+ p.pragcgo(pos, text)
+ pragma.Flag |= pragmaFlag("go:cgo_import_dynamic")
+ break
+ }
+ fallthrough
+ case strings.HasPrefix(text, "go:cgo_"):
+ // For security, we disallow //go:cgo_* directives other
+ // than cgo_import_dynamic outside cgo-generated files.
+ // Exception: they are allowed in the standard library, for runtime and syscall.
+ if !isCgoGeneratedFile(pos) && !compiling_std {
+ p.error(syntax.Error{Pos: pos, Msg: fmt.Sprintf("//%s only allowed in cgo-generated code", text)})
+ }
+ p.pragcgo(pos, text)
+ fallthrough // because of //go:cgo_unsafe_args
+ default:
+ verb := text
+ if i := strings.Index(text, " "); i >= 0 {
+ verb = verb[:i]
+ }
+ flag := pragmaFlag(verb)
+ const runtimePragmas = Systemstack | Nowritebarrier | Nowritebarrierrec | Yeswritebarrierrec
+ if !compiling_runtime && flag&runtimePragmas != 0 {
+ p.error(syntax.Error{Pos: pos, Msg: fmt.Sprintf("//%s only allowed in runtime", verb)})
+ }
+ if flag == 0 && !allowedStdPragmas[verb] && compiling_std {
+ p.error(syntax.Error{Pos: pos, Msg: fmt.Sprintf("//%s is not allowed in the standard library", verb)})
+ }
+ pragma.Flag |= flag
+ pragma.Pos = append(pragma.Pos, PragmaPos{flag, pos})
+ }
+
+ return pragma
+}
+
+// isCgoGeneratedFile reports whether pos is in a file
+// generated by cgo, which is to say a file with name
+// beginning with "_cgo_". Such files are allowed to
+// contain cgo directives, and for security reasons
+// (primarily misuse of linker flags), other files are not.
+// See golang.org/issue/23672.
+func isCgoGeneratedFile(pos syntax.Pos) bool {
+ return strings.HasPrefix(filepath.Base(filepath.Clean(fileh(pos.Base().Filename()))), "_cgo_")
+}
+
+// safeArg reports whether arg is a "safe" command-line argument,
+// meaning that when it appears in a command-line, it probably
+// doesn't have some special meaning other than its own name.
+// This is copied from SafeArg in cmd/go/internal/load/pkg.go.
+func safeArg(name string) bool {
+ if name == "" {
+ return false
+ }
+ c := name[0]
+ return '0' <= c && c <= '9' || 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || c == '.' || c == '_' || c == '/' || c >= utf8.RuneSelf
+}
+
+func mkname(sym *types.Sym) *Node {
+ n := oldname(sym)
+ if n.Name != nil && n.Name.Pack != nil {
+ n.Name.Pack.Name.SetUsed(true)
+ }
+ return n
+}
+
+// parseGoEmbed parses the text following "//go:embed" to extract the glob patterns.
+// It accepts unquoted space-separated patterns as well as double-quoted and back-quoted Go strings.
+// go/build/read.go also processes these strings and contains similar logic.
+func parseGoEmbed(args string) ([]string, error) {
+ var list []string
+ for args = strings.TrimSpace(args); args != ""; args = strings.TrimSpace(args) {
+ var path string
+ Switch:
+ switch args[0] {
+ default:
+ i := len(args)
+ for j, c := range args {
+ if unicode.IsSpace(c) {
+ i = j
+ break
+ }
+ }
+ path = args[:i]
+ args = args[i:]
+
+ case '`':
+ i := strings.Index(args[1:], "`")
+ if i < 0 {
+ return nil, fmt.Errorf("invalid quoted string in //go:embed: %s", args)
+ }
+ path = args[1 : 1+i]
+ args = args[1+i+1:]
+
+ case '"':
+ i := 1
+ for ; i < len(args); i++ {
+ if args[i] == '\\' {
+ i++
+ continue
+ }
+ if args[i] == '"' {
+ q, err := strconv.Unquote(args[:i+1])
+ if err != nil {
+ return nil, fmt.Errorf("invalid quoted string in //go:embed: %s", args[:i+1])
+ }
+ path = q
+ args = args[i+1:]
+ break Switch
+ }
+ }
+ if i >= len(args) {
+ return nil, fmt.Errorf("invalid quoted string in //go:embed: %s", args)
+ }
+ }
+
+ if args != "" {
+ r, _ := utf8.DecodeRuneInString(args)
+ if !unicode.IsSpace(r) {
+ return nil, fmt.Errorf("invalid quoted string in //go:embed: %s", args)
+ }
+ }
+ list = append(list, path)
+ }
+ return list, nil
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-15 11:13:50 +0000