blob: 82455f7d4a60dc139956a8f2ddf2b1fcf8acbdc3 [file] [log] [blame]
// Copyright 2021 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 noder
import (
"go/constant"
"cmd/compile/internal/base"
"cmd/compile/internal/ir"
"cmd/compile/internal/syntax"
"cmd/compile/internal/typecheck"
"cmd/compile/internal/types"
"cmd/compile/internal/types2"
)
// TODO(mdempsky): Skip blank declarations? Probably only safe
// for declarations without pragmas.
func (g *irgen) decls(res *ir.Nodes, decls []syntax.Decl) {
for _, decl := range decls {
switch decl := decl.(type) {
case *syntax.ConstDecl:
g.constDecl(res, decl)
case *syntax.FuncDecl:
g.funcDecl(res, decl)
case *syntax.TypeDecl:
if ir.CurFunc == nil {
continue // already handled in irgen.generate
}
g.typeDecl(res, decl)
case *syntax.VarDecl:
g.varDecl(res, decl)
default:
g.unhandled("declaration", decl)
}
}
}
func (g *irgen) importDecl(p *noder, decl *syntax.ImportDecl) {
g.pragmaFlags(decl.Pragma, 0)
// Get the imported package's path, as resolved already by types2
// and gcimporter. This is the same path as would be computed by
// parseImportPath.
switch pkgNameOf(g.info, decl).Imported().Path() {
case "unsafe":
p.importedUnsafe = true
case "embed":
p.importedEmbed = true
}
}
// pkgNameOf returns the PkgName associated with the given ImportDecl.
func pkgNameOf(info *types2.Info, decl *syntax.ImportDecl) *types2.PkgName {
if name := decl.LocalPkgName; name != nil {
return info.Defs[name].(*types2.PkgName)
}
return info.Implicits[decl].(*types2.PkgName)
}
func (g *irgen) constDecl(out *ir.Nodes, decl *syntax.ConstDecl) {
g.pragmaFlags(decl.Pragma, 0)
for _, name := range decl.NameList {
name, obj := g.def(name)
// For untyped numeric constants, make sure the value
// representation matches what the rest of the
// compiler (really just iexport) expects.
// TODO(mdempsky): Revisit after #43891 is resolved.
val := obj.(*types2.Const).Val()
switch name.Type() {
case types.UntypedInt, types.UntypedRune:
val = constant.ToInt(val)
case types.UntypedFloat:
val = constant.ToFloat(val)
case types.UntypedComplex:
val = constant.ToComplex(val)
}
name.SetVal(val)
out.Append(ir.NewDecl(g.pos(decl), ir.ODCLCONST, name))
}
}
func (g *irgen) funcDecl(out *ir.Nodes, decl *syntax.FuncDecl) {
// Set g.curDecl to the function name, as context for the type params declared
// during types2-to-types1 translation if this is a generic function.
g.curDecl = decl.Name.Value
obj2 := g.info.Defs[decl.Name]
recv := types2.AsSignature(obj2.Type()).Recv()
if recv != nil {
t2 := deref2(recv.Type())
// This is a method, so set g.curDecl to recvTypeName.methName instead.
g.curDecl = types2.AsNamed(t2).Obj().Name() + "." + g.curDecl
}
fn := ir.NewFunc(g.pos(decl))
fn.Nname, _ = g.def(decl.Name)
fn.Nname.Func = fn
fn.Nname.Defn = fn
fn.Pragma = g.pragmaFlags(decl.Pragma, funcPragmas)
if fn.Pragma&ir.Systemstack != 0 && fn.Pragma&ir.Nosplit != 0 {
base.ErrorfAt(fn.Pos(), "go:nosplit and go:systemstack cannot be combined")
}
if fn.Pragma&ir.Nointerface != 0 {
// Propagate //go:nointerface from Func.Pragma to Field.Nointerface.
// This is a bit roundabout, but this is the earliest point where we've
// processed the function's pragma flags, and we've also already created
// the Fields to represent the receiver's method set.
if recv := fn.Type().Recv(); recv != nil {
typ := types.ReceiverBaseType(recv.Type)
if typ.OrigSym() != nil {
// For a generic method, we mark the methods on the
// base generic type, since those are the methods
// that will be stenciled.
typ = typ.OrigSym().Def.Type()
}
meth := typecheck.Lookdot1(fn, typecheck.Lookup(decl.Name.Value), typ, typ.Methods(), 0)
meth.SetNointerface(true)
}
}
if decl.Body != nil && fn.Pragma&ir.Noescape != 0 {
base.ErrorfAt(fn.Pos(), "can only use //go:noescape with external func implementations")
}
if decl.Name.Value == "init" && decl.Recv == nil {
g.target.Inits = append(g.target.Inits, fn)
}
haveEmbed := g.haveEmbed
g.later(func() {
defer func(b bool) { g.haveEmbed = b }(g.haveEmbed)
g.haveEmbed = haveEmbed
if fn.Type().HasTParam() {
g.topFuncIsGeneric = true
}
g.funcBody(fn, decl.Recv, decl.Type, decl.Body)
g.topFuncIsGeneric = false
if fn.Type().HasTParam() && fn.Body != nil {
// Set pointers to the dcls/body of a generic function/method in
// the Inl struct, so it is marked for export, is available for
// stenciling, and works with Inline_Flood().
fn.Inl = &ir.Inline{
Cost: 1,
Dcl: fn.Dcl,
Body: fn.Body,
}
}
out.Append(fn)
})
}
func (g *irgen) typeDecl(out *ir.Nodes, decl *syntax.TypeDecl) {
// Set g.curDecl to the type name, as context for the type params declared
// during types2-to-types1 translation if this is a generic type.
g.curDecl = decl.Name.Value
if decl.Alias {
name, _ := g.def(decl.Name)
g.pragmaFlags(decl.Pragma, 0)
assert(name.Alias()) // should be set by irgen.obj
out.Append(ir.NewDecl(g.pos(decl), ir.ODCLTYPE, name))
return
}
// Prevent size calculations until we set the underlying type.
types.DeferCheckSize()
name, obj := g.def(decl.Name)
ntyp, otyp := name.Type(), obj.Type()
if ir.CurFunc != nil {
ntyp.SetVargen()
}
pragmas := g.pragmaFlags(decl.Pragma, typePragmas)
name.SetPragma(pragmas) // TODO(mdempsky): Is this still needed?
if pragmas&ir.NotInHeap != 0 {
ntyp.SetNotInHeap(true)
}
// We need to use g.typeExpr(decl.Type) here to ensure that for
// chained, defined-type declarations like:
//
// type T U
//
// //go:notinheap
// type U struct { … }
//
// we mark both T and U as NotInHeap. If we instead used just
// g.typ(otyp.Underlying()), then we'd instead set T's underlying
// type directly to the struct type (which is not marked NotInHeap)
// and fail to mark T as NotInHeap.
//
// Also, we rely here on Type.SetUnderlying allowing passing a
// defined type and handling forward references like from T to U
// above. Contrast with go/types's Named.SetUnderlying, which
// disallows this.
//
// [mdempsky: Subtleties like these are why I always vehemently
// object to new type pragmas.]
ntyp.SetUnderlying(g.typeExpr(decl.Type))
tparams := otyp.(*types2.Named).TypeParams()
if n := tparams.Len(); n > 0 {
rparams := make([]*types.Type, n)
for i := range rparams {
rparams[i] = g.typ(tparams.At(i))
}
// This will set hasTParam flag if any rparams are not concrete types.
ntyp.SetRParams(rparams)
}
types.ResumeCheckSize()
if otyp, ok := otyp.(*types2.Named); ok && otyp.NumMethods() != 0 {
methods := make([]*types.Field, otyp.NumMethods())
for i := range methods {
m := otyp.Method(i)
// Set g.curDecl to recvTypeName.methName, as context for the
// method-specific type params in the receiver.
g.curDecl = decl.Name.Value + "." + m.Name()
meth := g.obj(m)
methods[i] = types.NewField(meth.Pos(), g.selector(m), meth.Type())
methods[i].Nname = meth
}
ntyp.Methods().Set(methods)
}
out.Append(ir.NewDecl(g.pos(decl), ir.ODCLTYPE, name))
}
func (g *irgen) varDecl(out *ir.Nodes, decl *syntax.VarDecl) {
pos := g.pos(decl)
names := make([]*ir.Name, len(decl.NameList))
for i, name := range decl.NameList {
names[i], _ = g.def(name)
}
if decl.Pragma != nil {
pragma := decl.Pragma.(*pragmas)
varEmbed(g.makeXPos, names[0], decl, pragma, g.haveEmbed)
g.reportUnused(pragma)
}
haveEmbed := g.haveEmbed
do := func() {
defer func(b bool) { g.haveEmbed = b }(g.haveEmbed)
g.haveEmbed = haveEmbed
values := g.exprList(decl.Values)
var as2 *ir.AssignListStmt
if len(values) != 0 && len(names) != len(values) {
as2 = ir.NewAssignListStmt(pos, ir.OAS2, make([]ir.Node, len(names)), values)
}
for i, name := range names {
if ir.CurFunc != nil {
out.Append(ir.NewDecl(pos, ir.ODCL, name))
}
if as2 != nil {
as2.Lhs[i] = name
name.Defn = as2
} else {
as := ir.NewAssignStmt(pos, name, nil)
if len(values) != 0 {
as.Y = values[i]
name.Defn = as
} else if ir.CurFunc == nil {
name.Defn = as
}
lhs := []ir.Node{as.X}
rhs := []ir.Node{}
if as.Y != nil {
rhs = []ir.Node{as.Y}
}
transformAssign(as, lhs, rhs)
as.X = lhs[0]
if as.Y != nil {
as.Y = rhs[0]
}
as.SetTypecheck(1)
out.Append(as)
}
}
if as2 != nil {
transformAssign(as2, as2.Lhs, as2.Rhs)
as2.SetTypecheck(1)
out.Append(as2)
}
}
// If we're within a function, we need to process the assignment
// part of the variable declaration right away. Otherwise, we leave
// it to be handled after all top-level declarations are processed.
if ir.CurFunc != nil {
do()
} else {
g.later(do)
}
}
// pragmaFlags returns any specified pragma flags included in allowed,
// and reports errors about any other, unexpected pragmas.
func (g *irgen) pragmaFlags(pragma syntax.Pragma, allowed ir.PragmaFlag) ir.PragmaFlag {
if pragma == nil {
return 0
}
p := pragma.(*pragmas)
present := p.Flag & allowed
p.Flag &^= allowed
g.reportUnused(p)
return present
}
// reportUnused reports errors about any unused pragmas.
func (g *irgen) reportUnused(pragma *pragmas) {
for _, pos := range pragma.Pos {
if pos.Flag&pragma.Flag != 0 {
base.ErrorfAt(g.makeXPos(pos.Pos), "misplaced compiler directive")
}
}
if len(pragma.Embeds) > 0 {
for _, e := range pragma.Embeds {
base.ErrorfAt(g.makeXPos(e.Pos), "misplaced go:embed directive")
}
}
}