go/internal/gccgoimporter: update for gofrontend export data changes

This recognizes new features that the gofrontend has started emitting
in the export data to support cross-package inlinable functions.

This is a port of CL 180677 and 180758 from the gofrontend repo.

Change-Id: I48af6e71f9d8b04ba874ea0c204d39d1d461f8ad
Reviewed-on: https://go-review.googlesource.com/c/go/+/181118
Run-TryBot: Ian Lance Taylor <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Than McIntosh <[email protected]>

src/go/internal/gccgoimporter/parser.go

@@ -268,6 +268,10 @@ func (p *parser) parseField(pkg *types.Package) (field *types.Var, tag string) {
 // Param = Name ["..."] Type .
 func (p *parser) parseParam(pkg *types.Package) (param *types.Var, isVariadic bool) {
  name := p.parseName()
+ // Ignore names invented for inlinable functions.
+ if strings.HasPrefix(name, "p.") || strings.HasPrefix(name, "r.") || strings.HasPrefix(name, "$ret") {
+ name = ""
+ }
  if p.tok == '<' && p.scanner.Peek() == 'e' {
  // EscInfo = "<esc:" int ">" . (optional and ignored)
  p.next()
@@ -293,7 +297,14 @@ func (p *parser) parseParam(pkg *types.Package) (param *types.Var, isVariadic bo
 // Var = Name Type .
 func (p *parser) parseVar(pkg *types.Package) *types.Var {
  name := p.parseName()
- return types.NewVar(token.NoPos, pkg, name, p.parseType(pkg))
+ v := types.NewVar(token.NoPos, pkg, name, p.parseType(pkg))
+ if name[0] == '.' || name[0] == '<' {
+ // This is an unexported variable,
+ // or a variable defined in a different package.
+ // We only want to record exported variables.
+ return nil
+ }
+ return v
 }
 
 // Conversion = "convert" "(" Type "," ConstValue ")" .
@@ -547,10 +558,12 @@ func (p *parser) parseNamedType(nlist []int) types.Type {
  for p.tok == scanner.Ident {
  p.expectKeyword("func")
  if p.tok == '/' {
- // Skip a /*nointerface*/ comment.
+ // Skip a /*nointerface*/ or /*asm ID */ comment.
  p.expect('/')
  p.expect('*')
- p.expect(scanner.Ident)
+ if p.expect(scanner.Ident) == "asm" {
+ p.parseUnquotedString()
+ }
  p.expect('*')
  p.expect('/')
  }
@@ -736,15 +749,29 @@ func (p *parser) parseFunctionType(pkg *types.Package, nlist []int) *types.Signa
 
 // Func = Name FunctionType [InlineBody] .
 func (p *parser) parseFunc(pkg *types.Package) *types.Func {
- name := p.parseName()
- if strings.ContainsRune(name, '$') {
- // This is a Type$equal or Type$hash function, which we don't want to parse,
- // except for the types.
- p.discardDirectiveWhileParsingTypes(pkg)
- return nil
+ if p.tok == '/' {
+ // Skip an /*asm ID */ comment.
+ p.expect('/')
+ p.expect('*')
+ if p.expect(scanner.Ident) == "asm" {
+ p.parseUnquotedString()
+ }
+ p.expect('*')
+ p.expect('/')
  }
+
+ name := p.parseName()
  f := types.NewFunc(token.NoPos, pkg, name, p.parseFunctionType(pkg, nil))
  p.skipInlineBody()
+
+ if name[0] == '.' || name[0] == '<' || strings.ContainsRune(name, '$') {
+ // This is an unexported function,
+ // or a function defined in a different package,
+ // or a type$equal or type$hash function.
+ // We only want to record exported functions.
+ return nil
+ }
+
  return f
 }
 
@@ -765,7 +792,9 @@ func (p *parser) parseInterfaceType(pkg *types.Package, nlist []int) types.Type
  embeddeds = append(embeddeds, p.parseType(pkg))
  } else {
  method := p.parseFunc(pkg)
- methods = append(methods, method)
+ if method != nil {
+ methods = append(methods, method)
+ }
  }
  p.expect(';')
  }
@@ -1057,22 +1086,6 @@ func (p *parser) parsePackageInit() PackageInit {
  return PackageInit{Name: name, InitFunc: initfunc, Priority: priority}
 }
 
-// Throw away tokens until we see a ';'. If we see a '<', attempt to parse as a type.
-func (p *parser) discardDirectiveWhileParsingTypes(pkg *types.Package) {
- for {
- switch p.tok {
- case '\n', ';':
- return
- case '<':
- p.parseType(pkg)
- case scanner.EOF:
- p.error("unexpected EOF")
- default:
- p.next()
- }
- }
-}
-
 // Create the package if we have parsed both the package path and package name.
 func (p *parser) maybeCreatePackage() {
  if p.pkgname != "" && p.pkgpath != "" {
@@ -1210,7 +1223,9 @@ func (p *parser) parseDirective() {
  case "var":
  p.next()
  v := p.parseVar(p.pkg)
- p.pkg.Scope().Insert(v)
+ if v != nil {
+ p.pkg.Scope().Insert(v)
+ }
  p.expectEOL()
 
  case "const":