cmd/compile: switch to final unified IR export format

Now that there's a native go/types importer for unified IR, the
compiler no longer needs to stay backwards compatible with old iexport
importers.

This CL also updates the go/types and go/internal/gcimporter tests to
expect that the unified IR importer sets the receiver parameter type
to the underlying Interface type, rather than the Named type. This is
a temporary workaround until we make a decision on #49906.

Notably, this makes `GOEXPERIMENT=unified go test` work on generics
code without requiring `-vet=off` (because previously cmd/vet was
relying on unified IR's backwards-compatible iexport data, which
omitted generic types).

Change-Id: Iac7a2346bb7a91e6690fb2978fb702fadae5559d
Reviewed-on: https://go-review.googlesource.com/c/go/+/386004
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

1 files changed, 2 insertions, 14 deletions

diff --git a/src/cmd/compile/internal/noder/unified.go b/src/cmd/compile/internal/noder/unified.go
index f45c4a7ea8..2c1f2362ad 100644
--- a/src/cmd/compile/internal/noder/unified.go
+++ b/src/cmd/compile/internal/noder/unified.go
@@ -16,7 +16,6 @@ import (
 	"sort"
 
 	"cmd/compile/internal/base"
-	"cmd/compile/internal/importer"
 	"cmd/compile/internal/inline"
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/typecheck"
@@ -74,17 +73,6 @@ var localPkgReader *pkgReader
 func unified(noders []*noder) {
 	inline.NewInline = InlineCall
 
-	writeNewExportFunc = writeNewExport
-
-	newReadImportFunc = func(data string, pkg1 *types.Pkg, ctxt *types2.Context, packages map[string]*types2.Package) (pkg2 *types2.Package, err error) {
-		pr := pkgbits.NewPkgDecoder(pkg1.Path, data)
-
-		// Read package descriptors for both types2 and compiler backend.
-		readPackage(newPkgReader(pr), pkg1)
-		pkg2 = importer.ReadPackage(ctxt, packages, pr)
-		return
-	}
-
 	data := writePkgStub(noders)
 
 	// We already passed base.Flag.Lang to types2 to handle validating
@@ -266,7 +254,7 @@ func readPackage(pr *pkgReader, importpkg *types.Pkg) {
 	}
 }
 
-func writeNewExport(out io.Writer) {
+func writeUnifiedExport(out io.Writer) {
 	l := linker{
 		pw: pkgbits.NewPkgEncoder(base.Debug.SyncFrames),
 
@@ -332,5 +320,5 @@ func writeNewExport(out io.Writer) {
 		w.Flush()
 	}
 
-	l.pw.DumpTo(out)
+	base.Ctxt.Fingerprint = l.pw.DumpTo(out)
 }