update the list of runtime-related packages for 1.16 (#246)

With a few extra lines, we can keep Go 1.15 support in the table too.

Re-enables the goprivate.txt test for Go 1.16.

While at it, make the script's use of grep a bit simpler with -E, which
also uses the same syntax as Go's regexp. Its skip logic was also buggy,
resulting in the macos results always being empty.

Updates #124.

main.go

@@ -719,13 +719,14 @@ func (tf *transformer) handleDirectives(comments []string) {
 // Once we support go:linkname well and once we can obfuscate the runtime
 // package, this entire map can likely go away.
 //
-// The list was obtained via scripts/runtime-related.sh on Go 1.15.5.
+// The list was obtained via scripts/runtime-related.sh on Go 1.16.
 var runtimeRelated = map[string]bool{
 	"bufio":                                  true,
 	"bytes":                                  true,
 	"compress/flate":                         true,
 	"compress/gzip":                          true,
 	"context":                                true,
+	"crypto/x509/internal/macos":             true,
 	"encoding/binary":                        true,
 	"errors":                                 true,
 	"fmt":                                    true,
@@ -734,10 +735,12 @@ var runtimeRelated = map[string]bool{
 	"internal/bytealg":                       true,
 	"internal/cpu":                           true,
 	"internal/fmtsort":                       true,
+	"internal/nettrace":                      true,
 	"internal/oserror":                       true,
 	"internal/poll":                          true,
 	"internal/race":                          true,
 	"internal/reflectlite":                   true,
+	"internal/singleflight":                  true,
 	"internal/syscall/execenv":               true,
 	"internal/syscall/unix":                  true,
 	"internal/syscall/windows":               true,
@@ -746,12 +749,13 @@ var runtimeRelated = map[string]bool{
 	"internal/testlog":                       true,
 	"internal/unsafeheader":                  true,
 	"io":                                     true,
-	"io/ioutil":                         true,
+	"io/fs":                                  true,
 	"math":                                   true,
 	"math/bits":                              true,
+	"net":                                    true,
 	"os":                                     true,
 	"os/signal":                              true,
-	"path/filepath":                     true,
+	"path":                                   true,
 	"plugin":                                 true,
 	"reflect":                                true,
 	"runtime":                                true,
@@ -760,6 +764,7 @@ var runtimeRelated = map[string]bool{
 	"runtime/internal/atomic":                true,
 	"runtime/internal/math":                  true,
 	"runtime/internal/sys":                   true,
+	"runtime/metrics":                        true,
 	"runtime/pprof":                          true,
 	"runtime/trace":                          true,
 	"sort":                                   true,
@@ -774,6 +779,17 @@ var runtimeRelated = map[string]bool{
 	"unicode/utf16":                          true,
 	"unicode/utf8":                           true,
 	"unsafe":                                 true,
+	"vendor/golang.org/x/net/dns/dnsmessage": true,
+	"vendor/golang.org/x/net/route":          true,
+
+	// These packages were moved in Go 1.16, but 1.15's runtime still
+	// linknames to them.
+	"io/ioutil":     true,
+	"path/filepath": true,
+
+	// Go 1.15's "net" package depends on "math/rand", but 1.16's does not.
+	// Keep it here to support 1.15.
+	"math/rand": true,
 }
 
 // isPrivate checks if GOPRIVATE matches path.

scripts/runtime-related.sh

@@ -10,10 +10,10 @@ go version
 echo
 
 for GOOS in linux darwin windows; do
-	skip="macos"
+	skip="|macos"
 	if [[ $GOOS == "darwin" ]]; then
 		skip=""
 	fi
 
-	GOOS=$GOOS go list -deps $(sed -rn 's@//go:linkname .* ([^.]*)\.[^.]*@\1@p' $(go env GOROOT)/src/runtime/*.go | grep -v '^main\|\.\|js\|'$skip) runtime || exit 1
+	GOOS=$GOOS go list -deps $(sed -rn 's@//go:linkname .* ([^.]*)\.[^.]*@\1@p' $(go env GOROOT)/src/runtime/*.go | grep -vE '^main|^runtime\.|js'$skip) runtime || exit 1
 done | sort -u

testdata/scripts/goprivate.txt

@@ -8,8 +8,6 @@ stderr '^public package "test/main/importer" can''t depend on obfuscated package
 
 [short] stop
 
-[go1.16] skip 'TODO(mvdan): fix for Go 1.16'
-
 # Try garbling all of std, given some std packages.
 # No need for a main package here; building the std packages directly works the
 # same, and is faster as we don't need to link a binary.