drop support for Go 1.20

Go 1.21.0 was released in August 2023, so our upcoming release
will no longer support the Go 1.20 release series.

The first Go 1.22 release candidate is also due in December 2023,
less than a month from now, so dropping 1.20 will simplify 1.22 work.

.github/workflows/test.yml

@@ -25,7 +25,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.20.x, 1.21.x]
+        go-version: [1.21.x]
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:

go.mod

@@ -1,6 +1,6 @@
 module mvdan.cc/garble
 
-go 1.20
+go 1.21
 
 require (
 	github.com/bluekeyes/go-gitdiff v0.7.1

go.sum

@@ -19,6 +19,7 @@ golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa/go.mod h1:zk2irFbV9DP96SEBUU
 golang.org/x/mod v0.14.0 h1:dGoOF9QVLYng8IHTm7BAyWqCqSheQ5pYWGhzW00YJr0=
 golang.org/x/mod v0.14.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
 golang.org/x/sync v0.5.0 h1:60k92dhOjHxJkrqnwsfl8KuaHbn/5dl0lUPUklKo3qE=
+golang.org/x/sync v0.5.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.14.0 h1:Vz7Qs629MkJkGyHxUlRHizWJRG2j8fbQKjELVSNhy7Q=
 golang.org/x/sys v0.14.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/tools v0.15.0 h1:zdAyfUGbYmuVokhzVmghFl2ZJh5QhcfebBgmVPFYA+8=

main.go

@@ -267,7 +267,7 @@ func (e errJustExit) Error() string { return fmt.Sprintf("exit: %d", e) }
 
 func goVersionOK() bool {
 	const (
-		minGoVersionSemver = "v1.20.0"
+		minGoVersionSemver = "v1.21.0"
 		suggestedGoVersion = "1.21"
 	)
 
@@ -1329,7 +1329,7 @@ func (tf *transformer) processImportCfg(flags []string, requiredPkgs []string) (
 			// See exporttest/*.go in testdata/scripts/test.txt.
 			// For now, spot the pattern and avoid the unnecessary error;
 			// the dependency is unused, so the packagefile line is redundant.
-			// This still triggers as of go1.20.
+			// This still triggers as of go1.21.
 			if strings.HasSuffix(tf.curPkg.ImportPath, ".test]") && strings.HasPrefix(tf.curPkg.ImportPath, impPath) {
 				continue
 			}
@@ -2195,7 +2195,7 @@ func alterTrimpath(flags []string) []string {
 	return flagSetValue(flags, "-trimpath", sharedTempDir+"=>;"+trimpath)
 }
 
-// forwardBuildFlags is obtained from 'go help build' as of Go 1.20.
+// forwardBuildFlags is obtained from 'go help build' as of Go 1.21.
 var forwardBuildFlags = map[string]bool{
 	// These shouldn't be used in nested cmd/go calls.
 	"-a": false,
@@ -2235,7 +2235,7 @@ var forwardBuildFlags = map[string]bool{
 	"-workfile":      true,
 }
 
-// booleanFlags is obtained from 'go help build' and 'go help testflag' as of Go 1.20.
+// booleanFlags is obtained from 'go help build' and 'go help testflag' as of Go 1.21.
 var booleanFlags = map[string]bool{
 	// Shared build flags.
 	"-a":          true,

runtime_patch.go

@@ -9,8 +9,6 @@ import (
 	"strconv"
 	"strings"
 
-	"golang.org/x/mod/semver"
-
 	ah "mvdan.cc/garble/internal/asthelper"
 )
 
@@ -238,11 +236,7 @@ func stripRuntime(basename string, file *ast.File) {
 				"printAncestorTracebackFuncInfo", "goroutineheader", "tracebackothers", "tracebackHexdump", "printCgoTraceback":
 				funcDecl.Body.List = nil
 			case "printOneCgoTraceback":
-				if semver.Compare(sharedCache.GoVersionSemver, "v1.21") >= 0 {
-					funcDecl.Body = ah.BlockStmt(ah.ReturnStmt(ast.NewIdent("false")))
-				} else {
-					funcDecl.Body = ah.BlockStmt(ah.ReturnStmt(ah.IntLit(0)))
-				}
+				funcDecl.Body = ah.BlockStmt(ah.ReturnStmt(ast.NewIdent("false")))
 			default:
 				if strings.HasPrefix(funcDecl.Name.Name, "print") {
 					funcDecl.Body.List = nil

shared.go

@@ -53,8 +53,8 @@ type sharedCacheType struct {
 	// GoVersionSemver is a semver-compatible version of the Go toolchain
 	// currently being used, as reported by "go env GOVERSION".
 	// Note that the version of Go that built the garble binary might be newer.
-	// Also note that a devel version like "go1.21-231f290e51" is
-	// currently represented as "v1.21".
+	// Also note that a devel version like "go1.22-231f290e51" is
+	// currently represented as "v1.22".
 	GoVersionSemver string
 
 	// Filled directly from "go env".
@@ -266,8 +266,6 @@ func appendListedPackages(packages []string, mainBuild bool) error {
 				// Some packages in runtimeLinknamed need a build tag to be importable,
 				// like crypto/internal/boring/fipstls with boringcrypto,
 				// so any pkg.Error should be ignored when the build tag isn't set.
-			} else if pkg.ImportPath == "maps" && semver.Compare(sharedCache.GoVersionSemver, "v1.21") < 0 {
-				// added in Go 1.21, so Go 1.20 runs into a "not found" error.
 			} else if pkg.ImportPath == "math/rand/v2" && semver.Compare(sharedCache.GoVersionSemver, "v1.22") < 0 {
 				// added in Go 1.22, so Go 1.21 runs into a "not found" error.
 			} else {

testdata/script/asm.txtar

@@ -33,7 +33,7 @@ binsubstr main$exe 'addJmp' 'AddImpl'
 -- go.mod --
 module test/with.many.dots/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/atomic.txtar

@@ -18,7 +18,7 @@ cmp stderr main.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/basic.txtar

@@ -59,7 +59,7 @@ binsubstr main$exe 'garble_main.go' 'globalVar' 'globalFunc' $gofullversion
 -- go.mod --
 module test/mainfoo
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main
 

testdata/script/cache.txtar

@@ -28,7 +28,7 @@ cmp stderr main.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/cgo.txtar

@@ -29,7 +29,7 @@ binsubstr main$exe 'privateAdd'
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/crossbuild.txtar

@@ -21,7 +21,7 @@ stderr 'intrinsic substitution for Len64.*BitLen64'
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/ctrlflow.txtar

@@ -30,7 +30,7 @@ grep 'func\(int\) int' $WORK/debug/test/main/GARBLE_controlflow.go
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main
 

testdata/script/debugdir.txtar

@@ -18,7 +18,7 @@ stderr 'test/main' # we force rebuilds with -debugdir
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/embed.txtar

@@ -11,7 +11,7 @@ cmp stdout main.stdout
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/goenv.txtar

@@ -46,7 +46,7 @@ exec $NAME/garble$exe build
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/gogarble.txtar

@@ -54,7 +54,7 @@ bincmp out_rebuild out
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- standalone/main.go --
 package main
 

testdata/script/goversion.txtar

@@ -40,45 +40,45 @@ env TOOLCHAIN_GOVERSION='go1.28.2'
 stderr 'mocking the real build'
 
 # We should accept custom devel strings.
-env TOOLCHAIN_GOVERSION='devel go1.20-somecustomversion'
+env TOOLCHAIN_GOVERSION='devel go1.22-somecustomversion'
 ! exec garble build
 stderr 'mocking the real build'
 
 # The current toolchain may be older than the one that built garble.
-env GARBLE_TEST_GOVERSION='go1.21'
-env TOOLCHAIN_GOVERSION='go1.20.3'
+env GARBLE_TEST_GOVERSION='go1.22'
+env TOOLCHAIN_GOVERSION='go1.21.3'
 ! exec garble build
 stderr 'mocking the real build'
 
 # The current toolchain may be equal to the one that built garble.
-env GARBLE_TEST_GOVERSION='devel go1.20-6673d5d701 Sun Mar 20 16:05:03 2023 +0000'
-env TOOLCHAIN_GOVERSION='devel go1.20-6673d5d701 Sun Mar 20 16:05:03 2023 +0000'
+env GARBLE_TEST_GOVERSION='devel go1.21-6673d5d701 Sun Mar 20 16:05:03 2023 +0000'
+env TOOLCHAIN_GOVERSION='devel go1.21-6673d5d701 Sun Mar 20 16:05:03 2023 +0000'
 ! exec garble build
 stderr 'mocking the real build'
 
 # The current toolchain must not be newer than the one that built garble.
 env GARBLE_TEST_GOVERSION='go1.18'
-env TOOLCHAIN_GOVERSION='go1.20.1'
+env TOOLCHAIN_GOVERSION='go1.21.1'
 ! exec garble build
-stderr 'garble was built with "go1\.18" and is being used with "go1\.20\.1"; rebuild '
+stderr 'garble was built with "go1\.18" and is being used with "go1\.21\.1"; rebuild '
 
 # We'll error even if the difference is a minor (bugfix) level.
 # In practice it probably wouldn't matter, but in theory it could still lead to tricky bugs.
-env GARBLE_TEST_GOVERSION='go1.20.11'
-env TOOLCHAIN_GOVERSION='go1.20.14'
+env GARBLE_TEST_GOVERSION='go1.21.11'
+env TOOLCHAIN_GOVERSION='go1.21.14'
 ! exec garble build
-stderr 'garble was built with "go1\.20\.11" and is being used with "go1\.20\.14"; rebuild '
+stderr 'garble was built with "go1\.21\.11" and is being used with "go1\.21\.14"; rebuild '
 
 # If garble builds itself and is then used, it won't know what version built it.
 # As a fallback, we drop the comparison against the toolchain's version.
 env GARBLE_TEST_GOVERSION='bogus version'
-env TOOLCHAIN_GOVERSION='go1.20.3'
+env TOOLCHAIN_GOVERSION='go1.21.3'
 ! exec garble build
 stderr 'mocking the real build'
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/help.txtar

@@ -78,8 +78,7 @@ stderr 'must precede command, like: garble -seed=random build \./pkg'
 stderr 'did you run.*instead of "garble \[command\]"'
 
 ! exec garble build badpackage
-[!go1.21] stderr 'package badpackage is not in GOROOT'
-[go1.21]  stderr 'package badpackage is not in std'
+stderr 'package badpackage is not in std'
 ! stdout .
 
 ! exec garble build ./badpackage
@@ -118,6 +117,6 @@ stderr 'usage: garble version'
 -- go.mod --
 module dummy
 
-go 1.20
+go 1.21
 -- dummy.go --
 package dummy

testdata/script/implement.txtar

@@ -13,7 +13,7 @@ cmp stdout main.stdout
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/imports.txtar

@@ -42,7 +42,7 @@ cmp stdout main.stdout
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 
 require (
 	gopkg.in/garbletest.v2 v2.999.0

testdata/script/init.txtar

@@ -12,7 +12,7 @@ cmp stderr main.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/ldflags.txtar

@@ -28,7 +28,7 @@ binsubstr main$exe 'unexportedVersion' 'ExportedUnset' 'v1.22.33' 'garble_replac
 -- go.mod --
 module domain.test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/linker.txtar

@@ -34,7 +34,7 @@ cmp stderr main.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/linkname.txtar

@@ -14,7 +14,7 @@ cmp stderr main.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 
 replace big.chungus/meme => ./big.chungus/meme
 
@@ -149,7 +149,7 @@ func ByteIndex(s string, c byte) int
 -- big.chungus/meme/go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- big.chungus/meme/dante.go --
 package meme
 

testdata/script/list_error.txtar

@@ -1,19 +1,14 @@
 ! exec garble build ./...
-[!go1.21] cmpenv stderr stderr-go1.20.golden
-[go1.21]  cmpenv stderr stderr-go1.21.golden
+cmpenv stderr stderr.golden
 
--- stderr-go1.20.golden --
-# test/main/broken
-broken${/}broken.go:5:16: cannot use 123 (untyped int constant) as string value in variable declaration
-imports_missing${/}imports.go:5:8: package test/main/missing is not in GOROOT (${GOROOT}${/}src${/}test${/}main${/}missing)
--- stderr-go1.21.golden --
+-- stderr.golden --
 # test/main/broken
 broken${/}broken.go:5:16: cannot use 123 (untyped int constant) as string value in variable declaration
 imports_missing${/}imports.go:5:8: package test/main/missing is not in std (${GOROOT}${/}src${/}test${/}main${/}missing)
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- broken/broken.go --
 package broken
 

testdata/script/literals.txtar

@@ -59,7 +59,7 @@ exec garble -literals build std
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/modinfo.txtar

@@ -26,7 +26,7 @@ stdout 'build\s*vcs.revision='${HEAD_COMMIT_SHA}
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/plugin.txtar

@@ -26,7 +26,7 @@ cmp stderr main.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- plugin/main.go --
 package main
 

testdata/script/position.txtar

@@ -16,7 +16,7 @@ stdout 'varPositions is sorted'
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main
 

testdata/script/reflect.txtar

@@ -14,7 +14,7 @@ cmp stdout main.stdout
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main
 

testdata/script/reverse.txtar

@@ -53,7 +53,7 @@ cmp stdout main-literals.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- long_main.go --
 package main
 

testdata/script/run.txtar

@@ -14,7 +14,7 @@ stdout 'garble_main\.go 9$'
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main
 

testdata/script/seed-cache.txtar

@@ -32,7 +32,7 @@ cd ..
 -- mod1/go.mod --
 module test/main/mod1
 
-go 1.20
+go 1.21
 
 require gopkg.in/garbletest.v2 v2.999.0
 
@@ -52,7 +52,7 @@ func main() { garbletest.Test() }
 -- mod2/go.mod --
 module test/main/mod2
 
-go 1.20
+go 1.21
 
 require gopkg.in/garbletest.v2 v2.999.0
 

testdata/script/seed.txtar

@@ -97,7 +97,7 @@ cmp stderr importedpkg.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 

testdata/script/syntax.txtar

@@ -16,7 +16,7 @@ binsubstr main$exe 'globalVar' # 'globalType' matches on some, but not all, plat
 -- extra/go.mod --
 module private.source/extra
 
-go 1.20
+go 1.21
 -- extra/extra.go --
 package extra
 
@@ -26,7 +26,7 @@ func Func() string {
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 
 // We include an extra module to obfuscate, included in the same original source
 // code via a replace directive.

testdata/script/test.txtar

@@ -52,7 +52,7 @@ stdout 'package bar_test, func name: test/bar\.OriginalFuncName'
 -- go.mod --
 module test/bar
 
-go 1.20
+go 1.21
 -- bar.go --
 package bar
 

testdata/script/tiny.txtar

@@ -27,7 +27,7 @@ stderr 'funcStructExported false funcStructUnexported false'
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main
 

testdata/script/typeparams.txtar

@@ -3,7 +3,7 @@ exec garble build
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main