From 201f8b40dceb7a821fd9958b2061c33d436d107b Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Fri, 11 Aug 2023 10:58:26 -0400 Subject: [release-branch.go1.20] cmd/go: refuse to build Go 1.22 code With #60078 accepted, we expect Go 1.22 will have different for loop semantics than Go 1.20 did. Once Go 1.22 is released, Go 1.20 will be unsupported, but add a check anyway, just to help catch some mistakes and usage of old Go toolchains beyond their end-of-support. Note that Go 1.20 can keep being used indefinitely with pre-Go 1.22 code. This change only makes it refuse to build code that says it needs Go 1.22 semantics, because Go 1.20 does not provide those. For #60078. Change-Id: I75118d6fbd0cc08a6bc309aca54c389a255ba7dc Reviewed-on: https://go-review.googlesource.com/c/go/+/518675 Reviewed-by: Bryan Mills Run-TryBot: Russ Cox TryBot-Result: Gopher Robot --- src/cmd/go/internal/work/exec.go | 13 +++++++++++++ src/cmd/go/testdata/script/build_go122.txt | 24 ++++++++++++++++++++++++ src/cmd/go/testdata/script/mod_go_version.txt | 14 +++++++------- 3 files changed, 44 insertions(+), 7 deletions(-) create mode 100644 src/cmd/go/testdata/script/build_go122.txt diff --git a/src/cmd/go/internal/work/exec.go b/src/cmd/go/internal/work/exec.go index 9cf3362fbf..67d11939af 100644 --- a/src/cmd/go/internal/work/exec.go +++ b/src/cmd/go/internal/work/exec.go @@ -531,6 +531,19 @@ func (b *Builder) build(ctx context.Context, a *Action) (err error) { return errors.New("binary-only packages are no longer supported") } + // Go 1.22 is likely to change for loop semantics. + // If we try to build code written for Go 1.22, + // it may have aliasing bugs that it shouldn't have. + // See go.dev/issue/60078. + // When Go 1.22 is released, Go 1.20 will no longer + // be supported, so no one should ever run into this condition, + // but we are adding this check anyway, + // just to help catch some mistakes and usage of old + // Go toolchains beyond their end-of-support. + if p.Module != nil && !(allowedVersion(p.Module.GoVersion) || p.Module.GoVersion == "1.21") { + return errors.New("cannot compile Go " + p.Module.GoVersion + " code") + } + if err := b.Mkdir(a.Objdir); err != nil { return err } diff --git a/src/cmd/go/testdata/script/build_go122.txt b/src/cmd/go/testdata/script/build_go122.txt new file mode 100644 index 0000000000..a17fc253d9 --- /dev/null +++ b/src/cmd/go/testdata/script/build_go122.txt @@ -0,0 +1,24 @@ +! go build +stderr '^m: cannot compile Go 1.22 code$' + +cd dep +! go build +stderr '^m: cannot compile Go 1.22 code$' + +-- go.mod -- +module m +go 1.22 + +-- p.go -- +package p + +-- dep/go.mod -- +module dep +go 1.19 +require m v1.0.0 +replace m v1.0.0 => ../ + +-- dep/p.go -- +package p + +import "m" diff --git a/src/cmd/go/testdata/script/mod_go_version.txt b/src/cmd/go/testdata/script/mod_go_version.txt index 97d9975e68..7bee95b192 100644 --- a/src/cmd/go/testdata/script/mod_go_version.txt +++ b/src/cmd/go/testdata/script/mod_go_version.txt @@ -8,23 +8,23 @@ go build sub.1 go build subver.1 ! stderr 'module requires' ! go build badsub.1 -stderr '^note: module requires Go 1.11111$' +stderr '^note: module requires Go 1.21$' go build versioned.1 go mod edit -require versioned.1@v1.1.0 ! go build versioned.1 -stderr '^note: module requires Go 1.99999$' +stderr '^note: module requires Go 1.21$' [short] stop # The message should be printed even if the compiler emits no output. go build -o $WORK/nooutput.exe nooutput.go ! go build -toolexec=$WORK/nooutput.exe versioned.1 -stderr '^# versioned.1\nnote: module requires Go 1.99999$' +stderr '^# versioned.1\nnote: module requires Go 1.21$' -- go.mod -- module m -go 1.999 +go 1.21 require ( sub.1 v1.0.0 subver.1 v1.0.0 @@ -51,14 +51,14 @@ package x -- subver/go.mod -- module m -go 1.11111 +go 1.21 -- subver/x.go -- package x -- badsub/go.mod -- module m -go 1.11111 +go 1.21 -- badsub/x.go -- package x @@ -73,7 +73,7 @@ package x -- versioned2/go.mod -- module versioned -go 1.99999 +go 1.21 -- versioned2/x.go -- package x -- cgit v1.2.3-54-g00ecf