all: support for Go 1.27 by deadprogram · Pull Request #5477 · tinygo-org/tinygo

deadprogram · 2026-06-25T20:27:18Z

This PR is to add support for Go 1.27

Current passes tests on 1.27-rc2

github-actions · 2026-06-25T20:43:34Z

Size difference with the dev branch:

Binary size difference

drivers/sizes-dev.txt has more commands than drivers/sizes-pr.txt
    tinygo build -size short -o ./build/test.hex -target=feather-rp2040 ./examples/adafruit4650
 flash                          ram
 before   after   diff          before   after   diff

deadprogram · 2026-06-30T18:41:06Z

Added another commit with support for the new //go:linknamestd directive that is new in Go 1.27

deadprogram · 2026-06-30T20:29:24Z

It got further. I think perhaps the new set of errors might have to do with the SSA changes for generics we were just discussing @jakebailey @aykevl

/home/runner/go/bin/tinygo test -target=wasip1 -skip='TestExtraMethods|TestParseAndBytesRoundTrip/P256/Generic|TestAsValidation' cmp compress/lzw compress/zlib container/heap container/list container/ring crypto/ecdsa crypto/elliptic crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 database/sql/driver debug/macho embed/internal/embedtest encoding encoding/ascii85 errors encoding/asn1 encoding/base32 encoding/base64 encoding/csv encoding/hex expvar go/ast go/format go/scanner go/token go/version hash hash/adler32 hash/crc64 hash/fnv html internal/itoa internal/profile math math/cmplx net/http/internal/ascii net/mail net/url os path reflect sync testing testing/iotest text/scanner unicode unicode/utf16 unicode/utf8 unique  ./tests/runtime_wasi
ok  	cmp	1.389s
ok  	compress/lzw	1.318s
panic: expected nil interface constant

goroutine 1702 [running]:
github.com/tinygo-org/tinygo/compiler.(*compilerContext).createConst(0x36af075d1320, 0x36aeff5398a0, 0x2dc853)
	/__w/tinygo/tinygo/compiler/compiler.go:3149 +0xf65
github.com/tinygo-org/tinygo/compiler.(*builder).getValue(0x36af07de0a80, {0xa0a3c8?, 0x36aeff5398a0}, 0x36af07d870e8?)
	/__w/tinygo/tinygo/compiler/compiler.go:2116 +0xb8
github.com/tinygo-org/tinygo/compiler.(*builder).createExpr(0x36af07de0a80, {0xa0a800, 0x36af07acee70})
	/__w/tinygo/tinygo/compiler/compiler.go:2202 +0x1a46
github.com/tinygo-org/tinygo/compiler.(*builder).createInstruction(0x36af07de0a80, {0xa0b388, 0x36af07acee70})
	/__w/tinygo/tinygo/compiler/compiler.go:1514 +0xd9f
github.com/tinygo-org/tinygo/compiler.(*builder).createFunction(0x36af07de0a80)
	/__w/tinygo/tinygo/compiler/compiler.go:1398 +0x4c5
github.com/tinygo-org/tinygo/compiler.(*compilerContext).createPackage(0x36af075d1320, {0x36aefb24f600?}, 0x36aef73e7d00)
	/__w/tinygo/tinygo/compiler/compiler.go:934 +0x945
github.com/tinygo-org/tinygo/compiler.CompilePackage({0x36af0baaeb00?, 0x5a?}, 0x36aef8f9ba40, 0x36aef73e7d00, {0x83f05cdfec64b02a?}, 0xdf8308?, 0xe4?)
	/__w/tinygo/tinygo/compiler/compiler.go:334 +0x445
github.com/tinygo-org/tinygo/builder.Build.func3(0x36af06bab680)
	/__w/tinygo/tinygo/builder/build.go:405 +0x1ea
github.com/tinygo-org/tinygo/builder.runJob(0x36af06bab680, 0x36aefd3efdc0)
	/__w/tinygo/tinygo/builder/jobs.go:212 +0x4d
created by github.com/tinygo-org/tinygo/builder.runJobs in goroutine 1582
	/__w/tinygo/tinygo/builder/jobs.go:113 +0x6c9
make: *** [GNUmakefile:533: tinygo-test-wasip1-fast] Error 2

deadprogram · 2026-07-01T08:22:32Z

Added another commit that updates x/tools to a newer version that handles the new generics changes. The consequence of this is that the new minimum version of Go for TinyGo is 1.25, which is something that we also discussed in the monthly meeting.

jakebailey · 2026-07-03T22:00:12Z

For Windows, seems like you need the chkstk.S change for more platforms.

I think TestBuild/EmulatedCortexM3 is unavoidable, new json v2 is just larger.

jakebailey · 2026-07-03T22:45:32Z

I think I actually have all of the other failures figured out, but, not sure what to do with the fixes.

One or two of them I can send to dev first. E.g. when I added recover support, I totally forgot to also enable FailNow and SkipNow, and that's what some of the failure is.

deadprogram · 2026-07-11T11:33:46Z

@jakebailey I just overwrote your commits that you had already added to this branch by force puching without having pulled your changes to my local branch first. Sorry about that, my bad :(

Can you help get them back in please?

jakebailey · 2026-07-11T11:37:25Z

I don't have the ability to for a few days but you can download these and git apply them

deadprogram · 2026-07-11T11:44:07Z

@jakebailey thanks! Just ammended this PR with those 2 commits...

deadprogram · 2026-07-11T12:08:52Z

Looks like the test failures so far are perhaps related to crypto/ecdsa.

jakebailey · 2026-07-11T12:17:40Z

Yeah, I couldn't figure those out as they did not reproduce locally

deadprogram · 2026-07-11T12:51:45Z

Actually it seems like it was compress/flate. Skipping for now to see if other tests pass.

jakebailey · 2026-07-11T13:54:25Z

That last commit reminds me of #5508

deadprogram · 2026-07-11T14:16:15Z

That last commit reminds me of #5508

Indeed, it looks like #5508 is a better version of the same idea.

deadprogram · 2026-07-11T15:42:40Z

#5508 was merged, then I removed my commit from this branch and rebased in the latest dev

deadprogram · 2026-07-11T16:29:38Z

Looks like I needed a version of that commit after all to handle the float32/float64 difference.

deadprogram · 2026-07-11T20:29:48Z

All tests passing (except for a couple that were skipped).

Copilot

Pull request overview

Updates TinyGo’s toolchain/CI integration and compiler behavior to work with Go 1.27-rc2, including new Go 1.27 language/tooling patterns and platform/test adjustments.

Changes:

Bump supported Go minor range (min 1.25, max 1.27) and update CI/Docker to Go 1.27.0-rc.2.
Fix generic instantiation name collisions caused by function-local type aliases (Go 1.27 internal/strconv pattern) and add coverage in testdata/localtypes.
Add support for //go:linknamestd, adjust Windows runtime library/builtins selection, and tweak WASI fast stdlib test package selection.

Reviewed changes

Copilot reviewed 18 out of 19 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
testdata/localtypes.txt	Adds expected outputs for new alias-size regression checks.
testdata/localtypes.go	Adds a regression reproducer for Go 1.27’s function-local type alias generic pattern.
src/runtime/os_darwin_go126.go	Adjusts build tags to include Go 1.27.
main_test.go	Adds Go-minor-based test skipping for a size-constrained target on Go 1.27+.
go.mod	Updates Go language version directive and bumps `x/*` dependencies.
go.sum	Updates checksums for the bumped `x/*` dependencies.
GNUmakefile	Disables problematic stdlib tests and refines WASI “fast” package set.
Dockerfile	Updates build container images to Go 1.27rc2.
compiler/testdata/pragma.ll	Extends pragma IR test fixture for `linknamestd`.
compiler/testdata/pragma.go	Adds a test case using `//go:linknamestd`.
compiler/symbol.go	Disambiguates local type-alias instantiations and recognizes `//go:linknamestd`.
compileopts/target.go	Ensures Windows/amd64 and Windows/arm64 select `compiler-rt`.
builder/sizes_test.go	Updates expected binary size baselines.
builder/config.go	Updates supported Go minor range to include Go 1.27 and raise minimum to 1.25.
builder/builtins.go	Adds Windows chkstk builtins for amd64/arm64 and refines Windows triple detection.
.github/workflows/windows.yml	Updates CI to Go 1.27.0-rc.2 and refreshes caches/wasmtime.
.github/workflows/linux.yml	Updates CI/container images to Go 1.27rc2 and refreshes caches/wasmtime.
.github/workflows/compat.yml	Updates minimum-compat Go version to 1.25.
.github/workflows/build-macos.yml	Updates CI to Go 1.27.0-rc.2 and refreshes cache keys.

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deadprogram · 2026-07-12T10:52:37Z

I have moved 2 of the commits in the PR into #5514 and #5515 so they can be merged sooner and to cleanup the commits in this PR.

Signed-off-by: deadprogram <ron@hybridgroup.com>

Go 1.27 adds generic methods (golang/go#77273). golang.org/x/tools go/ssa v0.42.0 does not instantiate them: objectMethod only applies receiverTypeArgs and ignores method-level type parameters, so a call such as (*math/rand/v2.Rand).N resolves to the abstract generic method and its body reaches createConst with a type-parameter-typed zero constant, triggering "panic: expected nil interface constant". Upgrade golang.org/x/tools to v0.47.0, whose go/ssa returns nil from MethodValue for generic methods and instantiates method-level type parameters. No compiler changes are required. Since x/tools v0.47.0 requires Go 1.25, raise the minimum supported Go version from 1.24 to 1.25. Signed-off-by: deadprogram <ron@hybridgroup.com>

Go 1.27 packages can emit stack probes on Windows amd64 and arm64. Link the compiler-rt stack probe builtins and use compiler-rt for those targets so these packages build.

Go 1.27 jsonv2 pushes testdata/json.go beyond the LM3S6965 flash budget. Keep coverage on larger emulated targets while skipping only the too-small Cortex-M QEMU configuration.

Signed-off-by: deadprogram <ron@hybridgroup.com>

…ases x/tools go/ssa names instantiations using the type argument's String(). Function-local aliases like `type F = float64` therefore collide when two callers use distinct aliases named F (Go 1.27's internal/strconv.ftoa32 and ftoa64 do exactly this). Extend localTypeArgsSuffix to detect local aliases and include their declaration position, so the float32 and float64 instantiations get distinct LLVM symbols. Fixes wrong float formatting in strconv/math on Go 1.27, and adds a regression test to testdata/localtypes.go. Signed-off-by: deadprogram <ron@hybridgroup.com>

deadprogram · 2026-07-12T12:23:54Z

Cleaned up commits a bit and also rebased against dev.

#5514 was merged, #5515 is still pending feedback so I left it in this PR still so tests could pass.

deadprogram force-pushed the go1.27-ci branch from 76dafd0 to 4f4320b Compare June 30, 2026 18:40

deadprogram force-pushed the go1.27-ci branch from 1ea4589 to cbc6503 Compare July 3, 2026 20:39

deadprogram mentioned this pull request Jul 5, 2026

apply compiler patch for fix of #5496 #5497

Open

aykevl reviewed Jul 5, 2026

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Comment thread src/runtime/runtime_windows_go126.go Outdated

deadprogram force-pushed the go1.27-ci branch from cbc6503 to 68840b9 Compare July 8, 2026 07:14

deadprogram changed the title ~~all: build/test using Go 1.27-rc1~~ all: build/test using Go 1.27-rc2 Jul 8, 2026

jakebailey reviewed Jul 8, 2026

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Comment thread builder/builtins.go Outdated

jakebailey force-pushed the go1.27-ci branch 3 times, most recently from cfcf9cd to db17b48 Compare July 8, 2026 17:47

deadprogram force-pushed the go1.27-ci branch from db17b48 to 2218634 Compare July 11, 2026 11:22

deadprogram force-pushed the go1.27-ci branch from 09db5df to dc2f031 Compare July 11, 2026 11:51

deadprogram force-pushed the go1.27-ci branch from 0be8f04 to 348b1b4 Compare July 11, 2026 15:41

deadprogram marked this pull request as ready for review July 11, 2026 20:29

deadprogram changed the title ~~all: build/test using Go 1.27-rc2~~ all: support for Go 1.27-rc2 Jul 11, 2026

dkegel-fastly requested a review from Copilot July 11, 2026 23:05

Copilot started reviewing on behalf of dkegel-fastly July 11, 2026 23:06 View session

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deadprogram changed the title ~~all: support for Go 1.27-rc2~~ all: support for Go 1.27 Jul 12, 2026

deadprogram and others added 9 commits July 12, 2026 14:19

all: build/test using Go 1.27-rc2

17d2d5c

Signed-off-by: deadprogram <ron@hybridgroup.com>

builder: update max supported Go version to 1.27

d994c62

Signed-off-by: deadprogram <ron@hybridgroup.com>

builder: link stack probes on Windows amd64 and arm64

0fcaf21

Go 1.27 packages can emit stack probes on Windows amd64 and arm64. Link the compiler-rt stack probe builtins and use compiler-rt for those targets so these packages build.

main_test: skip json on Cortex-M QEMU with Go 1.27

59062d8

Go 1.27 jsonv2 pushes testdata/json.go beyond the LM3S6965 flash budget. Keep coverage on larger emulated targets while skipping only the too-small Cortex-M QEMU configuration.

test: skip compress/flate for now due to Go 1.27 changes

df8405b

Signed-off-by: deadprogram <ron@hybridgroup.com>

test: skip crypto/ecdsa on wasi for now, since it never finishes

0a59ade

Signed-off-by: deadprogram <ron@hybridgroup.com>

builder: adjust sizes test for tiny difference

d28b162

Signed-off-by: deadprogram <ron@hybridgroup.com>

deadprogram force-pushed the go1.27-ci branch from b840c5f to 452c68b Compare July 12, 2026 12:22

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