feat: support Go 1.27

.github/workflows/compatibility_test-windows.yml

@@ -6,7 +6,7 @@ jobs:
   build:
     strategy:
       matrix:
-        go-version: [1.18.x, 1.21.x, 1.25.x]
+        go-version: [1.18.x, 1.21.x, 1.25.x, '1.27.0-rc.1']
     runs-on: windows-latest
     steps:
       - uses: actions/checkout@v2

.github/workflows/compatibility_test.yml

@@ -6,8 +6,8 @@ jobs:
   build:
     strategy:
       matrix:
-        go-version: [1.18.x, 1.19.x, 1.20.x, 1.21.x, 1.22.x, 1.23.x, 1.24.x, 1.25.x]
-        os: [ubuntu-latest, ubuntu-24.04-arm, macos-latest]
+        go-version: [1.18.x, 1.19.x, 1.20.x, 1.21.x, 1.22.x, 1.23.x, 1.24.x, 1.25.x, '1.27.0-rc.1']
+        os: [ubuntu-latest, ubuntu-24.04-arm, macos-15]
     runs-on: ${{ matrix.os }}
     steps:
       - name: Clear repository

.github/workflows/test-arm64.yml

@@ -11,7 +11,7 @@ jobs:
 
     strategy:
       matrix:
-        go-version: [1.20.x, 1.22.x, 1.25.x]
+        go-version: [1.20.x, 1.22.x, 1.25.x, '1.27.0-rc.1']
         runner_arch: [ubuntu-24.04-arm, macos-latest]
 
     runs-on: ${{ matrix.runner_arch }}

.github/workflows/test-x86.yml

@@ -11,7 +11,7 @@ jobs:
 
     strategy:
       matrix:
-        go-version: [1.18.x, 1.21.x, 1.25.x]
+        go-version: [1.18.x, 1.21.x, 1.25.x, '1.27.0-rc.1']
         runner_arch: [ubuntu-latest]
 
     runs-on: ${{ matrix.runner_arch }}

README.md

@@ -6,7 +6,7 @@ A blazingly fast JSON serializing & deserializing library, accelerated by JI
 
 ## Requirement
 
-- Go: 1.18~1.26
+- Go: 1.18~1.27
   - Notice: Go1.24.0 is not supported due to the [issue](https://github.com/golang/go/issues/71672); please use a higher Go version or pass the build flag `-ldflags="-checklinkname=0"`.
 - OS: Linux / MacOS / Windows
 - CPU: AMD64 / (ARM64, need go1.20 above)

README_ZH_CN.md

@@ -6,7 +6,7 @@
 
 ## 依赖
 
-- Go: 1.18~1.26
+- Go: 1.18~1.27
   - 注意：Go1.24.0 由于 [issue](https://github.com/golang/go/issues/71672) 不可用，请升级到更高 Go 版本，或添加编译选项 `--ldflags="-checklinkname=0"` 
 - OS: Linux / MacOS / Windows
 - CPU: AMD64 / (ARM64, 需要 Go1.20 以上）

ast/api.go

@@ -1,5 +1,5 @@
-//go:build (amd64 && go1.17 && !go1.27) || (arm64 && go1.20 && !go1.27)
-// +build amd64,go1.17,!go1.27 arm64,go1.20,!go1.27
+//go:build (amd64 && go1.17 && !go1.28) || (arm64 && go1.20 && !go1.28)
+// +build amd64,go1.17,!go1.28 arm64,go1.20,!go1.28
 
 /*
  * Copyright 2022 ByteDance Inc.

ast/api_compat.go

@@ -1,5 +1,5 @@
-//go:build (!amd64 && !arm64) || go1.27 || !go1.17 || (arm64 && !go1.20)
-// +build !amd64,!arm64 go1.27 !go1.17 arm64,!go1.20
+//go:build (!amd64 && !arm64) || go1.28 || !go1.17 || (arm64 && !go1.20)
+// +build !amd64,!arm64 go1.28 !go1.17 arm64,!go1.20
 
 /*
 * Copyright 2022 ByteDance Inc.

ast/api_native_test.go

@@ -1,5 +1,5 @@
-//go:build (amd64 && go1.17 && !go1.27) || (arm64 && go1.20 && !go1.27)
-// +build amd64,go1.17,!go1.27 arm64,go1.20,!go1.27
+//go:build (amd64 && go1.17 && !go1.28) || (arm64 && go1.20 && !go1.28)
+// +build amd64,go1.17,!go1.28 arm64,go1.20,!go1.28
 
 /*
  * Copyright 2022 ByteDance Inc.

compat.go

@@ -1,5 +1,5 @@
-//go:build (!amd64 && !arm64) || go1.27 || !go1.17 || (arm64 && !go1.20)
-// +build !amd64,!arm64 go1.27 !go1.17 arm64,!go1.20
+//go:build (!amd64 && !arm64) || go1.28 || !go1.17 || (arm64 && !go1.20)
+// +build !amd64,!arm64 go1.28 !go1.17 arm64,!go1.20
 
 /*
  * Copyright 2021 ByteDance Inc.

decode_test.go

@@ -1,5 +1,5 @@
-//go:build (amd64 && go1.17 && !go1.27) || (arm64 && go1.20 && !go1.27)
-// +build amd64,go1.17,!go1.27 arm64,go1.20,!go1.27
+//go:build (amd64 && go1.17 && !go1.28) || (arm64 && go1.20 && !go1.28)
+// +build amd64,go1.17,!go1.28 arm64,go1.20,!go1.28
 
 /*
  * Copyright 2021 ByteDance Inc.

decoder/decoder_compat.go

@@ -1,5 +1,5 @@
-//go:build (!amd64 && !arm64) || go1.27 || !go1.17 || (arm64 && !go1.20)
-// +build !amd64,!arm64 go1.27 !go1.17 arm64,!go1.20
+//go:build (!amd64 && !arm64) || go1.28 || !go1.17 || (arm64 && !go1.20)
+// +build !amd64,!arm64 go1.28 !go1.17 arm64,!go1.20
 
 /*
 * Copyright 2023 ByteDance Inc.

decoder/decoder_native.go

@@ -1,5 +1,5 @@
-//go:build (amd64 && go1.17 && !go1.27) || (arm64 && go1.20 && !go1.27)
-// +build amd64,go1.17,!go1.27 arm64,go1.20,!go1.27
+//go:build (amd64 && go1.17 && !go1.28) || (arm64 && go1.20 && !go1.28)
+// +build amd64,go1.17,!go1.28 arm64,go1.20,!go1.28
 
 /*
 * Copyright 2023 ByteDance Inc.

decoder/decoder_native_test.go

@@ -1,5 +1,5 @@
-//go:build (amd64 && go1.17 && !go1.27) || (arm64 && go1.20 && !go1.27)
-// +build amd64,go1.17,!go1.27 arm64,go1.20,!go1.27
+//go:build (amd64 && go1.17 && !go1.28) || (arm64 && go1.20 && !go1.28)
+// +build amd64,go1.17,!go1.28 arm64,go1.20,!go1.28
 
 /*
  * Copyright 2021 ByteDance Inc.

docs/json-v2-alignment.md

@@ -0,0 +1,80 @@
+# Sonic and `encoding/json` v2 (Go 1.27+)
+
+## Background
+
+Starting with **Go 1.27**, the standard library `encoding/json` v1 package is
+implemented on top of the new **json v2** implementation (`encoding/json/v2` +
+`encoding/json/jsontext`) with v1 compatibility options. The v1 API remains
+supported, but some edge cases still produce different errors or values when the
+json v2 backend is active. Builds can temporarily opt out with
+`GOEXPERIMENT=nojsonv2` (this opt-out is expected to be removed in a future Go
+release).
+
+Sonic is a drop-in replacement for `encoding/json` and currently implements
+**v1 semantics**. On Go 1.27 with the default json v2 backend, a small set of
+legacy parity tests still diverge between `sonic` and the standard library. This
+document tracks those divergences.
+
+> Sonic still **builds and runs correctly** on Go 1.27 (native JIT path). These
+> are *semantic* differences against the new std reference, not crashes or
+> miscompilations in sonic.
+
+## How tests handle this
+
+`issue_test` contains cases that assert byte-for-byte parity or exact error/value
+parity against the *live* `encoding/json`. Those cases are gated on a
+build-tag-derived constant:
+
+- `issue_test/jsonv2_compat_test.go` (`//go:build goexperiment.jsonv2`) → `stdUsesJSONV2 = true`
+- `issue_test/jsonv1_compat_test.go` (`//go:build !goexperiment.jsonv2`) → `stdUsesJSONV2 = false`
+
+The `goexperiment.jsonv2` tag is set automatically when the json v2 backend is
+active (default on Go 1.27+, unset under `GOEXPERIMENT=nojsonv2` and on Go ≤1.26).
+Tests keep Sonic-only assertions where they have stable expected values and skip
+only the std parity check or whole parity-only test when `stdUsesJSONV2` is true,
+so:
+
+- Go ≤ 1.26, or Go 1.27 with `GOEXPERIMENT=nojsonv2`: full parity coverage runs.
+- Go 1.27 default (v2): the divergent std parity assertions are skipped.
+
+## Known divergences (surfaced by issue_test)
+
+| Test | Area | sonic / legacy behavior | Go 1.27 std jsonv2-backend behavior |
+|------|------|---------------------|---------------------------|
+| Issue460 | number → float32/float64 overflow | returns error, leaves dest at 0 | saturates dest to `±Inf` (still returns error) |
+| Issue491 | marshal/unmarshal unsupported types | `map[*T]*T`, `[]chan T`, etc. error as unsupported | some pointer-keyed maps now marshal successfully; unsupported unmarshal error handling differs |
+| Issue747 | map key float32/float64 | v1 parsing | v2 number/key parsing differs |
+| Issue144 | `,string` option on pointer/number fields | v1 string-option semantics | v2 string-option semantics |
+| Issue379 | unmarshal into `MyPtr`/`**T` with Unmarshaler | v1 pointer-allocation/Unmarshaler dispatch | v2 dispatch differs |
+| Issue670 | custom `UnmarshalJSON` error cases | v1 error/typing | v2 error/typing |
+| Issue758 | self-referential `interface{}` (`v = &v`) | sonic handles it | **v2 std recurses to stack overflow** (sonic is fine) |
+| Issue772 | skipping iface-typed fields (non-ptr / nil) | v1 skip behavior | v2 skip behavior differs |
+| Issue824 (`TestFloatMap`) | marshal `map[float64]string` | **errors** (`json: unsupported type: map[float64]string`) | **marshals successfully** (`{"1":""}`) |
+| Issue827 | `TextMarshaler` types (e.g. `string3`) | v1 TextMarshaler handling | v2 TextMarshaler handling differs |
+
+Additional documented json v2 behavior changes are likely to affect parity if
+Sonic later chooses to expose a v2-compatible mode (not all currently covered by
+a dedicated test):
+
+- **Stricter UTF-8**: invalid UTF-8 bytes in JSON strings are rejected.
+- **Duplicate object keys**: objects with duplicate member names are rejected.
+- Error message text differs (sonic already differs here, generally tolerated).
+
+## Decision / status
+
+- **Supporting Go 1.27 (build + run): done.** Native path validated; full test
+  suite green under `GOEXPERIMENT=nojsonv2` and with the v2 parity gates above.
+- **Aligning Sonic to json v2 behavior: not started — separate workstream.**
+  This is a larger design question (whether/when Sonic offers a v2-compatible
+  API). Track here as the list of behaviors to reconcile if/when that work is
+  scheduled.
+
+## Reproducing locally
+
+```sh
+# v2 default (skips parity tests)
+env -u GOROOT GOTOOLCHAIN=local /path/to/go1.27/bin/go test ./issue_test/...
+
+# force v1 semantics (full parity coverage)
+env -u GOROOT GOEXPERIMENT=nojsonv2 GOTOOLCHAIN=local /path/to/go1.27/bin/go test ./issue_test/...
+```

encode_test.go

@@ -1,5 +1,5 @@
-//go:build (amd64 && go1.17 && !go1.27) || (arm64 && go1.20 && !go1.27)
-// +build amd64,go1.17,!go1.27 arm64,go1.20,!go1.27
+//go:build (amd64 && go1.17 && !go1.28) || (arm64 && go1.20 && !go1.28)
+// +build amd64,go1.17,!go1.28 arm64,go1.20,!go1.28
 
 /*
  * Copyright 2021 ByteDance Inc.

encoder/encoder_compat.go

@@ -1,5 +1,5 @@
-//go:build (!amd64 && !arm64) || go1.27 || !go1.17 || (arm64 && !go1.20)
-// +build !amd64,!arm64 go1.27 !go1.17 arm64,!go1.20
+//go:build (!amd64 && !arm64) || go1.28 || !go1.17 || (arm64 && !go1.20)
+// +build !amd64,!arm64 go1.28 !go1.17 arm64,!go1.20
 
 /*
 * Copyright 2023 ByteDance Inc.

encoder/encoder_native.go

@@ -1,5 +1,5 @@
-//go:build (amd64 && go1.17 && !go1.27) || (arm64 && go1.20 && !go1.27)
-// +build amd64,go1.17,!go1.27 arm64,go1.20,!go1.27
+//go:build (amd64 && go1.17 && !go1.28) || (arm64 && go1.20 && !go1.28)
+// +build amd64,go1.17,!go1.28 arm64,go1.20,!go1.28
 
 /*
  * Copyright 2023 ByteDance Inc.

encoder/encoder_native_test.go

@@ -1,5 +1,5 @@
-//go:build (amd64 && go1.17 && !go1.27) || (arm64 && go1.20 && !go1.27)
-// +build amd64,go1.17,!go1.27 arm64,go1.20,!go1.27
+//go:build (amd64 && go1.17 && !go1.28) || (arm64 && go1.20 && !go1.28)
+// +build amd64,go1.17,!go1.28 arm64,go1.20,!go1.28
 
 /*
  * Copyright 2021 ByteDance Inc.

internal/compat/warn.go

@@ -1,12 +1,13 @@
-// +build !amd64,!arm64 go1.27 !go1.17 arm64,!go1.20
+//go:build (!amd64 && !arm64) || go1.28 || !go1.17 || (arm64 && !go1.20)
+// +build !amd64,!arm64 go1.28 !go1.17 arm64,!go1.20
 
 package compat
 
 import (
-    "fmt"
-    "os"
+	"fmt"
+	"os"
 )
 
 func Warn(prefix string) {
-    fmt.Fprintf(os.Stderr, "WARNING: %s only supports (go1.17~1.26 and amd64 CPU) or (go1.20~1.26 and arm64 CPU), but your environment is not suitable and will fallback to encoding/json\n", prefix)
+	fmt.Fprintf(os.Stderr, "WARNING: %s only supports (go1.17~1.27 and amd64 CPU) or (go1.20~1.27 and arm64 CPU), but your environment is not suitable and will fallback to encoding/json\n", prefix)
 }

internal/decoder/api/decoder_amd64.go

@@ -1,5 +1,5 @@
-//go:build go1.17 && !go1.27
-// +build go1.17,!go1.27
+//go:build go1.17 && !go1.28
+// +build go1.17,!go1.28
 
 /*
  * Copyright 2021 ByteDance Inc.

internal/decoder/api/decoder_arm64.go

@@ -1,5 +1,5 @@
-//go:build go1.17 && !go1.27
-// +build go1.17,!go1.27
+//go:build go1.17 && !go1.28
+// +build go1.17,!go1.28
 
 /*
  * Copyright 2021 ByteDance Inc.

internal/decoder/jitdec/asm_stubs_amd64_go121.go

@@ -1,5 +1,5 @@
-//go:build go1.21 && !go1.27
-// +build go1.21,!go1.27
+//go:build go1.21 && !go1.28
+// +build go1.21,!go1.28
 
 // Copyright 2023 CloudWeGo Authors
 //

internal/decoder/jitdec/assembler_regabi_amd64.go

@@ -1,5 +1,5 @@
-//go:build go1.17 && !go1.27
-// +build go1.17,!go1.27
+//go:build go1.17 && !go1.28
+// +build go1.17,!go1.28
 
 /*
  * Copyright 2021 ByteDance Inc.

internal/decoder/jitdec/generic_regabi_amd64.go

@@ -1,5 +1,5 @@
-//go:build go1.17 && !go1.27
-// +build go1.17,!go1.27
+//go:build go1.17 && !go1.28
+// +build go1.17,!go1.28
 
 /*
  * Copyright 2021 ByteDance Inc.

internal/encoder/alg/spec.go

@@ -1,5 +1,5 @@
-//go:build (amd64 && go1.16 && !go1.27) || (arm64 && go1.20 && !go1.27)
-// +build amd64,go1.16,!go1.27 arm64,go1.20,!go1.27
+//go:build (amd64 && go1.16 && !go1.28) || (arm64 && go1.20 && !go1.28)
+// +build amd64,go1.16,!go1.28 arm64,go1.20,!go1.28
 
 /**
  * Copyright 2024 ByteDance Inc.

internal/encoder/alg/spec_compat.go

@@ -1,5 +1,5 @@
-//go:build (!amd64 && !arm64) || go1.27 || !go1.16 || (arm64 && !go1.20)
-// +build !amd64,!arm64 go1.27 !go1.16 arm64,!go1.20
+//go:build (!amd64 && !arm64) || go1.28 || !go1.16 || (arm64 && !go1.20)
+// +build !amd64,!arm64 go1.28 !go1.16 arm64,!go1.20
 
 /**
  * Copyright 2024 ByteDance Inc.

internal/encoder/x86/asm_stubs_amd64_go121.go

@@ -1,5 +1,5 @@
-//go:build go1.21 && !go1.27
-// +build go1.21,!go1.27
+//go:build go1.21 && !go1.28
+// +build go1.21,!go1.28
 
 // Copyright 2023 CloudWeGo Authors
 //

internal/encoder/x86/assembler_export_amd64.go

@@ -1,5 +1,5 @@
-//go:build go1.17 && !go1.27
-// +build go1.17,!go1.27
+//go:build go1.17 && !go1.28
+// +build go1.17,!go1.28
 
 package x86
 

internal/encoder/x86/assembler_regabi_amd64.go

@@ -1,5 +1,5 @@
-//go:build go1.17 && !go1.27
-// +build go1.17,!go1.27
+//go:build go1.17 && !go1.28
+// +build go1.17,!go1.28
 
 /*
  * Copyright 2021 ByteDance Inc.

internal/encoder/x86/debug_go117.go

@@ -1,5 +1,5 @@
-//go:build go1.17 && !go1.27
-// +build go1.17,!go1.27
+//go:build go1.17 && !go1.28
+// +build go1.17,!go1.28
 
 /*
  * Copyright 2021 ByteDance Inc.

internal/rt/base64_amd64.go

@@ -1,5 +1,5 @@
-//go:build amd64 && go1.17 && !go1.27
-// +build amd64,go1.17,!go1.27
+//go:build amd64 && go1.17 && !go1.28
+// +build amd64,go1.17,!go1.28
 
 package rt
 

internal/rt/base64_compat.go

@@ -1,5 +1,5 @@
-//go:build !amd64 || !go1.17 || go1.27
-// +build !amd64 !go1.17 go1.27
+//go:build !amd64 || !go1.17 || go1.28
+// +build !amd64 !go1.17 go1.28
 
 package rt
 

internal/rt/gcwb.go

@@ -1,5 +1,5 @@
-//go:build go1.21 && !go1.27
-// +build go1.21,!go1.27
+//go:build go1.21 && !go1.28
+// +build go1.21,!go1.28
 
 /*
  * Copyright 2021 ByteDance Inc.

internal/rt/map.go

@@ -22,4 +22,6 @@ type GoMapIterator struct {
 	I           uint8
 	Bucket      uintptr
 	CheckBucket uintptr
+	// different from go1.23, noswissmap
+	ClearSeq uint64
 }