golang.org/x/sys v0.0.0-20210510120138-977fb7262007: cpu.X86

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify cpu.X86 in pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007
Demonstrate these symbols/APIs:
  - cpu.X86

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:2a2e9c119880cae0c17dd142f99ae151641b292d506f267ddfda79cc44172353","contract":["golang.org/x/sys/cpu.X86 exposes x86/amd64 CPU feature flag fields such as HasSSE2, HasAVX, and HasAVX2"],"goal":"verify cpu.X86 in pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007","kind":"HOW","packages":["pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007"],"schemaVersion":1,"symbols":["cpu.X86"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007","symbols":["cpu.X86"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.21

require golang.org/x/sys v0.0.0-20210510120138-977fb7262007

golang.org/x/sys v0.0.0-20210510120138-977fb7262007 h1:gG67DSER+11cZvqIMb8S8bt0vZtiN6xWYARwirrOSfE=
golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

{
  "schemaVersion": 1,
  "goal": "verify cpu.X86 in pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007"
  ],
  "symbols": [
    "cpu.X86"
  ]
}

package main

import (
	"fmt"
	"os"

	"golang.org/x/sys/cpu"
)

func main() {
	// cpu.X86 is populated on x86/amd64 and exists as a struct across architectures.
	// Verify we can read feature flags on cpu.X86 and inspect struct fields deterministically.
	_ = cpu.X86.HasSSE2
	_ = cpu.X86.HasAVX
	_ = cpu.X86.HasAVX2

	var copyX86 = cpu.X86
	copyX86.HasSSE2 = true
	if !copyX86.HasSSE2 {
		fmt.Fprintln(os.Stderr, "expected copyX86.HasSSE2 to be true")
		os.Exit(1)
	}
}