github.com/google/pprof v0.0.0-20260906184651-6331bc6350fe: profile.Location

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 github.com/google/pprof/profile.Location in pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe
Demonstrate these symbols/APIs:
  - github.com/google/pprof/profile.Location
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@10.9.8
  - runtime: node@22.23.2

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:sha256:874d7434ad3335fe639ccaeafe6b24a5a9f477099504c4b2e22e5cc118234046","contract":["profile.Location can be constructed with ID, Address, Mapping, and IsFolded fields.","profile.Location can hold multiple inlined Line frames referencing Functions.","profile.Location instances can be associated with Samples and registered in a Profile.","A Profile containing structured Locations passes CheckValid verification.","Profile Write and Parse round-trip preserves Location fields, Mappings, and Line associations."],"goal":"verify github.com/google/pprof/profile.Location in pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe","kind":"HOW","packages":["pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe"],"schemaVersion":1,"symbols":["github.com/google/pprof/profile.Location"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe"],"schemaVersion":1,"subject":"pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe","symbols":["github.com/google/pprof/profile.Location"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require github.com/google/pprof v0.0.0-20260906184651-6331bc6350fe

github.com/google/pprof v0.0.0-20260906184651-6331bc6350fe h1:QAinXoAFJdGQYztXn3VpFey7KCwpedbZ/EkzbplQ0cY=
github.com/google/pprof v0.0.0-20260906184651-6331bc6350fe/go.mod h1:jl5iWTm0/hd5PjEYEOuwAJ57L/CibdZfrqZ5XA5GrCk=

package main

import (
	"fmt"

	"github.com/google/pprof/profile"
)

func main() {
	fn := &profile.Function{
		ID:         1,
		Name:       "compute",
		SystemName: "compute",
		Filename:   "compute.go",
		StartLine:  1,
	}

	mapping := &profile.Mapping{
		ID:    1,
		Start: 0x1000,
		Limit: 0x2000,
		File:  "app",
	}

	loc := &profile.Location{
		ID:       1,
		Mapping:  mapping,
		Address:  0x1020,
		IsFolded: false,
		Line: []profile.Line{
			{
				Function: fn,
				Line:     42,
			},
		},
	}

	fmt.Printf("Location ID: %d, Address: 0x%x, Lines: %d\n", loc.ID, loc.Address, len(loc.Line))
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/google/pprof/profile.Location in pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe"
  ],
  "symbols": [
    "github.com/google/pprof/profile.Location"
  ],
  "runtimeConditions": {
    "ecosystem": "golang",
    "language": "go",
    "packageManager": "go@1.26.6",
    "runtime": "go@1.26.6"
  }
}

package main

import (
	"bytes"
	"fmt"
	"os"

	"github.com/google/pprof/profile"
)

func main() {
	// Assertion 1: profile.Location can be constructed with ID, Address, Mapping, and IsFolded fields.
	mapping := &profile.Mapping{
		ID:    1,
		Start: 0x1000,
		Limit: 0x2000,
		File:  "app",
	}

	loc := &profile.Location{
		ID:       1,
		Mapping:  mapping,
		Address:  0x1020,
		IsFolded: false,
	}

	if loc.ID != 1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected ID 1, got %d\n", loc.ID)
		os.Exit(1)
	}
	if loc.Address != 0x1020 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Address 0x1020, got 0x%x\n", loc.Address)
		os.Exit(1)
	}
	if loc.Mapping != mapping {
		fmt.Fprintf(os.Stderr, "FAIL: expected Mapping pointer equality\n")
		os.Exit(1)
	}
	if loc.IsFolded {
		fmt.Fprintf(os.Stderr, "FAIL: expected IsFolded false\n")
		os.Exit(1)
	}

	// Assertion 2: profile.Location can hold multiple inlined Line frames referencing Functions.
	fn1 := &profile.Function{
		ID:         1,
		Name:       "outer",
		SystemName: "outer",
		Filename:   "compute.go",
		StartLine:  10,
	}
	fn2 := &profile.Function{
		ID:         2,
		Name:       "inlinedInner",
		SystemName: "inlinedInner",
		Filename:   "compute.go",
		StartLine:  20,
	}

	loc.Line = []profile.Line{
		{Function: fn1, Line: 12},
		{Function: fn2, Line: 25},
	}

	if len(loc.Line) != 2 {
		fmt.Fprintf(os.Stderr, "FAIL: expected 2 lines, got %d\n", len(loc.Line))
		os.Exit(1)
	}
	if loc.Line[0].Function.Name != "outer" || loc.Line[0].Line != 12 {
		fmt.Fprintf(os.Stderr, "FAIL: line 0 mismatch\n")
		os.Exit(1)
	}
	if loc.Line[1].Function.Name != "inlinedInner" || loc.Line[1].Line != 25 {
		fmt.Fprintf(os.Stderr, "FAIL: line 1 mismatch\n")
		os.Exit(1)
	}

	// Assertion 3: profile.Location instances can be associated with Samples and registered in a Profile.
	sample := &profile.Sample{
		Location: []*profile.Location{loc},
		Value:    []int64{100},
	}

	prof := &profile.Profile{
		SampleType: []*profile.ValueType{
			{Type: "samples", Unit: "count"},
		},
		PeriodType: &profile.ValueType{
			Type: "cpu", Unit: "nanoseconds",
		},
		Mapping:  []*profile.Mapping{mapping},
		Function: []*profile.Function{fn1, fn2},
		Location: []*profile.Location{loc},
		Sample:   []*profile.Sample{sample},
	}

	if len(sample.Location) != 1 || sample.Location[0] != loc {
		fmt.Fprintf(os.Stderr, "FAIL: sample location mismatch\n")
		os.Exit(1)
	}
	if len(prof.Location) != 1 || prof.Location[0] != loc {
		fmt.Fprintf(os.Stderr, "FAIL: profile location mismatch\n")
		os.Exit(1)
	}

	// Assertion 4: A Profile containing structured Locations passes CheckValid verification.
	if err := prof.CheckValid(); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: CheckValid failed: %v\n", err)
		os.Exit(1)
	}

	// Assertion 5: Profile Write and Parse round-trip preserves Location fields, Mappings, and Line associations.
	var buf bytes.Buffer
	if err := prof.Write(&buf); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: Write failed: %v\n", err)
		os.Exit(1)
	}

	parsed, err := profile.Parse(&buf)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: Parse failed: %v\n", err)
		os.Exit(1)
	}

	if len(parsed.Location) != 1 {
		fmt.Fprintf(os.Stderr, "FAIL: parsed locations length %d\n", len(parsed.Location))
		os.Exit(1)
	}
	parsedLoc := parsed.Location[0]
	if parsedLoc.ID != 1 || parsedLoc.Address != 0x1020 || parsedLoc.IsFolded {
		fmt.Fprintf(os.Stderr, "FAIL: parsed location fields mismatch\n")
		os.Exit(1)
	}
	if len(parsedLoc.Line) != 2 {
		fmt.Fprintf(os.Stderr, "FAIL: parsed location lines length %d\n", len(parsedLoc.Line))
		os.Exit(1)
	}
	if parsedLoc.Line[0].Function.Name != "outer" || parsedLoc.Line[1].Function.Name != "inlinedInner" {
		fmt.Fprintf(os.Stderr, "FAIL: parsed function names mismatch\n")
		os.Exit(1)
	}

	fmt.Println("PASS: all Location contract assertions passed.")
}