modernc.org/ccgo/v4 v4.34.5: lib.NewTask

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 modernc.org/ccgo/v4/lib.NewTask in pkg:golang/modernc.org/ccgo/v4@v4.34.5
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/modernc.org/ccgo/v4@v4.34.5
Demonstrate these symbols/APIs:
  - modernc.org/ccgo/v4/lib.NewTask

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:sha256:9394f6443f2b8d5cb2b10f5081a077b4d5b03a7f07c1e9ad33d4818ad6048944","contract":["NewTask returns a non-nil Task configured with target OS and architecture","NewTask parses command line define and include flags into Task fields","NewTask parses undefine, optimization, and preprocessing flags","NewTask executes C preprocessing on virtual filesystem source and routes output to stdout","NewTask captures errors when preprocessing invalid or missing source files"],"goal":"verify modernc.org/ccgo/v4/lib.NewTask in pkg:golang/modernc.org/ccgo/v4@v4.34.5","kind":"HOW","packages":["pkg:golang/modernc.org/ccgo/v4@v4.34.5"],"schemaVersion":1,"symbols":["modernc.org/ccgo/v4/lib.NewTask"]},"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/modernc.org/ccgo/v4@v4.34.5"],"schemaVersion":1,"subject":"pkg:golang/modernc.org/ccgo/v4@v4.34.5","symbols":["modernc.org/ccgo/v4/lib.NewTask"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require modernc.org/ccgo/v4 v4.34.5

require (
	github.com/dustin/go-humanize v1.0.1 // indirect
	github.com/hashicorp/golang-lru/v2 v2.0.7 // indirect
	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
	golang.org/x/mod v0.37.0 // indirect
	golang.org/x/sync v0.21.0 // indirect
	golang.org/x/tools v0.46.0 // indirect
	modernc.org/cc/v4 v4.29.0 // indirect
	modernc.org/gc/v2 v2.6.5 // indirect
	modernc.org/gc/v3 v3.1.4 // indirect
	modernc.org/mathutil v1.7.1 // indirect
	modernc.org/opt v0.2.0 // indirect
	modernc.org/sortutil v1.2.1 // indirect
	modernc.org/strutil v1.2.1 // indirect
	modernc.org/token v1.1.0 // indirect
)

github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
github.com/hashicorp/golang-lru/v2 v2.0.7 h1:a+bsQ5rvGLjzHuww6tVxozPZFVghXaHOwFs4luLUK2k=
github.com/hashicorp/golang-lru/v2 v2.0.7/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
github.com/ncruces/go-strftime v1.0.0 h1:HMFp8mLCTPp341M/ZnA4qaf7ZlsbTc+miZjCLOFAw7w=
github.com/ncruces/go-strftime v1.0.0/go.mod h1:Fwc5htZGVVkseilnfgOVb9mKy6w1naJmn9CehxcKcls=
github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58 h1:onHthvaw9LFnH4t2DcNVpwGmV9E1BkGknEliJkfwQj0=
github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58/go.mod h1:DXv8WO4yhMYhSNPKjeNKa5WY9YCIEBRbNzFFPJbWO6Y=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec h1:W09IVJc94icq4NjY3clb7Lk8O1qJ8BdBEF8z0ibU0rE=
github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec/go.mod h1:qqbHyh8v60DhA7CoWK5oRCqLrMHRGoxYCSS9EjAz6Eo=
golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546 h1:mgKeJMpvi0yx/sU5GsxQ7p6s2wtOnGAHZWCHUM4KGzY=
golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546/go.mod h1:j/pmGrbnkbPtQfxEe5D0VQhZC6qKbfKifgD0oM7sR70=
golang.org/x/mod v0.37.0 h1:vF1DjpVEshcIqoEaauuHebaLk1O1forxjxBaVn884JQ=
golang.org/x/mod v0.37.0/go.mod h1:m8S8VeM9r4dzDwjrKO0a1sZP3YjeMamRRlD+fmR2Q/0=
golang.org/x/sync v0.21.0 h1:HLII4xRRTtCRkxYp4HNFF0Js/Og6q2i++KXbg0gHCwM=
golang.org/x/sync v0.21.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
golang.org/x/sys v0.46.0 h1:noSf2Fq6F8DBgS+LysIkx7rIExoNHJsxOAtPp4rthXw=
golang.org/x/sys v0.46.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
golang.org/x/tools v0.46.0 h1:7jTurBkPZu4moS/Uy4OQT1M+QBlsj3wejyZwsT8Z7rk=
golang.org/x/tools v0.46.0/go.mod h1:FrD85F8l+NWL+9XWBSyVSHO6Ne4jutsfIFba7AWQ5Ys=
modernc.org/cc/v4 v4.29.0 h1:CXgwL8cvxmyzBQZzbSl/6xFtMCryb6u8IOqDci39cgc=
modernc.org/cc/v4 v4.29.0/go.mod h1:OnovgIhbbMXMu1aISnJ0wvVD1KnW+cAUJkIrAWh+kVI=
modernc.org/ccgo/v4 v4.34.5 h1:hcwnthv2/LBl+mRLOYwnQA/LuW44Oln1NQlWppNaS1Q=
modernc.org/ccgo/v4 v4.34.5/go.mod h1:aow0HNkO30OSA/2NrtDXkis92ff8ZFiDOmDOPhqhF8U=
modernc.org/ccorpus2 v1.6.0 h1:JODbahvmixwZDoF1kZs/9Rj6aHA2vAPP7HKiNDq//xo=
modernc.org/ccorpus2 v1.6.0/go.mod h1:Wifvo4Q/qS/h1aRoC2TffcHsnxwTikmi1AuLANuucJQ=
modernc.org/fileutil v1.4.0 h1:j6ZzNTftVS054gi281TyLjHPp6CPHr2KCxEXjEbD6SM=
modernc.org/fileutil v1.4.0/go.mod h1:EqdKFDxiByqxLk8ozOxObDSfcVOv/54xDs/DUHdvCUU=
modernc.org/gc/v2 v2.6.5 h1:nyqdV8q46KvTpZlsw66kWqwXRHdjIlJOhG6kxiV/9xI=
modernc.org/gc/v2 v2.6.5/go.mod h1:YgIahr1ypgfe7chRuJi2gD7DBQiKSLMPgBQe9oIiito=
modernc.org/gc/v3 v3.1.4 h1:2g65LGVSmFQrXeITAw97x7hCRvZFcyE1uDP+7Vng7JI=
modernc.org/gc/v3 v3.1.4/go.mod h1:HFK/6AGESC7Ex+EZJhJ2Gni6cTaYpSMmU/cT9RmlfYY=
modernc.org/lex v1.1.1 h1:prSCNTLw1R4rn7M/RzwsuMtAuOytfyR3cnyM07P+Pas=
modernc.org/lex v1.1.1/go.mod h1:6r8o8DLJkAnOsQaGi8fMoi+Vt6LTbDaCrkUK729D8xM=
modernc.org/lexer v1.0.4 h1:hU7xVbZsqwPphyzChc7nMSGrsuaD2PDNOmzrzkS5AlE=
modernc.org/lexer v1.0.4/go.mod h1:tOajb8S4sdfOYitzCgXDFmbVJ/LE0v1fNJ7annTw36U=
modernc.org/libc v1.73.4 h1:+ra4Ui8ngyt8HDcO1FTDPWlkAh6yOdaO2yAoh8MddQA=
modernc.org/libc v1.73.4/go.mod h1:DXZ3eO8qMCNn2SnmTNCiC71nJ9Rcq3PsnpU6Vc4rWK8=
modernc.org/mathutil v1.7.1 h1:GCZVGXdaN8gTqB1Mf/usp1Y/hSqgI2vAGGP4jZMCxOU=
modernc.org/mathutil v1.7.1/go.mod h1:4p5IwJITfppl0G4sUEDtCr4DthTaT47/N3aT6MhfgJg=
modernc.org/memory v1.11.0 h1:o4QC8aMQzmcwCK3t3Ux/ZHmwFPzE6hf2Y5LbkRs+hbI=
modernc.org/memory v1.11.0/go.mod h1:/JP4VbVC+K5sU2wZi9bHoq2MAkCnrt2r98UGeSK7Mjw=
modernc.org/opt v0.2.0 h1:tGyef5ApycA7FSEOMraay9SaTk5zmbx7Tu+cJs4QKZg=
modernc.org/opt v0.2.0/go.mod h1:03fq9lsNfvkYSfxrfUhZCWPk1lm4cq4N+Bh//bEtgns=
modernc.org/scannertest v1.0.2 h1:JPtfxcVdbRvzmRf2YUvsDibJsQRw8vKA/3jb31y7cy0=
modernc.org/scannertest v1.0.2/go.mod h1:RzTm5RwglF/6shsKoEivo8N91nQIoWtcWI7ns+zPyGA=
modernc.org/sortutil v1.2.1 h1:+xyoGf15mM3NMlPDnFqrteY07klSFxLElE2PVuWIJ7w=
modernc.org/sortutil v1.2.1/go.mod h1:7ZI3a3REbai7gzCLcotuw9AC4VZVpYMjDzETGsSMqJE=
modernc.org/strutil v1.2.1 h1:UneZBkQA+DX2Rp35KcM69cSsNES9ly8mQWD71HKlOA0=
modernc.org/strutil v1.2.1/go.mod h1:EHkiggD70koQxjVdSBM3JKM7k6L0FbGE5eymy9i3B9A=
modernc.org/token v1.1.0 h1:Xl7Ap9dKaEs5kLoOQeQmPWevfnk/DM5qcLcYlA8ys6Y=
modernc.org/token v1.1.0/go.mod h1:UGzOrNV1mAFSEB63lOFHIpNRUVMvYTc6yu1SMY/XTDM=

package main

import (
	"bytes"
	"fmt"
	"os"
	"testing/fstest"

	ccgo "modernc.org/ccgo/v4/lib"
)

func main() {
	mfs := fstest.MapFS{
		"sample.c": &fstest.MapFile{
			Data: []byte("#define BUFFER_CAPACITY 1024\nint default_capacity = BUFFER_CAPACITY;\n"),
		},
	}

	var stdout, stderr bytes.Buffer
	args := []string{"ccgo", "-E", "sample.c"}

	task := ccgo.NewTask("linux", "amd64", args, &stdout, &stderr, mfs)
	if task == nil {
		fmt.Fprintln(os.Stderr, "failed to create task")
		os.Exit(1)
	}

	if err := task.Main(); err != nil {
		fmt.Fprintf(os.Stderr, "preprocessing failed: %v\n", err)
		os.Exit(1)
	}

	fmt.Println("Preprocessing completed successfully:")
	fmt.Print(stdout.String())
}

{
  "schemaVersion": 1,
  "goal": "verify modernc.org/ccgo/v4/lib.NewTask in pkg:golang/modernc.org/ccgo/v4@v4.34.5",
  "kind": "HOW",
  "packages": [
    "pkg:golang/modernc.org/ccgo/v4@v4.34.5"
  ],
  "symbols": [
    "modernc.org/ccgo/v4/lib.NewTask"
  ]
}

package main

import (
	"bytes"
	"fmt"
	"os"
	"strings"
	"testing/fstest"

	ccgo "modernc.org/ccgo/v4/lib"
)

func main() {
	// Assertion 1: NewTask returns a non-nil Task configured with target OS and architecture
	{
		var stdout, stderr bytes.Buffer
		task := ccgo.NewTask("linux", "amd64", []string{"ccgo"}, &stdout, &stderr, nil)
		if task == nil {
			fmt.Fprintln(os.Stderr, "assertion 1 failed: NewTask returned nil")
			os.Exit(1)
		}
	}

	// Assertion 2: NewTask parses command line define and include flags into Task fields
	{
		mfs := fstest.MapFS{
			"dummy.c": &fstest.MapFile{Data: []byte("int dummy = 1;\n")},
		}
		var stdout, stderr bytes.Buffer
		args := []string{"ccgo", "-D", "CONFIG_FLAG=1", "-I", "include/path", "-E", "dummy.c"}
		task := ccgo.NewTask("linux", "amd64", args, &stdout, &stderr, mfs)
		if task == nil {
			fmt.Fprintln(os.Stderr, "assertion 2 failed: NewTask returned nil")
			os.Exit(1)
		}
		if err := task.Main(); err != nil {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: task.Main error: %v\n", err)
			os.Exit(1)
		}

		foundD := false
		for _, d := range task.D {
			if strings.Contains(d, "CONFIG_FLAG=1") {
				foundD = true
				break
			}
		}
		if !foundD {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: define flag not found in task.D: %v\n", task.D)
			os.Exit(1)
		}

		foundI := false
		for _, i := range task.I {
			if i == "include/path" {
				foundI = true
				break
			}
		}
		if !foundI {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: include flag not found in task.I: %v\n", task.I)
			os.Exit(1)
		}
	}

	// Assertion 3: NewTask parses undefine, optimization, and preprocessing flags
	{
		mfs := fstest.MapFS{
			"dummy.c": &fstest.MapFile{Data: []byte("int dummy = 2;\n")},
		}
		var stdout, stderr bytes.Buffer
		args := []string{"ccgo", "-U", "LEGACY_MODE", "-O2", "-E", "dummy.c"}
		task := ccgo.NewTask("linux", "amd64", args, &stdout, &stderr, mfs)
		if task == nil {
			fmt.Fprintln(os.Stderr, "assertion 3 failed: NewTask returned nil")
			os.Exit(1)
		}
		if err := task.Main(); err != nil {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: task.Main error: %v\n", err)
			os.Exit(1)
		}

		foundU := false
		for _, u := range task.U {
			if strings.Contains(u, "LEGACY_MODE") {
				foundU = true
				break
			}
		}
		if !foundU {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: undefine flag not found in task.U: %v\n", task.U)
			os.Exit(1)
		}
		if task.O != "-O2" {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: unexpected optimization flag: %q\n", task.O)
			os.Exit(1)
		}
		if !task.E {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: expected task.E to be true\n")
			os.Exit(1)
		}
	}

	// Assertion 4: NewTask executes C preprocessing on virtual filesystem source and routes output to stdout
	{
		mfs := fstest.MapFS{
			"input.c": &fstest.MapFile{
				Data: []byte("#define BUFFER_LEN 512\nint capacity = BUFFER_LEN;\n"),
			},
		}
		var stdout, stderr bytes.Buffer
		args := []string{"ccgo", "-E", "input.c"}
		task := ccgo.NewTask("linux", "amd64", args, &stdout, &stderr, mfs)
		if task == nil {
			fmt.Fprintln(os.Stderr, "assertion 4 failed: NewTask returned nil")
			os.Exit(1)
		}
		if err := task.Main(); err != nil {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: task.Main error: %v\n", err)
			os.Exit(1)
		}
		if !strings.Contains(stdout.String(), "int capacity = 512;") {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: output missing expanded macro: %q\n", stdout.String())
			os.Exit(1)
		}
	}

	// Assertion 5: NewTask captures errors when preprocessing invalid or missing source files
	{
		mfs := fstest.MapFS{}
		var stdout, stderr bytes.Buffer
		args := []string{"ccgo", "-E", "nonexistent.c"}
		task := ccgo.NewTask("linux", "amd64", args, &stdout, &stderr, mfs)
		if task == nil {
			fmt.Fprintln(os.Stderr, "assertion 5 failed: NewTask returned nil")
			os.Exit(1)
		}
		err := task.Main()
		if err == nil {
			fmt.Fprintln(os.Stderr, "assertion 5 failed: expected error for missing file, got nil")
			os.Exit(1)
		}
	}

	fmt.Println("All contract assertions passed successfully.")
}