Method rewriteCompile

cmd/errtrace/toolexec.go:162–236

(pkg string, p toolExecParams)

}

func (cmd *mainCmd) rewriteCompile(pkg string, p toolExecParams) (exitCode int, _ error) {
	var canRewrite, needRewrite bool
	parsed := make(map[string]parsedFile)
	for _, arg := range p.ToolArgs {
		if !isGoFile(arg) {
			continue
		}

		contents, err := os.ReadFile(arg)
		if err != nil {
			return -1, errtrace.Wrap(err)
		}

		f, err := cmd.parseFile(arg, contents, rewriteOpts{})
		if err != nil {
			return -1, errtrace.Wrap(err)
		}
		parsed[arg] = f

		// TODO: Support an "unsafe" mode to rewrite packages without errtrace imports.
		if f.importsErrtrace {
			canRewrite = true
		}
		if len(f.inserts) > 0 {
			needRewrite = true
		}
	}

	if !needRewrite {
		return cmd.runOriginal(p), nil
	}

	if !canRewrite {
		if p.requiredPackage(pkg) {
			logf(cmd.Stderr, "errtrace required package %v missing errtrace import, needs rewrite", pkg)
			return 1, nil
		}
		return cmd.runOriginal(p), nil
	}

	// Use a temporary directory per-package that is rewritten.
	tempDir, err := os.MkdirTemp("", filepath.Base(pkg))
	if err != nil {
		return -1, errtrace.Wrap(err)
	}
	defer os.RemoveAll(tempDir) //nolint:errcheck // best-effort removal of temp files.

	newArgs := make([]string, 0, len(p.ToolArgs))
	for _, arg := range p.ToolArgs {
		f, ok := parsed[arg]
		if !ok || len(f.inserts) == 0 {
			newArgs = append(newArgs, arg)
			continue
		}

		// Add a //line directive so the original filepath is used in errors and panics.
		var out bytes.Buffer
		_, _ = fmt.Fprintf(&out, "//line %v:1\n", arg)