if !*flags.SymABIs {
		buf.WriteString(objabi.HeaderString())
		fmt.Fprintf(buf, "!\n")
	}

	// Set macros for GOEXPERIMENTs so we can easily switch
	// runtime assembly code based on them.
	if objabi.LookupPkgSpecial(ctxt.Pkgpath).AllowAsmABI {
		for _, exp := range buildcfg.Experiment.Enabled() {
			flags.D = append(flags.D, "GOEXPERIMENT_"+exp)
		}
	}

	var ok, diag bool
	var failedFile string

		ctxt:        ctxt,
		arch:        ar,
		lex:         lexer,
		labels:      make(map[string]*obj.Prog),
		dataAddr:    make(map[string]int64),
		errorWriter: os.Stderr,
		allowABI:    ctxt != nil && objabi.LookupPkgSpecial(ctxt.Pkgpath).AllowAsmABI,
		pkgPrefix:   pkgPrefix,
	}
}

// panicOnError is enabled when testing to abort execution on the first error
// and turn it into a recoverable panic.
var panicOnError bool