garble/testdata/script/linker.txtar

# Past garble versions might not properly patch cmd/link with "git apply"
# when running inside a git repository. Skip the extra check with -short.
[!short] [exec:git] exec git init -q
[!short] [exec:git] env GARBLE_CACHE=${WORK}/garble-cache

# Any build settings for the main build shouldn't affect building the linker.
# If this flag makes it through when using build commands on std or cmd,
# those commands are likely to fail as std and cmd are their own modules.
env GOFLAGS=-modfile=${WORK}/go.mod

exec garble build
exec ./main
! cmp stderr main.stderr

[short] stop # no need to verify this with -short

# The rebuilt linker should use the executable extension for the host GOOS,
# not the target one. Not doing so might be harmless, but can result in
# building the linker twice, wasting CPU and disk.
[!windows] env GOOS=windows
[windows] env GOOS=linux
exec garble build
[!windows] [exec:git]   exists ${GARBLE_CACHE}/tool/link
[!windows] [exec:git] ! exists ${GARBLE_CACHE}/tool/link.exe
[windows]  [exec:git] ! exists ${GARBLE_CACHE}/tool/link
[windows]  [exec:git]   exists ${GARBLE_CACHE}/tool/link.exe
env GOOS=

# Verify a build without garble.
go build
exec ./main
cmp stderr main.stderr

-- go.mod --
module test/main

go 1.22
-- main.go --
package main

import (
	"strconv"
	"strings"
	_ "unsafe"
)

type fakeModuleData struct {
	pcHeader *struct {
		magic uint32
	}
}

//go:linkname activeModules runtime.activeModules
func activeModules() []*fakeModuleData

// genericMagicValue returns magic value without last digit
func genericMagicValue() string {
	mod := activeModules()[0]
	magicValHex := strings.ToUpper(strconv.FormatUint(uint64(mod.pcHeader.magic), 16))
	return "0x" + magicValHex[:len(magicValHex)-1] + "?"
}

func main() {
	println(genericMagicValue())
}

-- main.stderr --
0xFFFFFFF?