# Regression test for https://go.dev/issue/62119:
# A 'go' command cross-compiled with a different GOHOSTOS
# should be able to locate its GOROOT using os.Executable.
#
# (This also tests a 'go' command built with -trimpath
# that is not cross-compiled, since we need to build that
# configuration for the test anyway.)

[short] skip 'builds and links another cmd/go'

mkdir $WORK/new/bin
mkdir $WORK/new/bin/${GOOS}_${GOARCH}

# In this test, we are specifically checking the logic for deriving
# the value of GOROOT from os.Executable when runtime.GOROOT is
# trimmed away.
# GOROOT_FINAL changes the default behavior of runtime.GOROOT,
# so we explicitly clear it to remove it as a confounding variable.
env GOROOT_FINAL=

# $GOROOT/bin/go is whatever the user has already installed
# (using make.bash or similar). We can't make assumptions about what
# options it may have been built with, such as -trimpath or GOROOT_FINAL.
# Instead, we build a fresh copy of the binary with known settings.
go build -trimpath -o $WORK/new/bin/go$GOEXE cmd/go &
go build -trimpath -o $WORK/bin/check$GOEXE check.go &
wait

env TESTGOROOT=$GOROOT
env GOROOT=

# Unset GOPATH and any variables that its default may be derived from,
# so that we can check for a spurious warning.
env GOPATH=
env HOME=''
env USERPROFILE=''
env home=''

# Relocated Executable
# Since we built with -trimpath and the binary isn't installed in a
# normal-looking GOROOT, this command should fail.

! exec $WORK/new/bin/go$GOEXE env GOROOT
stderr '^go: cannot find GOROOT directory: ''go'' binary is trimmed and GOROOT is not set$'
! stderr 'GOPATH set to GOROOT'

# Cross-compiled binaries in cmd are installed to a ${GOOS}_${GOARCH} subdirectory,
# so we also want to try a copy there.
# (Note that the script engine's 'exec' engine already works around
# https://go.dev/issue/22315, so we don't have to do that explicitly in the
# 'check' program we use later.)
cp $WORK/new/bin/go$GOEXE $WORK/new/bin/${GOOS}_${GOARCH}/go$GOEXE
! exec $WORK/new/bin/${GOOS}_${GOARCH}/go$GOEXE env GOROOT
stderr '^go: cannot find GOROOT directory: ''go'' binary is trimmed and GOROOT is not set$'
! stderr 'GOPATH set to GOROOT'

# Relocated Tree:
# If the binary is sitting in a bin dir next to ../pkg/tool, that counts as a GOROOT,
# so it should find the new tree.
mkdir $WORK/new/pkg/tool
exec $WORK/bin/check$GOEXE $WORK/new/bin/go$GOEXE $WORK/new
exec $WORK/bin/check$GOEXE $WORK/new/bin/${GOOS}_${GOARCH}/go$GOEXE $WORK/new
! stderr 'GOPATH set to GOROOT'

-- check.go --
package main

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
)

func main() {
	exe := os.Args[1]
	want := os.Args[2]
	cmd := exec.Command(exe, "env", "GOROOT")
	out, err := cmd.CombinedOutput()
	if err != nil {
		fmt.Fprintf(os.Stderr, "%s env GOROOT: %v, %s\n", exe, err, out)
		os.Exit(1)
	}
	goroot, err := filepath.EvalSymlinks(strings.TrimSpace(string(out)))
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
	want, err = filepath.EvalSymlinks(want)
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
	if !strings.EqualFold(goroot, want) {
		fmt.Fprintf(os.Stderr, "go env GOROOT:\nhave %s\nwant %s\n", goroot, want)
		os.Exit(1)
	}
	fmt.Fprintf(os.Stderr, "go env GOROOT: %s\n", goroot)

}