"cmd/internal/sys"
)

var CheckFunc = checkFunc
var Opt = opt
var Deadcode = deadcode
var Copyelim = copyelim

var testCtxts = map[string]*obj.Link{
	"amd64": obj.Linknew(&x86.Linkamd64),
	"s390x": obj.Linknew(&s390x.Links390x),
	"arm64": obj.Linknew(&arm64.Linkarm64),
}

func testConfig(tb testing.TB) *Conf      { return testConfigArch(tb, "amd64") }
func testConfigS390X(tb testing.TB) *Conf { return testConfigArch(tb, "s390x") }

	telemetry.CountFlags("asm/flag:", *flag.CommandLine)

	architecture := arch.Set(GOARCH, *flags.Shared || *flags.Dynlink)
	if architecture == nil {
		log.Fatalf("unrecognized architecture %s", GOARCH)
	}
	ctxt := obj.Linknew(architecture.LinkArch)
	ctxt.Debugasm = flags.PrintOut
	ctxt.Debugvlog = flags.DebugV
	ctxt.Flag_dynlink = *flags.Dynlink
	ctxt.Flag_linkshared = *flags.Linkshared
	ctxt.Flag_shared = *flags.Shared || *flags.Dynlink

)

func init() {
	flag.Var(&rpath, "r", "set the ELF dynamic linker search `path` to dir1:dir2:...")
	flag.Var(&flagExtld, "extld", "use `linker` when linking in external mode")
	flag.Var(&flagExtldflags, "extldflags", "pass `flags` to external linker")
	flag.Var(&flagW, "w", "disable DWARF generation")
}

package obj

import (
	"cmd/internal/goobj"
	"cmd/internal/notsha256"
	"cmd/internal/objabi"
	"encoding/base64"
	"encoding/binary"
	"fmt"
	"internal/buildcfg"
	"log"
	"math"
	"sort"
)

func Linknew(arch *LinkArch) *Link {
	ctxt := new(Link)
	ctxt.hash = make(map[string]*LSym)
	ctxt.funchash = make(map[string]*LSym)
	ctxt.statichash = make(map[string]*LSym)
	ctxt.Arch = arch
	ctxt.Pathname = objabi.WorkingDir()

## Assembler {#assembler}

## Linker {#linker}

<!-- go.dev/issue/67401, CL 585556, CL 587220, and many more -->
The linker now disallows using a `//go:linkname` directive to refer to
internal symbols in the standard library (including the runtime) that
are not marked with `//go:linkname` on their definitions.
Similarly, the linker disallows references to such symbols from assembly
code.

// command? See issue #64947 for more detail, but the short answer is
// that newer versions of the Macos toolchain (the newer linker in
// particular) appear to compute the UUID based not just on the
// content of the object files being linked but also on things like
// the timestamps/paths of the objects; this makes it
// difficult/impossible to support reproducible builds. Since we try

the host linker. The default value for the host linker is $CC, split
into fields, or else "gcc". The specific host linker command line can
be overridden using command line flags: cmd/link -extld=clang
-extldflags='-ggdb -O3'. If any package in a build includes a .cc or
other file compiled by the C++ compiler, the go tool will use the
-extld option to set the host linker to the C++ compiler.

	return nil
}

// extld returns the current external linker.
func (ctxt *Link) extld() []string {
	if len(flagExtld) == 0 {
		// Return the default external linker for the platform.
		// This only matters when link tool is called directly without explicit -extld,
		// go tool already passes the correct linker in other cases.
		switch buildcfg.GOOS {
		case "darwin", "freebsd", "openbsd":

	// linkedit section, but all the others can be copied directly.
	linkseg := exem.Segment("__LINKEDIT")
	if linkseg == nil {
		return fmt.Errorf("missing __LINKEDIT segment")
	}

	if _, err := exef.Seek(0, 0); err != nil {
		return err
	}
	if _, err := io.CopyN(outf, exef, int64(linkseg.Offset)); err != nil {
		return err
	}

	realdwarf := dwarfm.Segment("__DWARF")

// (1) scheme is enough to express any kind of operand combination.
//
// Jump instructions use the To.Val field to point to the target *Prog,
// which must be in the same linked list as the jump instruction.
//
// The Progs for a given function are arranged in a list linked through the Link field.
//
// Each Prog is charged to a specific source line in the debug information,
// specified by Pos.Line().