var set_crosscall2 func()

// cgoHasExtraM is set on startup when an extra M is created for cgo.
// The extra M must be created before any C/C++ code calls cgocallback.
var cgoHasExtraM bool

// cgoUse is called by cgo-generated code (using go:linkname to get at
// an unexported name). The calls serve two purposes:
// 1) they are opaque to escape analysis, so the argument is considered to
// escape to the heap.

Carlos Amedee <******@****.***> 1715265901 -0400

// On those systems the cgo resolver does not require the cgo tool.
// (The term "cgo resolver" was locked in by GODEBUG settings
// at a time when the cgo resolver did require the cgo tool.)
//
// Adding netdns=go to GODEBUG will prefer the go resolver.
// Adding netdns=cgo to GODEBUG will prefer the cgo resolver.
//
// The Resolver struct has a PreferGo field that user code
// may set to prefer the go resolver. It is documented as being

go build -x runtime/cgo
[!short] stderr '[/\\]cgo'$GOEXE'["]? .* -importpath runtime/cgo'

# https://go.dev/issue/47215: a missing $(go env CC) caused the precompiled net
# to be stale. But as of https://go.dev/cl/452457 the precompiled libraries are
# no longer installed anyway! Since we're requiring a C compiler in order to
# build and use cgo libraries in the standard library, we should make sure it

[!GOOS:darwin] skip
[!cgo] skip

! go build
stderr 'invalid flag in #cgo LDFLAGS: -lto_library'

-- go.mod --
module ldflag

-- main.go --
package main

// #cgo CFLAGS: -flto
// #cgo LDFLAGS: -lto_library bad.dylib
import "C"

environment variable when running the go tool: set it to 1 to enable
the use of cgo, and to 0 to disable it. The go tool will set the
build constraint "cgo" if cgo is enabled. The special import "C"
implies the "cgo" build constraint, as though the file also said
"//go:build cgo".  Therefore, if cgo is disabled, files that import
"C" will not be built by the go tool. (For more about build constraints

// license that can be found in the LICENSE file.

//go:build cgo && !((ppc64 || ppc64le) && internal)

// Test that we can link together two different cgo packages that both
// use the same libgcc function.

package cgotest

import (
	"runtime"
	"testing"

	"cmd/cgo/internal/test/issue9510a"
	"cmd/cgo/internal/test/issue9510b"
)

func test9510(t *testing.T) {
	if runtime.GOARCH == "arm" {

	ret = mach_port_allocate(mach_task_self(), MACH_PORT_RIGHT_RECEIVE, &port);
	if (ret) {
		fprintf(stderr, "runtime/cgo: mach_port_allocate failed: %d\n", ret);
		abort();
	}
	ret = mach_port_insert_right(
		mach_task_self(),
		port,
		port,
		MACH_MSG_TYPE_MAKE_SEND);
	if (ret) {
		fprintf(stderr, "runtime/cgo: mach_port_insert_right failed: %d\n", ret);
		abort();
	}

	ret = thread_set_exception_ports(

	if !cgoAvailable {
		t.Skip("cgo resolver not available")
	}
	defer forceCgoDNS()()
	order, _ := systemConf().hostLookupOrder(nil, "go.dev")
	if order != hostLookupCgo {
		t.Fatalf("hostLookupOrder returned: %v, want cgo", order)
	}
	order, _ = systemConf().addrLookupOrder(nil, "192.0.2.1")
	if order != hostLookupCgo {
		t.Fatalf("addrLookupOrder returned: %v, want cgo", order)
	}

# Issue #66456

[!cgo] skip
[GOOS:windows] skip
[GOOS:plan9] skip

# Generate a file with a very long #cgo LDFLAGS line.
# This used to cause "go build" to fail with "argument list too long".
go generate

# Build with the generated file.
go build

-- go.mod --
module cgolongcmd

go 1.22
-- generate.go --
//go:build ignore

package main

import (
	"fmt"
	"log"
	"os"
	"bytes"
)