// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package runtime

import (
	"unsafe"
)

// Don't split the stack as this function may be invoked without a valid G,
// which prevents us from allocating more stack.
//
//go:nosplit
func sysAllocOS(n uintptr) unsafe.Pointer {
	v, err := mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
	if err != 0 {
		return nil

	g.strings[s] = id
	return id
}

// Stack registers a stack with the trace.
//
// This is a convenience function for easily adding correct
// stacks to traces.
func (g *Generation) Stack(stk []trace.StackFrame) uint64 {
	if len(stk) == 0 {
		return 0
	}
	if len(stk) > 32 {
		panic("stack too big for test")
	}
	var stkc stack
	copy(stkc.stk[:], stk)
	stkc.len = len(stk)

	//
	// For cdecl and stdcall, all arguments are on the stack.
	//
	// For fastcall, the trampoline spills register arguments to
	// the reserved spill slots below the stack arguments,
	// resulting in a layout equivalent to stdcall.
	//
	// For arm, the trampoline stores the register arguments just
	// below the stack arguments, so again we can treat it as one
	// big stack arguments frame.
	args unsafe.Pointer

// Test that a linkname applied on an assembly declaration
// does not affect stack map generation.

package main

import (
	"runtime"
	_ "unsafe"
)

//go:linkname asm
func asm(*int)

func main() {
	x := new(int)
	asm(x)
}

// called from asm
func callback() {
	runtime.GC() // scan stack

	// running the remaining deferred functions.
	//
	// This test does not verify the accuracy of the call stack (it
	// currently includes a frame from runtime.deferreturn which would
	// normally be omitted). It is only intended to check that producing the
	// call stack won't crash.
	defer func() {
		pcs := make([]uintptr, 32)
		for i := range pcs {
			// If runtime.recovery doesn't properly restore the

// preparePanic sets up the stack to look like a call to sigpanic.
func (c *sigctxt) preparePanic(sig uint32, gp *g) {
	// We arrange RA, and pc to pretend the panicking
	// function calls sigpanic directly.
	// Always save RA to stack so that panics in leaf
	// functions are correctly handled. This smashes
	// the stack frame but we're not going back there
	// anyway.
	sp := c.sp() - goarch.PtrSize

//
// nosplit because it's called on the syscall path when stack movement is forbidden.
//
//go:nosplit
func (tl traceLocker) ok() bool {
	return tl.gen != 0
}

// traceRelease indicates that this M is done writing trace events.
//
// nosplit because it's called on the syscall path when stack movement is forbidden.
//
//go:nosplit
func traceRelease(tl traceLocker) {

		_ = v
	}
}

type R struct{ *T }

type Q interface {
	Foo([]interface{})
}

func main() {
	var count = 10000
	if runtime.Compiler == "gccgo" {
		// On targets without split-stack libgo allocates
		// a large stack for each goroutine. On 32-bit
		// systems this test can run out of memory.
		const intSize = 32 << (^uint(0) >> 63) // 32 or 64
		if intSize < 64 {
			count = 100
		}
	}

	var q Q = &R{&T{}}

	_PAGE_READWRITE = 0x0004
	_PAGE_NOACCESS  = 0x0001

	_ERROR_NOT_ENOUGH_MEMORY = 8
	_ERROR_COMMITMENT_LIMIT  = 1455
)

// Don't split the stack as this function may be invoked without a valid G,
// which prevents us from allocating more stack.
//
//go:nosplit
func sysAllocOS(n uintptr) unsafe.Pointer {
	return unsafe.Pointer(stdcall4(_VirtualAlloc, 0, n, _MEM_COMMIT|_MEM_RESERVE, _PAGE_READWRITE))
}

	testenv.MustHaveGoBuild(t)

	// This test does a build of a specific canned package to
	// check whether merging of stack slots is taking place.
	// The idea is to do the compile with a trace option turned
	// on and then pick up on the frame offsets of specific
	// variables.
	//
	// Stack slot merging is a greedy algorithm, and there can
	// be many possible ways to overlap a given set of candidate