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

package codegen

import "runtime"

// This file contains code generation tests related to the use of the
// stack.

// Check that stack stores are optimized away.

// 386:"TEXT\t.*, [$]0-"
// amd64:"TEXT\t.*, [$]0-"
// arm:"TEXT\t.*, [$]-4-"
// arm64:"TEXT\t.*, [$]0-"
// mips:"TEXT\t.*, [$]-4-"
// ppc64x:"TEXT\t.*, [$]0-"

)

// PrintStack prints to standard error the stack trace returned by runtime.Stack.
func PrintStack() {
	os.Stderr.Write(Stack())
}

// Stack returns a formatted stack trace of the goroutine that calls it.
// It calls [runtime.Stack] with a large enough buffer to capture the entire trace.
func Stack() []byte {
	buf := make([]byte, 1024)
	for {
		n := runtime.Stack(buf, false)
		if n < len(buf) {
			return buf[:n]
		}

			}

			if len(stack) > 0 {
				stack += " "
			}
			stack += FmtSprintf("%s:%d", name, line-tiuStart)
		}

		if stack != prevStack {
			prevStack = stack

			t.Logf("tiuTest+%#x: %s", pc-pc1, stack)

			if _, ok := want[stack]; ok {
				want[stack]++
			}
		}
	}

	// Check that we got all the stacks we wanted.
	for stack, count := range want {
		if count == 0 {

// explaining why.
//
//go:nosplit
func debugCallCheck(pc uintptr) string {
	// No user calls from the system stack.
	if getg() != getg().m.curg {
		return debugCallSystemStack
	}
	if sp := getcallersp(); !(getg().stack.lo < sp && sp <= getg().stack.hi) {
		// Fast syscalls (nanotime) and racecall switch to the
		// g0 stack without switching g. We can't safely make
		// a call in this state. (We can't even safely
		// systemstack.)

	{
		var x Ptr
		verifyGCInfo(t, "stack Ptr", &x, infoPtr)
		runtime.KeepAlive(x)
	}
	{
		var x ScalarPtr
		verifyGCInfo(t, "stack ScalarPtr", &x, infoScalarPtr)
		runtime.KeepAlive(x)
	}
	{
		var x PtrScalar
		verifyGCInfo(t, "stack PtrScalar", &x, infoPtrScalar)
		runtime.KeepAlive(x)
	}
	{
		var x BigStruct
		verifyGCInfo(t, "stack BigStruct", &x, infoBigStruct())
		runtime.KeepAlive(x)
	}

	child6bad()
	child6() // appears in stack trace
}

//go:noinline
func child6bad() {
}

//go:noinline
func child6() { // test trace through first of two call instructions
	child7() // appears in stack trace
	child7bad()
}

//go:noinline
func child7bad() {
}

//go:noinline
func child7() {
	// Write runtime.Caller's view of the stack to stderr, for debugging.
	var pcs [16]uintptr

// 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)

// 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

// 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