// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build gc

#include "_cgo_export.h"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

/* Test calling panic from C.  This is what SWIG does.  */

extern void crosscall2(void (*fn)(void *, int), void *, int);
extern void _cgo_panic(void *, int);

the translation process.

Translating Go

Given the input Go files x.go and y.go, cgo generates these source
files:

	x.cgo1.go       # for gc (cmd/compile)
	y.cgo1.go       # for gc
	_cgo_gotypes.go # for gc
	_cgo_import.go  # for gc (if -dynout _cgo_import.go)
	x.cgo2.c        # for gcc
	y.cgo2.c        # for gcc
	_cgo_defun.c    # for gcc (if -gccgo)
	_cgo_export.c   # for gcc

// into Go.
func testCallbackCallersSEH(t *testing.T) {
	testenv.SkipIfOptimizationOff(t) // This test requires inlining.
	if runtime.Compiler != "gc" {
		// The exact function names are not going to be the same.
		t.Skip("skipping for non-gc toolchain")
	}
	if runtime.GOARCH != "amd64" {
		// TODO: support SEH on other architectures.
		t.Skip("skipping on non-amd64")
	}

starting with Go 1.21.6.
This setting may be removed in a future release, and users impacted by this issue
should adjust their Linux configuration according to the recommendations in the
[GC guide](/doc/gc-guide#Linux_transparent_huge_pages), or switch to a Linux
distribution that disables transparent huge pages altogether.

Go 1.22 added contention on runtime-internal locks to the [`mutex`

		}
	})
}

// Test that the stack can be unwound through a call out and call back
// into Go.
func testCallbackCallers(t *testing.T) {
	if runtime.Compiler != "gc" {
		// The exact function names are not going to be the same.
		t.Skip("skipping for non-gc toolchain")
	}
	pc := make([]uintptr, 100)
	n := 0
	name := []string{
		"runtime.cgocallbackg1",
		"runtime.cgocallbackg",
		"runtime.cgocallback",

multiprecision library gmp's integer type mpz_t wrapped to look like
the Go package big's integer type Int.

This is a syntactically valid Go program—it can be parsed with the Go
parser and processed by godoc—but it is not compiled directly by gc.
Instead, a separate tool, cgo, processes it to produce three output
files.  The first two, 6g.go and 6c.c, are a Go source file for 6g and
a C source file for 6c; both compile as part of the named package

	"Title": "A Quick Guide to Go's Assembler",
	"Path":  "/doc/asm"
}-->

<h2 id="introduction">A Quick Guide to Go's Assembler</h2>

<p>
This document is a quick outline of the unusual form of assembly language used by the <code>gc</code> Go compiler.
The document is not comprehensive.
</p>

<p>
The assembler is based on the input style of the Plan 9 assemblers, which is documented in detail
<a href="https://9p.io/sys/doc/asm.html">elsewhere</a>.

	fld = fld[0 : n+1]
	fld[n] = &ast.Field{Names: []*ast.Ident{c.Ident("_")}, Type: c.Opaque(size)}
	sizes = sizes[0 : n+1]
	sizes[n] = size
	return fld, sizes
}

// Struct conversion: return Go and (gc) C syntax for type.
func (c *typeConv) Struct(dt *dwarf.StructType, pos token.Pos) (expr *ast.StructType, csyntax string, align int64) {
	// Minimum alignment for a struct is 1 byte.
	align = 1

pkg runtime, func CPUProfile() []uint8
pkg runtime, func Caller(int) (uintptr, string, int, bool)
pkg runtime, func Callers(int, []uintptr) int
pkg runtime, func FuncForPC(uintptr) *Func
pkg runtime, func GC()
pkg runtime, func GOMAXPROCS(int) int
pkg runtime, func GOROOT() string
pkg runtime, func Goexit()
pkg runtime, func GoroutineProfile([]StackRecord) (int, bool)
pkg runtime, func Gosched()

pkg runtime (windows-386), const GOOS = "windows"
pkg runtime (windows-amd64), const GOARCH = "amd64"
pkg runtime (windows-amd64), const GOOS = "windows"
pkg runtime, const Compiler = "gc"
pkg runtime, func BlockProfile([]BlockProfileRecord) (int, bool)
pkg runtime, func SetBlockProfileRate(int)
pkg runtime, method (*BlockProfileRecord) Stack() []uintptr
pkg runtime, type BlockProfileRecord struct