#define NULL ((void *)0)
typedef unsigned long size_t; // Customize by platform.
typedef long intptr_t;
typedef unsigned long uintptr_t;
typedef long scalar_t__; // Either arithmetic or pointer type.
/* By default, we understand bool (as a convenience). */
typedef int bool;
#define false 0
#define true 1

/* Forward declarations */

/* Type definitions */
struct addrinfo {
  int /*<<< orphan*/ ai_addrlen;
  int /*<<< orphan*/ ai_addr;
  int /*<<< orphan*/ ai_protocol;
  int /*<<< orphan*/ ai_socktype;
  int /*<<< orphan*/ ai_family;
  struct addrinfo *ai_next;
  int /*<<< orphan*/ ai_flags;
};

/* Variables and functions */
int /*<<< orphan*/ AF_INET;
int /*<<< orphan*/ AI_PASSIVE;
int /*<<< orphan*/ SOCK_STREAM;
scalar_t__ bind(int, int /*<<< orphan*/, int /*<<< orphan*/);
int /*<<< orphan*/ close(int);
int /*<<< orphan*/ freeaddrinfo(struct addrinfo *);
char *gai_strerror(int);
int getaddrinfo(int /*<<< orphan*/ *, char *, struct addrinfo *,
                struct addrinfo **);
scalar_t__ listen(int, int);
int /*<<< orphan*/ log_exit(char *);
int /*<<< orphan*/ memset(struct addrinfo *, int /*<<< orphan*/, int);
int socket(int /*<<< orphan*/, int /*<<< orphan*/, int /*<<< orphan*/);
int listen_socket(char *port) {
  struct addrinfo hints, *res, *ai;
  int err;
  memset(&hints, 0, sizeof(struct addrinfo));
  hints.ai_family = AF_INET;
  hints.ai_socktype = SOCK_STREAM;
  hints.ai_flags = AI_PASSIVE;
  if ((err = getaddrinfo(NULL, port, &hints, &res)) != 0) {
    log_exit(gai_strerror(err));
  }
  for (ai = res; ai; ai = ai->ai_next) {
    int sock;
    sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
    if (sock < 0) {
      continue;
    }
    if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
      close(sock);
      continue;
    }
    if (listen(sock, 5) < 0) {
      close(sock);
      continue;
    }
    freeaddrinfo(res);
    return sock;
  }
  log_exit("failed to listen socket");
  return -1;
}


x86 assembly (clang, -O0):
<listen_socket>:
push   %rbp
mov    %rsp,%rbp
sub    $0x50,%rsp
mov    %rdi,-0x10(%rbp)
lea    -0x38(%rbp),%rdi
xor    %esi,%esi
mov    $0x28,%edx
call   1040 <memset@plt>
mov    0x2e2d(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x28(%rbp)
mov    0x2e11(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x2c(%rbp)
mov    0x2e1d(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x18(%rbp)
mov    -0x10(%rbp),%rsi
xor    %eax,%eax
mov    %eax,%edi
lea    -0x38(%rbp),%rdx
lea    -0x40(%rbp),%rcx
call   1090 <getaddrinfo@plt>
mov    %eax,-0x4c(%rbp)
cmp    $0x0,%eax
je     1201 <listen_socket+0x71>
mov    -0x4c(%rbp),%edi
call   1030 <gai_strerror@plt>
mov    %rax,%rdi
call   1080 <log_exit@plt>
mov    -0x40(%rbp),%rax
mov    %rax,-0x48(%rbp)
cmpq   $0x0,-0x48(%rbp)
je     12b5 <listen_socket+0x125>
mov    -0x48(%rbp),%rax
mov    0x10(%rax),%edi
mov    -0x48(%rbp),%rax
mov    0xc(%rax),%esi
mov    -0x48(%rbp),%rax
mov    0x8(%rax),%edx
call   10b0 <socket@plt>
mov    %eax,-0x50(%rbp)
cmpl   $0x0,-0x50(%rbp)
jge    1240 <listen_socket+0xb0>
jmp    12a4 <listen_socket+0x114>
mov    -0x50(%rbp),%edi
mov    -0x48(%rbp),%rax
mov    0x4(%rax),%esi
mov    -0x48(%rbp),%rax
mov    (%rax),%edx
call   1070 <bind@plt>
cmp    $0x0,%rax
jge    126c <listen_socket+0xdc>
mov    -0x50(%rbp),%edi
call   1050 <close@plt>
jmp    12a4 <listen_socket+0x114>
mov    -0x50(%rbp),%edi
mov    $0x5,%esi
call   1060 <listen@plt>
cmp    $0x0,%rax
jge    1290 <listen_socket+0x100>
mov    -0x50(%rbp),%edi
call   1050 <close@plt>
jmp    12a4 <listen_socket+0x114>
mov    -0x40(%rbp),%rdi
call   10a0 <freeaddrinfo@plt>
mov    -0x50(%rbp),%eax
mov    %eax,-0x4(%rbp)
jmp    12c8 <listen_socket+0x138>
mov    -0x48(%rbp),%rax
mov    0x18(%rax),%rax
mov    %rax,-0x48(%rbp)
jmp    1209 <listen_socket+0x79>
lea    0xd44(%rip),%rdi
call   1080 <log_exit@plt>
movl   $0xffffffff,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x50,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<listen_socket>:
push   %rbp
push   %r14
push   %rbx
sub    $0x30,%rsp
mov    %rdi,%rbx
lea    0x8(%rsp),%r14
mov    %r14,%rdi
xor    %esi,%esi
mov    $0x28,%edx
call   1040 <memset@plt>
mov    0x2e2a(%rip),%rax
mov    (%rax),%eax
mov    %eax,0x18(%rsp)
mov    0x2e0d(%rip),%rax
mov    (%rax),%eax
mov    %eax,0x14(%rsp)
mov    0x2e18(%rip),%rax
mov    (%rax),%eax
mov    %eax,0x28(%rsp)
mov    %rsp,%rcx
xor    %edi,%edi
mov    %rbx,%rsi
mov    %r14,%rdx
call   1090 <getaddrinfo@plt>
test   %eax,%eax
je     11f9 <listen_socket+0x69>
mov    %eax,%edi
call   1030 <gai_strerror@plt>
mov    %rax,%rdi
call   1080 <log_exit@plt>
mov    (%rsp),%rbx
jmp    120b <listen_socket+0x7b>
nop
mov    %ebp,%edi
call   1050 <close@plt>
mov    0x18(%rbx),%rbx
test   %rbx,%rbx
je     1251 <listen_socket+0xc1>
mov    0x10(%rbx),%edi
mov    0x8(%rbx),%edx
mov    0xc(%rbx),%esi
call   10b0 <socket@plt>
test   %eax,%eax
js     1207 <listen_socket+0x77>
mov    %eax,%ebp
mov    (%rbx),%edx
mov    0x4(%rbx),%esi
mov    %eax,%edi
call   1070 <bind@plt>
test   %rax,%rax
js     1200 <listen_socket+0x70>
mov    %ebp,%edi
mov    $0x5,%esi
call   1060 <listen@plt>
test   %rax,%rax
js     1200 <listen_socket+0x70>
mov    (%rsp),%rdi
call   10a0 <freeaddrinfo@plt>
jmp    1262 <listen_socket+0xd2>
lea    0xda8(%rip),%rdi
call   1080 <log_exit@plt>
mov    $0xffffffff,%ebp
mov    %ebp,%eax
add    $0x30,%rsp
pop    %rbx
pop    %r14
pop    %rbp
ret

LLVM IR (-O0):
%struct.addrinfo = type { i32, i32, i32, i32, i32, %struct.addrinfo*, i32 }
@AF_INET = global i32 0
@SOCK_STREAM = global i32 0
@AI_PASSIVE = global i32 0
@.str = [24 x i8] c"failed to listen socket\00"
define i32 @listen_socket(i8* %0) {
%2 = alloca i32
%3 = alloca i8*
%4 = alloca %struct.addrinfo
%5 = alloca %struct.addrinfo*
%6 = alloca %struct.addrinfo*
%7 = alloca i32
%8 = alloca i32
store i8* %0, i8** %3
%9 = call i32 @memset(%struct.addrinfo* %4, i32 0, i32 40)
%10 = load i32, i32* @AF_INET
%11 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %4, i32 0, i32 4
store i32 %10, i32* %11
%12 = load i32, i32* @SOCK_STREAM
%13 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %4, i32 0, i32 3
store i32 %12, i32* %13
%14 = load i32, i32* @AI_PASSIVE
%15 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %4, i32 0, i32 6
store i32 %14, i32* %15
%16 = load i8*, i8** %3
%17 = call i32 @getaddrinfo(i32* null, i8* %16, %struct.addrinfo* %4, %struct.addrinfo** %5)
store i32 %17, i32* %7
%18 = icmp ne i32 %17, 0
br i1 %18, label %19, label %23
19: ; preds = %1
%20 = load i32, i32* %7
%21 = call i8* @gai_strerror(i32 %20)
%22 = call i32 @log_exit(i8* %21)
br label %23
23: ; preds = %19, %1
%24 = load %struct.addrinfo*, %struct.addrinfo** %5
store %struct.addrinfo* %24, %struct.addrinfo** %6
br label %25
25: ; preds = %66, %23
%26 = load %struct.addrinfo*, %struct.addrinfo** %6
%27 = icmp ne %struct.addrinfo* %26, null
br i1 %27, label %28, label %70
28: ; preds = %25
%29 = load %struct.addrinfo*, %struct.addrinfo** %6
%30 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %29, i32 0, i32 4
%31 = load i32, i32* %30
%32 = load %struct.addrinfo*, %struct.addrinfo** %6
%33 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %32, i32 0, i32 3
%34 = load i32, i32* %33
%35 = load %struct.addrinfo*, %struct.addrinfo** %6
%36 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %35, i32 0, i32 2
%37 = load i32, i32* %36
%38 = call i32 @socket(i32 %31, i32 %34, i32 %37)
store i32 %38, i32* %8
%39 = load i32, i32* %8
%40 = icmp slt i32 %39, 0
br i1 %40, label %41, label %42
41: ; preds = %28
br label %66
42: ; preds = %28
%43 = load i32, i32* %8
%44 = load %struct.addrinfo*, %struct.addrinfo** %6
%45 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %44, i32 0, i32 1
%46 = load i32, i32* %45
%47 = load %struct.addrinfo*, %struct.addrinfo** %6
%48 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %47, i32 0, i32 0
%49 = load i32, i32* %48
%50 = call i64 @bind(i32 %43, i32 %46, i32 %49)
%51 = icmp slt i64 %50, 0
br i1 %51, label %52, label %55
52: ; preds = %42
%53 = load i32, i32* %8
%54 = call i32 @close(i32 %53)
br label %66
55: ; preds = %42
%56 = load i32, i32* %8
%57 = call i64 @listen(i32 %56, i32 5)
%58 = icmp slt i64 %57, 0
br i1 %58, label %59, label %62
59: ; preds = %55
%60 = load i32, i32* %8
%61 = call i32 @close(i32 %60)
br label %66
62: ; preds = %55
%63 = load %struct.addrinfo*, %struct.addrinfo** %5
%64 = call i32 @freeaddrinfo(%struct.addrinfo* %63)
%65 = load i32, i32* %8
store i32 %65, i32* %2
br label %72
66: ; preds = %59, %52, %41
%67 = load %struct.addrinfo*, %struct.addrinfo** %6
%68 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %67, i32 0, i32 5
%69 = load %struct.addrinfo*, %struct.addrinfo** %68
store %struct.addrinfo* %69, %struct.addrinfo** %6
br label %25
70: ; preds = %25
%71 = call i32 @log_exit(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str, i64 0, i64 0))
store i32 -1, i32* %2
br label %72
72: ; preds = %70, %62
%73 = load i32, i32* %2
ret i32 %73
}

LLVM IR (-O2):
%struct.addrinfo = type { i32, i32, i32, i32, i32, %struct.addrinfo*, i32 }
@AF_INET = global i32 0
@SOCK_STREAM = global i32 0
@AI_PASSIVE = global i32 0
@.str = [24 x i8] c"failed to listen socket\00"
define i32 @listen_socket(i8* %0) {
%2 = alloca %struct.addrinfo
%3 = alloca %struct.addrinfo*
%4 = bitcast %struct.addrinfo* %2 to i8*
%5 = bitcast %struct.addrinfo** %3 to i8*
%6 = call i32 @memset(%struct.addrinfo* %2, i32 0, i32 40)
%7 = load i32, i32* @AF_INET
%8 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %2, i64 0, i32 4
store i32 %7, i32* %8
%9 = load i32, i32* @SOCK_STREAM
%10 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %2, i64 0, i32 3
store i32 %9, i32* %10
%11 = load i32, i32* @AI_PASSIVE
%12 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %2, i64 0, i32 6
store i32 %11, i32* %12
%13 = call i32 @getaddrinfo(i32* null, i8* %0, %struct.addrinfo* %2, %struct.addrinfo** %3)
%14 = icmp eq i32 %13, 0
br i1 %14, label %18, label %15
15: ; preds = %1
%16 = call i8* @gai_strerror(i32 %13)
%17 = call i32 @log_exit(i8* %16)
br label %18
18: ; preds = %15, %1
%19 = load %struct.addrinfo*, %struct.addrinfo** %3
%20 = icmp eq %struct.addrinfo* %19, null
br i1 %20, label %50, label %21
21: ; preds = %18, %46
%22 = phi %struct.addrinfo* [ %48, %46 ], [ %19, %18 ]
%23 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %22, i64 0, i32 4
%24 = load i32, i32* %23
%25 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %22, i64 0, i32 3
%26 = load i32, i32* %25
%27 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %22, i64 0, i32 2
%28 = load i32, i32* %27
%29 = call i32 @socket(i32 %24, i32 %26, i32 %28)
%30 = icmp slt i32 %29, 0
br i1 %30, label %46, label %31
31: ; preds = %21
%32 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %22, i64 0, i32 1
%33 = load i32, i32* %32
%34 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %22, i64 0, i32 0
%35 = load i32, i32* %34
%36 = call i64 @bind(i32 %29, i32 %33, i32 %35)
%37 = icmp slt i64 %36, 0
br i1 %37, label %44, label %38
38: ; preds = %31
%39 = call i64 @listen(i32 %29, i32 5)
%40 = icmp slt i64 %39, 0
br i1 %40, label %44, label %41
41: ; preds = %38
%42 = load %struct.addrinfo*, %struct.addrinfo** %3
%43 = call i32 @freeaddrinfo(%struct.addrinfo* %42)
br label %52
44: ; preds = %38, %31
%45 = call i32 @close(i32 %29)
br label %46
46: ; preds = %44, %21
%47 = getelementptr inbounds %struct.addrinfo, %struct.addrinfo* %22, i64 0, i32 5
%48 = load %struct.addrinfo*, %struct.addrinfo** %47
%49 = icmp eq %struct.addrinfo* %48, null
br i1 %49, label %50, label %21
50: ; preds = %46, %18
%51 = call i32 @log_exit(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str, i64 0, i64 0))
br label %52
52: ; preds = %41, %50
%53 = phi i32 [ %29, %41 ], [ -1, %50 ]
ret i32 %53
}