#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 sigaction {
  void (*sa_handler)(int);
  int /*<<< orphan*/ sa_mask;
};

/* Variables and functions */
int /*<<< orphan*/ fprintf(int /*<<< orphan*/, char *);
int /*<<< orphan*/ memset(struct sigaction *, int /*<<< orphan*/, int);
scalar_t__ sigaction(int, struct sigaction *, int /*<<< orphan*/ *);
int /*<<< orphan*/ sigemptyset(int /*<<< orphan*/ *);
int /*<<< orphan*/ stderr;
void connect_signal(int signum, void (*func)(int)) {
  struct sigaction sa;
  memset(&sa, 0, sizeof(struct sigaction));
  sa.sa_handler = func;
  sigemptyset(&sa.sa_mask);
  if (sigaction(signum, &sa, NULL) < 0) {
    fprintf(stderr, "sigaction() error!");
  }
}


x86 assembly (clang, -O0):
<connect_signal>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %edi,-0x4(%rbp)
mov    %rsi,-0x10(%rbp)
lea    -0x20(%rbp),%rdi
xor    %esi,%esi
mov    $0x10,%edx
call   1040 <memset@plt>
mov    -0x10(%rbp),%rax
mov    %rax,-0x20(%rbp)
lea    -0x20(%rbp),%rdi
add    $0x8,%rdi
call   1060 <sigemptyset@plt>
mov    -0x4(%rbp),%edi
lea    -0x20(%rbp),%rsi
xor    %eax,%eax
mov    %eax,%edx
call   1030 <sigaction@plt>
cmp    $0x0,%rax
jge    11a3 <connect_signal+0x63>
mov    0x2e4b(%rip),%rax
mov    (%rax),%edi
lea    0xe62(%rip),%rsi
call   1050 <fprintf@plt>
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<connect_signal>:
push   %rbp
push   %r14
push   %rbx
sub    $0x10,%rsp
mov    %rsi,%rbx
mov    %edi,%ebp
mov    %rsp,%r14
mov    %r14,%rdi
xor    %esi,%esi
mov    $0x10,%edx
call   1040 <memset@plt>
mov    %rbx,(%rsp)
lea    0x8(%rsp),%rdi
call   1060 <sigemptyset@plt>
mov    %ebp,%edi
mov    %r14,%rsi
xor    %edx,%edx
call   1030 <sigaction@plt>
test   %rax,%rax
jns    1193 <connect_signal+0x53>
mov    0x2e5b(%rip),%rax
mov    (%rax),%edi
lea    0xe72(%rip),%rsi
call   1050 <fprintf@plt>
add    $0x10,%rsp
pop    %rbx
pop    %r14
pop    %rbp
ret

LLVM IR (-O0):
%struct.sigaction = type { void (i32)*, i32 }
@stderr = global i32 0
@.str = [19 x i8] c"sigaction() error!\00"
define void @connect_signal(i32 %0, void (i32)* %1) {
%3 = alloca i32
%4 = alloca void (i32)*
%5 = alloca %struct.sigaction
store i32 %0, i32* %3
store void (i32)* %1, void (i32)** %4
%6 = call i32 @memset(%struct.sigaction* %5, i32 0, i32 16)
%7 = load void (i32)*, void (i32)** %4
%8 = getelementptr inbounds %struct.sigaction, %struct.sigaction* %5, i32 0, i32 0
store void (i32)* %7, void (i32)** %8
%9 = getelementptr inbounds %struct.sigaction, %struct.sigaction* %5, i32 0, i32 1
%10 = call i32 @sigemptyset(i32* %9)
%11 = load i32, i32* %3
%12 = call i64 @sigaction(i32 %11, %struct.sigaction* %5, i32* null)
%13 = icmp slt i64 %12, 0
br i1 %13, label %14, label %17
14: ; preds = %2
%15 = load i32, i32* @stderr
%16 = call i32 @fprintf(i32 %15, i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str, i64 0, i64 0))
br label %17
17: ; preds = %14, %2
ret void
}

LLVM IR (-O2):
%struct.sigaction = type { void (i32)*, i32 }
@stderr = global i32 0
@.str = [19 x i8] c"sigaction() error!\00"
define void @connect_signal(i32 %0, void (i32)* %1) {
%3 = alloca %struct.sigaction
%4 = bitcast %struct.sigaction* %3 to i8*
%5 = call i32 @memset(%struct.sigaction* %3, i32 0, i32 16)
%6 = getelementptr inbounds %struct.sigaction, %struct.sigaction* %3, i64 0, i32 0
store void (i32)* %1, void (i32)** %6
%7 = getelementptr inbounds %struct.sigaction, %struct.sigaction* %3, i64 0, i32 1
%8 = call i32 @sigemptyset(i32* %7)
%9 = call i64 @sigaction(i32 %0, %struct.sigaction* %3, i32* null)
%10 = icmp slt i64 %9, 0
br i1 %10, label %11, label %14
11: ; preds = %2
%12 = load i32, i32* @stderr
%13 = call i32 @fprintf(i32 %12, i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str, i64 0, i64 0))
br label %14
14: ; preds = %11, %2
ret void
}