#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 */
typedef int /*<<< orphan*/ FILE;

/* Variables and functions */
int /*<<< orphan*/ SEEK_END;
int /*<<< orphan*/ SEEK_SET;
int /*<<< orphan*/ debug_out(char *, char const *);
int /*<<< orphan*/ fclose(int /*<<< orphan*/ *);
int /*<<< orphan*/ *fopen(char const *, char *);
int /*<<< orphan*/ fread(char *, size_t, int, int /*<<< orphan*/ *);
int /*<<< orphan*/ fseek(int /*<<< orphan*/ *, int /*<<< orphan*/,
                         int /*<<< orphan*/);
size_t ftell(int /*<<< orphan*/ *);
char *malloc(size_t);
char *read_file(const char *filename) {
  FILE *fp = fopen(filename, "rt");
  if (!fp) {
    debug_out("read_file: Could not open file '%s'\n", filename);
    return NULL;
  }
  fseek(fp, 0, SEEK_END);
  size_t filesize = ftell(fp);
  fseek(fp, 0, SEEK_SET);
  char *file = malloc(filesize + 1);
  fread(file, filesize, 1, fp);
  file[filesize] = 0;
  fclose(fp);
  return file;
}


x86 assembly (clang, -O0):
<read_file>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
mov    %rdi,-0x10(%rbp)
mov    -0x10(%rbp),%rdi
lea    0xe79(%rip),%rsi
call   1090 <fopen@plt>
mov    %rax,-0x18(%rbp)
cmpq   $0x0,-0x18(%rbp)
jne    11b8 <read_file+0x48>
mov    -0x10(%rbp),%rsi
lea    0xe5d(%rip),%rdi
call   1030 <debug_out@plt>
movq   $0x0,-0x8(%rbp)
jmp    1231 <read_file+0xc1>
mov    -0x18(%rbp),%rdi
mov    0x2e25(%rip),%rax
mov    (%rax),%edx
xor    %esi,%esi
call   1080 <fseek@plt>
mov    -0x18(%rbp),%rdi
call   1060 <ftell@plt>
mov    %rax,-0x20(%rbp)
mov    -0x18(%rbp),%rdi
mov    0x2df4(%rip),%rax
mov    (%rax),%edx
xor    %esi,%esi
call   1080 <fseek@plt>
mov    -0x20(%rbp),%rdi
add    $0x1,%rdi
call   1070 <malloc@plt>
mov    %rax,-0x28(%rbp)
mov    -0x28(%rbp),%rdi
mov    -0x20(%rbp),%rsi
mov    -0x18(%rbp),%rcx
mov    $0x1,%edx
call   1040 <fread@plt>
mov    -0x28(%rbp),%rax
mov    -0x20(%rbp),%rcx
movb   $0x0,(%rax,%rcx,1)
mov    -0x18(%rbp),%rdi
call   1050 <fclose@plt>
mov    -0x28(%rbp),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<read_file>:
push   %r15
push   %r14
push   %rbx
mov    %rdi,%r14
lea    0xe81(%rip),%rsi
call   1090 <fopen@plt>
test   %rax,%rax
je     11eb <read_file+0x7b>
mov    %rax,%rbx
mov    0x2e55(%rip),%rax
mov    (%rax),%edx
mov    %rbx,%rdi
xor    %esi,%esi
call   1080 <fseek@plt>
mov    %rbx,%rdi
call   1060 <ftell@plt>
mov    %rax,%r15
mov    0x2e27(%rip),%rax
mov    (%rax),%edx
mov    %rbx,%rdi
xor    %esi,%esi
call   1080 <fseek@plt>
lea    0x1(%r15),%rdi
call   1070 <malloc@plt>
mov    %rax,%r14
mov    %rax,%rdi
mov    %r15,%rsi
mov    $0x1,%edx
mov    %rbx,%rcx
call   1040 <fread@plt>
movb   $0x0,(%r14,%r15,1)
mov    %rbx,%rdi
call   1050 <fclose@plt>
jmp    11fd <read_file+0x8d>
lea    0xe11(%rip),%rdi
mov    %r14,%rsi
call   1030 <debug_out@plt>
xor    %r14d,%r14d
mov    %r14,%rax
pop    %rbx
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [3 x i8] c"rt\00"
@.str.1 = [37 x i8] c"read_file: Could not open file '%s'\0A\00"
@SEEK_END = global i32 0
@SEEK_SET = global i32 0
define i8* @read_file(i8* %0) {
%2 = alloca i8*
%3 = alloca i8*
%4 = alloca i32*
%5 = alloca i64
%6 = alloca i8*
store i8* %0, i8** %3
%7 = load i8*, i8** %3
%8 = call i32* @fopen(i8* %7, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0))
store i32* %8, i32** %4
%9 = load i32*, i32** %4
%10 = icmp ne i32* %9, null
br i1 %10, label %14, label %11
11: ; preds = %1
%12 = load i8*, i8** %3
%13 = call i32 @debug_out(i8* getelementptr inbounds ([37 x i8], [37 x i8]* @.str.1, i64 0, i64 0), i8* %12)
store i8* null, i8** %2
br label %36
14: ; preds = %1
%15 = load i32*, i32** %4
%16 = load i32, i32* @SEEK_END
%17 = call i32 @fseek(i32* %15, i32 0, i32 %16)
%18 = load i32*, i32** %4
%19 = call i64 @ftell(i32* %18)
store i64 %19, i64* %5
%20 = load i32*, i32** %4
%21 = load i32, i32* @SEEK_SET
%22 = call i32 @fseek(i32* %20, i32 0, i32 %21)
%23 = load i64, i64* %5
%24 = add i64 %23, 1
%25 = call i8* @malloc(i64 %24)
store i8* %25, i8** %6
%26 = load i8*, i8** %6
%27 = load i64, i64* %5
%28 = load i32*, i32** %4
%29 = call i32 @fread(i8* %26, i64 %27, i32 1, i32* %28)
%30 = load i8*, i8** %6
%31 = load i64, i64* %5
%32 = getelementptr inbounds i8, i8* %30, i64 %31
store i8 0, i8* %32
%33 = load i32*, i32** %4
%34 = call i32 @fclose(i32* %33)
%35 = load i8*, i8** %6
store i8* %35, i8** %2
br label %36
36: ; preds = %14, %11
%37 = load i8*, i8** %2
ret i8* %37
}

LLVM IR (-O2):
@.str = [3 x i8] c"rt\00"
@.str.1 = [37 x i8] c"read_file: Could not open file '%s'\0A\00"
@SEEK_END = global i32 0
@SEEK_SET = global i32 0
define noalias i8* @read_file(i8* %0) {
%2 = tail call i32* @fopen(i8* %0, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0))
%3 = icmp eq i32* %2, null
br i1 %3, label %4, label %6
4: ; preds = %1
%5 = tail call i32 @debug_out(i8* getelementptr inbounds ([37 x i8], [37 x i8]* @.str.1, i64 0, i64 0), i8* %0)
br label %17
6: ; preds = %1
%7 = load i32, i32* @SEEK_END
%8 = tail call i32 @fseek(i32* %2, i32 0, i32 %7)
%9 = tail call i64 @ftell(i32* %2)
%10 = load i32, i32* @SEEK_SET
%11 = tail call i32 @fseek(i32* %2, i32 0, i32 %10)
%12 = add i64 %9, 1
%13 = tail call i8* @malloc(i64 %12)
%14 = tail call i32 @fread(i8* %13, i64 %9, i32 1, i32* %2)
%15 = getelementptr inbounds i8, i8* %13, i64 %9
store i8 0, i8* %15
%16 = tail call i32 @fclose(i32* %2)
br label %17
17: ; preds = %6, %4
%18 = phi i8* [ %13, %6 ], [ null, %4 ]
ret i8* %18
}