Tafelbilder, Beispiele, Screenshots und Fotos 7.6.2019

20190607/crash.c

+main(){puts(1);}

20190607/fak-1.c

+#include <stdio.h>
+
+int fak (int n)
+{
+  if (n <= 1)
+    return 1;
+  else
+    return n * fak (n - 1);
+}
+
+int main (void)
+{
+  printf ("7! = %d\n", fak (7));
+  return 0;
+}

20190607/fak-1.s

+	.file	"fak-1.c"
+	.text
+	.globl	fak
+	.type	fak, @function
+fak:
+.LFB11:
+	.cfi_startproc
+	movl	$1, %eax
+	cmpl	$1, %edi                      # #include <stdio.h>
+	jle	.L8                           # 
+	pushq	%rbx                          # int fak (int n)
+	.cfi_def_cfa_offset 16                # {
+	.cfi_offset 3, -16                    #   if (n <= 1)
+	movl	%edi, %ebx                    #     return 1;
+	leal	-1(%rdi), %edi                #   else
+	call	fak                           #     return n * fak (n - 1);
+	imull	%ebx, %eax                    # }
+	popq	%rbx                          # 
+	.cfi_restore 3                        # int main (void)
+	.cfi_def_cfa_offset 8                 # {
+.L8:                                          #   printf ("7! = %d\n", fak (7));
+	rep ret                               #   return 0;
+	.cfi_endproc                          # }
+.LFE11:
+	.size	fak, .-fak
+	.section	.rodata.str1.1,"aMS",@progbits,1
+.LC0:
+	.string	"7! = %d\n"
+	.text
+	.globl	main
+	.type	main, @function
+main:
+.LFB12:
+	.cfi_startproc
+	subq	$8, %rsp
+	.cfi_def_cfa_offset 16
+	movl	$7, %edi
+	call	fak
+	movl	%eax, %esi
+	leaq	.LC0(%rip), %rdi
+	movl	$0, %eax
+	call	printf@PLT
+	movl	$0, %eax
+	addq	$8, %rsp
+	.cfi_def_cfa_offset 8
+	ret
+	.cfi_endproc
+.LFE12:
+	.size	main, .-main
+	.ident	"GCC: (Debian 6.3.0-18+deb9u1) 6.3.0 20170516"
+	.section	.note.GNU-stack,"",@progbits

20190607/gdb-hello-1.log

+   +--hello-1.c------------------------------------------------------------------------------------------+
+   |2                                                                                                    |
+   |3       int main (void)                                                                              |
+B+>|4       {                                                                                            |
+   |5         printf ("Hello, world!\n");                                                                |
+   |6         return 0;                                                                                  |
+   |7       }                                                                                            |
+   |8                                                                                                    |
+   |9                                                                                                    |
+   |10                                                                                                   |
+   |11                                                                                                   |
+   |12                                                                                                   |
+   |13                                                                                                   |
+   |14                                                                                                   |
+   |15                                                                                                   |
+   |16                                                                                                   |
+   |17                                                                                                   |
+   |18                                                                                                   |
+   +-----------------------------------------------------------------------------------------------------+
+native process 24957 In: main                                                    L4    PC: 0x5555555546b0
+(gdb) disassemble /r main
+Dump of assembler code for function main:
+=> 0x00005555555546b0 <+0>:     48 83 ec 08     sub    $0x8,%rsp
+   0x00005555555546b4 <+4>:     48 8d 3d 99 00 00 00    lea    0x99(%rip),%rdi        # 0x555555554754
+   0x00005555555546bb <+11>:    e8 a0 fe ff ff  callq  0x555555554560 <puts@plt>
+   0x00005555555546c0 <+16>:    b8 00 00 00 00  mov    $0x0,%eax
+   0x00005555555546c5 <+21>:    48 83 c4 08     add    $0x8,%rsp
+   0x00005555555546c9 <+25>:    c3      retq
+End of assembler dump.
+(gdb)

20190607/hello-1.c

+#include <stdio.h>
+
+int main (void)
+{
+  printf ("Hello, world!\n");
+  return 0;
+}

20190607/hello-1.s

+	.file	"hello-1.c"
+	.section	.rodata.str1.1,"aMS",@progbits,1
+.LC0:
+	.string	"Hello, world!"
+	.text
+	.globl	main
+	.type	main, @function
+main:
+.LFB11:
+	.cfi_startproc                               # #include <stdio.h>
+	subq	$8, %rsp                             # 
+	.cfi_def_cfa_offset 16                       # int main (void)
+	leaq	.LC0(%rip), %rdi                     # {
+	call	puts@PLT                             #   printf ("Hello, world!\n");
+	movl	$0, %eax                             #   return 0;
+	addq	$8, %rsp                             # }
+	.cfi_def_cfa_offset 8
+	ret
+	.cfi_endproc
+.LFE11:
+	.size	main, .-main
+	.ident	"GCC: (Debian 6.3.0-18+deb9u1) 6.3.0 20170516"
+	.section	.note.GNU-stack,"",@progbits

20190607/strings-1.c

+#include <stdio.h>
+
+int main (void)
+{
+  char *hello = "Hello, wörld!\n";
+  hello[8] = 'o';
+  printf (hello);
+  return 0;
+}

20190607/strings-2.c

+#include <stdio.h>
+
+int main (void)
+{
+  char hello[] = "Hello, wörld!\n";
+  hello[8] = 'o';
+  printf (hello);
+  return 0;
+}

20190607/strings-3.c

+#include <stdio.h>
+
+int main (void)
+{
+  static char hello[] = "Hello, wörld!\n";
+  hello[8] = 'o';
+  printf (hello);
+  return 0;
+}

20190607/strings-4.c

+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main (void)
+{
+  char *hello = malloc (42);
+  strcpy (hello, "Hello, wörld!\n");
+  hello[8] = 'o';
+  printf (hello);
+  return 0;
+}