Beispiele 19.1.2020, README.md

20201119/arrays-1.c

+#include <stdio.h>
+
+int main (void)
+{
+  int prime[5] = { 2, 3, 5, 7, 11 };
+  int *p = prime;
+  for (int i = 0; i < 5; i++)
+    printf ("%d\n", *(p + i));
+  return 0;
+}

20201119/arrays-10.c

+#include <stdio.h>
+
+int main (void)
+{
+  int prime[];
+  for (int *p = prime; *p; p++)
+    printf ("%d\n", *p);
+  return 0;
+}

20201119/arrays-11.c

+#include <stdio.h>
+
+int main (void)
+{
+  int prime[] = { 2, 3, 5, 7, 11, 0 };
+  for (int *p = prime; *p; p++)
+    printf ("%d\n", *p);
+  prime[5] = 13;              /* Dies funktioniert zwar im Moment, ist aber falsch! */
+                              /* Wir schreiben über das Array hinaus. Dies kann zu einem */
+  for (int *p = prime; *p; p++)                                    /* Absturz führen. */
+    printf ("%d\n", *p);
+  return 0;
+}

20201119/arrays-12.c

+#include <stdio.h>
+
+int main (void)
+{
+  int prime[] = { };
+  for (int *p = prime; *p; p++)
+    printf ("%d\n", *p);
+  return 0;
+}

20201119/arrays-13.c

+#include <stdio.h>
+
+int main (void)
+{
+  int prime[] = { 0 };
+  for (int *p = prime; *p; p++)
+    printf ("%d\n", *p);
+  return 0;
+}

20201119/arrays-2.c

+#include <stdio.h>
+
+int main (void)
+{
+  int prime[5] = { 2, 3, 5, 7, 11 };
+  int *p = prime;
+  for (int i = 0; i < 5; i++)
+    printf ("%d\n", p[i]);
+  return 0;
+}

20201119/arrays-3.c

+#include <stdio.h>
+
+int main (void)
+{
+  int prime[5] = { 2, 3, 5, 7, 11 };
+  int *p;
+  p = prime;
+  for (int i = 0; i < 5; i++)
+    printf ("%d\n", p[i]);
+  return 0;
+}

20201119/arrays-4-O0.s

+	.file	"arrays-4.c"
+	.text
+	.section	.rodata
+.LC0:
+	.string	"%d\n"
+	.text
+	.globl	main
+	.type	main, @function
+main:
+.LFB0:
+	.cfi_startproc
+	pushq	%rbp
+	.cfi_def_cfa_offset 16
+	.cfi_offset 6, -16
+	movq	%rsp, %rbp
+	.cfi_def_cfa_register 6
+	subq	$32, %rsp
+	movl	$2, -32(%rbp)
+	movl	$3, -28(%rbp)
+	movl	$5, -24(%rbp)
+	movl	$7, -20(%rbp)
+	movl	$11, -16(%rbp)
+	movl	$0, -4(%rbp)
+	jmp	.L2
+.L3:
+	movl	-4(%rbp), %eax
+	cltq
+	movl	-32(%rbp,%rax,4), %eax
+	movl	%eax, %esi
+	leaq	.LC0(%rip), %rdi
+	movl	$0, %eax
+	call	printf@PLT
+	addl	$1, -4(%rbp)
+.L2:
+	cmpl	$4, -4(%rbp)
+	jle	.L3
+	movl	$0, %eax
+	leave
+	.cfi_def_cfa 7, 8
+	ret
+	.cfi_endproc
+.LFE0:
+	.size	main, .-main
+	.ident	"GCC: (Debian 8.3.0-6) 8.3.0"
+	.section	.note.GNU-stack,"",@progbits

20201119/arrays-4-m32.s

+	.file	"arrays-4.c"
+	.text
+	.section	.rodata.str1.1,"aMS",@progbits,1
+.LC0:
+	.string	"%d\n"
+	.text
+	.globl	main
+	.type	main, @function
+main:
+.LFB11:
+	.cfi_startproc
+	leal	4(%esp), %ecx
+	.cfi_def_cfa 1, 0
+	andl	$-16, %esp
+	pushl	-4(%ecx)
+	pushl	%ebp
+	.cfi_escape 0x10,0x5,0x2,0x75,0
+	movl	%esp, %ebp
+	pushl	%edi
+	pushl	%esi
+	pushl	%ebx
+	pushl	%ecx
+	.cfi_escape 0xf,0x3,0x75,0x70,0x6
+	.cfi_escape 0x10,0x7,0x2,0x75,0x7c
+	.cfi_escape 0x10,0x6,0x2,0x75,0x78
+	.cfi_escape 0x10,0x3,0x2,0x75,0x74
+	subl	$56, %esp
+	call	__x86.get_pc_thunk.bx
+	addl	$_GLOBAL_OFFSET_TABLE_, %ebx
+	movl	$2, -44(%ebp)
+	movl	$3, -40(%ebp)
+	movl	$5, -36(%ebp)
+	movl	$7, -32(%ebp)
+	movl	$11, -28(%ebp)
+	leal	-44(%ebp), %esi
+	leal	-24(%ebp), %eax
+	movl	%eax, -60(%ebp)
+	leal	.LC0@GOTOFF(%ebx), %edi
+.L2:
+	subl	$8, %esp
+	pushl	(%esi)
+	pushl	%edi
+	call	printf@PLT
+	addl	$4, %esi
+	addl	$16, %esp
+	cmpl	-60(%ebp), %esi
+	jne	.L2
+	movl	$0, %eax
+	leal	-16(%ebp), %esp
+	popl	%ecx
+	.cfi_restore 1
+	.cfi_def_cfa 1, 0
+	popl	%ebx
+	.cfi_restore 3
+	popl	%esi
+	.cfi_restore 6
+	popl	%edi
+	.cfi_restore 7
+	popl	%ebp
+	.cfi_restore 5
+	leal	-4(%ecx), %esp
+	.cfi_def_cfa 4, 4
+	ret
+	.cfi_endproc
+.LFE11:
+	.size	main, .-main
+	.section	.text.__x86.get_pc_thunk.bx,"axG",@progbits,__x86.get_pc_thunk.bx,comdat
+	.globl	__x86.get_pc_thunk.bx
+	.hidden	__x86.get_pc_thunk.bx
+	.type	__x86.get_pc_thunk.bx, @function
+__x86.get_pc_thunk.bx:
+.LFB12:
+	.cfi_startproc
+	movl	(%esp), %ebx
+	ret
+	.cfi_endproc
+.LFE12:
+	.ident	"GCC: (Debian 8.3.0-6) 8.3.0"
+	.section	.note.GNU-stack,"",@progbits

20201119/arrays-4.c

+#include <stdio.h>
+
+int main (void)
+{
+  int prime[5] = { 2, 3, 5, 7, 11 };
+  for (int i = 0; i < 5; i++)
+    printf ("%d\n", prime[i]);
+  return 0;
+}

20201119/arrays-4.s

+	.file	"arrays-4.c"
+	.text
+	.section	.rodata.str1.1,"aMS",@progbits,1
+.LC0:
+	.string	"%d\n"
+	.text
+	.globl	main
+	.type	main, @function
+main:
+.LFB11:
+	.cfi_startproc
+	pushq	%r12
+	.cfi_def_cfa_offset 16
+	.cfi_offset 12, -16
+	pushq	%rbp
+	.cfi_def_cfa_offset 24
+	.cfi_offset 6, -24
+	pushq	%rbx
+	.cfi_def_cfa_offset 32
+	.cfi_offset 3, -32
+	subq	$32, %rsp
+	.cfi_def_cfa_offset 64
+	movl	$2, (%rsp)                   # #include <stdio.h>
+	movl	$3, 4(%rsp)                  # 
+	movl	$5, 8(%rsp)                  # int main (void)
+	movl	$7, 12(%rsp)                 # {
+	movl	$11, 16(%rsp)                #   int prime[5] = { 2, 3, 5, 7, 11 };
+	movq	%rsp, %rbx                   #   for (int i = 0; i < 5; i++)
+	leaq	20(%rbx), %r12               #     printf ("%d\n", prime[i]);
+	leaq	.LC0(%rip), %rbp             #   return 0;
+.L2:                                         # }
+	movl	(%rbx), %esi
+	movq	%rbp, %rdi
+	movl	$0, %eax
+	call	printf@PLT
+	addq	$4, %rbx
+	cmpq	%r12, %rbx
+	jne	.L2
+	movl	$0, %eax
+	addq	$32, %rsp
+	.cfi_def_cfa_offset 32
+	popq	%rbx
+	.cfi_def_cfa_offset 24
+	popq	%rbp
+	.cfi_def_cfa_offset 16
+	popq	%r12
+	.cfi_def_cfa_offset 8
+	ret
+	.cfi_endproc
+.LFE11:
+	.size	main, .-main
+	.ident	"GCC: (Debian 8.3.0-6) 8.3.0"
+	.section	.note.GNU-stack,"",@progbits

20201119/arrays-5.c

+#include <stdio.h>
+
+int main (void)
+{
+  int prime[5] = { 2, 3, 5, 7, 11 };
+  for (int *p = prime; p < prime + 5; p++)
+    printf ("%d\n", *p);
+  return 0;
+}

20201119/arrays-5.s

+	.file	"arrays-5.c"
+	.text
+	.section	.rodata.str1.1,"aMS",@progbits,1
+.LC0:
+	.string	"%d\n"
+	.text
+	.globl	main
+	.type	main, @function
+main:
+.LFB11:
+	.cfi_startproc
+	pushq	%rbp
+	.cfi_def_cfa_offset 16
+	.cfi_offset 6, -16
+	pushq	%rbx
+	.cfi_def_cfa_offset 24
+	.cfi_offset 3, -24
+	subq	$40, %rsp
+	.cfi_def_cfa_offset 64
+	movl	$2, (%rsp)                       # #include <stdio.h>
+	movl	$3, 4(%rsp)                      # 
+	movl	$5, 8(%rsp)                      # int main (void)
+	movl	$7, 12(%rsp)                     # {
+	movl	$11, 16(%rsp)                    #   int prime[5] = { 2, 3, 5, 7, 11 };
+	movq	%rsp, %rbx                       #   for (int *p = prime; p < prime + 5; p++)
+	leaq	20(%rsp), %rbp                   #     printf ("%d\n", *p);
+.L2:                                             #   return 0;
+	movl	(%rbx), %esi                     # }
+	leaq	.LC0(%rip), %rdi
+	movl	$0, %eax
+	call	printf@PLT
+	addq	$4, %rbx
+	cmpq	%rbp, %rbx
+	jne	.L2
+	movl	$0, %eax
+	addq	$40, %rsp
+	.cfi_def_cfa_offset 24
+	popq	%rbx
+	.cfi_def_cfa_offset 16
+	popq	%rbp
+	.cfi_def_cfa_offset 8
+	ret
+	.cfi_endproc
+.LFE11:
+	.size	main, .-main
+	.ident	"GCC: (Debian 8.3.0-6) 8.3.0"
+	.section	.note.GNU-stack,"",@progbits

20201119/arrays-6.c

+#include <stdio.h>
+
+int main (void)
+{
+  int prime[6] = { 2, 3, 5, 7, 11, 0 };
+  for (int *p = prime; *p != 0; p++)
+    printf ("%d\n", *p);
+  return 0;
+}

20201119/arrays-7.c

+#include <stdio.h>
+
+int main (void)
+{
+  int prime[6] = { 2, 3, 5, 7, 11, 0 };
+  for (int *p = prime; *p; p++)
+    printf ("%d\n", *p);
+  return 0;
+}

20201119/arrays-8.c

+#include <stdio.h>
+
+int main (void)
+{
+  int prime[] = { 2, 3, 5, 7, 11, 0 };
+  for (int *p = prime; *p; p++)
+    printf ("%d\n", *p);
+  return 0;
+}

20201119/arrays-9.c

+#include <stdio.h>
+
+int main (void)
+{
+  int prime[] = { 2, 3, 5, 7, 11, 0 };
+  for (int *p = prime; *p; p++)
+    printf ("%d\n", *p);
+  prime[5] = 13;              /* Dies funktioniert zwar im Moment, ist aber falsch! */
+  prime[6] = 0;               /* Wir schreiben über das Array hinaus. Dies kann zu einem */
+  for (int *p = prime; *p; p++)                                    /* Absturz führen. */
+    printf ("%d\n", *p);
+  return 0;
+}

20201119/break-1.c

+#include <stdio.h>
+
+int main (void)
+{
+  int a = 0;
+  int b = 1;
+  printf ("%d\n", b);
+  for (int i = 0; i < 10; i++)
+    {
+      int c = a + b;
+      a = b;
+      b = c;
+      printf ("%d\n", b);
+    }
+  return 0;
+}

20201119/break-2.c

+#include <stdio.h>
+
+/* Aufgabe: Finde die erste Fibonacci-Zahl, die größer ist als 10. */
+
+int main (void)
+{
+  int a = 0;
+  int b = 1;
+  while (1)
+    {
+      int c = a + b;
+      a = b;
+      b = c;
+      if (b > 10)
+        {
+          printf ("Die erste Fibonacci-Zahl, die größer ist als 10, lautet: %d\n", b);
+          /* Dieses printf() erfolgt von der Logik her nach der Schleife,
+             es steht aber im Quelltext _innerhalb_ der Schleife. */
+          break;
+        }
+    }
+  return 0;
+}

20201119/break-3.c

+#include <stdio.h>
+
+/* Aufgabe: Finde die erste Fibonacci-Zahl, die größer ist als 10. */
+
+int main (void)
+{
+  int a = 0;
+  int b = 1;
+  while (b <= 10)
+    {
+      int c = a + b;
+      a = b;
+      b = c;
+    }
+  printf ("Die erste Fibonacci-Zahl, die größer ist als 10, lautet: %d\n", b);  /* nach der Schleife */
+  return 0;
+}