tools/testing/selftests/bpf/progs/btf_dump_test_case_bitfields.c

   1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
   2
   3 /*
   4  * BTF-to-C dumper tests for bitfield.
   5  *
   6  * Copyright (c) 2019 Facebook
   7  */
   8 #include <stdbool.h>
   9
  10 /* ----- START-EXPECTED-OUTPUT ----- */
  11 /*
  12  *struct bitfields_only_mixed_types {
  13  *      int a: 3;
  14  *      long int b: 2;
  15  *      _Bool c: 1;
  16  *      enum {
  17  *              A = 0,
  18  *              B = 1,
  19  *      } d: 1;
  20  *      short e: 5;
  21  *      int: 20;
  22  *      unsigned int f: 30;
  23  *};
  24  *
  25  */
  26 /* ------ END-EXPECTED-OUTPUT ------ */
  27
  28 struct bitfields_only_mixed_types {
  29         int a: 3;
  30         long int b: 2;
  31         bool c: 1; /* it's really a _Bool type */
  32         enum {
  33                 A, /* A = 0, dumper is very explicit */
  34                 B, /* B = 1, same */
  35         } d: 1;
  36         short e: 5;
  37         /* 20-bit padding here */
  38         unsigned f: 30; /* this gets aligned on 4-byte boundary */
  39 };
  40
  41 /* ----- START-EXPECTED-OUTPUT ----- */
  42 /*
  43  *struct bitfield_mixed_with_others {
  44  *      char: 4;
  45  *      int a: 4;
  46  *      short b;
  47  *      long int c;
  48  *      long int d: 8;
  49  *      int e;
  50  *      int f;
  51  *};
  52  *
  53  */
  54 /* ------ END-EXPECTED-OUTPUT ------ */
  55 struct bitfield_mixed_with_others {
  56         long: 4; /* char is enough as a backing field */
  57         int a: 4;
  58         /* 8-bit implicit padding */
  59         short b; /* combined with previous bitfield */
  60         /* 4 more bytes of implicit padding */
  61         long c;
  62         long d: 8;
  63         /* 24 bits implicit padding */
  64         int e; /* combined with previous bitfield */
  65         int f;
  66         /* 4 bytes of padding */
  67 };
  68
  69 /* ----- START-EXPECTED-OUTPUT ----- */
  70 /*
  71  *struct bitfield_flushed {
  72  *      int a: 4;
  73  *      long: 60;
  74  *      long int b: 16;
  75  *};
  76  *
  77  */
  78 /* ------ END-EXPECTED-OUTPUT ------ */
  79 struct bitfield_flushed {
  80         int a: 4;
  81         long: 0; /* flush until next natural alignment boundary */
  82         long b: 16;
  83 };
  84
  85 int f(struct {
  86         struct bitfields_only_mixed_types _1;
  87         struct bitfield_mixed_with_others _2;
  88         struct bitfield_flushed _3;
  89 } *_)
  90 {
  91         return 0;
  92 }