Compile Variables

Compile variables are accessible by importing the "builtin" package, which the compiler makes available to every Zig source file. It contains compile-time constants such as the current target, endianness, and release mode.

  1. const builtin = @import("builtin");
  2. const separator = if (builtin.os == builtin.Os.windows) '\\' else '/';

Example of what is imported with @import("builtin"):

  1. usingnamespace @import("std").builtin;
  2. /// Deprecated
  3. pub const arch = Target.current.cpu.arch;
  4. /// Deprecated
  5. pub const endian = Target.current.cpu.arch.endian();
  6. pub const output_mode = OutputMode.Obj;
  7. pub const link_mode = LinkMode.Static;
  8. pub const is_test = false;
  9. pub const single_threaded = false;
  10. pub const abi = Abi.gnu;
  11. pub const cpu: Cpu = Cpu{
  12.     .arch = .x86_64,
  13.     .model = &Target.x86.cpu.skylake,
  14.     .features = Target.x86.featureSet(&[_]Target.x86.Feature{
  15.         .@"64bit",
  16.         .@"adx",
  17.         .@"aes",
  18.         .@"avx",
  19.         .@"avx2",
  20.         .@"bmi",
  21.         .@"bmi2",
  22.         .@"clflushopt",
  23.         .@"cmov",
  24.         .@"cx16",
  25.         .@"cx8",
  26.         .@"ermsb",
  27.         .@"f16c",
  28.         .@"false_deps_popcnt",
  29.         .@"fast_15bytenop",
  30.         .@"fast_gather",
  31.         .@"fast_scalar_fsqrt",
  32.         .@"fast_shld_rotate",
  33.         .@"fast_variable_shuffle",
  34.         .@"fast_vector_fsqrt",
  35.         .@"fma",
  36.         .@"fsgsbase",
  37.         .@"fxsr",
  38.         .@"idivq_to_divl",
  39.         .@"invpcid",
  40.         .@"lzcnt",
  41.         .@"macrofusion",
  42.         .@"merge_to_threeway_branch",
  43.         .@"mmx",
  44.         .@"movbe",
  45.         .@"nopl",
  46.         .@"pclmul",
  47.         .@"popcnt",
  48.         .@"prfchw",
  49.         .@"rdrnd",
  50.         .@"rdseed",
  51.         .@"sahf",
  52.         .@"sgx",
  53.         .@"slow_3ops_lea",
  54.         .@"sse",
  55.         .@"sse2",
  56.         .@"sse3",
  57.         .@"sse4_1",
  58.         .@"sse4_2",
  59.         .@"ssse3",
  60.         .@"vzeroupper",
  61.         .@"x87",
  62.         .@"xsave",
  63.         .@"xsavec",
  64.         .@"xsaveopt",
  65.         .@"xsaves",
  66.     }),
  67. };
  68. pub const os = Os{
  69.     .tag = .linux,
  70.     .version_range = .{ .linux = .{
  71.         .range = .{
  72.             .min = .{
  73.                 .major = 5,
  74.                 .minor = 4,
  75.                 .patch = 77,
  76.             },
  77.             .max = .{
  78.                 .major = 5,
  79.                 .minor = 4,
  80.                 .patch = 77,
  81.             },
  82.         },
  83.         .glibc = .{
  84.             .major = 2,
  85.             .minor = 31,
  86.             .patch = 0,
  87.         },
  88.     }},
  89. };
  90. pub const object_format = ObjectFormat.elf;
  91. pub const mode = Mode.Debug;
  92. pub const link_libc = false;
  93. pub const link_libcpp = false;
  94. pub const have_error_return_tracing = true;
  95. pub const valgrind_support = true;
  96. pub const position_independent_code = false;
  97. pub const strip_debug_info = false;
  98. pub const code_model = CodeModel.default;

See also: