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

See also: