module Crystal

Overview

Here lies the logic of the representation of the MixedUnionType.

Which structure is used to represent them is defined in LLVMTyper#create_llvm_type.

The #union_type_and_value_pointer will allow to read the current value of the union. The #store*_in_union operations allow to write the value in a unions. The #{assign|downcast|upcast}_distinct_union_types operation matches the semantics described in ./casts.cr

Together these operations should encapsulate the binary representation of the MixedUnionType.

Other unions like ReferenceUnionType that have a more trivial representation are not handled here.

Defined in:

Constant Summary

BUILD_COMMIT = "2482c62c1"

The build commit identifier of the Crystal compiler.

BUILD_DATE = "2026-05-15"

The build date of the Crystal compiler.

CACHE_DIR = "/home/runner/.cache/crystal"

The cache directory configured for the Crystal compiler.

The value is defined by the environment variable CRYSTAL_CACHE_DIR and defaults to the user's configured cache directory.

DEFAULT_PATH = "$ORIGIN/../share/crystal/src"

The default Crystal path configured in the compiler. This value is baked into the compiler and usually points to the accompanying version of the standard library.

DESCRIPTION = "Crystal 1.20.2 [2482c62c1] (2026-05-15)\n\nLLVM: 20.1.8\nDefault target: x86_64-unknown-linux-gnu\n"

Full version information of the Crystal compiler. Equivalent to crystal --version.

GET_EXCEPTION_NAME = "__crystal_get_exception"

HOST_TRIPLE = "x86_64-unknown-linux-gnu"

The LLVM target triple of the host system (the machine that the compiler runs on).

LIBRARY_PATH = "/home/runner/work/_temp/crystal-latest-true-undefined/bin/../lib/crystal"

Colon-separated paths where the compiler searches for (binary) libraries.

The value is defined by the environment variables CRYSTAL_LIBRARY_PATH.

LLVM_VERSION = "20.1.8"

The version of LLVM used by the Crystal compiler.

MAIN_NAME = "__crystal_main"

MALLOC_ATOMIC_NAME = "__crystal_malloc_atomic64"

MALLOC_NAME = "__crystal_malloc64"

ONCE = "__crystal_once"

ONCE_INIT = "__crystal_once_init"

PATH = "./lib:/home/runner/work/crystal_compiler_explained/crystal_compiler_explained/crystal-master/src"

Colon-separated paths where the compiler searches for required source files.

The value is defined by the environment variable CRYSTAL_PATH and defaults to DEFAULT_PATH.

RAISE_CAST_FAILED_NAME = "__crystal_raise_cast_failed"

RAISE_NAME = "__crystal_raise"

RAISE_OVERFLOW_NAME = "__crystal_raise_overflow"

REALLOC_NAME = "__crystal_realloc64"

TARGET_TRIPLE = "x86_64-unknown-linux-gnu"

The LLVM target triple of the target system (the machine that the compiler builds for).

VERSION = "1.20.2"

The version of the Crystal compiler.

Class Method Summary

• .format(source, filename = nil, report_warnings : IO | Nil = nil, flags : Array(String) | Nil = nil)
• .main(&)

  Defines the main routine run by normal Crystal programs:

• .main(argc : Int32, argv : Pointer(Pointer(UInt8)))

  Main method run by all Crystal programs at startup.

• .main_user_code(argc : Int32, argv : Pointer(Pointer(UInt8)))

  Executes the main user code.

• .normalize_path(path)
• .print_buffered(message : String, *args, to io : IO, exception = nil, backtrace = nil) : Nil

  Prepares an error message, with an optional exception or backtrace, to an in-memory buffer, before writing to an IO, usually STDERR, in a single write operation.

• .print_error(msg, color, stderr = STDERR, leading_error = true)
• .print_error_buffered(message : String, *args, exception = nil, backtrace = nil) : Nil

  Identical to #print_buffered but eventually calls System.print_error(bytes) to write to stderr without going through the event loop.

• .print_hierarchy(program, io, exp, format)
• .print_types(node)
• .relative_filename(filename)
• .safe_mangling(program, name)
• .temp_executable(basename)
• .tempfile(basename)
• .trace(section : Tracing::Section, operation : String, time : UInt64 | Nil = nil, **metadata, &)
• .trace(section : Tracing::Section, operation : String, time : UInt64 | Nil = nil, **metadata)
• .with_line_numbers(source : String | Array(String), highlight_line_number = nil, color = false, line_number_start = 1)

Class Method Detail

fun main(argc : Int32, argv : UInt8**) : Int32
  Crystal.main do
    elapsed = Time.measure do
      Crystal.main_user_code(argc, argv)
    end
    puts "Time to execute program: #{elapsed}"
  end
end

fun main(argc : Int32, argv : UInt8**) : Int32
  # some setup before Crystal main
  Crystal.main(argc, argv)
  # some cleanup logic after Crystal main
end

fun main(argc : Int32, argv : UInt8**) : Int32
  LibFoo.init_foo_and_invoke_main(argc, argv, ->Crystal.main(Int32, UInt8**))
end