### 18.29 D ABI parameters

D Target Hook: void TARGET_D_CPU_VERSIONS (void)

  Declare all environmental version identifiers relating to the target CPU using the function `builtin_version`, which takes a string representing the name of the version. Version identifiers predefined by this hook apply to all modules that are being compiled and imported.

D Target Hook: void TARGET_D_OS_VERSIONS (void)

  Similarly to `TARGET_D_CPU_VERSIONS`, but is used for versions relating to the target operating system.

D Target Hook: unsigned TARGET_D_CRITSEC_SIZE (void)

  Returns the size of the data structure used by the target operating system for critical sections and monitors. For example, on Microsoft Windows this would return the `sizeof(CRITICAL_SECTION)`, while other platforms that implement pthreads would return `sizeof(pthread_mutex_t)`.