experiments/CStandard.README at master · robohack/experiments · GitHub

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source file  CStandard.c
include file CStandard.h
explanation  README       (this file)

Which version of the C standard are we using?
Print some information to stdout.

Mind the indentation!

We used the preprocessor operator "defined", but if the implementation is really
old that might not be available.  In that case, rewrite the tests to use #ifdef
and not to use #elif.  For example,
  #if defined(foo)
    part 1
  #elif defined(bar)
    part 2
  #else
    part 3
  #endif
becomes
  #ifdef foo
    part 1
  #else
    #ifdef bar
      part 2
    #else
      part 3
    #endif
  #endif
You would probably want to change the function header and prototype also, to go
back to the original K&R style.  Just take out the second void.

References:
  C:ARM, Sec. 3.3.4, Predefined Macros; Sec. 10.1, Standard C Facilities.
    This code is an expansion of an example given there.
  C:ARM, Sec. 3.9, 10.2, C++ Compatibility.
    These sections describe __cplusplus and its use.
  man pages for Sun's C compiler and for GCC
  The C Standard, C99, through Technical Corrigendum 3
    Sec. 6.10.8, Predefined macro names
      __STDC__ The integer constant 1, intended to indicate a conforming
        implementation. [required]
      __STDC_VERSION__ The integer constant 199901L. [required]
          The only earlier defined value was 199409L.  The draft version of C1X
          has not yet defined a new value.
      __STDC_HOSTED__ The integer constant 1 if the implementation is a
        hosted implementation or the integer constant 0 if it is not.
        [required]
      __STDC_MB_MIGHT_NEQ_WC__ The integer constant 1, intended to indicate
        that, in the encoding for wchar_t, a member of the basic character
        set need not have a code value equal to its value when used as the
        lone character in an integer character constant. [required]
          (See also, Sec. 7.17, Common definitions <stddef.h>, which states:
          wchar_t is an integer type whose range of values can represent
          distinct codes for all members of the largest extended character set
          specified among the supported locales; the null character shall have
          the code value zero. Each member of the basic character set shall
          have a code value equal to its value when used as the lone character
          in an integer character constant if an implementation does not define
          __STDC_MB_MIGHT_NEQ_WC__.)
          (Not in C:ARM, since this was added in TC 3. It's not clear what the
          proper use of this macro would be if we don't know whether or not the
          implementation claims to be standard but has not yet implemented TC 3.)
      __STDC_IEC_559__ The integer constant 1, intended to indicate conformance
        to the specifications in annex F (IEC 60559 floating-point arithmetic).
        [optional]
      __STDC_IEC_559_COMPLEX__ The integer constant 1, intended to indicate
        adherence to the specifications in informative annex G (IEC 60559
        compatible complex arithmetic). [optional]
      __STDC_ISO_10646__ An integer constant of the form yyyymmL (for example,
        199712L). If this symbol is defined, then every character in the Unicode
        required set, when stored in an object of type wchar_t, has the same
        value as the short identifier of that character. The Unicode required
        set consists of all the characters that are defined by ISO/IEC 10646,
        along with all amendments and technical corrigenda, as of the specified
        year and month. [optional]
    The macros
      __STDC_CONSTANT_MACROS
      __STDC_FORMAT_MACROS
      __STDC_LIMIT_MACROS
    are only relevant to C++ when using <inttypes.h> or <stdint.h>.
    Other macro names beginning with __STDC_ are reserved.
    The macro __cplusplus should not be defined when using Standard C.
    Sec. 7.16, Boolean type and values, <stdbool.h>
      The macro __bool_true_false_are_defined is defined when <stdbool.h> is used.
  The C Standard, draft of C1X, as of March 1, 2009
    The macros
      __STDC_UTF_16__
      __STDC_UTF_32__
    are proposed, and would be used with <uchar.h> for Unicode utilities.
  The C Standard, draft of C1X, as of April 12, 2011
    Lots more stuff.