VMS Help CC, Language topics, Storage Class Modifiers, inline  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Similar to the __inline storage-class modifier, the inline
  storage-class modifier can be used as a declaration specifier in
  the declaration of a function.  This modifier is supported in
  relaxed ANSI C mode (/STANDARD=RELAXED_ANSI89) or if the
  /ACCEPT=C99_KEYWORDS or /ACCEPT=GCCINLINE qualifier is specified.

  With static functions, inline has the same effect as applying
  __inline or #pragma inline to the function.

  However, when inline is applied to a function with external
  linkage, besides allowing calls within that translation unit to be
  inlined, the inline semantics provide additional rules that also
  allow calls to the function to be inlined in other translation
  units or for the function to be called as an external function, at
  the compiler's discretion:

   o  If the inline keyword is used on a function declaration with
      external linkage, then the function must also be defined in the
      same translation unit.

   o  If all of the file scope declarations of the function use the
      inline keyword but do not use the extern keyword, then the
      definition in that translation unit is called an inline
      definition, and no externally-callable definition is produced
      by that compilation unit.

      Otherwise, the compilation unit does produce an
      externally-callable definition.

   o  An inline definition must not contain a definition of a
      modifiable object with static storage duration, and it must not
      refer to an identifier with internal linkage.  These
      restrictions do not apply to the externally-callable
      definition.

   o  As usual, at most one compilation unit in an entire program can
      supply an externally-callable definition of a given function.

   o  Any call to a function with external linkage may be translated
      as a call to an external function, regardless of the presence
      of the inline qualifier.  It follows from this and the previous
      point that any function with external linkage that is called
      must have exactly one externally-callable definition among all
      the compilation units of an entire program.

   o  The address of an inline function with external linkage is
      always computed as the address of the unique
      externally-callable definition, never the address of an inline
      definition.

   o  A call to inline function made through a pointer to the
      externally-callable definition may still be inlined or
      translated as a call to an inline definition, if the compiler
      can determine the name of the function whose address was stored
      in the pointer.

  2 Link_libraries
   Both the VAX C RTL and the Compaq C RTL can coexist on your
   OpenVMS VAX system.  The VAX C RTL supports existing VAX C
   applications.  The Compaq C RTL supports ANSI-compliant Compaq C
   and Compaq C++, as well as other components of the OpenVMS
   environment.  In addition, the
   Compaq C RTL provides a mechanism for thread safety, performance
   improvements, and problem fixes.

   Applications developed with VAX C will continue to use the
   VAX C RTL.  However, VAX C applications can be relinked to use
   the Compaq C RTL instead.  This lets you take advantage of the new
   features of the Compaq C RTL and solve potential interoperability
   problems in complex applications that incorporate both the VAX C
   and and the Compaq C RTLs.  Existing applications that are
   relinked to use the Compaq C RTL should be carefully tested for
   possible problems resulting from the differences in behavior
   between the VAX C RTL and the Compaq C RTL.  See the applicable
   Compaq C release notes and OpenVMS release notes for additional
   detail.

   Most linking needs should be satisfied by using the Compaq C RTL
   shareable image DECC$SHR.EXE in the SYS$LIBRARY directory.  Use
   this linking method for programs that are written entirely in
   Compaq C or Compaq C++ code; that is, with no VAX C object
   modules.

   Because DECC$SHR.EXE has only prefixed names (no unprefixed
   names), to successfully link against it, make sure you cause
   prefixing to occur for all Compaq C RTL entry points.  Do this by
   compiling in one of two ways:

   1.  Compile with the /PREFIX_LIBRARY_ENTRIES=ALL_ENTRIES
       qualifier.

   2.  Compile with the /STANDARD=VAXC or /STANDARD=COMMON qualifier;
       you get /PREFIX_LIBRARY_ENTRIES=ALL_ENTRIES as the default.

   After making sure that all Compaq C RTL entry points are prefixed,
   link against the shareable image using the LINK command.  For
   example:

   $ CC/DECC/PREFIX_LIBRARY_ENTRIES=ALL_ENTRIES PROG1
   $ LINK PROG1

   For a description of additional ways to link to the Compaq C RTL,
   see the Compaq C Run-Time Library Reference Manual for OpenVMS
   Systems.