gcc/doc/gccint/gimple/adding-a-new-gimple-statement-code.rst

   1 ..
   2   Copyright 1988-2022 Free Software Foundation, Inc.
   3   This is part of the GCC manual.
   4   For copying conditions, see the copyright.rst file.
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   6 .. index:: Adding a new GIMPLE statement code
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   8 .. _adding-a-new-gimple-statement-code:
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  10 Adding a new GIMPLE statement code
  11 **********************************
  12
  13 The first step in adding a new GIMPLE statement code, is
  14 modifying the file ``gimple.def``, which contains all the GIMPLE
  15 codes.  Then you must add a corresponding gimple subclass
  16 located in ``gimple.h``.  This in turn, will require you to add a
  17 corresponding ``GTY`` tag in ``gsstruct.def``, and code to handle
  18 this tag in ``gss_for_code`` which is located in ``gimple.cc``.
  19
  20 In order for the garbage collector to know the size of the
  21 structure you created in ``gimple.h``, you need to add a case to
  22 handle your new GIMPLE statement in ``gimple_size`` which is located
  23 in ``gimple.cc``.
  24
  25 You will probably want to create a function to build the new
  26 gimple statement in ``gimple.cc``.  The function should be called
  27 ``gimple_build_new-tuple-name``, and should return the new tuple
  28 as a pointer to the appropriate gimple subclass.
  29
  30 If your new statement requires accessors for any members or
  31 operands it may have, put simple inline accessors in
  32 ``gimple.h`` and any non-trivial accessors in ``gimple.cc`` with a
  33 corresponding prototype in ``gimple.h``.
  34
  35 You should add the new statement subclass to the class hierarchy diagram
  36 in ``gimple.texi``.