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      1 /* Generic relocation support for BFD.
      2    Copyright (C) 1998-2016 Free Software Foundation, Inc.
      3 
      4    This file is part of BFD, the Binary File Descriptor library.
      5 
      6    This program is free software; you can redistribute it and/or modify
      7    it under the terms of the GNU General Public License as published by
      8    the Free Software Foundation; either version 3 of the License, or
      9    (at your option) any later version.
     10 
     11    This program is distributed in the hope that it will be useful,
     12    but WITHOUT ANY WARRANTY; without even the implied warranty of
     13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     14    GNU General Public License for more details.
     15 
     16    You should have received a copy of the GNU General Public License
     17    along with this program; if not, write to the Free Software Foundation,
     18    Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
     19 
     20 /* These macros are used by the various *.h target specific header
     21    files to either generate an enum containing all the known relocations
     22    for that target, or if RELOC_MACROS_GEN_FUNC is defined, a recognition
     23    function is generated instead.  (This is used by binutils/readelf.c)
     24 
     25    Given a header file like this:
     26 
     27    	START_RELOC_NUMBERS (foo)
     28    	    RELOC_NUMBER (R_foo_NONE,    0)
     29    	    RELOC_NUMBER (R_foo_32,      1)
     30    	    EMPTY_RELOC  (R_foo_good)
     31    	    FAKE_RELOC   (R_foo_illegal, 9)
     32    	END_RELOC_NUMBERS (R_foo_count)
     33 
     34    Then the following will be produced by default (ie if
     35    RELOC_MACROS_GEN_FUNC is *not* defined).
     36 
     37    	enum foo
     38 	{
     39    	  R_foo_NONE = 0,
     40    	  R_foo_32 = 1,
     41 	  R_foo_good,
     42    	  R_foo_illegal = 9,
     43    	  R_foo_count
     44    	};
     45 
     46    Note: The value of the symbol defined in the END_RELOC_NUMBERS
     47    macro (R_foo_count in the case of the example above) will be
     48    set to the value of the whichever *_RELOC macro precedes it plus
     49    one.  Therefore if you intend to use the symbol as a sentinel for
     50    the highest valid macro value you should make sure that the
     51    preceding *_RELOC macro is the highest valid number.  ie a
     52    declaration like this:
     53 
     54    	START_RELOC_NUMBERS (foo)
     55    	    RELOC_NUMBER (R_foo_NONE,    0)
     56    	    RELOC_NUMBER (R_foo_32,      1)
     57    	    FAKE_RELOC   (R_foo_illegal, 9)
     58    	    FAKE_RELOC   (R_foo_synonym, 0)
     59    	END_RELOC_NUMBERS (R_foo_count)
     60 
     61    will result in R_foo_count having a value of 1 (R_foo_synonym + 1)
     62    rather than 10 or 2 as might be expected.
     63 
     64    Alternatively you can assign a value to END_RELOC_NUMBERS symbol
     65    explicitly, like this:
     66 
     67    	START_RELOC_NUMBERS (foo)
     68    	    RELOC_NUMBER (R_foo_NONE,    0)
     69    	    RELOC_NUMBER (R_foo_32,      1)
     70    	    FAKE_RELOC   (R_foo_illegal, 9)
     71    	    FAKE_RELOC   (R_foo_synonym, 0)
     72    	END_RELOC_NUMBERS (R_foo_count = 2)
     73 
     74    If RELOC_MACROS_GEN_FUNC *is* defined, then instead the
     75    following function will be generated:
     76 
     77    	static const char *foo (unsigned long rtype);
     78    	static const char *
     79    	foo (unsigned long rtype)
     80    	{
     81    	   switch (rtype)
     82    	   {
     83    	   case 0: return "R_foo_NONE";
     84    	   case 1: return "R_foo_32";
     85    	   default: return NULL;
     86    	   }
     87    	}
     88    */
     89 
     90 #ifndef _RELOC_MACROS_H
     91 #define _RELOC_MACROS_H
     92 
     93 #ifdef RELOC_MACROS_GEN_FUNC
     94 
     95 /* This function takes the relocation number and returns the
     96    string version name of the name of that relocation.  If
     97    the relocation is not recognised, NULL is returned.  */
     98 
     99 #define START_RELOC_NUMBERS(name)   				\
    100 static const char *name (unsigned long rtype);			\
    101 static const char *						\
    102 name (unsigned long rtype)					\
    103 {								\
    104   switch (rtype)						\
    105     {
    106 
    107 #define RELOC_NUMBER(name, number) \
    108     case number: return #name;
    109 
    110 #define FAKE_RELOC(name, number)
    111 #define EMPTY_RELOC(name)
    112 
    113 #define END_RELOC_NUMBERS(name)	\
    114     default: return NULL;	\
    115     }				\
    116 }
    117 
    118 
    119 #else /* Default to generating enum.  */
    120 
    121 #define START_RELOC_NUMBERS(name)   enum name {
    122 #define RELOC_NUMBER(name, number)  name = number,
    123 #define FAKE_RELOC(name, number)    name = number,
    124 #define EMPTY_RELOC(name)           name,
    125 #define END_RELOC_NUMBERS(name)     name };
    126 
    127 #endif
    128 
    129 #endif /* _RELOC_MACROS_H */
    130