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