2 * $FreeBSD: src/gnu/usr.bin/ld/ld.h,v 1.21 1999/08/27 23:36:01 peter Exp $
3 * $DragonFly: src/gnu/usr.bin/ld/Attic/ld.h,v 1.2 2003/06/17 04:25:46 dillon Exp $
6 * This code is derived from software copyrighted by the Free Software
9 * Modified 1991 by Donn Seeley at UUNET Technologies, Inc.
19 #define min(a,b) ((a) < (b) ? (a) : (b))
30 /* If compiled with GNU C, use the built-in alloca */
31 #if defined(__GNUC__) || defined(sparc)
32 #define alloca __builtin_alloca
38 /* Macro to control the number of undefined references printed */
39 #define MAX_UREFS_PRINTED 10
41 /* Align to power-of-two boundary */
42 #define PALIGN(x,p) (((x) + (u_long)(p) - 1) & (-(u_long)(p)))
44 /* Align to machine dependent boundary */
45 #define MALIGN(x) PALIGN(x,MAX_ALIGNMENT)
47 /* Define this to specify the default executable format. */
50 #define DEFAULT_MAGIC QMAGIC
53 #define DEFAULT_MAGIC ZMAGIC
57 #ifdef DEMANGLE_CPLUSPLUS
58 extern char *demangle __P((char*));
60 #define demangle(name) name
64 * Ok. Following are the relocation information macros. If your
65 * system should not be able to use the default set (below), you must
66 * define the following:
68 * relocation_info: This must be typedef'd (or #define'd) to the type
69 * of structure that is stored in the relocation info section of your
70 * a.out files. Often this is defined in the a.out.h for your system.
72 * RELOC_ADDRESS (rval): Offset into the current section of the
73 * <whatever> to be relocated. *Must be an lvalue*.
75 * RELOC_EXTERN_P (rval): Is this relocation entry based on an
76 * external symbol (1), or was it fully resolved upon entering the
77 * loader (0) in which case some combination of the value in memory
78 * (if RELOC_MEMORY_ADD_P) and the extra (if RELOC_ADD_EXTRA) contains
79 * what the value of the relocation actually was. *Must be an lvalue*.
81 * RELOC_TYPE (rval): If this entry was fully resolved upon
82 * entering the loader, what type should it be relocated as?
84 * RELOC_SYMBOL (rval): If this entry was not fully resolved upon
85 * entering the loader, what is the index of it's symbol in the symbol
86 * table? *Must be a lvalue*.
88 * RELOC_MEMORY_ADD_P (rval): This should return true if the final
89 * relocation value output here should be added to memory, or if the
90 * section of memory described should simply be set to the relocation
93 * RELOC_ADD_EXTRA (rval): (Optional) This macro, if defined, gives
94 * an extra value to be added to the relocation value based on the
95 * individual relocation entry. *Must be an lvalue if defined*.
97 * RELOC_PCREL_P (rval): True if the relocation value described is
100 * RELOC_VALUE_RIGHTSHIFT (rval): Number of bits right to shift the
101 * final relocation value before putting it where it belongs.
103 * RELOC_TARGET_SIZE (rval): log to the base 2 of the number of
104 * bytes of size this relocation entry describes; 1 byte == 0; 2 bytes
105 * == 1; 4 bytes == 2, and etc. This is somewhat redundant (we could
106 * do everything in terms of the bit operators below), but having this
107 * macro could end up producing better code on machines without fancy
108 * bit twiddling. Also, it's easier to understand/code big/little
109 * endian distinctions with this macro.
111 * RELOC_TARGET_BITPOS (rval): The starting bit position within the
112 * object described in RELOC_TARGET_SIZE in which the relocation value
115 * RELOC_TARGET_BITSIZE (rval): How many bits are to be replaced
116 * with the bits of the relocation value. It may be assumed by the
117 * code that the relocation value will fit into this many bits. This
118 * may be larger than RELOC_TARGET_SIZE if such be useful.
121 * Things I haven't implemented
122 * ----------------------------
124 * Values for RELOC_TARGET_SIZE other than 0, 1, or 2.
126 * Pc relative relocation for External references.
133 #ifndef RELOC_ADDRESS
135 #define RELOC_ADDRESS(r) ((r)->r_address)
136 #define RELOC_EXTERN_P(r) ((r)->r_extern)
137 #define RELOC_TYPE(r) ((r)->r_symbolnum)
138 #define RELOC_SYMBOL(r) ((r)->r_symbolnum)
139 #define RELOC_MEMORY_SUB_P(r) 0
140 #define RELOC_MEMORY_ADD_P(r) 1
141 #undef RELOC_ADD_EXTRA
142 #define RELOC_PCREL_P(r) ((r)->r_pcrel)
143 #define RELOC_VALUE_RIGHTSHIFT(r) 0
144 #if defined(RTLD) && defined(SUN_COMPAT)
145 #define RELOC_TARGET_SIZE(r) (2) /* !!!!! Sun BUG compatible */
147 #define RELOC_TARGET_SIZE(r) ((r)->r_length)
149 #define RELOC_TARGET_BITPOS(r) 0
150 #define RELOC_TARGET_BITSIZE(r) 32
161 #define TEXT_START(x) N_TXTADDR(x)
165 #define DATA_START(x) N_DATADDR(x)
168 /* If a this type of symbol is encountered, its name is a warning
169 message to print each time the symbol referenced by the next symbol
170 table entry is referenced.
172 This feature may be used to allow backwards compatibility with
173 certain functions (eg. gets) but to discourage programmers from
176 So if, for example, you wanted to have ld print a warning whenever
177 the function "gets" was used in their C program, you would add the
178 following to the assembler file in which gets is defined:
180 .stabs "Obsolete function \"gets\" referenced",30,0,0,0
181 .stabs "_gets",1,0,0,0
183 These .stabs do not necessarily have to be in the same file as the
184 gets function, they simply must exist somewhere in the compilation. */
187 #define N_WARNING 0x1E /* Warning message to print if symbol
189 #endif /* This is input to ld */
191 /* Special global symbol types understood by GNU LD. */
193 /* The following type indicates the definition of a symbol as being
194 an indirect reference to another symbol. The other symbol
195 appears as an undefined reference, immediately following this symbol.
197 Indirection is asymmetrical. The other symbol's value will be used
198 to satisfy requests for the indirect symbol, but not vice versa.
199 If the other symbol does not have a definition, libraries will
200 be searched to find a definition.
202 So, for example, the following two lines placed in an assembler
203 input file would result in an object file which would direct gnu ld
204 to resolve all references to symbol "foo" as references to symbol
207 .stabs "_foo",11,0,0,0
208 .stabs "_bar",1,0,0,0
210 Note that (11 == (N_INDR | N_EXT)) and (1 == (N_UNDF | N_EXT)). */
216 /* The following symbols refer to set elements. These are expected
217 only in input to the loader; they should not appear in loader
218 output (unless relocatable output is requested). To be recognized
219 by the loader, the input symbols must have their N_EXT bit set.
220 All the N_SET[ATDB] symbols with the same name form one set. The
221 loader collects all of these elements at load time and outputs a
222 vector for each name.
223 Space (an array of 32 bit words) is allocated for the set in the
224 data section, and the n_value field of each set element value is
225 stored into one word of the array.
226 The first word of the array is the length of the set (number of
227 elements). The last word of the vector is set to zero for possible
228 use by incremental loaders. The array is ordered by the linkage
229 order; the first symbols which the linker encounters will be first
232 In C syntax this looks like:
236 unsigned int vector[length];
237 unsigned int always_zero;
240 Before being placed into the array, each element is relocated
241 according to its type. This allows the loader to create an array
242 of pointers to objects automatically. N_SETA type symbols will not
245 The address of the set is made into an N_SETV symbol
246 whose name is the same as the name of the set.
247 This symbol acts like a N_DATA global symbol
248 in that it can satisfy undefined external references.
250 For the purposes of determining whether or not to load in a library
251 file, set element definitions are not considered "real
252 definitions"; they will not cause the loading of a library
255 If relocatable output is requested, none of this processing is
256 done. The symbols are simply relocated and passed through to the
259 So, for example, the following three lines of assembler code
260 (whether in one file or scattered between several different ones)
261 will produce a three element vector (total length is five words;
262 see above), referenced by the symbol "_xyzzy", which will have the
263 addresses of the routines _init1, _init2, and _init3.
265 *NOTE*: If symbolic addresses are used in the n_value field of the
266 defining .stabs, those symbols must be defined in the same file as
267 that containing the .stabs.
269 .stabs "_xyzzy",23,0,0,_init1
270 .stabs "_xyzzy",23,0,0,_init2
271 .stabs "_xyzzy",23,0,0,_init3
273 Note that (23 == (N_SETT | N_EXT)). */
276 #define N_SETA 0x14 /* Absolute set element symbol */
277 #endif /* This is input to LD, in a .o file. */
280 #define N_SETT 0x16 /* Text set element symbol */
281 #endif /* This is input to LD, in a .o file. */
284 #define N_SETD 0x18 /* Data set element symbol */
285 #endif /* This is input to LD, in a .o file. */
288 #define N_SETB 0x1A /* Bss set element symbol */
289 #endif /* This is input to LD, in a .o file. */
291 /* Macros dealing with the set element symbols defined in a.out.h */
292 #define SET_ELEMENT_P(x) ((x) >= N_SETA && (x) <= (N_SETB|N_EXT))
293 #define TYPE_OF_SET_ELEMENT(x) ((x) - N_SETA + N_ABS)
296 #define N_SETV 0x1C /* Pointer to set vector in data area. */
297 #endif /* This is output from LD. */
301 /* Line number for the data section. This is to be used to describe
302 the source location of a variable declaration. */
304 #define N_DSLINE (N_SLINE+N_DATA-N_TEXT)
307 /* Line number for the bss section. This is to be used to describe
308 the source location of a variable declaration. */
310 #define N_BSLINE (N_SLINE+N_BSS-N_TEXT)
312 #endif /* not __GNU_STAB__ */
315 /* Number of buckets in symbol hash table */
316 #define SYMTABSIZE 1009
318 /* # of global symbols referenced and not defined. */
319 extern int undefined_global_sym_count;
321 /* # of weak symbols referenced and not defined. */
322 extern int undefined_weak_sym_count;
324 /* # of undefined symbols referenced by shared objects */
325 extern int undefined_shobj_sym_count;
327 /* # of multiply defined symbols. */
328 extern int multiple_def_count;
330 /* # of common symbols. */
331 extern int common_defined_global_count;
333 /* # of warning symbols encountered. */
334 extern int warn_sym_count;
335 extern int list_warning_symbols;
338 * Define a linked list of strings which define symbols which should be
339 * treated as set elements even though they aren't. Any symbol with a prefix
340 * matching one of these should be treated as a set element.
342 * This is to make up for deficiencies in many assemblers which aren't willing
343 * to pass any stabs through to the loader which they don't understand.
345 struct string_list_element {
347 struct string_list_element *next;
351 #ifndef __symbol_defined__
352 #define __symbol_defined__
353 typedef struct glosym symbol;
356 extern symbol *entry_symbol; /* the entry symbol, if any */
357 extern symbol *edata_symbol; /* the symbol _edata */
358 extern symbol *etext_symbol; /* the symbol _etext */
359 extern symbol *end_symbol; /* the symbol _end */
362 * Section start addresses.
364 extern int text_size; /* total size of text. */
365 extern int text_start; /* start of text */
366 extern int text_pad; /* clear space between text and data */
367 extern int data_size; /* total size of data. */
368 extern int data_start; /* start of data */
369 extern int data_pad; /* part of bss segment within data */
371 extern int bss_size; /* total size of bss. */
372 extern int bss_start; /* start of bss */
374 extern int text_reloc_size; /* total size of text relocation. */
375 extern int data_reloc_size; /* total size of data relocation. */
377 extern int magic; /* Output file magic. */
378 extern int relocatable_output;
380 /* Size of a page. */
381 extern int page_size;
383 extern char **search_dirs; /* Directories to search for libraries. */
384 extern int n_search_dirs; /* Length of above. */
386 extern int write_map; /* write a load map (`-M') */