1 /* Native support for the SGI Iris running IRIX version 5, for GDB.
2 Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994
3 Free Software Foundation, Inc.
4 Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU
5 and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin.
6 Implemented for Irix 4.x by Garrett A. Wollman.
7 Modified for Irix 5.x by Ian Lance Taylor.
9 This file is part of GDB.
11 This program is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 2 of the License, or
14 (at your option) any later version.
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
21 You should have received a copy of the GNU General Public License
22 along with this program; if not, write to the Free Software
23 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
31 #include <sys/procfs.h>
32 #include <setjmp.h> /* For JB_XXX. */
34 /* Size of elements in jmpbuf */
36 #define JB_ELEMENT_SIZE 4
39 * See the comment in m68k-tdep.c regarding the utility of these functions.
41 * These definitions are from the MIPS SVR4 ABI, so they may work for
42 * any MIPS SVR4 target.
46 supply_gregset (gregsetp
)
50 register greg_t
*regp
= &(*gregsetp
)[0];
52 for(regi
= 0; regi
<= CTX_RA
; regi
++)
53 supply_register (regi
, (char *)(regp
+ regi
));
55 supply_register (PC_REGNUM
, (char *)(regp
+ CTX_EPC
));
56 supply_register (HI_REGNUM
, (char *)(regp
+ CTX_MDHI
));
57 supply_register (LO_REGNUM
, (char *)(regp
+ CTX_MDLO
));
58 supply_register (CAUSE_REGNUM
, (char *)(regp
+ CTX_CAUSE
));
62 fill_gregset (gregsetp
, regno
)
67 register greg_t
*regp
= &(*gregsetp
)[0];
69 for (regi
= 0; regi
<= CTX_RA
; regi
++)
70 if ((regno
== -1) || (regno
== regi
))
71 *(regp
+ regi
) = *(greg_t
*) ®isters
[REGISTER_BYTE (regi
)];
73 if ((regno
== -1) || (regno
== PC_REGNUM
))
74 *(regp
+ CTX_EPC
) = *(greg_t
*) ®isters
[REGISTER_BYTE (PC_REGNUM
)];
76 if ((regno
== -1) || (regno
== CAUSE_REGNUM
))
77 *(regp
+ CTX_CAUSE
) = *(greg_t
*) ®isters
[REGISTER_BYTE (PS_REGNUM
)];
79 if ((regno
== -1) || (regno
== HI_REGNUM
))
80 *(regp
+ CTX_MDHI
) = *(greg_t
*) ®isters
[REGISTER_BYTE (HI_REGNUM
)];
82 if ((regno
== -1) || (regno
== LO_REGNUM
))
83 *(regp
+ CTX_MDLO
) = *(greg_t
*) ®isters
[REGISTER_BYTE (LO_REGNUM
)];
87 * Now we do the same thing for floating-point registers.
88 * We don't bother to condition on FP0_REGNUM since any
89 * reasonable MIPS configuration has an R3010 in it.
91 * Again, see the comments in m68k-tdep.c.
95 supply_fpregset (fpregsetp
)
96 fpregset_t
*fpregsetp
;
100 for (regi
= 0; regi
< 32; regi
++)
101 supply_register (FP0_REGNUM
+ regi
,
102 (char *)&fpregsetp
->fp_r
.fp_regs
[regi
]);
104 supply_register (FCRCS_REGNUM
, (char *)&fpregsetp
->fp_csr
);
106 /* FIXME: how can we supply FCRIR_REGNUM? SGI doesn't tell us. */
110 fill_fpregset (fpregsetp
, regno
)
111 fpregset_t
*fpregsetp
;
117 for (regi
= FP0_REGNUM
; regi
< FP0_REGNUM
+ 32; regi
++)
119 if ((regno
== -1) || (regno
== regi
))
121 from
= (char *) ®isters
[REGISTER_BYTE (regi
)];
122 to
= (char *) &(fpregsetp
->fp_r
.fp_regs
[regi
- FP0_REGNUM
]);
123 memcpy(to
, from
, REGISTER_RAW_SIZE (regi
));
127 if ((regno
== -1) || (regno
== FCRCS_REGNUM
))
128 fpregsetp
->fp_csr
= *(unsigned *) ®isters
[REGISTER_BYTE(FCRCS_REGNUM
)];
132 /* Figure out where the longjmp will land.
133 We expect the first arg to be a pointer to the jmp_buf structure from which
134 we extract the pc (JB_PC) that we will land at. The pc is copied into PC.
135 This routine returns true on success. */
138 get_longjmp_target (pc
)
141 char buf
[TARGET_PTR_BIT
/ TARGET_CHAR_BIT
];
144 jb_addr
= read_register (A0_REGNUM
);
146 if (target_read_memory (jb_addr
+ JB_PC
* JB_ELEMENT_SIZE
, buf
,
147 TARGET_PTR_BIT
/ TARGET_CHAR_BIT
))
150 *pc
= extract_address (buf
, TARGET_PTR_BIT
/ TARGET_CHAR_BIT
);
156 fetch_core_registers (core_reg_sect
, core_reg_size
, which
, reg_addr
)
158 unsigned core_reg_size
;
159 int which
; /* Unused */
160 unsigned int reg_addr
; /* Unused */
162 if (core_reg_size
!= REGISTER_BYTES
)
164 warning ("wrong size gregset struct in core file");
168 memcpy ((char *)registers
, core_reg_sect
, core_reg_size
);
171 /* Irix 5 uses what appears to be a unique form of shared library
172 support. This is a copy of solib.c modified for Irix 5. */
174 #include <sys/types.h>
177 #include <sys/param.h>
180 /* <obj.h> includes <sym.h> and <symconst.h>, which causes conflicts
181 with our versions of those files included by tm-mips.h. Prevent
182 <obj.h> from including them with some appropriate defines. */
184 #define __SYMCONST_H__
190 #include "objfiles.h"
194 #include "inferior.h"
195 #include "language.h"
197 /* We need to set a breakpoint at a point when we know that the
198 mapping of shared libraries is complete. dbx simply breaks at main
199 (or, for FORTRAN, MAIN__), so we do the same. We can not break at
200 the very beginning of main, because the startup code will jump into
201 main after the GP initialization instructions. SOLIB_BKPT_OFFSET
202 is used to skip those instructions. */
204 #define SOLIB_BKPT_OFFSET 12
206 static char *bkpt_names
[] = {
212 /* The symbol which starts off the list of shared libraries. */
213 #define DEBUG_BASE "__rld_obj_head"
215 /* How to get the loaded address of a shared library. */
216 #define LM_ADDR(so) ((so)->lm.o_praw)
218 char shadow_contents
[BREAKPOINT_MAX
]; /* Stash old bkpt addr contents */
221 struct so_list
*next
; /* next structure in linked list */
223 struct obj lm
; /* copy of link map from inferior */
224 struct obj_list
*lladdr
; /* addr in inferior lm was read from */
225 CORE_ADDR lmend
; /* upper addr bound of mapped object */
226 char symbols_loaded
; /* flag: symbols read in yet? */
227 char from_tty
; /* flag: print msgs? */
228 struct objfile
*objfile
; /* objfile for loaded lib */
229 struct section_table
*sections
;
230 struct section_table
*sections_end
;
231 struct section_table
*textsection
;
235 static struct so_list
*so_list_head
; /* List of known shared objects */
236 static CORE_ADDR debug_base
; /* Base of dynamic linker structures */
237 static CORE_ADDR breakpoint_addr
; /* Address where end bkpt is set */
239 /* Local function prototypes */
242 sharedlibrary_command
PARAMS ((char *, int));
245 enable_break
PARAMS ((void));
248 disable_break
PARAMS ((void));
251 info_sharedlibrary_command
PARAMS ((char *, int));
254 symbol_add_stub
PARAMS ((char *));
256 static struct so_list
*
257 find_solib
PARAMS ((struct so_list
*));
259 static struct obj_list
*
260 first_link_map_member
PARAMS ((void));
263 locate_base
PARAMS ((void));
266 solib_map_sections
PARAMS ((struct so_list
*));
272 solib_map_sections -- open bfd and build sections for shared lib
276 static void solib_map_sections (struct so_list *so)
280 Given a pointer to one of the shared objects in our list
281 of mapped objects, use the recorded name to open a bfd
282 descriptor for the object, build a section table, and then
283 relocate all the section addresses by the base address at
284 which the shared object was mapped.
288 In most (all?) cases the shared object file name recorded in the
289 dynamic linkage tables will be a fully qualified pathname. For
290 cases where it isn't, do we really mimic the systems search
291 mechanism correctly in the below code (particularly the tilde
296 solib_map_sections (so
)
300 char *scratch_pathname
;
302 struct section_table
*p
;
303 struct cleanup
*old_chain
;
307 filename
= tilde_expand (so
-> lm
.o_path
);
308 old_chain
= make_cleanup (free
, filename
);
310 scratch_chan
= openp (getenv ("PATH"), 1, filename
, O_RDONLY
, 0,
312 if (scratch_chan
< 0)
314 scratch_chan
= openp (getenv ("LD_LIBRARY_PATH"), 1, filename
,
315 O_RDONLY
, 0, &scratch_pathname
);
317 if (scratch_chan
< 0)
319 perror_with_name (filename
);
321 /* Leave scratch_pathname allocated. abfd->name will point to it. */
323 abfd
= bfd_fdopenr (scratch_pathname
, gnutarget
, scratch_chan
);
326 close (scratch_chan
);
327 error ("Could not open `%s' as an executable file: %s",
328 scratch_pathname
, bfd_errmsg (bfd_get_error ()));
330 /* Leave bfd open, core_xfer_memory and "info files" need it. */
332 abfd
-> cacheable
= true;
334 if (!bfd_check_format (abfd
, bfd_object
))
336 error ("\"%s\": not in executable format: %s.",
337 scratch_pathname
, bfd_errmsg (bfd_get_error ()));
339 if (build_section_table (abfd
, &so
-> sections
, &so
-> sections_end
))
341 error ("Can't find the file sections in `%s': %s",
342 bfd_get_filename (exec_bfd
), bfd_errmsg (bfd_get_error ()));
345 /* Irix 5 shared objects are pre-linked to particular addresses
346 although the dynamic linker may have to relocate them if the
347 address ranges of the libraries used by the main program clash.
348 The offset is the difference between the address where the object
349 is mapped and the binding address of the shared library. */
350 offset
= (CORE_ADDR
) LM_ADDR (so
) - so
-> lm
.o_base_address
;
352 for (p
= so
-> sections
; p
< so
-> sections_end
; p
++)
354 /* Relocate the section binding addresses as recorded in the shared
355 object's file by the offset to get the address to which the
356 object was actually mapped. */
358 p
-> endaddr
+= offset
;
359 so
-> lmend
= (CORE_ADDR
) max (p
-> endaddr
, so
-> lmend
);
360 if (STREQ (p
-> the_bfd_section
-> name
, ".text"))
362 so
-> textsection
= p
;
366 /* Free the file names, close the file now. */
367 do_cleanups (old_chain
);
374 locate_base -- locate the base address of dynamic linker structs
378 CORE_ADDR locate_base (void)
382 For both the SunOS and SVR4 shared library implementations, if the
383 inferior executable has been linked dynamically, there is a single
384 address somewhere in the inferior's data space which is the key to
385 locating all of the dynamic linker's runtime structures. This
386 address is the value of the symbol defined by the macro DEBUG_BASE.
387 The job of this function is to find and return that address, or to
388 return 0 if there is no such address (the executable is statically
391 For SunOS, the job is almost trivial, since the dynamic linker and
392 all of it's structures are statically linked to the executable at
393 link time. Thus the symbol for the address we are looking for has
394 already been added to the minimal symbol table for the executable's
395 objfile at the time the symbol file's symbols were read, and all we
396 have to do is look it up there. Note that we explicitly do NOT want
397 to find the copies in the shared library.
399 The SVR4 version is much more complicated because the dynamic linker
400 and it's structures are located in the shared C library, which gets
401 run as the executable's "interpreter" by the kernel. We have to go
402 to a lot more work to discover the address of DEBUG_BASE. Because
403 of this complexity, we cache the value we find and return that value
404 on subsequent invocations. Note there is no copy in the executable
407 Irix 5 is basically like SunOS.
409 Note that we can assume nothing about the process state at the time
410 we need to find this address. We may be stopped on the first instruc-
411 tion of the interpreter (C shared library), the first instruction of
412 the executable itself, or somewhere else entirely (if we attached
413 to the process for example).
420 struct minimal_symbol
*msymbol
;
421 CORE_ADDR address
= 0;
423 msymbol
= lookup_minimal_symbol (DEBUG_BASE
, symfile_objfile
);
424 if ((msymbol
!= NULL
) && (SYMBOL_VALUE_ADDRESS (msymbol
) != 0))
426 address
= SYMBOL_VALUE_ADDRESS (msymbol
);
435 first_link_map_member -- locate first member in dynamic linker's map
439 static struct link_map *first_link_map_member (void)
443 Read in a copy of the first member in the inferior's dynamic
444 link map from the inferior's dynamic linker structures, and return
445 a pointer to the copy in our address space.
448 static struct obj_list
*
449 first_link_map_member ()
454 read_memory (debug_base
, (char *) &lm
, sizeof (struct obj_list
*));
459 /* The first entry in the list is the object file we are debugging,
461 read_memory ((CORE_ADDR
) lm
, (char *) &s
, sizeof (struct obj_list
));
470 find_solib -- step through list of shared objects
474 struct so_list *find_solib (struct so_list *so_list_ptr)
478 This module contains the routine which finds the names of any
479 loaded "images" in the current process. The argument in must be
480 NULL on the first call, and then the returned value must be passed
481 in on subsequent calls. This provides the capability to "step" down
482 the list of loaded objects. On the last object, a NULL value is
486 static struct so_list
*
487 find_solib (so_list_ptr
)
488 struct so_list
*so_list_ptr
; /* Last lm or NULL for first one */
490 struct so_list
*so_list_next
= NULL
;
491 struct obj_list
*lm
= NULL
;
494 if (so_list_ptr
== NULL
)
496 /* We are setting up for a new scan through the loaded images. */
497 if ((so_list_next
= so_list_head
) == NULL
)
499 /* We have not already read in the dynamic linking structures
500 from the inferior, lookup the address of the base structure. */
501 debug_base
= locate_base ();
504 /* Read the base structure in and find the address of the first
505 link map list member. */
506 lm
= first_link_map_member ();
512 /* We have been called before, and are in the process of walking
513 the shared library list. Advance to the next shared object. */
514 if ((lm
= so_list_ptr
->ll
.next
) == NULL
)
516 /* We have hit the end of the list, so check to see if any were
517 added, but be quiet if we can't read from the target any more. */
518 int status
= target_read_memory ((CORE_ADDR
) so_list_ptr
-> lladdr
,
519 (char *) &(so_list_ptr
-> ll
),
520 sizeof (struct obj_list
));
523 lm
= so_list_ptr
->ll
.next
;
530 so_list_next
= so_list_ptr
-> next
;
532 if ((so_list_next
== NULL
) && (lm
!= NULL
))
537 /* Get next link map structure from inferior image and build a local
538 abbreviated load_map structure */
539 new = (struct so_list
*) xmalloc (sizeof (struct so_list
));
540 memset ((char *) new, 0, sizeof (struct so_list
));
542 /* Add the new node as the next node in the list, or as the root
543 node if this is the first one. */
544 if (so_list_ptr
!= NULL
)
546 so_list_ptr
-> next
= new;
553 read_memory ((CORE_ADDR
) lm
, (char *) &(new -> ll
),
554 sizeof (struct obj_list
));
555 read_memory ((CORE_ADDR
) new->ll
.data
, (char *) &(new -> lm
),
556 sizeof (struct obj
));
557 target_read_string ((CORE_ADDR
)new->lm
.o_path
, &buffer
,
560 memory_error (errcode
, (CORE_ADDR
)new->lm
.o_path
);
561 new->lm
.o_path
= buffer
;
562 solib_map_sections (new);
564 return (so_list_next
);
567 /* A small stub to get us past the arg-passing pinhole of catch_errors. */
570 symbol_add_stub (arg
)
573 register struct so_list
*so
= (struct so_list
*) arg
; /* catch_errs bogon */
575 so
-> objfile
= symbol_file_add (so
-> lm
.o_path
, so
-> from_tty
,
576 (unsigned int) so
-> textsection
-> addr
,
585 solib_add -- add a shared library file to the symtab and section list
589 void solib_add (char *arg_string, int from_tty,
590 struct target_ops *target)
597 solib_add (arg_string
, from_tty
, target
)
600 struct target_ops
*target
;
602 register struct so_list
*so
= NULL
; /* link map state variable */
604 /* Last shared library that we read. */
605 struct so_list
*so_last
= NULL
;
611 if ((re_err
= re_comp (arg_string
? arg_string
: ".")) != NULL
)
613 error ("Invalid regexp: %s", re_err
);
616 /* Add the shared library sections to the section table of the
617 specified target, if any. We have to do this before reading the
618 symbol files as symbol_file_add calls reinit_frame_cache and
619 creating a new frame might access memory in the shared library. */
622 /* Count how many new section_table entries there are. */
625 while ((so
= find_solib (so
)) != NULL
)
627 if (so
-> lm
.o_path
[0])
629 count
+= so
-> sections_end
- so
-> sections
;
635 /* Reallocate the target's section table including the new size. */
636 if (target
-> to_sections
)
638 old
= target
-> to_sections_end
- target
-> to_sections
;
639 target
-> to_sections
= (struct section_table
*)
640 xrealloc ((char *)target
-> to_sections
,
641 (sizeof (struct section_table
)) * (count
+ old
));
646 target
-> to_sections
= (struct section_table
*)
647 xmalloc ((sizeof (struct section_table
)) * count
);
649 target
-> to_sections_end
= target
-> to_sections
+ (count
+ old
);
651 /* Add these section table entries to the target's table. */
652 while ((so
= find_solib (so
)) != NULL
)
654 if (so
-> lm
.o_path
[0])
656 count
= so
-> sections_end
- so
-> sections
;
657 memcpy ((char *) (target
-> to_sections
+ old
),
659 (sizeof (struct section_table
)) * count
);
666 /* Now add the symbol files. */
667 while ((so
= find_solib (so
)) != NULL
)
669 if (so
-> lm
.o_path
[0] && re_exec (so
-> lm
.o_path
))
671 so
-> from_tty
= from_tty
;
672 if (so
-> symbols_loaded
)
676 printf_unfiltered ("Symbols already loaded for %s\n", so
-> lm
.o_path
);
679 else if (catch_errors
680 (symbol_add_stub
, (char *) so
,
681 "Error while reading shared library symbols:\n",
685 so
-> symbols_loaded
= 1;
695 info_sharedlibrary_command -- code for "info sharedlibrary"
699 static void info_sharedlibrary_command ()
703 Walk through the shared library list and print information
704 about each attached library.
708 info_sharedlibrary_command (ignore
, from_tty
)
712 register struct so_list
*so
= NULL
; /* link map state variable */
715 if (exec_bfd
== NULL
)
717 printf_unfiltered ("No exec file.\n");
720 while ((so
= find_solib (so
)) != NULL
)
722 if (so
-> lm
.o_path
[0])
726 printf_unfiltered("%-12s%-12s%-12s%s\n", "From", "To", "Syms Read",
727 "Shared Object Library");
730 printf_unfiltered ("%-12s",
731 local_hex_string_custom ((unsigned long) LM_ADDR (so
),
733 printf_unfiltered ("%-12s",
734 local_hex_string_custom ((unsigned long) so
-> lmend
,
736 printf_unfiltered ("%-12s", so
-> symbols_loaded
? "Yes" : "No");
737 printf_unfiltered ("%s\n", so
-> lm
.o_path
);
740 if (so_list_head
== NULL
)
742 printf_unfiltered ("No shared libraries loaded at this time.\n");
750 solib_address -- check to see if an address is in a shared lib
754 int solib_address (CORE_ADDR address)
758 Provides a hook for other gdb routines to discover whether or
759 not a particular address is within the mapped address space of
760 a shared library. Any address between the base mapping address
761 and the first address beyond the end of the last mapping, is
762 considered to be within the shared library address space, for
765 For example, this routine is called at one point to disable
766 breakpoints which are in shared libraries that are not currently
771 solib_address (address
)
774 register struct so_list
*so
= 0; /* link map state variable */
776 while ((so
= find_solib (so
)) != NULL
)
778 if (so
-> lm
.o_path
[0])
780 if ((address
>= (CORE_ADDR
) LM_ADDR (so
)) &&
781 (address
< (CORE_ADDR
) so
-> lmend
))
790 /* Called by free_all_symtabs */
795 struct so_list
*next
;
800 if (so_list_head
-> sections
)
802 free ((PTR
)so_list_head
-> sections
);
804 if (so_list_head
-> abfd
)
806 bfd_filename
= bfd_get_filename (so_list_head
-> abfd
);
807 bfd_close (so_list_head
-> abfd
);
810 /* This happens for the executable on SVR4. */
813 next
= so_list_head
-> next
;
815 free ((PTR
)bfd_filename
);
816 free (so_list_head
->lm
.o_path
);
817 free ((PTR
)so_list_head
);
827 disable_break -- remove the "mapping changed" breakpoint
831 static int disable_break ()
835 Removes the breakpoint that gets hit when the dynamic linker
836 completes a mapping change.
846 /* Note that breakpoint address and original contents are in our address
847 space, so we just need to write the original contents back. */
849 if (memory_remove_breakpoint (breakpoint_addr
, shadow_contents
) != 0)
854 /* For the SVR4 version, we always know the breakpoint address. For the
855 SunOS version we don't know it until the above code is executed.
856 Grumble if we are stopped anywhere besides the breakpoint address. */
858 if (stop_pc
!= breakpoint_addr
)
860 warning ("stopped at unknown breakpoint while handling shared libraries");
870 enable_break -- arrange for dynamic linker to hit breakpoint
874 int enable_break (void)
878 Both the SunOS and the SVR4 dynamic linkers have, as part of their
879 debugger interface, support for arranging for the inferior to hit
880 a breakpoint after mapping in the shared libraries. This function
881 enables that breakpoint.
883 For SunOS, there is a special flag location (in_debugger) which we
884 set to 1. When the dynamic linker sees this flag set, it will set
885 a breakpoint at a location known only to itself, after saving the
886 original contents of that place and the breakpoint address itself,
887 in it's own internal structures. When we resume the inferior, it
888 will eventually take a SIGTRAP when it runs into the breakpoint.
889 We handle this (in a different place) by restoring the contents of
890 the breakpointed location (which is only known after it stops),
891 chasing around to locate the shared libraries that have been
892 loaded, then resuming.
894 For SVR4, the debugger interface structure contains a member (r_brk)
895 which is statically initialized at the time the shared library is
896 built, to the offset of a function (_r_debug_state) which is guaran-
897 teed to be called once before mapping in a library, and again when
898 the mapping is complete. At the time we are examining this member,
899 it contains only the unrelocated offset of the function, so we have
900 to do our own relocation. Later, when the dynamic linker actually
901 runs, it relocates r_brk to be the actual address of _r_debug_state().
903 The debugger interface structure also contains an enumeration which
904 is set to either RT_ADD or RT_DELETE prior to changing the mapping,
905 depending upon whether or not the library is being mapped or unmapped,
906 and then set to RT_CONSISTENT after the library is mapped/unmapped.
908 Irix 5, on the other hand, has no such features. Instead, we
909 set a breakpoint at main.
916 struct minimal_symbol
*msymbol
;
920 /* Scan through the list of symbols, trying to look up the symbol and
921 set a breakpoint there. Terminate loop when we/if we succeed. */
924 for (bkpt_namep
= bkpt_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
926 msymbol
= lookup_minimal_symbol (*bkpt_namep
, symfile_objfile
);
927 if ((msymbol
!= NULL
) && (SYMBOL_VALUE_ADDRESS (msymbol
) != 0))
929 bkpt_addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
930 #ifdef SOLIB_BKPT_OFFSET
931 /* We only want to skip if bkpt_addr is currently pointing
932 at a GP setting instruction. */
936 if (target_read_memory (bkpt_addr
, buf
, 4) == 0)
940 insn
= extract_unsigned_integer (buf
, 4);
941 if ((insn
& 0xffff0000) == 0x3c1c0000) /* lui $gp,n */
942 bkpt_addr
+= SOLIB_BKPT_OFFSET
;
946 if (target_insert_breakpoint (bkpt_addr
, shadow_contents
) == 0)
948 breakpoint_addr
= bkpt_addr
;
962 solib_create_inferior_hook -- shared library startup support
966 void solib_create_inferior_hook()
970 When gdb starts up the inferior, it nurses it along (through the
971 shell) until it is ready to execute it's first instruction. At this
972 point, this function gets called via expansion of the macro
973 SOLIB_CREATE_INFERIOR_HOOK.
975 For SunOS executables, this first instruction is typically the
976 one at "_start", or a similar text label, regardless of whether
977 the executable is statically or dynamically linked. The runtime
978 startup code takes care of dynamically linking in any shared
979 libraries, once gdb allows the inferior to continue.
981 For SVR4 executables, this first instruction is either the first
982 instruction in the dynamic linker (for dynamically linked
983 executables) or the instruction at "start" for statically linked
984 executables. For dynamically linked executables, the system
985 first exec's /lib/libc.so.N, which contains the dynamic linker,
986 and starts it running. The dynamic linker maps in any needed
987 shared libraries, maps in the actual user executable, and then
988 jumps to "start" in the user executable.
990 For both SunOS shared libraries, and SVR4 shared libraries, we
991 can arrange to cooperate with the dynamic linker to discover the
992 names of shared libraries that are dynamically linked, and the
993 base addresses to which they are linked.
995 This function is responsible for discovering those names and
996 addresses, and saving sufficient information about them to allow
997 their symbols to be read at a later time.
1001 Between enable_break() and disable_break(), this code does not
1002 properly handle hitting breakpoints which the user might have
1003 set in the startup code or in the dynamic linker itself. Proper
1004 handling will probably have to wait until the implementation is
1005 changed to use the "breakpoint handler function" method.
1007 Also, what if child has exit()ed? Must exit loop somehow.
1011 solib_create_inferior_hook()
1013 if (!enable_break ())
1015 warning ("shared library handler failed to enable breakpoint");
1019 /* Now run the target. It will eventually hit the breakpoint, at
1020 which point all of the libraries will have been mapped in and we
1021 can go groveling around in the dynamic linker structures to find
1022 out what we need to know about them. */
1024 clear_proceed_status ();
1025 stop_soon_quietly
= 1;
1029 target_resume (-1, 0, stop_signal
);
1030 wait_for_inferior ();
1032 while (stop_signal
!= SIGTRAP
);
1033 stop_soon_quietly
= 0;
1035 /* We are now either at the "mapping complete" breakpoint (or somewhere
1036 else, a condition we aren't prepared to deal with anyway), so adjust
1037 the PC as necessary after a breakpoint, disable the breakpoint, and
1038 add any shared libraries that were mapped in. */
1040 if (DECR_PC_AFTER_BREAK
)
1042 stop_pc
-= DECR_PC_AFTER_BREAK
;
1043 write_register (PC_REGNUM
, stop_pc
);
1046 if (!disable_break ())
1048 warning ("shared library handler failed to disable breakpoint");
1051 solib_add ((char *) 0, 0, (struct target_ops
*) 0);
1058 sharedlibrary_command -- handle command to explicitly add library
1062 static void sharedlibrary_command (char *args, int from_tty)
1069 sharedlibrary_command (args
, from_tty
)
1074 solib_add (args
, from_tty
, (struct target_ops
*) 0);
1081 add_com ("sharedlibrary", class_files
, sharedlibrary_command
,
1082 "Load shared object library symbols for files matching REGEXP.");
1083 add_info ("sharedlibrary", info_sharedlibrary_command
,
1084 "Status of loaded shared object libraries.");