588 lines
22 KiB
C
588 lines
22 KiB
C
/* Definitions for symbol file management in GDB.
|
|
Copyright (C) 1992, 1993, 1994, 1995, 1999 Free Software Foundation, Inc.
|
|
|
|
This file is part of GDB.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
#if !defined (OBJFILES_H)
|
|
#define OBJFILES_H
|
|
|
|
/* This structure maintains information on a per-objfile basis about the
|
|
"entry point" of the objfile, and the scope within which the entry point
|
|
exists. It is possible that gdb will see more than one objfile that is
|
|
executable, each with its own entry point.
|
|
|
|
For example, for dynamically linked executables in SVR4, the dynamic linker
|
|
code is contained within the shared C library, which is actually executable
|
|
and is run by the kernel first when an exec is done of a user executable
|
|
that is dynamically linked. The dynamic linker within the shared C library
|
|
then maps in the various program segments in the user executable and jumps
|
|
to the user executable's recorded entry point, as if the call had been made
|
|
directly by the kernel.
|
|
|
|
The traditional gdb method of using this info is to use the recorded entry
|
|
point to set the variables entry_file_lowpc and entry_file_highpc from
|
|
the debugging information, where these values are the starting address
|
|
(inclusive) and ending address (exclusive) of the instruction space in the
|
|
executable which correspond to the "startup file", I.E. crt0.o in most
|
|
cases. This file is assumed to be a startup file and frames with pc's
|
|
inside it are treated as nonexistent. Setting these variables is necessary
|
|
so that backtraces do not fly off the bottom of the stack.
|
|
|
|
Gdb also supports an alternate method to avoid running off the bottom
|
|
of the stack.
|
|
|
|
There are two frames that are "special", the frame for the function
|
|
containing the process entry point, since it has no predecessor frame,
|
|
and the frame for the function containing the user code entry point
|
|
(the main() function), since all the predecessor frames are for the
|
|
process startup code. Since we have no guarantee that the linked
|
|
in startup modules have any debugging information that gdb can use,
|
|
we need to avoid following frame pointers back into frames that might
|
|
have been built in the startup code, as we might get hopelessly
|
|
confused. However, we almost always have debugging information
|
|
available for main().
|
|
|
|
These variables are used to save the range of PC values which are valid
|
|
within the main() function and within the function containing the process
|
|
entry point. If we always consider the frame for main() as the outermost
|
|
frame when debugging user code, and the frame for the process entry
|
|
point function as the outermost frame when debugging startup code, then
|
|
all we have to do is have FRAME_CHAIN_VALID return false whenever a
|
|
frame's current PC is within the range specified by these variables.
|
|
In essence, we set "ceilings" in the frame chain beyond which we will
|
|
not proceed when following the frame chain back up the stack.
|
|
|
|
A nice side effect is that we can still debug startup code without
|
|
running off the end of the frame chain, assuming that we have usable
|
|
debugging information in the startup modules, and if we choose to not
|
|
use the block at main, or can't find it for some reason, everything
|
|
still works as before. And if we have no startup code debugging
|
|
information but we do have usable information for main(), backtraces
|
|
from user code don't go wandering off into the startup code.
|
|
|
|
To use this method, define your FRAME_CHAIN_VALID macro like:
|
|
|
|
#define FRAME_CHAIN_VALID(chain, thisframe) \
|
|
(chain != 0 \
|
|
&& !(inside_main_func ((thisframe)->pc)) \
|
|
&& !(inside_entry_func ((thisframe)->pc)))
|
|
|
|
and add initializations of the four scope controlling variables inside
|
|
the object file / debugging information processing modules. */
|
|
|
|
struct entry_info
|
|
{
|
|
|
|
/* The value we should use for this objects entry point.
|
|
The illegal/unknown value needs to be something other than 0, ~0
|
|
for instance, which is much less likely than 0. */
|
|
|
|
CORE_ADDR entry_point;
|
|
|
|
#define INVALID_ENTRY_POINT (~0) /* ~0 will not be in any file, we hope. */
|
|
|
|
/* Start (inclusive) and end (exclusive) of function containing the
|
|
entry point. */
|
|
|
|
CORE_ADDR entry_func_lowpc;
|
|
CORE_ADDR entry_func_highpc;
|
|
|
|
/* Start (inclusive) and end (exclusive) of object file containing the
|
|
entry point. */
|
|
|
|
CORE_ADDR entry_file_lowpc;
|
|
CORE_ADDR entry_file_highpc;
|
|
|
|
/* Start (inclusive) and end (exclusive) of the user code main() function. */
|
|
|
|
CORE_ADDR main_func_lowpc;
|
|
CORE_ADDR main_func_highpc;
|
|
|
|
/* Use these values when any of the above ranges is invalid. */
|
|
|
|
/* We use these values because it guarantees that there is no number that is
|
|
both >= LOWPC && < HIGHPC. It is also highly unlikely that 3 is a valid
|
|
module or function start address (as opposed to 0). */
|
|
|
|
#define INVALID_ENTRY_LOWPC (3)
|
|
#define INVALID_ENTRY_HIGHPC (1)
|
|
|
|
};
|
|
|
|
/* Sections in an objfile.
|
|
|
|
It is strange that we have both this notion of "sections"
|
|
and the one used by section_offsets. Section as used
|
|
here, (currently at least) means a BFD section, and the sections
|
|
are set up from the BFD sections in allocate_objfile.
|
|
|
|
The sections in section_offsets have their meaning determined by
|
|
the symbol format, and they are set up by the sym_offsets function
|
|
for that symbol file format.
|
|
|
|
I'm not sure this could or should be changed, however. */
|
|
|
|
struct obj_section
|
|
{
|
|
CORE_ADDR addr; /* lowest address in section */
|
|
CORE_ADDR endaddr; /* 1+highest address in section */
|
|
|
|
/* This field is being used for nefarious purposes by syms_from_objfile.
|
|
It is said to be redundant with section_offsets; it's not really being
|
|
used that way, however, it's some sort of hack I don't understand
|
|
and am not going to try to eliminate (yet, anyway). FIXME.
|
|
|
|
It was documented as "offset between (end)addr and actual memory
|
|
addresses", but that's not true; addr & endaddr are actual memory
|
|
addresses. */
|
|
CORE_ADDR offset;
|
|
|
|
sec_ptr the_bfd_section; /* BFD section pointer */
|
|
|
|
/* Objfile this section is part of. */
|
|
struct objfile *objfile;
|
|
|
|
/* True if this "overlay section" is mapped into an "overlay region". */
|
|
int ovly_mapped;
|
|
};
|
|
|
|
/* An import entry contains information about a symbol that
|
|
is used in this objfile but not defined in it, and so needs
|
|
to be imported from some other objfile */
|
|
/* Currently we just store the name; no attributes. 1997-08-05 */
|
|
typedef char *ImportEntry;
|
|
|
|
|
|
/* An export entry contains information about a symbol that
|
|
is defined in this objfile and available for use in other
|
|
objfiles */
|
|
typedef struct
|
|
{
|
|
char *name; /* name of exported symbol */
|
|
int address; /* offset subject to relocation */
|
|
/* Currently no other attributes 1997-08-05 */
|
|
}
|
|
ExportEntry;
|
|
|
|
|
|
/* The "objstats" structure provides a place for gdb to record some
|
|
interesting information about its internal state at runtime, on a
|
|
per objfile basis, such as information about the number of symbols
|
|
read, size of string table (if any), etc. */
|
|
|
|
struct objstats
|
|
{
|
|
int n_minsyms; /* Number of minimal symbols read */
|
|
int n_psyms; /* Number of partial symbols read */
|
|
int n_syms; /* Number of full symbols read */
|
|
int n_stabs; /* Number of ".stabs" read (if applicable) */
|
|
int n_types; /* Number of types */
|
|
int sz_strtab; /* Size of stringtable, (if applicable) */
|
|
};
|
|
|
|
#define OBJSTAT(objfile, expr) (objfile -> stats.expr)
|
|
#define OBJSTATS struct objstats stats
|
|
extern void print_objfile_statistics PARAMS ((void));
|
|
extern void print_symbol_bcache_statistics PARAMS ((void));
|
|
|
|
/* Number of entries in the minimal symbol hash table. */
|
|
#define MINIMAL_SYMBOL_HASH_SIZE 349
|
|
|
|
/* Master structure for keeping track of each file from which
|
|
gdb reads symbols. There are several ways these get allocated: 1.
|
|
The main symbol file, symfile_objfile, set by the symbol-file command,
|
|
2. Additional symbol files added by the add-symbol-file command,
|
|
3. Shared library objfiles, added by ADD_SOLIB, 4. symbol files
|
|
for modules that were loaded when GDB attached to a remote system
|
|
(see remote-vx.c). */
|
|
|
|
struct objfile
|
|
{
|
|
|
|
/* All struct objfile's are chained together by their next pointers.
|
|
The global variable "object_files" points to the first link in this
|
|
chain.
|
|
|
|
FIXME: There is a problem here if the objfile is reusable, and if
|
|
multiple users are to be supported. The problem is that the objfile
|
|
list is linked through a member of the objfile struct itself, which
|
|
is only valid for one gdb process. The list implementation needs to
|
|
be changed to something like:
|
|
|
|
struct list {struct list *next; struct objfile *objfile};
|
|
|
|
where the list structure is completely maintained separately within
|
|
each gdb process. */
|
|
|
|
struct objfile *next;
|
|
|
|
/* The object file's name. Malloc'd; free it if you free this struct. */
|
|
|
|
char *name;
|
|
|
|
/* Some flag bits for this objfile. */
|
|
|
|
unsigned short flags;
|
|
|
|
/* Each objfile points to a linked list of symtabs derived from this file,
|
|
one symtab structure for each compilation unit (source file). Each link
|
|
in the symtab list contains a backpointer to this objfile. */
|
|
|
|
struct symtab *symtabs;
|
|
|
|
/* Each objfile points to a linked list of partial symtabs derived from
|
|
this file, one partial symtab structure for each compilation unit
|
|
(source file). */
|
|
|
|
struct partial_symtab *psymtabs;
|
|
|
|
/* List of freed partial symtabs, available for re-use */
|
|
|
|
struct partial_symtab *free_psymtabs;
|
|
|
|
/* The object file's BFD. Can be null if the objfile contains only
|
|
minimal symbols, e.g. the run time common symbols for SunOS4. */
|
|
|
|
bfd *obfd;
|
|
|
|
/* The modification timestamp of the object file, as of the last time
|
|
we read its symbols. */
|
|
|
|
long mtime;
|
|
|
|
/* Obstacks to hold objects that should be freed when we load a new symbol
|
|
table from this object file. */
|
|
|
|
struct obstack psymbol_obstack; /* Partial symbols */
|
|
struct obstack symbol_obstack; /* Full symbols */
|
|
struct obstack type_obstack; /* Types */
|
|
|
|
/* A byte cache where we can stash arbitrary "chunks" of bytes that
|
|
will not change. */
|
|
|
|
struct bcache psymbol_cache; /* Byte cache for partial syms */
|
|
|
|
/* Vectors of all partial symbols read in from file. The actual data
|
|
is stored in the psymbol_obstack. */
|
|
|
|
struct psymbol_allocation_list global_psymbols;
|
|
struct psymbol_allocation_list static_psymbols;
|
|
|
|
/* Each file contains a pointer to an array of minimal symbols for all
|
|
global symbols that are defined within the file. The array is terminated
|
|
by a "null symbol", one that has a NULL pointer for the name and a zero
|
|
value for the address. This makes it easy to walk through the array
|
|
when passed a pointer to somewhere in the middle of it. There is also
|
|
a count of the number of symbols, which does not include the terminating
|
|
null symbol. The array itself, as well as all the data that it points
|
|
to, should be allocated on the symbol_obstack for this file. */
|
|
|
|
struct minimal_symbol *msymbols;
|
|
int minimal_symbol_count;
|
|
|
|
/* This is a hash table used to index the minimal symbols by name. */
|
|
|
|
struct minimal_symbol *msymbol_hash[MINIMAL_SYMBOL_HASH_SIZE];
|
|
|
|
/* This hash table is used to index the minimal symbols by their
|
|
demangled names. */
|
|
|
|
struct minimal_symbol *msymbol_demangled_hash[MINIMAL_SYMBOL_HASH_SIZE];
|
|
|
|
/* For object file formats which don't specify fundamental types, gdb
|
|
can create such types. For now, it maintains a vector of pointers
|
|
to these internally created fundamental types on a per objfile basis,
|
|
however it really should ultimately keep them on a per-compilation-unit
|
|
basis, to account for linkage-units that consist of a number of
|
|
compilation units that may have different fundamental types, such as
|
|
linking C modules with ADA modules, or linking C modules that are
|
|
compiled with 32-bit ints with C modules that are compiled with 64-bit
|
|
ints (not inherently evil with a smarter linker). */
|
|
|
|
struct type **fundamental_types;
|
|
|
|
/* The mmalloc() malloc-descriptor for this objfile if we are using
|
|
the memory mapped malloc() package to manage storage for this objfile's
|
|
data. NULL if we are not. */
|
|
|
|
PTR md;
|
|
|
|
/* The file descriptor that was used to obtain the mmalloc descriptor
|
|
for this objfile. If we call mmalloc_detach with the malloc descriptor
|
|
we should then close this file descriptor. */
|
|
|
|
int mmfd;
|
|
|
|
/* Structure which keeps track of functions that manipulate objfile's
|
|
of the same type as this objfile. I.E. the function to read partial
|
|
symbols for example. Note that this structure is in statically
|
|
allocated memory, and is shared by all objfiles that use the
|
|
object module reader of this type. */
|
|
|
|
struct sym_fns *sf;
|
|
|
|
/* The per-objfile information about the entry point, the scope (file/func)
|
|
containing the entry point, and the scope of the user's main() func. */
|
|
|
|
struct entry_info ei;
|
|
|
|
/* Information about stabs. Will be filled in with a dbx_symfile_info
|
|
struct by those readers that need it. */
|
|
|
|
struct dbx_symfile_info *sym_stab_info;
|
|
|
|
/* Hook for information for use by the symbol reader (currently used
|
|
for information shared by sym_init and sym_read). It is
|
|
typically a pointer to malloc'd memory. The symbol reader's finish
|
|
function is responsible for freeing the memory thusly allocated. */
|
|
|
|
PTR sym_private;
|
|
|
|
/* Hook for target-architecture-specific information. This must
|
|
point to memory allocated on one of the obstacks in this objfile,
|
|
so that it gets freed automatically when reading a new object
|
|
file. */
|
|
|
|
PTR obj_private;
|
|
|
|
/* Set of relocation offsets to apply to each section.
|
|
Currently on the psymbol_obstack (which makes no sense, but I'm
|
|
not sure it's harming anything).
|
|
|
|
These offsets indicate that all symbols (including partial and
|
|
minimal symbols) which have been read have been relocated by this
|
|
much. Symbols which are yet to be read need to be relocated by
|
|
it. */
|
|
|
|
struct section_offsets *section_offsets;
|
|
int num_sections;
|
|
|
|
/* These pointers are used to locate the section table, which
|
|
among other things, is used to map pc addresses into sections.
|
|
SECTIONS points to the first entry in the table, and
|
|
SECTIONS_END points to the first location past the last entry
|
|
in the table. Currently the table is stored on the
|
|
psymbol_obstack (which makes no sense, but I'm not sure it's
|
|
harming anything). */
|
|
|
|
struct obj_section
|
|
*sections, *sections_end;
|
|
|
|
/* two auxiliary fields, used to hold the fp of separate symbol files */
|
|
FILE *auxf1, *auxf2;
|
|
|
|
/* Imported symbols */
|
|
ImportEntry *import_list;
|
|
int import_list_size;
|
|
|
|
/* Exported symbols */
|
|
ExportEntry *export_list;
|
|
int export_list_size;
|
|
|
|
/* Place to stash various statistics about this objfile */
|
|
OBJSTATS;
|
|
};
|
|
|
|
/* Defines for the objfile flag word. */
|
|
|
|
/* Gdb can arrange to allocate storage for all objects related to a
|
|
particular objfile in a designated section of its address space,
|
|
managed at a low level by mmap() and using a special version of
|
|
malloc that handles malloc/free/realloc on top of the mmap() interface.
|
|
This allows the "internal gdb state" for a particular objfile to be
|
|
dumped to a gdb state file and subsequently reloaded at a later time. */
|
|
|
|
#define OBJF_MAPPED (1 << 0) /* Objfile data is mmap'd */
|
|
|
|
/* When using mapped/remapped predigested gdb symbol information, we need
|
|
a flag that indicates that we have previously done an initial symbol
|
|
table read from this particular objfile. We can't just look for the
|
|
absence of any of the three symbol tables (msymbols, psymtab, symtab)
|
|
because if the file has no symbols for example, none of these will
|
|
exist. */
|
|
|
|
#define OBJF_SYMS (1 << 1) /* Have tried to read symbols */
|
|
|
|
/* When an object file has its functions reordered (currently Irix-5.2
|
|
shared libraries exhibit this behaviour), we will need an expensive
|
|
algorithm to locate a partial symtab or symtab via an address.
|
|
To avoid this penalty for normal object files, we use this flag,
|
|
whose setting is determined upon symbol table read in. */
|
|
|
|
#define OBJF_REORDERED (1 << 2) /* Functions are reordered */
|
|
|
|
/* Distinguish between an objfile for a shared library and a "vanilla"
|
|
objfile. (If not set, the objfile may still actually be a solib.
|
|
This can happen if the user created the objfile by using the
|
|
add-symbol-file command. GDB doesn't in that situation actually
|
|
check whether the file is a solib. Rather, the target's
|
|
implementation of the solib interface is responsible for setting
|
|
this flag when noticing solibs used by an inferior.) */
|
|
|
|
#define OBJF_SHARED (1 << 3) /* From a shared library */
|
|
|
|
/* User requested that this objfile be read in it's entirety. */
|
|
|
|
#define OBJF_READNOW (1 << 4) /* Immediate full read */
|
|
|
|
/* This objfile was created because the user explicitly caused it
|
|
(e.g., used the add-symbol-file command). This bit offers a way
|
|
for run_command to remove old objfile entries which are no longer
|
|
valid (i.e., are associated with an old inferior), but to preserve
|
|
ones that the user explicitly loaded via the add-symbol-file
|
|
command. */
|
|
|
|
#define OBJF_USERLOADED (1 << 5) /* User loaded */
|
|
|
|
/* The object file that the main symbol table was loaded from (e.g. the
|
|
argument to the "symbol-file" or "file" command). */
|
|
|
|
extern struct objfile *symfile_objfile;
|
|
|
|
/* The object file that contains the runtime common minimal symbols
|
|
for SunOS4. Note that this objfile has no associated BFD. */
|
|
|
|
extern struct objfile *rt_common_objfile;
|
|
|
|
/* When we need to allocate a new type, we need to know which type_obstack
|
|
to allocate the type on, since there is one for each objfile. The places
|
|
where types are allocated are deeply buried in function call hierarchies
|
|
which know nothing about objfiles, so rather than trying to pass a
|
|
particular objfile down to them, we just do an end run around them and
|
|
set current_objfile to be whatever objfile we expect to be using at the
|
|
time types are being allocated. For instance, when we start reading
|
|
symbols for a particular objfile, we set current_objfile to point to that
|
|
objfile, and when we are done, we set it back to NULL, to ensure that we
|
|
never put a type someplace other than where we are expecting to put it.
|
|
FIXME: Maybe we should review the entire type handling system and
|
|
see if there is a better way to avoid this problem. */
|
|
|
|
extern struct objfile *current_objfile;
|
|
|
|
/* All known objfiles are kept in a linked list. This points to the
|
|
root of this list. */
|
|
|
|
extern struct objfile *object_files;
|
|
|
|
/* Declarations for functions defined in objfiles.c */
|
|
|
|
extern struct objfile *
|
|
allocate_objfile PARAMS ((bfd *, int));
|
|
|
|
extern int
|
|
build_objfile_section_table PARAMS ((struct objfile *));
|
|
|
|
extern void objfile_to_front PARAMS ((struct objfile *));
|
|
|
|
extern void
|
|
unlink_objfile PARAMS ((struct objfile *));
|
|
|
|
extern void
|
|
free_objfile PARAMS ((struct objfile *));
|
|
|
|
extern void
|
|
free_all_objfiles PARAMS ((void));
|
|
|
|
extern void
|
|
objfile_relocate PARAMS ((struct objfile *, struct section_offsets *));
|
|
|
|
extern int
|
|
have_partial_symbols PARAMS ((void));
|
|
|
|
extern int
|
|
have_full_symbols PARAMS ((void));
|
|
|
|
/* This operation deletes all objfile entries that represent solibs that
|
|
weren't explicitly loaded by the user, via e.g., the add-symbol-file
|
|
command.
|
|
*/
|
|
extern void
|
|
objfile_purge_solibs PARAMS ((void));
|
|
|
|
/* Functions for dealing with the minimal symbol table, really a misc
|
|
address<->symbol mapping for things we don't have debug symbols for. */
|
|
|
|
extern int
|
|
have_minimal_symbols PARAMS ((void));
|
|
|
|
extern struct obj_section *
|
|
find_pc_section PARAMS ((CORE_ADDR pc));
|
|
|
|
extern struct obj_section *
|
|
find_pc_sect_section PARAMS ((CORE_ADDR pc, asection * section));
|
|
|
|
extern int
|
|
in_plt_section PARAMS ((CORE_ADDR, char *));
|
|
|
|
extern int
|
|
is_in_import_list PARAMS ((char *, struct objfile *));
|
|
|
|
/* Traverse all object files. ALL_OBJFILES_SAFE works even if you delete
|
|
the objfile during the traversal. */
|
|
|
|
#define ALL_OBJFILES(obj) \
|
|
for ((obj) = object_files; (obj) != NULL; (obj) = (obj)->next)
|
|
|
|
#define ALL_OBJFILES_SAFE(obj,nxt) \
|
|
for ((obj) = object_files; \
|
|
(obj) != NULL? ((nxt)=(obj)->next,1) :0; \
|
|
(obj) = (nxt))
|
|
|
|
/* Traverse all symtabs in one objfile. */
|
|
|
|
#define ALL_OBJFILE_SYMTABS(objfile, s) \
|
|
for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next)
|
|
|
|
/* Traverse all psymtabs in one objfile. */
|
|
|
|
#define ALL_OBJFILE_PSYMTABS(objfile, p) \
|
|
for ((p) = (objfile) -> psymtabs; (p) != NULL; (p) = (p) -> next)
|
|
|
|
/* Traverse all minimal symbols in one objfile. */
|
|
|
|
#define ALL_OBJFILE_MSYMBOLS(objfile, m) \
|
|
for ((m) = (objfile) -> msymbols; SYMBOL_NAME(m) != NULL; (m)++)
|
|
|
|
/* Traverse all symtabs in all objfiles. */
|
|
|
|
#define ALL_SYMTABS(objfile, s) \
|
|
ALL_OBJFILES (objfile) \
|
|
ALL_OBJFILE_SYMTABS (objfile, s)
|
|
|
|
/* Traverse all psymtabs in all objfiles. */
|
|
|
|
#define ALL_PSYMTABS(objfile, p) \
|
|
ALL_OBJFILES (objfile) \
|
|
ALL_OBJFILE_PSYMTABS (objfile, p)
|
|
|
|
/* Traverse all minimal symbols in all objfiles. */
|
|
|
|
#define ALL_MSYMBOLS(objfile, m) \
|
|
ALL_OBJFILES (objfile) \
|
|
if ((objfile)->msymbols) \
|
|
ALL_OBJFILE_MSYMBOLS (objfile, m)
|
|
|
|
#define ALL_OBJFILE_OSECTIONS(objfile, osect) \
|
|
for (osect = objfile->sections; osect < objfile->sections_end; osect++)
|
|
|
|
#define ALL_OBJSECTIONS(objfile, osect) \
|
|
ALL_OBJFILES (objfile) \
|
|
ALL_OBJFILE_OSECTIONS (objfile, osect)
|
|
|
|
#endif /* !defined (OBJFILES_H) */
|