Subversion Repositories openrisc_2011-10-31

/* Definitions for symbol file management in GDB.

   Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,

   2002, 2003, 2004, 2007, 2008, 2009, 2010 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 3 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, see <http://www.gnu.org/licenses/>.  */

#if !defined (OBJFILES_H)

#define OBJFILES_H

#include "gdb_obstack.h"        /* For obstack internals.  */

#include "symfile.h"            /* For struct psymbol_allocation_list */

#include "progspace.h"

struct bcache;

struct htab;

struct symtab;

struct objfile_data;

/* 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 was to use the

   recorded entry point to set the entry-file's lowpc and 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.

   NOTE: cagney/2003-09-09: It turns out that this "traditional"

   method doesn't work.  Corinna writes: ``It turns out that the call

   to test for "inside entry file" destroys a meaningful backtrace

   under some conditions.  E. g. the backtrace tests in the asm-source

   testcase are broken for some targets.  In this test the functions

   are all implemented as part of one file and the testcase is not

   necessarily linked with a start file (depending on the target).

   What happens is, that the first frame is printed normaly and

   following frames are treated as being inside the enttry file then.

   This way, only the #0 frame is printed in the backtrace output.''

   Ref "frame.c" "NOTE: vinschen/2003-04-01".

   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

   DEPRECATED_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.  */

struct entry_info

  {

    /* The relocated value we should use for this objfile entry point.  */

    CORE_ADDR entry_point;

    /* Set to 1 iff ENTRY_POINT contains a valid value.  */

    unsigned entry_point_p : 1;

  };

/* Sections in an objfile.  The section offsets are stored in the

   OBJFILE.  */

struct obj_section

  {

    struct bfd_section *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;

  };

/* Relocation offset applied to S.  */

#define obj_section_offset(s)                                           \

  (((s)->objfile->section_offsets)->offsets[(s)->the_bfd_section->index])

/* The memory address of section S (vma + offset).  */

#define obj_section_addr(s)                                             \

  (bfd_get_section_vma ((s)->objfile->abfd, s->the_bfd_section)         \

   + obj_section_offset (s))

/* The one-passed-the-end memory address of section S

   (vma + size + offset).  */

#define obj_section_endaddr(s)                                          \

  (bfd_get_section_vma ((s)->objfile->abfd, s->the_bfd_section)         \

   + bfd_get_section_size ((s)->the_bfd_section)                        \

   + obj_section_offset (s))

/* 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 (void);

extern void print_symbol_bcache_statistics (void);

/* Number of entries in the minimal symbol hash table.  */

#define MINIMAL_SYMBOL_HASH_SIZE 2039

/* 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, tilde-expanded and absolute.

       Malloc'd; free it if you free this struct.  */

    char *name;

    /* Some flag bits for this objfile. */

    unsigned short flags;

    /* The program space associated with this objfile.  */

    struct program_space *pspace;

    /* 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;

    /* Map addresses to the entries of PSYMTABS.  It would be more efficient to

       have a map per the whole process but ADDRMAP cannot selectively remove

       its items during FREE_OBJFILE.  This mapping is already present even for

       PARTIAL_SYMTABs which still have no corresponding full SYMTABs read.  */

    struct addrmap *psymtabs_addrmap;

    /* 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 gdbarch associated with the BFD.  Note that this gdbarch is

       determined solely from BFD information, without looking at target

       information.  The gdbarch determined from a running target may

       differ from this e.g. with respect to register types and names.  */

    struct gdbarch *gdbarch;

    /* The modification timestamp of the object file, as of the last time

       we read its symbols.  */

    long mtime;

    /* Obstack to hold objects that should be freed when we load a new symbol

       table from this object file. */

    struct obstack objfile_obstack;

    /* A byte cache where we can stash arbitrary "chunks" of bytes that

       will not change. */

    struct bcache *psymbol_cache;       /* Byte cache for partial syms */

    struct bcache *macro_cache;          /* Byte cache for macros */

    struct bcache *filename_cache;       /* Byte cache for file names.  */

    /* Hash table for mapping symbol names to demangled names.  Each

       entry in the hash table is actually two consecutive strings,

       both null-terminated; the first one is a mangled or linkage

       name, and the second is the demangled name or just a zero byte

       if the name doesn't demangle.  */

    struct htab *demangled_names_hash;

    /* Vectors of all partial symbols read in from file.  The actual data

       is stored in the objfile_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 objfile_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];

    /* 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. */

    /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile

       data points implemented using "data" and "num_data" below.  For

       an example of how to use this replacement, see "objfile_data"

       in "mips-tdep.c".  */

    struct dbx_symfile_info *deprecated_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.  */

    /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile

       data points implemented using "data" and "num_data" below.  For

       an example of how to use this replacement, see "objfile_data"

       in "mips-tdep.c".  */

    void *deprecated_sym_private;

    /* Per objfile data-pointers required by other GDB modules.  */

    /* FIXME: kettenis/20030711: This mechanism could replace

       deprecated_sym_stab_info and deprecated_sym_private

       entirely.  */

    void **data;

    unsigned num_data;

    /* Set of relocation offsets to apply to each section.

       Currently on the objfile_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;

    /* Indexes in the section_offsets array. These are initialized by the

       *_symfile_offsets() family of functions (som_symfile_offsets,

       xcoff_symfile_offsets, default_symfile_offsets). In theory they

       should correspond to the section indexes used by bfd for the

       current objfile. The exception to this for the time being is the

       SOM version. */

    int sect_index_text;

    int sect_index_data;

    int sect_index_bss;

    int sect_index_rodata;

    /* 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

       objfile_obstack (which makes no sense, but I'm not sure it's

       harming anything).  */

    struct obj_section

     *sections, *sections_end;

    /* GDB allows to have debug symbols in separate object files.  This is

       used by .gnu_debuglink, ELF build id note and Mach-O OSO.

       Although this is a tree structure, GDB only support one level

       (ie a separate debug for a separate debug is not supported).  Note that

       separate debug object are in the main chain and therefore will be

       visited by ALL_OBJFILES & co iterators.  Separate debug objfile always

       has a non-nul separate_debug_objfile_backlink.  */

    /* Link to the first separate debug object, if any.  */

    struct objfile *separate_debug_objfile;

    /* If this is a separate debug object, this is used as a link to the

       actual executable objfile. */

    struct objfile *separate_debug_objfile_backlink;

    /* If this is a separate debug object, this is a link to the next one

       for the same executable objfile.  */

    struct objfile *separate_debug_objfile_link;

    /* Place to stash various statistics about this objfile */

      OBJSTATS;

    /* A symtab that the C++ code uses to stash special symbols

       associated to namespaces.  */

    /* FIXME/carlton-2003-06-27: Delete this in a few years once

       "possible namespace symbols" go away.  */

    struct symtab *cp_namespace_symtab;

  };

/* Defines for the objfile flag word. */

/* 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 << 0)        /* 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 << 1)        /* From a shared library */

/* User requested that this objfile be read in it's entirety. */

#define OBJF_READNOW    (1 << 2)        /* 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 << 3)        /* User loaded */

/* 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 objfile_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;

/* Declarations for functions defined in objfiles.c */

extern struct objfile *allocate_objfile (bfd *, int);

extern struct gdbarch *get_objfile_arch (struct objfile *);

extern void init_entry_point_info (struct objfile *);

extern int entry_point_address_query (CORE_ADDR *entry_p);

extern CORE_ADDR entry_point_address (void);

extern int build_objfile_section_table (struct objfile *);

extern void terminate_minimal_symbol_table (struct objfile *objfile);

extern struct objfile *objfile_separate_debug_iterate (const struct objfile *,

                                                       const struct objfile *);

extern void put_objfile_before (struct objfile *, struct objfile *);

extern void objfile_to_front (struct objfile *);

extern void add_separate_debug_objfile (struct objfile *, struct objfile *);

extern void unlink_objfile (struct objfile *);

extern void free_objfile (struct objfile *);

extern void free_objfile_separate_debug (struct objfile *);

extern struct cleanup *make_cleanup_free_objfile (struct objfile *);

extern void free_all_objfiles (void);

extern void objfile_relocate (struct objfile *, struct section_offsets *);

extern int objfile_has_partial_symbols (struct objfile *objfile);

extern int objfile_has_full_symbols (struct objfile *objfile);

extern int objfile_has_symbols (struct objfile *objfile);

extern int have_partial_symbols (void);

extern int have_full_symbols (void);

extern void objfiles_changed (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 (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 (void);

extern struct obj_section *find_pc_section (CORE_ADDR pc);

extern int in_plt_section (CORE_ADDR, char *);

/* Keep a registry of per-objfile data-pointers required by other GDB

   modules.  */

/* Allocate an entry in the per-objfile registry.  */

extern const struct objfile_data *register_objfile_data (void);

/* Allocate an entry in the per-objfile registry.

   SAVE and FREE are called when clearing objfile data.

   First all registered SAVE functions are called.

   Then all registered FREE functions are called.

   Either or both of SAVE, FREE may be NULL.  */

extern const struct objfile_data *register_objfile_data_with_cleanup

  (void (*save) (struct objfile *, void *),

   void (*free) (struct objfile *, void *));

extern void clear_objfile_data (struct objfile *objfile);

extern void set_objfile_data (struct objfile *objfile,

                              const struct objfile_data *data, void *value);

extern void *objfile_data (struct objfile *objfile,

                           const struct objfile_data *data);

extern struct bfd *gdb_bfd_ref (struct bfd *abfd);

extern void gdb_bfd_unref (struct bfd *abfd);

extern int gdb_bfd_close_or_warn (struct bfd *abfd);

/* Traverse all object files in the current program space.

   ALL_OBJFILES_SAFE works even if you delete the objfile during the

   traversal.  */

/* Traverse all object files in program space SS.  */

#define ALL_PSPACE_OBJFILES(ss, obj)                                    \

  for ((obj) = ss->objfiles; (obj) != NULL; (obj) = (obj)->next)        \

#define ALL_PSPACE_OBJFILES_SAFE(ss, obj, nxt)          \

  for ((obj) = ss->objfiles;                    \

       (obj) != NULL? ((nxt)=(obj)->next,1) :0;  \

       (obj) = (nxt))

#define ALL_OBJFILES(obj)                           \

  for ((obj) = current_program_space->objfiles; \

       (obj) != NULL;                               \

       (obj) = (obj)->next)

#define ALL_OBJFILES_SAFE(obj,nxt)                      \

  for ((obj) = current_program_space->objfiles; \

       (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 minimal symbols in one objfile.  */

#define ALL_OBJFILE_MSYMBOLS(objfile, m) \

    for ((m) = (objfile) -> msymbols; SYMBOL_LINKAGE_NAME(m) != NULL; (m)++)

/* Traverse all symtabs in all objfiles in the current symbol

   space.  */

#define ALL_SYMTABS(objfile, s) \

  ALL_OBJFILES (objfile)         \

    ALL_OBJFILE_SYMTABS (objfile, s)

#define ALL_PSPACE_SYMTABS(ss, objfile, s)              \

  ALL_PSPACE_OBJFILES (ss, objfile)                     \

    ALL_OBJFILE_SYMTABS (objfile, s)

/* Traverse all symtabs in all objfiles in the current program space,

   skipping included files (which share a blockvector with their

   primary symtab).  */

#define ALL_PRIMARY_SYMTABS(objfile, s) \

  ALL_OBJFILES (objfile)                \

    ALL_OBJFILE_SYMTABS (objfile, s)    \

      if ((s)->primary)

#define ALL_PSPACE_PRIMARY_SYMTABS(pspace, objfile, s)  \

  ALL_PSPACE_OBJFILES (ss, objfile)                     \

    ALL_OBJFILE_SYMTABS (objfile, s)                    \

      if ((s)->primary)

/* Traverse all minimal symbols in all objfiles in the current symbol

   space.  */

#define ALL_MSYMBOLS(objfile, m) \

  ALL_OBJFILES (objfile)         \

    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)

#define SECT_OFF_DATA(objfile) \

     ((objfile->sect_index_data == -1) \

      ? (internal_error (__FILE__, __LINE__, _("sect_index_data not initialized")), -1) \

      : objfile->sect_index_data)

#define SECT_OFF_RODATA(objfile) \

     ((objfile->sect_index_rodata == -1) \

      ? (internal_error (__FILE__, __LINE__, _("sect_index_rodata not initialized")), -1) \

      : objfile->sect_index_rodata)

#define SECT_OFF_TEXT(objfile) \

     ((objfile->sect_index_text == -1) \

      ? (internal_error (__FILE__, __LINE__, _("sect_index_text not initialized")), -1) \

      : objfile->sect_index_text)

/* Sometimes the .bss section is missing from the objfile, so we don't

   want to die here. Let the users of SECT_OFF_BSS deal with an

   uninitialized section index. */

#define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss

/* Answer whether there is more than one object file loaded.  */

#define MULTI_OBJFILE_P() (object_files && object_files->next)

#endif /* !defined (OBJFILES_H) */