/* Generic symbol file reading for the GNU debugger, GDB. Copyright 1990, 1991, 1992 Free Software Foundation, Inc. Contributed by Cygnus Support, using pieces from other GDB modules. 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "defs.h" #include "symtab.h" #include "gdbtypes.h" #include "gdbcore.h" #include "frame.h" #include "target.h" #include "value.h" #include "symfile.h" #include "objfiles.h" #include "gdbcmd.h" #include "breakpoint.h" #include #include #include #include #include #include /* Global variables owned by this file */ int readnow_symbol_files; /* Read full symbols immediately */ /* External variables and functions referenced. */ extern int info_verbose; /* Functions this file defines */ static void load_command PARAMS ((char *, int)); static void add_symbol_file_command PARAMS ((char *, int)); static void cashier_psymtab PARAMS ((struct partial_symtab *)); static int compare_psymbols PARAMS ((const void *, const void *)); static int compare_symbols PARAMS ((const void *, const void *)); static bfd * symfile_bfd_open PARAMS ((char *)); static void find_sym_fns PARAMS ((struct objfile *)); static void clear_symtab_users_once PARAMS ((void)); /* List of all available sym_fns. On gdb startup, each object file reader calls add_symtab_fns() to register information on each format it is prepared to read. */ static struct sym_fns *symtab_fns = NULL; /* Structures with which to manage partial symbol allocation. */ struct psymbol_allocation_list global_psymbols = {0}, static_psymbols = {0}; /* Flag for whether user will be reloading symbols multiple times. Defaults to ON for VxWorks, otherwise OFF. */ #ifdef SYMBOL_RELOADING_DEFAULT int symbol_reloading = SYMBOL_RELOADING_DEFAULT; #else int symbol_reloading = 0; #endif /* Structure to manage complaints about symbol file contents. */ struct complaint complaint_root[1] = { {(char *) 0, 0, complaint_root}, }; /* Some actual complaints. */ struct complaint oldsyms_complaint = { "Replacing old symbols for `%s'", 0, 0 }; struct complaint empty_symtab_complaint = { "Empty symbol table found for `%s'", 0, 0 }; /* In the following sort, we always make sure that register debug symbol declarations always come before regular debug symbol declarations (as might happen when parameters are then put into registers by the compiler). Since this function is called from within qsort, in an ANSI environment it must conform to the prototype for qsort, which specifies that the comparison function takes two "void *" pointers. */ static int compare_symbols (s1p, s2p) const PTR s1p; const PTR s2p; { register struct symbol **s1, **s2; register int namediff; s1 = (struct symbol **) s1p; s2 = (struct symbol **) s2p; /* Compare the initial characters. */ namediff = SYMBOL_NAME (*s1)[0] - SYMBOL_NAME (*s2)[0]; if (namediff != 0) return namediff; /* If they match, compare the rest of the names. */ namediff = strcmp (SYMBOL_NAME (*s1), SYMBOL_NAME (*s2)); if (namediff != 0) return namediff; /* For symbols of the same name, registers should come first. */ return ((SYMBOL_CLASS (*s2) == LOC_REGISTER) - (SYMBOL_CLASS (*s1) == LOC_REGISTER)); } /* LOCAL FUNCTION compare_psymbols -- compare two partial symbols by name DESCRIPTION Given pointer to two partial symbol table entries, compare them by name and return -N, 0, or +N (ala strcmp). Typically used by sorting routines like qsort(). NOTES Does direct compare of first two characters before punting and passing to strcmp for longer compares. Note that the original version had a bug whereby two null strings or two identically named one character strings would return the comparison of memory following the null byte. */ static int compare_psymbols (s1p, s2p) const PTR s1p; const PTR s2p; { register char *st1 = SYMBOL_NAME ((struct partial_symbol *) s1p); register char *st2 = SYMBOL_NAME ((struct partial_symbol *) s2p); if ((st1[0] - st2[0]) || !st1[0]) { return (st1[0] - st2[0]); } else if ((st1[1] - st2[1]) || !st1[1]) { return (st1[1] - st2[1]); } else { return (strcmp (st1 + 2, st2 + 2)); } } void sort_pst_symbols (pst) struct partial_symtab *pst; { /* Sort the global list; don't sort the static list */ qsort (pst -> objfile -> global_psymbols.list + pst -> globals_offset, pst -> n_global_syms, sizeof (struct partial_symbol), compare_psymbols); } /* Call sort_block_syms to sort alphabetically the symbols of one block. */ void sort_block_syms (b) register struct block *b; { qsort (&BLOCK_SYM (b, 0), BLOCK_NSYMS (b), sizeof (struct symbol *), compare_symbols); } /* Call sort_symtab_syms to sort alphabetically the symbols of each block of one symtab. */ void sort_symtab_syms (s) register struct symtab *s; { register struct blockvector *bv; int nbl; int i; register struct block *b; if (s == 0) return; bv = BLOCKVECTOR (s); nbl = BLOCKVECTOR_NBLOCKS (bv); for (i = 0; i < nbl; i++) { b = BLOCKVECTOR_BLOCK (bv, i); if (BLOCK_SHOULD_SORT (b)) sort_block_syms (b); } } void sort_all_symtab_syms () { register struct symtab *s; register struct objfile *objfile; for (objfile = object_files; objfile != NULL; objfile = objfile -> next) { for (s = objfile -> symtabs; s != NULL; s = s -> next) { sort_symtab_syms (s); } } } /* Make a copy of the string at PTR with SIZE characters in the symbol obstack (and add a null character at the end in the copy). Returns the address of the copy. */ char * obsavestring (ptr, size, obstackp) char *ptr; int size; struct obstack *obstackp; { register char *p = (char *) obstack_alloc (obstackp, size + 1); /* Open-coded bcopy--saves function call time. These strings are usually short. */ { register char *p1 = ptr; register char *p2 = p; char *end = ptr + size; while (p1 != end) *p2++ = *p1++; } p[size] = 0; return p; } /* Concatenate strings S1, S2 and S3; return the new string. Space is found in the symbol_obstack. */ char * obconcat (obstackp, s1, s2, s3) struct obstack *obstackp; const char *s1, *s2, *s3; { register int len = strlen (s1) + strlen (s2) + strlen (s3) + 1; register char *val = (char *) obstack_alloc (obstackp, len); strcpy (val, s1); strcat (val, s2); strcat (val, s3); return val; } /* Get the symbol table that corresponds to a partial_symtab. This is fast after the first time you do it. In fact, there is an even faster macro PSYMTAB_TO_SYMTAB that does the fast case inline. */ struct symtab * psymtab_to_symtab (pst) register struct partial_symtab *pst; { /* If it's been looked up before, return it. */ if (pst->symtab) return pst->symtab; /* If it has not yet been read in, read it. */ if (!pst->readin) { (*pst->read_symtab) (pst); } return pst->symtab; } /* Initialize entry point information for this objfile. */ void init_entry_point_info (objfile) struct objfile *objfile; { /* Save startup file's range of PC addresses to help blockframe.c decide where the bottom of the stack is. */ if (bfd_get_file_flags (objfile -> obfd) & EXEC_P) { /* Executable file -- record its entry point so we'll recognize the startup file because it contains the entry point. */ objfile -> ei.entry_point = bfd_get_start_address (objfile -> obfd); } else { /* Examination of non-executable.o files. Short-circuit this stuff. */ /* ~0 will not be in any file, we hope. */ objfile -> ei.entry_point = ~0; /* set the startup file to be an empty range. */ objfile -> ei.entry_file_lowpc = 0; objfile -> ei.entry_file_highpc = 0; } } /* Process a symbol file, as either the main file or as a dynamically loaded file. NAME is the file name (which will be tilde-expanded and made absolute herein) (but we don't free or modify NAME itself). FROM_TTY says how verbose to be. MAINLINE specifies whether this is the main symbol file, or whether it's an extra symbol file such as dynamically loaded code. If !mainline, ADDR is the address where the text segment was loaded. If VERBO, the caller has printed a verbose message about the symbol reading (and complaints can be more terse about it). */ void syms_from_objfile (objfile, addr, mainline, verbo) struct objfile *objfile; CORE_ADDR addr; int mainline; int verbo; { asection *text_sect; /* There is a distinction between having no symbol table (we refuse to read the file, leaving the old set of symbols around) and having no debugging symbols in your symbol table (we read the file and end up with a mostly empty symbol table). FIXME: This strategy works correctly when the debugging symbols are intermixed with "normal" symbols. However, when the debugging symbols are separate, such as with ELF/DWARF, it is perfectly plausible for the symbol table to be missing but still have all the DWARF info intact. Thus in general it is wrong to assume that having no symbol table implies no debugging information. */ if (!(bfd_get_file_flags (objfile -> obfd) & HAS_SYMS)) return; init_entry_point_info (objfile); find_sym_fns (objfile); if (mainline) { /* Since no error yet, throw away the old symbol table. */ if (symfile_objfile != NULL) { free_objfile (symfile_objfile); symfile_objfile = NULL; } (*objfile -> sf -> sym_new_init) (objfile); /* For mainline, caller didn't know the specified address of the text section. We fix that here. */ text_sect = bfd_get_section_by_name (objfile -> obfd, ".text"); addr = bfd_section_vma (objfile -> obfd, text_sect); } /* Initialize symbol reading routines for this objfile, allow complaints to appear for this new file, and record how verbose to be, then do the initial symbol reading for this file. */ (*objfile -> sf -> sym_init) (objfile); clear_complaints (1, verbo); (*objfile -> sf -> sym_read) (objfile, addr, mainline); /* Don't allow char * to have a typename (else would get caddr_t.) */ /* Ditto void *. FIXME should do this for all the builtin types. */ TYPE_NAME (lookup_pointer_type (builtin_type_char)) = 0; TYPE_NAME (lookup_pointer_type (builtin_type_void)) = 0; if (mainline) { /* OK, make it the "real" symbol file. */ symfile_objfile = objfile; } /* If we have wiped out any old symbol tables, clean up. */ clear_symtab_users_once (); /* We're done reading the symbol file; finish off complaints. */ clear_complaints (0, verbo); /* Fixup all the breakpoints that may have been redefined by this symbol file. */ breakpoint_re_set (); } /* Process a symbol file, as either the main file or as a dynamically loaded file. NAME is the file name (which will be tilde-expanded and made absolute herein) (but we don't free or modify NAME itself). FROM_TTY says how verbose to be. MAINLINE specifies whether this is the main symbol file, or whether it's an extra symbol file such as dynamically loaded code. If !mainline, ADDR is the address where the text segment was loaded. Upon success, returns a pointer to the objfile that was added. Upon failure, jumps back to command level (never returns). */ struct objfile * symbol_file_add (name, from_tty, addr, mainline, mapped, readnow) char *name; int from_tty; CORE_ADDR addr; int mainline; int mapped; int readnow; { struct objfile *objfile; struct partial_symtab *psymtab; bfd *abfd; /* Open a bfd for the file and then check to see if the file has a symbol table. There is a distinction between having no symbol table (we refuse to read the file, leaving the old set of symbols around) and having no debugging symbols in the symbol table (we read the file and end up with a mostly empty symbol table, but with lots of stuff in the minimal symbol table). We need to make the decision about whether to continue with the file before allocating and building a objfile. FIXME: This strategy works correctly when the debugging symbols are intermixed with "normal" symbols. However, when the debugging symbols are separate, such as with ELF/DWARF, it is perfectly plausible for the symbol table to be missing but still have all the DWARF info intact. Thus in general it is wrong to assume that having no symbol table implies no debugging information. */ abfd = symfile_bfd_open (name); if (!(bfd_get_file_flags (abfd) & HAS_SYMS)) { error ("%s has no symbol-table", name); } if ((have_full_symbols () || have_partial_symbols ()) && mainline && from_tty && !query ("Load new symbol table from \"%s\"? ", name)) error ("Not confirmed."); objfile = allocate_objfile (abfd, mapped); /* If the objfile uses a mapped symbol file, and we have a psymtab for it, then skip reading any symbols at this time. */ if ((objfile -> flags & OBJF_MAPPED) && (objfile -> flags & OBJF_SYMS)) { /* We mapped in an existing symbol table file that already has had initial symbol reading performed, so we can skip that part. Notify the user that instead of reading the symbols, they have been mapped. */ if (from_tty || info_verbose) { printf_filtered ("Mapped symbols for %s...", name); wrap_here (""); fflush (stdout); } } else { /* We either created a new mapped symbol table, mapped an existing symbol table file which has not had initial symbol reading performed, or need to read an unmapped symbol table. */ if (from_tty || info_verbose) { printf_filtered ("Reading symbols from %s...", name); wrap_here (""); fflush (stdout); } syms_from_objfile (objfile, addr, mainline, from_tty); objfile -> flags |= OBJF_SYMS; } /* We now have at least a partial symbol table. Check to see if the user requested that all symbols be read on initial access via either the gdb startup command line or on a per symbol file basis. Expand all partial symbol tables for this objfile if so. */ if (readnow || readnow_symbol_files) { if (from_tty || info_verbose) { printf_filtered ("expanding to full symbols..."); wrap_here (""); fflush (stdout); } for (psymtab = objfile -> psymtabs; psymtab != NULL; psymtab = psymtab -> next) { (void) psymtab_to_symtab (psymtab); } } if (from_tty || info_verbose) { printf_filtered ("done.\n"); fflush (stdout); } return (objfile); } /* This is the symbol-file command. Read the file, analyze its symbols, and add a struct symtab to a symtab list. */ void symbol_file_command (args, from_tty) char *args; int from_tty; { char **argv; char *name = NULL; struct cleanup *cleanups; int mapped = 0; int readnow = 0; dont_repeat (); if (args == NULL) { if ((have_full_symbols () || have_partial_symbols ()) && from_tty && !query ("Discard symbol table from `%s'? ", symfile_objfile -> name)) error ("Not confirmed."); free_all_objfiles (); symfile_objfile = NULL; } else { if ((argv = buildargv (args)) == NULL) { nomem (0); } cleanups = make_cleanup (freeargv, (char *) argv); while (*argv != NULL) { if (strcmp (*argv, "-mapped") == 0) { mapped = 1; } else if (strcmp (*argv, "-readnow") == 0) { readnow = 1; } else if (**argv == '-') { error ("unknown option `%s'", *argv); } else { name = *argv; } argv++; } if (name == NULL) { error ("no symbol file name was specified"); } else { /* Getting new symbols may change our opinion about what is frameless. */ reinit_frame_cache (); (void) symbol_file_add (name, from_tty, (CORE_ADDR)0, 1, mapped, readnow); } do_cleanups (cleanups); } } /* Open file specified by NAME and hand it off to BFD for preliminary analysis. Result is a newly initialized bfd *, which includes a newly malloc'd` copy of NAME (tilde-expanded and made absolute). In case of trouble, error() is called. */ static bfd * symfile_bfd_open (name) char *name; { bfd *sym_bfd; int desc; char *absolute_name; name = tilde_expand (name); /* Returns 1st new malloc'd copy */ /* Look down path for it, allocate 2nd new malloc'd copy. */ desc = openp (getenv ("PATH"), 1, name, O_RDONLY, 0, &absolute_name); if (desc < 0) { make_cleanup (free, name); perror_with_name (name); } free (name); /* Free 1st new malloc'd copy */ name = absolute_name; /* Keep 2nd malloc'd copy in bfd */ sym_bfd = bfd_fdopenr (name, NULL, desc); if (!sym_bfd) { close (desc); make_cleanup (free, name); error ("\"%s\": can't open to read symbols: %s.", name, bfd_errmsg (bfd_error)); } if (!bfd_check_format (sym_bfd, bfd_object)) { bfd_close (sym_bfd); /* This also closes desc */ make_cleanup (free, name); error ("\"%s\": can't read symbols: %s.", name, bfd_errmsg (bfd_error)); } return (sym_bfd); } /* Link a new symtab_fns into the global symtab_fns list. Called on gdb startup by the _initialize routine in each object file format reader, to register information about each format the the reader is prepared to handle. */ void add_symtab_fns (sf) struct sym_fns *sf; { sf->next = symtab_fns; symtab_fns = sf; } /* Initialize to read symbols from the symbol file sym_bfd. It either returns or calls error(). The result is an initialized struct sym_fns in the objfile structure, that contains cached information about the symbol file. */ static void find_sym_fns (objfile) struct objfile *objfile; { struct sym_fns *sf; for (sf = symtab_fns; sf != NULL; sf = sf -> next) { if (strncmp (bfd_get_target (objfile -> obfd), sf -> sym_name, sf -> sym_namelen) == 0) { objfile -> sf = sf; return; } } error ("I'm sorry, Dave, I can't do that. Symbol format `%s' unknown.", bfd_get_target (objfile -> obfd)); } /* This function runs the load command of our current target. */ static void load_command (arg, from_tty) char *arg; int from_tty; { target_load (arg, from_tty); } /* This function allows the addition of incrementally linked object files. It does not modify any state in the target, only in the debugger. */ /* ARGSUSED */ static void add_symbol_file_command (args, from_tty) char *args; int from_tty; { char *name = NULL; CORE_ADDR text_addr; char *arg; int readnow = 0; int mapped = 0; dont_repeat (); if (args == NULL) { error ("add-symbol-file takes a file name and an address"); } /* Make a copy of the string that we can safely write into. */ args = strdup (args); make_cleanup (free, args); /* Pick off any -option args and the file name. */ while ((*args != '\000') && (name == NULL)) { while (isspace (*args)) {args++;} arg = args; while ((*args != '\000') && !isspace (*args)) {args++;} if (*args != '\000') { *args++ = '\000'; } if (*arg != '-') { name = arg; } else if (strcmp (arg, "-mapped") == 0) { mapped = 1; } else if (strcmp (arg, "-readnow") == 0) { readnow = 1; } else { error ("unknown option `%s'", arg); } } /* After picking off any options and the file name, args should be left pointing at the remainder of the command line, which should be the address expression to evaluate. */ if ((name == NULL) || (*args == '\000') ) { error ("add-symbol-file takes a file name and an address"); } name = tilde_expand (name); make_cleanup (free, name); text_addr = parse_and_eval_address (args); if (!query ("add symbol table from file \"%s\" at text_addr = %s?\n", name, local_hex_string (text_addr))) error ("Not confirmed."); /* Getting new symbols may change our opinion about what is frameless. */ reinit_frame_cache (); (void) symbol_file_add (name, 0, text_addr, 0, mapped, readnow); } /* Re-read symbols if a symbol-file has changed. */ void reread_symbols () { struct objfile *objfile; long new_modtime; int reread_one = 0; struct stat new_statbuf; int res; /* With the addition of shared libraries, this should be modified, the load time should be saved in the partial symbol tables, since different tables may come from different source files. FIXME. This routine should then walk down each partial symbol table and see if the symbol table that it originates from has been changed */ the_big_top: for (objfile = object_files; objfile; objfile = objfile->next) { if (objfile->obfd) { #ifdef IBM6000_TARGET /* If this object is from a shared library, then you should stat on the library name, not member name. */ if (objfile->obfd->my_archive) res = stat (objfile->obfd->my_archive->filename, &new_statbuf); else #endif res = stat (objfile->name, &new_statbuf); if (res != 0) { /* FIXME, should use print_sys_errmsg but it's not filtered. */ printf_filtered ("`%s' has disappeared; keeping its symbols.\n", objfile->name); continue; } new_modtime = new_statbuf.st_mtime; if (new_modtime != objfile->mtime) { printf_filtered ("`%s' has changed; re-reading symbols.\n", objfile->name); /* FIXME, this should use a different command...that would only affect this objfile's symbols, and would reset objfile->mtime. (objfile->mtime = new_modtime;) HOWEVER, that command isn't written yet -- so call symbol_file_ command, and restart the scan from the top, because it munges the object_files list. */ symbol_file_command (objfile->name, 0); reread_one = 1; goto the_big_top; /* Start over. */ } } } if (reread_one) breakpoint_re_set (); } /* Functions to handle complaints during symbol reading. */ /* How many complaints about a particular thing should be printed before we stop whining about it? Default is no whining at all, since so many systems have ill-constructed symbol files. */ static unsigned stop_whining = 0; /* Should each complaint be self explanatory, or should we assume that a series of complaints is being produced? case 0: self explanatory message. case 1: First message of a series that must start off with explanation. case 2: Subsequent message, when user already knows we are reading symbols and we can just state our piece. */ static int complaint_series = 0; /* Print a complaint about the input symbols, and link the complaint block into a chain for later handling. */ void complain (complaint, val) struct complaint *complaint; char *val; { complaint->counter++; if (complaint->next == 0) { complaint->next = complaint_root->next; complaint_root->next = complaint; } if (complaint->counter > stop_whining) return; wrap_here (""); switch (complaint_series + (info_verbose << 1)) { /* Isolated messages, must be self-explanatory. */ case 0: puts_filtered ("During symbol reading, "); wrap_here(""); printf_filtered (complaint->message, val); puts_filtered (".\n"); break; /* First of a series, without `set verbose'. */ case 1: puts_filtered ("During symbol reading..."); printf_filtered (complaint->message, val); puts_filtered ("..."); wrap_here(""); complaint_series++; break; /* Subsequent messages of a series, or messages under `set verbose'. (We'll already have produced a "Reading in symbols for XXX..." message and will clean up at the end with a newline.) */ default: printf_filtered (complaint->message, val); puts_filtered ("..."); wrap_here(""); } } /* Clear out all complaint counters that have ever been incremented. If sym_reading is 1, be less verbose about successive complaints, since the messages are appearing all together during a command that reads symbols (rather than scattered around as psymtabs get fleshed out into symtabs at random times). If noisy is 1, we are in a noisy symbol reading command, and our caller will print enough context for the user to figure it out. */ void clear_complaints (sym_reading, noisy) int sym_reading; int noisy; { struct complaint *p; for (p = complaint_root->next; p != complaint_root; p = p->next) p->counter = 0; if (!sym_reading && !noisy && complaint_series > 1) { /* Terminate previous series, since caller won't. */ puts_filtered ("\n"); } complaint_series = sym_reading? 1 + noisy: 0; } enum language deduce_language_from_filename (filename) char *filename; { char *c = strrchr (filename, '.'); if (!c) ; /* Get default. */ else if(!strcmp(c,".mod")) return language_m2; else if(!strcmp(c,".c")) return language_c; else if(!strcmp(c,".cc") || !strcmp(c,".C")) return language_cplus; return language_unknown; /* default */ } /* allocate_symtab: Allocate and partly initialize a new symbol table. Return a pointer to it. error() if no space. Caller must set these fields: LINETABLE(symtab) symtab->blockvector symtab->dirname symtab->free_code symtab->free_ptr initialize any EXTRA_SYMTAB_INFO possibly free_named_symtabs (symtab->filename); */ struct symtab * allocate_symtab (filename, objfile) char *filename; struct objfile *objfile; { register struct symtab *symtab; symtab = (struct symtab *) obstack_alloc (&objfile -> symbol_obstack, sizeof (struct symtab)); (void) memset (symtab, 0, sizeof (*symtab)); symtab -> filename = obsavestring (filename, strlen (filename), &objfile -> symbol_obstack); symtab -> fullname = NULL; symtab -> language = deduce_language_from_filename (filename); /* Hook it to the objfile it comes from */ symtab -> objfile = objfile; symtab -> next = objfile -> symtabs; objfile -> symtabs = symtab; #ifdef INIT_EXTRA_SYMTAB_INFO INIT_EXTRA_SYMTAB_INFO (symtab); #endif return (symtab); } struct partial_symtab * allocate_psymtab (filename, objfile) char *filename; struct objfile *objfile; { struct partial_symtab *psymtab; if (objfile -> free_psymtabs) { psymtab = objfile -> free_psymtabs; objfile -> free_psymtabs = psymtab -> next; } else psymtab = (struct partial_symtab *) obstack_alloc (&objfile -> psymbol_obstack, sizeof (struct partial_symtab)); (void) memset (psymtab, 0, sizeof (struct partial_symtab)); psymtab -> filename = obsavestring (filename, strlen (filename), &objfile -> psymbol_obstack); psymtab -> symtab = NULL; /* Hook it to the objfile it comes from */ psymtab -> objfile = objfile; psymtab -> next = objfile -> psymtabs; objfile -> psymtabs = psymtab; return (psymtab); } /* clear_symtab_users_once: This function is run after symbol reading, or from a cleanup. If an old symbol table was obsoleted, the old symbol table has been blown away, but the other GDB data structures that may reference it have not yet been cleared or re-directed. (The old symtab was zapped, and the cleanup queued, in free_named_symtab() below.) This function can be queued N times as a cleanup, or called directly; it will do all the work the first time, and then will be a no-op until the next time it is queued. This works by bumping a counter at queueing time. Much later when the cleanup is run, or at the end of symbol processing (in case the cleanup is discarded), if the queued count is greater than the "done-count", we do the work and set the done-count to the queued count. If the queued count is less than or equal to the done-count, we just ignore the call. This is needed because reading a single .o file will often replace many symtabs (one per .h file, for example), and we don't want to reset the breakpoints N times in the user's face. The reason we both queue a cleanup, and call it directly after symbol reading, is because the cleanup protects us in case of errors, but is discarded if symbol reading is successful. */ static int clear_symtab_users_queued; static int clear_symtab_users_done; static void clear_symtab_users_once () { /* Enforce once-per-`do_cleanups'-semantics */ if (clear_symtab_users_queued <= clear_symtab_users_done) return; clear_symtab_users_done = clear_symtab_users_queued; printf ("Resetting debugger state after updating old symbol tables\n"); /* Someday, we should do better than this, by only blowing away the things that really need to be blown. */ clear_value_history (); clear_displays (); clear_internalvars (); breakpoint_re_set (); set_default_breakpoint (0, 0, 0, 0); current_source_symtab = 0; } /* Delete the specified psymtab, and any others that reference it. */ static void cashier_psymtab (pst) struct partial_symtab *pst; { struct partial_symtab *ps, *pprev; int i; /* Find its previous psymtab in the chain */ for (ps = pst->objfile->psymtabs; ps; ps = ps->next) { if (ps == pst) break; pprev = ps; } if (ps) { /* Unhook it from the chain. */ if (ps == pst->objfile->psymtabs) pst->objfile->psymtabs = ps->next; else pprev->next = ps->next; /* FIXME, we can't conveniently deallocate the entries in the partial_symbol lists (global_psymbols/static_psymbols) that this psymtab points to. These just take up space until all the psymtabs are reclaimed. Ditto the dependencies list and filename, which are all in the psymbol_obstack. */ /* We need to cashier any psymtab that has this one as a dependency... */ again: for (ps = pst->objfile->psymtabs; ps; ps = ps->next) { for (i = 0; i < ps->number_of_dependencies; i++) { if (ps->dependencies[i] == pst) { cashier_psymtab (ps); goto again; /* Must restart, chain has been munged. */ } } } } } /* If a symtab or psymtab for filename NAME is found, free it along with any dependent breakpoints, displays, etc. Used when loading new versions of object modules with the "add-file" command. This is only called on the top-level symtab or psymtab's name; it is not called for subsidiary files such as .h files. Return value is 1 if we blew away the environment, 0 if not. FIXME. The return valu appears to never be used. FIXME. I think this is not the best way to do this. We should work on being gentler to the environment while still cleaning up all stray pointers into the freed symtab. */ int free_named_symtabs (name) char *name; { #if 0 /* FIXME: With the new method of each objfile having it's own psymtab list, this function needs serious rethinking. In particular, why was it ever necessary to toss psymtabs with specific compilation unit filenames, as opposed to all psymtabs from a particular symbol file? -- fnf Well, the answer is that some systems permit reloading of particular compilation units. We want to blow away any old info about these compilation units, regardless of which objfiles they arrived in. --gnu. */ register struct symtab *s; register struct symtab *prev; register struct partial_symtab *ps; struct blockvector *bv; int blewit = 0; /* We only wack things if the symbol-reload switch is set. */ if (!symbol_reloading) return 0; /* Some symbol formats have trouble providing file names... */ if (name == 0 || *name == '\0') return 0; /* Look for a psymtab with the specified name. */ again2: for (ps = partial_symtab_list; ps; ps = ps->next) { if (!strcmp (name, ps->filename)) { cashier_psymtab (ps); /* Blow it away...and its little dog, too. */ goto again2; /* Must restart, chain has been munged */ } } /* Look for a symtab with the specified name. */ for (s = symtab_list; s; s = s->next) { if (!strcmp (name, s->filename)) break; prev = s; } if (s) { if (s == symtab_list) symtab_list = s->next; else prev->next = s->next; /* For now, queue a delete for all breakpoints, displays, etc., whether or not they depend on the symtab being freed. This should be changed so that only those data structures affected are deleted. */ /* But don't delete anything if the symtab is empty. This test is necessary due to a bug in "dbxread.c" that causes empty symtabs to be created for N_SO symbols that contain the pathname of the object file. (This problem has been fixed in GDB 3.9x). */ bv = BLOCKVECTOR (s); if (BLOCKVECTOR_NBLOCKS (bv) > 2 || BLOCK_NSYMS (BLOCKVECTOR_BLOCK (bv, GLOBAL_BLOCK)) || BLOCK_NSYMS (BLOCKVECTOR_BLOCK (bv, STATIC_BLOCK))) { complain (&oldsyms_complaint, name); clear_symtab_users_queued++; make_cleanup (clear_symtab_users_once, 0); blewit = 1; } else { complain (&empty_symtab_complaint, name); } free_symtab (s); } else { /* It is still possible that some breakpoints will be affected even though no symtab was found, since the file might have been compiled without debugging, and hence not be associated with a symtab. In order to handle this correctly, we would need to keep a list of text address ranges for undebuggable files. For now, we do nothing, since this is a fairly obscure case. */ ; } /* FIXME, what about the minimal symbol table? */ return blewit; #else return (0); #endif } /* Allocate and partially fill a partial symtab. It will be completely filled at the end of the symbol list. SYMFILE_NAME is the name of the symbol-file we are reading from, and ADDR is the address relative to which its symbols are (incremental) or 0 (normal). */ struct partial_symtab * start_psymtab_common (objfile, addr, filename, textlow, global_syms, static_syms) struct objfile *objfile; CORE_ADDR addr; char *filename; CORE_ADDR textlow; struct partial_symbol *global_syms; struct partial_symbol *static_syms; { struct partial_symtab *psymtab; psymtab = allocate_psymtab (filename, objfile); psymtab -> addr = addr; psymtab -> textlow = textlow; psymtab -> texthigh = psymtab -> textlow; /* default */ psymtab -> globals_offset = global_syms - objfile -> global_psymbols.list; psymtab -> statics_offset = static_syms - objfile -> static_psymbols.list; return (psymtab); } void _initialize_symfile () { add_com ("symbol-file", class_files, symbol_file_command, "Load symbol table from executable file FILE.\n\ The `file' command can also load symbol tables, as well as setting the file\n\ to execute."); add_com ("add-symbol-file", class_files, add_symbol_file_command, "Load the symbols from FILE, assuming FILE has been dynamically loaded.\n\ The second argument provides the starting address of the file's text."); add_com ("load", class_files, load_command, "Dynamically load FILE into the running program, and record its symbols\n\ for access from GDB."); add_show_from_set (add_set_cmd ("complaints", class_support, var_zinteger, (char *)&stop_whining, "Set max number of complaints about incorrect symbols.", &setlist), &showlist); add_show_from_set (add_set_cmd ("symbol-reloading", class_support, var_boolean, (char *)&symbol_reloading, "Set dynamic symbol table reloading multiple times in one run.", &setlist), &showlist); }