From 35f5886ebb1a049991b3fee67a00ff10ffb1ad74 Mon Sep 17 00:00:00 2001 From: Fred Fish Date: Thu, 24 Oct 1991 11:28:54 +0000 Subject: New files for DWARF debugging format support, ELF object file support, SVR4 /proc (process file system) support, Amiga UNIX target and host defines, SVR4 target and host defines, and m68k hosts defines. --- gdb/elfread.c | 208 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 208 insertions(+) create mode 100644 gdb/elfread.c (limited to 'gdb/elfread.c') diff --git a/gdb/elfread.c b/gdb/elfread.c new file mode 100644 index 0000000..8c8e8c0 --- /dev/null +++ b/gdb/elfread.c @@ -0,0 +1,208 @@ +/* Read ELF (Executable and Linking Format) object files for GDB. + Copyright (C) 1991 Free Software Foundation, Inc. + Written by Fred Fish at Cygnus Support. + +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. */ + +/************************************************************************ + * * + * NOTICE * + * * + * This file is still under construction. When it is complete, this * + * notice will be removed. Until then, direct any questions or changes * + * to Fred Fish at Cygnus Support (fnf@cygint) * + * * + * FIXME Still needs support for shared libraries. * + * FIXME Still needs support for core files. * + * FIXME The ".debug" and ".line" section names are hardwired. * + * FIXME Still needs support ELF symbol tables (as distinct * + * from DWARF support). Can use them to build the misc * + * function vector at least. This is fairly trivial once * + * bfd is extended to handle ELF symbol tables. * + * * + ************************************************************************/ + +#include + +#include "defs.h" +#include "param.h" +#include "elf-common.h" +#include "elf-external.h" +#include "elf-internal.h" +#include "bfd.h" +#include "symfile.h" +#include "symtab.h" +#include "ansidecl.h" + +extern int EXFUN(strcmp, (CONST char *a, CONST char *b)); +#define STREQ(a,b) (strcmp((a),(b))==0) + +struct elfinfo { + unsigned int dboffset; /* Offset to dwarf debug section */ + unsigned int dbsize; /* Size of dwarf debug section */ + unsigned int lnoffset; /* Offset to dwarf line number section */ + unsigned int lnsize; /* Size of dwarf line number section */ +}; + +/* FIXME - crude hack to resolve undefined global. This function is + part of support for corefiles, which is not yet implemented. */ + +unsigned int +DEFUN(register_addr, (regno, blockend), + int regno AND + int blockend) +{ + error ("Fetching registers from corefiles unimplemented."); +} + +/* We are called once per section from elf_symfile_read. We + need to examine each section we are passed, check to see + if it is something we are interested in processing, and + if so, stash away some access information for the section. + + For now we recognize the dwarf debug information sections and + line number sections from matching their section names. The + ELF definition is no real help here since it has no direct + knowledge of DWARF (by design, so any debugging format can be + used). + + FIXME: The section names should not be hardwired strings. */ + +static void +DEFUN(elf_locate_sections, (abfd, sectp, ei), + bfd *abfd AND + asection *sectp AND + struct elfinfo *ei) +{ + if (STREQ (sectp -> name, ".debug")) + { + ei -> dboffset = sectp -> filepos; + ei -> dbsize = sectp -> size; + } + else if (STREQ (sectp -> name, ".line")) + { + ei -> lnoffset = sectp -> filepos; + ei -> lnsize = sectp -> size; + } +} + +/* Scan and build partial symbols for a symbol file. + We have been initialized by a call to elf_symfile_init, which + currently does nothing. + + ADDR is the address relative to which the symbols in it are (e.g. + the base address of the text segment). + + MAINLINE is true if we are reading the main symbol + table (as opposed to a shared lib or dynamically loaded file). + + This function only does the minimum work necessary for letting the + user "name" things symbolically; it does not read the entire symtab. + Instead, it reads the external and static symbols and puts them in partial + symbol tables. When more extensive information is requested of a + file, the corresponding partial symbol table is mutated into a full + fledged symbol table by going back and reading the symbols + for real. The function dwarf_psymtab_to_symtab() is the function that + does this for DWARF symbols. */ + +static void +DEFUN(elf_symfile_read, (sf, addr, mainline), + struct sym_fns *sf AND + CORE_ADDR addr AND + int mainline) +{ + bfd *abfd = sf -> sym_bfd; + struct elfinfo ei; + + bfd_map_over_sections (abfd, elf_locate_sections, &ei); + if (ei.dboffset && ei.lnoffset) + { + addr = 0; /* FIXME: force address base to zero for now */ + dwarf_build_psymtabs (fileno ((FILE *)(abfd -> iostream)), + bfd_get_filename (abfd), + addr, mainline, + ei.dboffset, ei.dbsize, + ei.lnoffset, ei.lnsize); + } + if (!partial_symtab_list) + { + wrap_here (""); + printf_filtered ("(no debugging symbols found)..."); + wrap_here (""); + } +} + +/* Initialize anything that needs initializing when a completely new symbol + file is specified (not just adding some symbols from another file, e.g. a + shared library). + + For now at least, we have nothing in particular to do, so this function is + just a stub. */ + +static void +DEFUN_VOID (elf_new_init) +{ +} + +/* ELF specific initialization routine for reading symbols. + + It is passed a pointer to a struct sym_fns which contains, among other + things, the BFD for the file whose symbols are being read, and a slot for + a pointer to "private data" which we can fill with goodies. + + For now at least, we have nothing in particular to do, so this function is + just a stub. */ + +static void +DEFUN(elf_symfile_init, (sf), + struct sym_fns *sf) +{ +} + + +/* Register that we are able to handle ELF object file formats and DWARF + debugging formats. + + Unlike other object file formats, where the debugging information format + is implied by the object file format, the ELF object file format and the + DWARF debugging information format are two distinct, and potentially + separate entities. I.E. it is perfectly possible to have ELF objects + with debugging formats other than DWARF. And it is conceivable that the + DWARF debugging format might be used with another object file format, + like COFF, by simply using COFF's custom section feature. + + GDB, and to a lesser extent BFD, should support the notion of separate + object file formats and debugging information formats. For now, we just + use "elf" in the same sense as "a.out" or "coff", to imply both the ELF + object file format and the DWARF debugging format. */ + +static struct sym_fns elf_sym_fns = { + "elf", /* sym_name: name or name prefix of BFD target type */ + 3, /* sym_namelen: number of significant sym_name chars */ + elf_new_init, /* sym_new_init: init anything gbl to entire symtab */ + elf_symfile_init, /* sym_init: read initial info, setup for sym_read() */ + elf_symfile_read, /* sym_read: read a symbol file into symtab */ + NULL, /* sym_bfd: accessor for symbol file being read */ + NULL, /* sym_private: sym_init & sym_read shared info */ + NULL /* next: pointer to next struct sym_fns */ +}; + +void +DEFUN_VOID (_initialize_elfread) +{ + add_symtab_fns (&elf_sym_fns); +} -- cgit v1.1