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Diffstat (limited to 'gdb/exec.c')
| -rw-r--r-- | gdb/exec.c | 350 |
1 files changed, 350 insertions, 0 deletions
diff --git a/gdb/exec.c b/gdb/exec.c new file mode 100644 index 0000000..eefe772 --- /dev/null +++ b/gdb/exec.c @@ -0,0 +1,350 @@ +/* Work with executable files, for GDB. + Copyright (C) 1988, 1989 Free Software Foundation, Inc. + +This file is part of GDB. + +GDB 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 1, or (at your option) +any later version. + +GDB 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 GDB; see the file COPYING. If not, write to +the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include <stdio.h> +#include "defs.h" +#include "param.h" +#include "frame.h" +#include "inferior.h" +#include "target.h" + +#ifdef USG +#include <sys/types.h> +#endif + +#include <sys/param.h> +#include <fcntl.h> + +#include "gdbcore.h" + +#ifdef STILL_NEEDED_FOR_DECSTATION +#include <sys/dir.h> /* For DECstations */ +#include <sys/user.h> /* After a.out.h */ +#include <sys/file.h> +#endif + +#include <sys/stat.h> + +extern char *getenv(); +extern void child_create_inferior (), child_attach (); +extern void symbol_file_command (); + +/* The Binary File Descriptor handle for the executable file. */ + +bfd *exec_bfd = NULL; + +/* The base and bounds of the table of the exec file's sections. */ + +struct section_table *exec_sections, *exec_sections_end; + +/* Forward decl */ + +extern struct target_ops exec_ops; + +void +exec_close (quitting) + int quitting; +{ + if (exec_bfd) { + bfd_close (exec_bfd); + exec_bfd = NULL; + } +} + +void +exec_file_command (filename, from_tty) + char *filename; + int from_tty; +{ + + /* Remove any previous exec file. */ + unpush_target (&exec_ops); + + /* Now open and digest the file the user requested, if any. */ + + if (filename) + { + char *scratch_pathname; + int scratch_chan; + + filename = tilde_expand (filename); + make_cleanup (free, filename); + +/* FIXME, if writeable is set, open for read/write. */ + scratch_chan = openp (getenv ("PATH"), 1, filename, O_RDONLY, 0, + &scratch_pathname); + if (scratch_chan < 0) + perror_with_name (filename); + + exec_bfd = bfd_fdopenr (scratch_pathname, NULL, scratch_chan); + if (!exec_bfd) + error ("Could not open `%s' as an executable file: %s", + scratch_pathname, bfd_errmsg (bfd_error)); + if (!bfd_check_format (exec_bfd, bfd_object)) + error ("\"%s\": not in executable format: %s.", + scratch_pathname, bfd_errmsg (bfd_error)); + +#if FIXME +/* This code needs to be incorporated into BFD */ +#ifdef COFF_ENCAPSULATE + /* If we have a coff header, it can give us better values for + text_start and exec_data_start. This is particularly useful + for remote debugging of embedded systems. */ + if (N_FLAGS(exec_aouthdr) & N_FLAGS_COFF_ENCAPSULATE) + { + struct coffheader ch; + int val; + val = lseek (execchan, -(sizeof (AOUTHDR) + sizeof (ch)), 1); + if (val == -1) + perror_with_name (filename); + val = myread (execchan, &ch, sizeof (ch)); + if (val < 0) + perror_with_name (filename); + text_start = ch.text_start; + exec_data_start = ch.data_start; + } else +#endif + { + text_start = + IS_OBJECT_FILE (exec_aouthdr) ? 0 : N_TXTADDR (exec_aouthdr); + exec_data_start = IS_OBJECT_FILE (exec_aouthdr) + ? exec_aouthdr.a_text : N_DATADDR (exec_aouthdr); + } +#endif FIXME + + if (build_section_table (exec_bfd, &exec_sections, &exec_sections_end)) + error ("Can't find the file sections in `%s': %s", + exec_bfd->filename, bfd_errmsg (bfd_error)); + + validate_files (); + + push_target (&exec_ops); + + /* Tell display code (if any) about the changed file name. */ + if (exec_file_display_hook) + (*exec_file_display_hook) (filename); + } + else if (from_tty) + printf ("No exec file now.\n"); +} + +/* Set both the exec file and the symbol file, in one command. + What a novelty. Why did GDB go through four major releases before this + command was added? */ + +void +file_command (arg, from_tty) + char *arg; + int from_tty; +{ + /* FIXME, if we lose on reading the symbol file, we should revert + the exec file, but that's rough. */ + exec_file_command (arg, from_tty); + symbol_file_command (arg, from_tty); +} + + +/* Locate all mappable sections of a BFD file. */ + +void +add_to_section_table (abfd, asect, table_pp) + bfd *abfd; + sec_ptr asect; + struct section_table **table_pp; +{ + flagword aflag; + + aflag = bfd_get_section_flags (abfd, asect); + /* FIXME, we need to handle BSS segment here...it alloc's but doesn't load */ + if (!(aflag & SEC_LOAD)) + return; + (*table_pp)->sec_ptr = asect; + (*table_pp)->addr = bfd_section_vma (abfd, asect); + (*table_pp)->endaddr = (*table_pp)->addr + bfd_section_size (abfd, asect); + (*table_pp)++; +} + +int +build_section_table (some_bfd, start, end) + bfd *some_bfd; + struct section_table **start, **end; +{ + unsigned count; + + count = bfd_count_sections (some_bfd); + if (count == 0) + abort(); /* return 1? */ + *start = (struct section_table *) xmalloc (count * sizeof (**start)); + *end = *start; + bfd_map_over_sections (some_bfd, add_to_section_table, end); + if (*end > *start + count) + abort(); + /* We could realloc the table, but it probably loses for most files. */ + return 0; +} + +/* Read or write the exec file. + + Args are address within exec file, address within gdb address-space, + length, and a flag indicating whether to read or write. + + Result is a length: + + 0: We cannot handle this address and length. + > 0: We have handled N bytes starting at this address. + (If N == length, we did it all.) We might be able + to handle more bytes beyond this length, but no + promises. + < 0: We cannot handle this address, but if somebody + else handles (-N) bytes, we can start from there. + + The same routine is used to handle both core and exec files; + we just tail-call it with more arguments to select between them. */ + +int +xfer_memory (memaddr, myaddr, len, write, abfd, sections, sections_end) + CORE_ADDR memaddr; + char *myaddr; + int len; + int write; + bfd *abfd; + struct section_table *sections, *sections_end; +{ + boolean res; + struct section_table *p; + CORE_ADDR nextsectaddr, memend; + boolean (*xfer_fn) (); + + if (len <= 0) + abort(); + + memend = memaddr + len; + xfer_fn = write? bfd_set_section_contents: bfd_get_section_contents; + nextsectaddr = memend; + + for (p = sections; p < sections_end; p++) + { + if (p->addr <= memaddr) + if (p->endaddr >= memend) + { + /* Entire transfer is within this section. */ + res = xfer_fn (abfd, p->sec_ptr, myaddr, memaddr - p->addr, len); + return (res != false)? len: 0; + } + else if (p->endaddr <= memaddr) + { + /* This section ends before the transfer starts. */ + continue; + } + else + { + /* This section overlaps the transfer. Just do half. */ + len = p->endaddr - memaddr; + res = xfer_fn (abfd, p->sec_ptr, myaddr, memaddr - p->addr, len); + return (res != false)? len: 0; + } + else if (p->addr < nextsectaddr) + nextsectaddr = p->addr; + } + + if (nextsectaddr >= memend) + return 0; /* We can't help */ + else + return - (nextsectaddr - memaddr); /* Next boundary where we can help */ +} + +/* The function called by target_xfer_memory via our target_ops */ + +int +exec_xfer_memory (memaddr, myaddr, len, write) + CORE_ADDR memaddr; + char *myaddr; + int len; + int write; +{ + return xfer_memory (memaddr, myaddr, len, write, + exec_bfd, exec_sections, exec_sections_end); +} + + +#ifdef FIXME +#ifdef REG_STACK_SEGMENT +/* MOVE TO BFD... */ + /* Pyramids and AM29000s have an extra segment in the virtual address space + for the (control) stack of register-window frames. The AM29000 folk + call it the "register stack" rather than the "memory stack". */ + else if (memaddr >= reg_stack_start && memaddr < reg_stack_end) + { + i = min (len, reg_stack_end - memaddr); + fileptr = memaddr - reg_stack_start + reg_stack_offset; + wanna_xfer = coredata; + } +#endif /* REG_STACK_SEGMENT */ +#endif FIXME + +static void +exec_files_info () +{ + struct section_table *p; + + printf ("\tExecutable file `%s'.\n", bfd_get_filename(exec_bfd)); + + for (p = exec_sections; p < exec_sections_end; p++) + printf("\texecutable from 0x%08x to 0x%08x is %s\n", + p->addr, p->endaddr, + bfd_section_name (exec_bfd, p->sec_ptr)); +} + +struct target_ops exec_ops = { + "exec", "Local exec file", + exec_file_command, exec_close, /* open, close */ + child_attach, 0, 0, 0, /* attach, detach, resume, wait, */ + 0, 0, /* fetch_registers, store_registers, */ + 0, 0, 0, /* prepare_to_store, conv_to, conv_from, */ + exec_xfer_memory, exec_files_info, + 0, 0, /* insert_breakpoint, remove_breakpoint, */ + 0, 0, 0, 0, 0, /* terminal stuff */ + 0, 0, 0, 0, 0, /* kill, load, add_syms, call fn, lookup sym */ + child_create_inferior, + 0, /* mourn_inferior */ + file_stratum, 0, /* next */ + 0, 1, 0, 0, 0, /* all mem, mem, stack, regs, exec */ + OPS_MAGIC, /* Always the last thing */ +}; + +void +_initialize_exec() +{ + + add_com ("file", class_files, file_command, + "Use FILE as program to be debugged.\n\ +It is read for its symbols, for getting the contents of pure memory,\n\ +and it is the program executed when you use the `run' command.\n\ +If FILE cannot be found as specified, your execution directory path\n\ +($PATH) is searched for a command of that name.\n\ +No arg means to have no executable file and no symbols."); + + add_com ("exec-file", class_files, exec_file_command, + "Use FILE as program for getting contents of pure memory.\n\ +If FILE cannot be found as specified, your execution directory path\n\ +is searched for a command of that name.\n\ +No arg means have no executable file."); + + add_target (&exec_ops); +} |