/* Dynamic architecture support for GDB, the GNU debugger. Copyright (C) 1998-2012 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/>. */ #include "defs.h" #include "arch-utils.h" #include "buildsym.h" #include "gdbcmd.h" #include "inferior.h" /* enum CALL_DUMMY_LOCATION et al. */ #include "gdb_string.h" #include "regcache.h" #include "gdb_assert.h" #include "sim-regno.h" #include "gdbcore.h" #include "osabi.h" #include "target-descriptions.h" #include "objfiles.h" #include "language.h" #include "version.h" #include "floatformat.h" struct displaced_step_closure * simple_displaced_step_copy_insn (struct gdbarch *gdbarch, CORE_ADDR from, CORE_ADDR to, struct regcache *regs) { size_t len = gdbarch_max_insn_length (gdbarch); gdb_byte *buf = xmalloc (len); read_memory (from, buf, len); write_memory (to, buf, len); if (debug_displaced) { fprintf_unfiltered (gdb_stdlog, "displaced: copy %s->%s: ", paddress (gdbarch, from), paddress (gdbarch, to)); displaced_step_dump_bytes (gdb_stdlog, buf, len); } return (struct displaced_step_closure *) buf; } void simple_displaced_step_free_closure (struct gdbarch *gdbarch, struct displaced_step_closure *closure) { xfree (closure); } int default_displaced_step_hw_singlestep (struct gdbarch *gdbarch, struct displaced_step_closure *closure) { return !gdbarch_software_single_step_p (gdbarch); } CORE_ADDR displaced_step_at_entry_point (struct gdbarch *gdbarch) { CORE_ADDR addr; int bp_len; addr = entry_point_address (); /* Inferior calls also use the entry point as a breakpoint location. We don't want displaced stepping to interfere with those breakpoints, so leave space. */ gdbarch_breakpoint_from_pc (gdbarch, &addr, &bp_len); addr += bp_len * 2; return addr; } int legacy_register_sim_regno (struct gdbarch *gdbarch, int regnum) { /* Only makes sense to supply raw registers. */ gdb_assert (regnum >= 0 && regnum < gdbarch_num_regs (gdbarch)); /* NOTE: cagney/2002-05-13: The old code did it this way and it is suspected that some GDB/SIM combinations may rely on this behavour. The default should be one2one_register_sim_regno (below). */ if (gdbarch_register_name (gdbarch, regnum) != NULL && gdbarch_register_name (gdbarch, regnum)[0] != '\0') return regnum; else return LEGACY_SIM_REGNO_IGNORE; } CORE_ADDR generic_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc) { return 0; } CORE_ADDR generic_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc) { return 0; } int generic_in_solib_return_trampoline (struct gdbarch *gdbarch, CORE_ADDR pc, const char *name) { return 0; } int generic_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc) { return 0; } /* Helper functions for gdbarch_inner_than */ int core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs) { return (lhs < rhs); } int core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs) { return (lhs > rhs); } /* Misc helper functions for targets. */ CORE_ADDR core_addr_identity (struct gdbarch *gdbarch, CORE_ADDR addr) { return addr; } CORE_ADDR convert_from_func_ptr_addr_identity (struct gdbarch *gdbarch, CORE_ADDR addr, struct target_ops *targ) { return addr; } int no_op_reg_to_regnum (struct gdbarch *gdbarch, int reg) { return reg; } void default_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym) { return; } void default_coff_make_msymbol_special (int val, struct minimal_symbol *msym) { return; } int cannot_register_not (struct gdbarch *gdbarch, int regnum) { return 0; } /* Legacy version of target_virtual_frame_pointer(). Assumes that there is an gdbarch_deprecated_fp_regnum and that it is the same, cooked or raw. */ void legacy_virtual_frame_pointer (struct gdbarch *gdbarch, CORE_ADDR pc, int *frame_regnum, LONGEST *frame_offset) { /* FIXME: cagney/2002-09-13: This code is used when identifying the frame pointer of the current PC. It is assuming that a single register and an offset can determine this. I think it should instead generate a byte code expression as that would work better with things like Dwarf2's CFI. */ if (gdbarch_deprecated_fp_regnum (gdbarch) >= 0 && gdbarch_deprecated_fp_regnum (gdbarch) < gdbarch_num_regs (gdbarch)) *frame_regnum = gdbarch_deprecated_fp_regnum (gdbarch); else if (gdbarch_sp_regnum (gdbarch) >= 0 && gdbarch_sp_regnum (gdbarch) < gdbarch_num_regs (gdbarch)) *frame_regnum = gdbarch_sp_regnum (gdbarch); else /* Should this be an internal error? I guess so, it is reflecting an architectural limitation in the current design. */ internal_error (__FILE__, __LINE__, _("No virtual frame pointer available")); *frame_offset = 0; } int generic_convert_register_p (struct gdbarch *gdbarch, int regnum, struct type *type) { return 0; } int default_stabs_argument_has_addr (struct gdbarch *gdbarch, struct type *type) { return 0; } int generic_instruction_nullified (struct gdbarch *gdbarch, struct regcache *regcache) { return 0; } int default_remote_register_number (struct gdbarch *gdbarch, int regno) { return regno; } /* Functions to manipulate the endianness of the target. */ static int target_byte_order_user = BFD_ENDIAN_UNKNOWN; static const char endian_big[] = "big"; static const char endian_little[] = "little"; static const char endian_auto[] = "auto"; static const char *const endian_enum[] = { endian_big, endian_little, endian_auto, NULL, }; static const char *set_endian_string; enum bfd_endian selected_byte_order (void) { return target_byte_order_user; } /* Called by ``show endian''. */ static void show_endian (struct ui_file *file, int from_tty, struct cmd_list_element *c, const char *value) { if (target_byte_order_user == BFD_ENDIAN_UNKNOWN) if (gdbarch_byte_order (get_current_arch ()) == BFD_ENDIAN_BIG) fprintf_unfiltered (file, _("The target endianness is set automatically " "(currently big endian)\n")); else fprintf_unfiltered (file, _("The target endianness is set automatically " "(currently little endian)\n")); else if (target_byte_order_user == BFD_ENDIAN_BIG) fprintf_unfiltered (file, _("The target is assumed to be big endian\n")); else fprintf_unfiltered (file, _("The target is assumed to be little endian\n")); } static void set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c) { struct gdbarch_info info; gdbarch_info_init (&info); if (set_endian_string == endian_auto) { target_byte_order_user = BFD_ENDIAN_UNKNOWN; if (! gdbarch_update_p (info)) internal_error (__FILE__, __LINE__, _("set_endian: architecture update failed")); } else if (set_endian_string == endian_little) { info.byte_order = BFD_ENDIAN_LITTLE; if (! gdbarch_update_p (info)) printf_unfiltered (_("Little endian target not supported by GDB\n")); else target_byte_order_user = BFD_ENDIAN_LITTLE; } else if (set_endian_string == endian_big) { info.byte_order = BFD_ENDIAN_BIG; if (! gdbarch_update_p (info)) printf_unfiltered (_("Big endian target not supported by GDB\n")); else target_byte_order_user = BFD_ENDIAN_BIG; } else internal_error (__FILE__, __LINE__, _("set_endian: bad value")); show_endian (gdb_stdout, from_tty, NULL, NULL); } /* Given SELECTED, a currently selected BFD architecture, and TARGET_DESC, the current target description, return what architecture to use. SELECTED may be NULL, in which case we return the architecture associated with TARGET_DESC. If SELECTED specifies a variant of the architecture associtated with TARGET_DESC, return the more specific of the two. If SELECTED is a different architecture, but it is accepted as compatible by the target, we can use the target architecture. If SELECTED is obviously incompatible, warn the user. */ static const struct bfd_arch_info * choose_architecture_for_target (const struct target_desc *target_desc, const struct bfd_arch_info *selected) { const struct bfd_arch_info *from_target = tdesc_architecture (target_desc); const struct bfd_arch_info *compat1, *compat2; if (selected == NULL) return from_target; if (from_target == NULL) return selected; /* struct bfd_arch_info objects are singletons: that is, there's supposed to be exactly one instance for a given machine. So you can tell whether two are equivalent by comparing pointers. */ if (from_target == selected) return selected; /* BFD's 'A->compatible (A, B)' functions return zero if A and B are incompatible. But if they are compatible, it returns the 'more featureful' of the two arches. That is, if A can run code written for B, but B can't run code written for A, then it'll return A. Some targets (e.g. MIPS as of 2006-12-04) don't fully implement this, instead always returning NULL or the first argument. We detect that case by checking both directions. */ compat1 = selected->compatible (selected, from_target); compat2 = from_target->compatible (from_target, selected); if (compat1 == NULL && compat2 == NULL) { /* BFD considers the architectures incompatible. Check our target description whether it accepts SELECTED as compatible anyway. */ if (tdesc_compatible_p (target_desc, selected)) return from_target; warning (_("Selected architecture %s is not compatible " "with reported target architecture %s"), selected->printable_name, from_target->printable_name); return selected; } if (compat1 == NULL) return compat2; if (compat2 == NULL) return compat1; if (compat1 == compat2) return compat1; /* If the two didn't match, but one of them was a default architecture, assume the more specific one is correct. This handles the case where an executable or target description just says "mips", but the other knows which MIPS variant. */ if (compat1->the_default) return compat2; if (compat2->the_default) return compat1; /* We have no idea which one is better. This is a bug, but not a critical problem; warn the user. */ warning (_("Selected architecture %s is ambiguous with " "reported target architecture %s"), selected->printable_name, from_target->printable_name); return selected; } /* Functions to manipulate the architecture of the target. */ enum set_arch { set_arch_auto, set_arch_manual }; static const struct bfd_arch_info *target_architecture_user; static const char *set_architecture_string; const char * selected_architecture_name (void) { if (target_architecture_user == NULL) return NULL; else return set_architecture_string; } /* Called if the user enters ``show architecture'' without an argument. */ static void show_architecture (struct ui_file *file, int from_tty, struct cmd_list_element *c, const char *value) { if (target_architecture_user == NULL) fprintf_filtered (file, _("The target architecture is set " "automatically (currently %s)\n"), gdbarch_bfd_arch_info (get_current_arch ())->printable_name); else fprintf_filtered (file, _("The target architecture is assumed to be %s\n"), set_architecture_string); } /* Called if the user enters ``set architecture'' with or without an argument. */ static void set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c) { struct gdbarch_info info; gdbarch_info_init (&info); if (strcmp (set_architecture_string, "auto") == 0) { target_architecture_user = NULL; if (!gdbarch_update_p (info)) internal_error (__FILE__, __LINE__, _("could not select an architecture automatically")); } else { info.bfd_arch_info = bfd_scan_arch (set_architecture_string); if (info.bfd_arch_info == NULL) internal_error (__FILE__, __LINE__, _("set_architecture: bfd_scan_arch failed")); if (gdbarch_update_p (info)) target_architecture_user = info.bfd_arch_info; else printf_unfiltered (_("Architecture `%s' not recognized.\n"), set_architecture_string); } show_architecture (gdb_stdout, from_tty, NULL, NULL); } /* Try to select a global architecture that matches "info". Return non-zero if the attempt succeds. */ int gdbarch_update_p (struct gdbarch_info info) { struct gdbarch *new_gdbarch; /* Check for the current file. */ if (info.abfd == NULL) info.abfd = exec_bfd; if (info.abfd == NULL) info.abfd = core_bfd; /* Check for the current target description. */ if (info.target_desc == NULL) info.target_desc = target_current_description (); new_gdbarch = gdbarch_find_by_info (info); /* If there no architecture by that name, reject the request. */ if (new_gdbarch == NULL) { if (gdbarch_debug) fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: " "Architecture not found\n"); return 0; } /* If it is the same old architecture, accept the request (but don't swap anything). */ if (new_gdbarch == target_gdbarch) { if (gdbarch_debug) fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: " "Architecture %s (%s) unchanged\n", host_address_to_string (new_gdbarch), gdbarch_bfd_arch_info (new_gdbarch)->printable_name); return 1; } /* It's a new architecture, swap it in. */ if (gdbarch_debug) fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: " "New architecture %s (%s) selected\n", host_address_to_string (new_gdbarch), gdbarch_bfd_arch_info (new_gdbarch)->printable_name); deprecated_target_gdbarch_select_hack (new_gdbarch); return 1; } /* Return the architecture for ABFD. If no suitable architecture could be find, return NULL. */ struct gdbarch * gdbarch_from_bfd (bfd *abfd) { struct gdbarch_info info; gdbarch_info_init (&info); info.abfd = abfd; return gdbarch_find_by_info (info); } /* Set the dynamic target-system-dependent parameters (architecture, byte-order) using information found in the BFD */ void set_gdbarch_from_file (bfd *abfd) { struct gdbarch_info info; struct gdbarch *gdbarch; gdbarch_info_init (&info); info.abfd = abfd; info.target_desc = target_current_description (); gdbarch = gdbarch_find_by_info (info); if (gdbarch == NULL) error (_("Architecture of file not recognized.")); deprecated_target_gdbarch_select_hack (gdbarch); } /* Initialize the current architecture. Update the ``set architecture'' command so that it specifies a list of valid architectures. */ #ifdef DEFAULT_BFD_ARCH extern const bfd_arch_info_type DEFAULT_BFD_ARCH; static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH; #else static const bfd_arch_info_type *default_bfd_arch; #endif #ifdef DEFAULT_BFD_VEC extern const bfd_target DEFAULT_BFD_VEC; static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC; #else static const bfd_target *default_bfd_vec; #endif static int default_byte_order = BFD_ENDIAN_UNKNOWN; void initialize_current_architecture (void) { const char **arches = gdbarch_printable_names (); struct gdbarch_info info; /* determine a default architecture and byte order. */ gdbarch_info_init (&info); /* Find a default architecture. */ if (default_bfd_arch == NULL) { /* Choose the architecture by taking the first one alphabetically. */ const char *chosen = arches[0]; const char **arch; for (arch = arches; *arch != NULL; arch++) { if (strcmp (*arch, chosen) < 0) chosen = *arch; } if (chosen == NULL) internal_error (__FILE__, __LINE__, _("initialize_current_architecture: No arch")); default_bfd_arch = bfd_scan_arch (chosen); if (default_bfd_arch == NULL) internal_error (__FILE__, __LINE__, _("initialize_current_architecture: Arch not found")); } info.bfd_arch_info = default_bfd_arch; /* Take several guesses at a byte order. */ if (default_byte_order == BFD_ENDIAN_UNKNOWN && default_bfd_vec != NULL) { /* Extract BFD's default vector's byte order. */ switch (default_bfd_vec->byteorder) { case BFD_ENDIAN_BIG: default_byte_order = BFD_ENDIAN_BIG; break; case BFD_ENDIAN_LITTLE: default_byte_order = BFD_ENDIAN_LITTLE; break; default: break; } } if (default_byte_order == BFD_ENDIAN_UNKNOWN) { /* look for ``*el-*'' in the target name. */ const char *chp; chp = strchr (target_name, '-'); if (chp != NULL && chp - 2 >= target_name && strncmp (chp - 2, "el", 2) == 0) default_byte_order = BFD_ENDIAN_LITTLE; } if (default_byte_order == BFD_ENDIAN_UNKNOWN) { /* Wire it to big-endian!!! */ default_byte_order = BFD_ENDIAN_BIG; } info.byte_order = default_byte_order; info.byte_order_for_code = info.byte_order; if (! gdbarch_update_p (info)) internal_error (__FILE__, __LINE__, _("initialize_current_architecture: Selection of " "initial architecture failed")); /* Create the ``set architecture'' command appending ``auto'' to the list of architectures. */ { /* Append ``auto''. */ int nr; for (nr = 0; arches[nr] != NULL; nr++); arches = xrealloc (arches, sizeof (char*) * (nr + 2)); arches[nr + 0] = "auto"; arches[nr + 1] = NULL; add_setshow_enum_cmd ("architecture", class_support, arches, &set_architecture_string, _("Set architecture of target."), _("Show architecture of target."), NULL, set_architecture, show_architecture, &setlist, &showlist); add_alias_cmd ("processor", "architecture", class_support, 1, &setlist); } } /* Initialize a gdbarch info to values that will be automatically overridden. Note: Originally, this ``struct info'' was initialized using memset(0). Unfortunately, that ran into problems, namely BFD_ENDIAN_BIG is zero. An explicit initialization function that can explicitly set each field to a well defined value is used. */ void gdbarch_info_init (struct gdbarch_info *info) { memset (info, 0, sizeof (struct gdbarch_info)); info->byte_order = BFD_ENDIAN_UNKNOWN; info->byte_order_for_code = info->byte_order; info->osabi = GDB_OSABI_UNINITIALIZED; } /* Similar to init, but this time fill in the blanks. Information is obtained from the global "set ..." options and explicitly initialized INFO fields. */ void gdbarch_info_fill (struct gdbarch_info *info) { /* "(gdb) set architecture ...". */ if (info->bfd_arch_info == NULL && target_architecture_user) info->bfd_arch_info = target_architecture_user; /* From the file. */ if (info->bfd_arch_info == NULL && info->abfd != NULL && bfd_get_arch (info->abfd) != bfd_arch_unknown && bfd_get_arch (info->abfd) != bfd_arch_obscure) info->bfd_arch_info = bfd_get_arch_info (info->abfd); /* From the target. */ if (info->target_desc != NULL) info->bfd_arch_info = choose_architecture_for_target (info->target_desc, info->bfd_arch_info); /* From the default. */ if (info->bfd_arch_info == NULL) info->bfd_arch_info = default_bfd_arch; /* "(gdb) set byte-order ...". */ if (info->byte_order == BFD_ENDIAN_UNKNOWN && target_byte_order_user != BFD_ENDIAN_UNKNOWN) info->byte_order = target_byte_order_user; /* From the INFO struct. */ if (info->byte_order == BFD_ENDIAN_UNKNOWN && info->abfd != NULL) info->byte_order = (bfd_big_endian (info->abfd) ? BFD_ENDIAN_BIG : bfd_little_endian (info->abfd) ? BFD_ENDIAN_LITTLE : BFD_ENDIAN_UNKNOWN); /* From the default. */ if (info->byte_order == BFD_ENDIAN_UNKNOWN) info->byte_order = default_byte_order; info->byte_order_for_code = info->byte_order; /* "(gdb) set osabi ...". Handled by gdbarch_lookup_osabi. */ /* From the manual override, or from file. */ if (info->osabi == GDB_OSABI_UNINITIALIZED) info->osabi = gdbarch_lookup_osabi (info->abfd); /* From the target. */ if (info->osabi == GDB_OSABI_UNKNOWN && info->target_desc != NULL) info->osabi = tdesc_osabi (info->target_desc); /* From the configured default. */ #ifdef GDB_OSABI_DEFAULT if (info->osabi == GDB_OSABI_UNKNOWN) info->osabi = GDB_OSABI_DEFAULT; #endif /* Must have at least filled in the architecture. */ gdb_assert (info->bfd_arch_info != NULL); } /* Return "current" architecture. If the target is running, this is the architecture of the selected frame. Otherwise, the "current" architecture defaults to the target architecture. This function should normally be called solely by the command interpreter routines to determine the architecture to execute a command in. */ struct gdbarch * get_current_arch (void) { if (has_stack_frames ()) return get_frame_arch (get_selected_frame (NULL)); else return target_gdbarch; } int default_has_shared_address_space (struct gdbarch *gdbarch) { /* Simply say no. In most unix-like targets each inferior/process has its own address space. */ return 0; } int default_fast_tracepoint_valid_at (struct gdbarch *gdbarch, CORE_ADDR addr, int *isize, char **msg) { /* We don't know if maybe the target has some way to do fast tracepoints that doesn't need gdbarch, so always say yes. */ if (msg) *msg = NULL; return 1; } void default_remote_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr, int *kindptr) { gdbarch_breakpoint_from_pc (gdbarch, pcptr, kindptr); } void default_gen_return_address (struct gdbarch *gdbarch, struct agent_expr *ax, struct axs_value *value, CORE_ADDR scope) { error (_("This architecture has no method to collect a return address.")); } int default_return_in_first_hidden_param_p (struct gdbarch *gdbarch, struct type *type) { /* Usually, the return value's address is stored the in the "first hidden" parameter if the return value should be passed by reference, as specified in ABI. */ return language_pass_by_reference (type); } /* */ /* -Wmissing-prototypes */ extern initialize_file_ftype _initialize_gdbarch_utils; void _initialize_gdbarch_utils (void) { add_setshow_enum_cmd ("endian", class_support, endian_enum, &set_endian_string, _("Set endianness of target."), _("Show endianness of target."), NULL, set_endian, show_endian, &setlist, &showlist); }