From 1a8da44df3a27ece21de383e0e0571957bfc56cb Mon Sep 17 00:00:00 2001 From: Andrew Cagney Date: Sat, 30 Oct 2004 20:26:26 +0000 Subject: 2004-10-30 Andrew Cagney * config/mips/embed.mt (TDEPFILES): Add mips-mdebug-tdep.o. * mips-mdebug-tdep.h, mips-mdebug-tdep.c: New files. * mips-tdep.c (mips_mdebug_frame_cache) (mips_mdebug_frame_this_id, mips_mdebug_frame_prev_register) (mips_mdebug_frame_unwind, mips_mdebug_frame_sniffer) (mips_mdebug_frame_base_address, mips_mdebug_frame_sniffer) (mips_mdebug_frame_base_sniffer, non_heuristic_proc_desc) (compare_pdr_entries, the_bfd, mips16_fetch_instruction): Delete. (mips_gdbarch_init): Do not append mdebug sniffers. (PROC_LOW_ADDR, PROC_HIGH_ADDR, PROC_FRAME_OFFSET) (PROC_FRAME_REG, PROC_FRAME_ADJUST, PROC_REG_MASK) (PROC_FREG_MASK, PROC_REG_OFFSET, PROC_FREG_OFFSET, PROC_PC_REG) (PROC_SYMBOL, _PROC_MAGIC_): Delete. * Makefile.in: Update dependencies. --- gdb/mips-mdebug-tdep.c | 493 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 493 insertions(+) create mode 100644 gdb/mips-mdebug-tdep.c (limited to 'gdb/mips-mdebug-tdep.c') diff --git a/gdb/mips-mdebug-tdep.c b/gdb/mips-mdebug-tdep.c new file mode 100644 index 0000000..efb105d --- /dev/null +++ b/gdb/mips-mdebug-tdep.c @@ -0,0 +1,493 @@ +/* Target-dependent code for the MDEBUG MIPS architecture, for GDB, + the GNU Debugger. + + Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, + 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 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 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., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include "defs.h" +#include "frame.h" +#include "mips-tdep.h" +#include "trad-frame.h" +#include "block.h" +#include "symtab.h" +#include "objfiles.h" +#include "elf/mips.h" +#include "elf-bfd.h" +#include "gdb_assert.h" +#include "frame-unwind.h" +#include "frame-base.h" +#include "mips-mdebug-tdep.h" + +#define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) /* least address */ +#define PROC_HIGH_ADDR(proc) ((proc)->high_addr) /* upper address bound */ +#define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset) +#define PROC_FRAME_REG(proc) ((proc)->pdr.framereg) +#define PROC_FRAME_ADJUST(proc) ((proc)->frame_adjust) +#define PROC_REG_MASK(proc) ((proc)->pdr.regmask) +#define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask) +#define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset) +#define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset) +#define PROC_PC_REG(proc) ((proc)->pdr.pcreg) +/* FIXME drow/2002-06-10: If a pointer on the host is bigger than a long, + this will corrupt pdr.iline. Fortunately we don't use it. */ +#define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym) +#define _PROC_MAGIC_ 0x0F0F0F0F + +struct mips_objfile_private +{ + bfd_size_type size; + char *contents; +}; + +/* Global used to communicate between non_heuristic_proc_desc and + compare_pdr_entries within qsort (). */ +static bfd *the_bfd; + +static int +compare_pdr_entries (const void *a, const void *b) +{ + CORE_ADDR lhs = bfd_get_32 (the_bfd, (bfd_byte *) a); + CORE_ADDR rhs = bfd_get_32 (the_bfd, (bfd_byte *) b); + + if (lhs < rhs) + return -1; + else if (lhs == rhs) + return 0; + else + return 1; +} + +static const struct objfile_data *mips_pdr_data; + +static mips_extra_func_info_t +non_heuristic_proc_desc (CORE_ADDR pc, CORE_ADDR *addrptr) +{ + CORE_ADDR startaddr; + mips_extra_func_info_t proc_desc; + struct block *b = block_for_pc (pc); + struct symbol *sym; + struct obj_section *sec; + struct mips_objfile_private *priv; + + find_pc_partial_function (pc, NULL, &startaddr, NULL); + if (addrptr) + *addrptr = startaddr; + + priv = NULL; + + sec = find_pc_section (pc); + if (sec != NULL) + { + priv = (struct mips_objfile_private *) objfile_data (sec->objfile, mips_pdr_data); + + /* Search the ".pdr" section generated by GAS. This includes most of + the information normally found in ECOFF PDRs. */ + + the_bfd = sec->objfile->obfd; + if (priv == NULL + && (the_bfd->format == bfd_object + && bfd_get_flavour (the_bfd) == bfd_target_elf_flavour + && elf_elfheader (the_bfd)->e_ident[EI_CLASS] == ELFCLASS64)) + { + /* Right now GAS only outputs the address as a four-byte sequence. + This means that we should not bother with this method on 64-bit + targets (until that is fixed). */ + + priv = obstack_alloc (&sec->objfile->objfile_obstack, + sizeof (struct mips_objfile_private)); + priv->size = 0; + set_objfile_data (sec->objfile, mips_pdr_data, priv); + } + else if (priv == NULL) + { + asection *bfdsec; + + priv = obstack_alloc (&sec->objfile->objfile_obstack, + sizeof (struct mips_objfile_private)); + + bfdsec = bfd_get_section_by_name (sec->objfile->obfd, ".pdr"); + if (bfdsec != NULL) + { + priv->size = bfd_section_size (sec->objfile->obfd, bfdsec); + priv->contents = obstack_alloc (&sec->objfile->objfile_obstack, + priv->size); + bfd_get_section_contents (sec->objfile->obfd, bfdsec, + priv->contents, 0, priv->size); + + /* In general, the .pdr section is sorted. However, in the + presence of multiple code sections (and other corner cases) + it can become unsorted. Sort it so that we can use a faster + binary search. */ + qsort (priv->contents, priv->size / 32, 32, + compare_pdr_entries); + } + else + priv->size = 0; + + set_objfile_data (sec->objfile, mips_pdr_data, priv); + } + the_bfd = NULL; + + if (priv->size != 0) + { + int low, mid, high; + char *ptr; + CORE_ADDR pdr_pc; + + low = 0; + high = priv->size / 32; + + /* We've found a .pdr section describing this objfile. We want to + find the entry which describes this code address. The .pdr + information is not very descriptive; we have only a function + start address. We have to look for the closest entry, because + the local symbol at the beginning of this function may have + been stripped - so if we ask the symbol table for the start + address we may get a preceding global function. */ + + /* First, find the last .pdr entry starting at or before PC. */ + do + { + mid = (low + high) / 2; + + ptr = priv->contents + mid * 32; + pdr_pc = bfd_get_signed_32 (sec->objfile->obfd, ptr); + pdr_pc += ANOFFSET (sec->objfile->section_offsets, + SECT_OFF_TEXT (sec->objfile)); + + if (pdr_pc > pc) + high = mid; + else + low = mid + 1; + } + while (low != high); + + /* Both low and high point one past the PDR of interest. If + both are zero, that means this PC is before any region + covered by a PDR, i.e. pdr_pc for the first PDR entry is + greater than PC. */ + if (low > 0) + { + ptr = priv->contents + (low - 1) * 32; + pdr_pc = bfd_get_signed_32 (sec->objfile->obfd, ptr); + pdr_pc += ANOFFSET (sec->objfile->section_offsets, + SECT_OFF_TEXT (sec->objfile)); + } + + /* We don't have a range, so we have no way to know for sure + whether we're in the correct PDR or a PDR for a preceding + function and the current function was a stripped local + symbol. But if the PDR's PC is at least as great as the + best guess from the symbol table, assume that it does cover + the right area; if a .pdr section is present at all then + nearly every function will have an entry. The biggest exception + will be the dynamic linker stubs; conveniently these are + placed before .text instead of after. */ + + if (pc >= pdr_pc && pdr_pc >= startaddr) + { + struct symbol *sym = find_pc_function (pc); + + if (addrptr) + *addrptr = pdr_pc; + + /* Fill in what we need of the proc_desc. */ + proc_desc = (mips_extra_func_info_t) + obstack_alloc (&sec->objfile->objfile_obstack, + sizeof (struct mips_extra_func_info)); + PROC_LOW_ADDR (proc_desc) = pdr_pc; + + /* Only used for dummy frames. */ + PROC_HIGH_ADDR (proc_desc) = 0; + + PROC_FRAME_OFFSET (proc_desc) + = bfd_get_32 (sec->objfile->obfd, ptr + 20); + PROC_FRAME_REG (proc_desc) = bfd_get_32 (sec->objfile->obfd, + ptr + 24); + PROC_FRAME_ADJUST (proc_desc) = 0; + PROC_REG_MASK (proc_desc) = bfd_get_32 (sec->objfile->obfd, + ptr + 4); + PROC_FREG_MASK (proc_desc) = bfd_get_32 (sec->objfile->obfd, + ptr + 12); + PROC_REG_OFFSET (proc_desc) = bfd_get_32 (sec->objfile->obfd, + ptr + 8); + PROC_FREG_OFFSET (proc_desc) + = bfd_get_32 (sec->objfile->obfd, ptr + 16); + PROC_PC_REG (proc_desc) = bfd_get_32 (sec->objfile->obfd, + ptr + 28); + proc_desc->pdr.isym = (long) sym; + + return proc_desc; + } + } + } + + if (b == NULL) + return NULL; + + if (startaddr > BLOCK_START (b)) + { + /* This is the "pathological" case referred to in a comment in + print_frame_info. It might be better to move this check into + symbol reading. */ + return NULL; + } + + sym = lookup_symbol (MIPS_EFI_SYMBOL_NAME, b, LABEL_DOMAIN, 0, NULL); + + /* If we never found a PDR for this function in symbol reading, then + examine prologues to find the information. */ + if (sym) + { + proc_desc = (mips_extra_func_info_t) SYMBOL_VALUE (sym); + if (PROC_FRAME_REG (proc_desc) == -1) + return NULL; + else + return proc_desc; + } + else + return NULL; +} + +struct mips_frame_cache +{ + CORE_ADDR base; + struct trad_frame_saved_reg *saved_regs; +}; + +static struct mips_frame_cache * +mips_mdebug_frame_cache (struct frame_info *next_frame, void **this_cache) +{ + CORE_ADDR startaddr = 0; + mips_extra_func_info_t proc_desc; + struct mips_frame_cache *cache; + struct gdbarch *gdbarch = get_frame_arch (next_frame); + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + /* r0 bit means kernel trap */ + int kernel_trap; + /* What registers have been saved? Bitmasks. */ + unsigned long gen_mask, float_mask; + + if ((*this_cache) != NULL) + return (*this_cache); + cache = FRAME_OBSTACK_ZALLOC (struct mips_frame_cache); + (*this_cache) = cache; + cache->saved_regs = trad_frame_alloc_saved_regs (next_frame); + + /* Get the mdebug proc descriptor. */ + proc_desc = non_heuristic_proc_desc (frame_pc_unwind (next_frame), + &startaddr); + /* Must be true. This is only called when the sniffer detected a + proc descriptor. */ + gdb_assert (proc_desc != NULL); + + /* Extract the frame's base. */ + cache->base = (frame_unwind_register_signed (next_frame, NUM_REGS + PROC_FRAME_REG (proc_desc)) + + PROC_FRAME_OFFSET (proc_desc) - PROC_FRAME_ADJUST (proc_desc)); + + kernel_trap = PROC_REG_MASK (proc_desc) & 1; + gen_mask = kernel_trap ? 0xFFFFFFFF : PROC_REG_MASK (proc_desc); + float_mask = kernel_trap ? 0xFFFFFFFF : PROC_FREG_MASK (proc_desc); + + /* Must be true. The in_prologue case is left for the heuristic + unwinder. This is always used on kernel traps. */ + gdb_assert (!in_prologue (frame_pc_unwind (next_frame), PROC_LOW_ADDR (proc_desc)) + || kernel_trap); + + /* Fill in the offsets for the registers which gen_mask says were + saved. */ + { + CORE_ADDR reg_position = (cache->base + PROC_REG_OFFSET (proc_desc)); + int ireg; + + for (ireg = MIPS_NUMREGS - 1; gen_mask; --ireg, gen_mask <<= 1) + if (gen_mask & 0x80000000) + { + cache->saved_regs[NUM_REGS + ireg].addr = reg_position; + reg_position -= mips_abi_regsize (gdbarch); + } + } + + /* Fill in the offsets for the registers which float_mask says were + saved. */ + { + CORE_ADDR reg_position = (cache->base + + PROC_FREG_OFFSET (proc_desc)); + int ireg; + /* Fill in the offsets for the float registers which float_mask + says were saved. */ + for (ireg = MIPS_NUMREGS - 1; float_mask; --ireg, float_mask <<= 1) + if (float_mask & 0x80000000) + { + if (mips_abi_regsize (gdbarch) == 4 + && TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) + { + /* On a big endian 32 bit ABI, floating point registers + are paired to form doubles such that the most + significant part is in $f[N+1] and the least + significant in $f[N] vis: $f[N+1] ||| $f[N]. The + registers are also spilled as a pair and stored as a + double. + + When little-endian the least significant part is + stored first leading to the memory order $f[N] and + then $f[N+1]. + + Unfortunately, when big-endian the most significant + part of the double is stored first, and the least + significant is stored second. This leads to the + registers being ordered in memory as firt $f[N+1] and + then $f[N]. + + For the big-endian case make certain that the + addresses point at the correct (swapped) locations + $f[N] and $f[N+1] pair (keep in mind that + reg_position is decremented each time through the + loop). */ + if ((ireg & 1)) + cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->fp0 + ireg] + .addr = reg_position - mips_abi_regsize (gdbarch); + else + cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->fp0 + ireg] + .addr = reg_position + mips_abi_regsize (gdbarch); + } + else + cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->fp0 + ireg] + .addr = reg_position; + reg_position -= mips_abi_regsize (gdbarch); + } + + cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->pc] + = cache->saved_regs[NUM_REGS + MIPS_RA_REGNUM]; + } + + /* SP_REGNUM, contains the value and not the address. */ + trad_frame_set_value (cache->saved_regs, NUM_REGS + MIPS_SP_REGNUM, cache->base); + + return (*this_cache); +} + +static void +mips_mdebug_frame_this_id (struct frame_info *next_frame, void **this_cache, + struct frame_id *this_id) +{ + struct mips_frame_cache *info = mips_mdebug_frame_cache (next_frame, + this_cache); + (*this_id) = frame_id_build (info->base, frame_func_unwind (next_frame)); +} + +static void +mips_mdebug_frame_prev_register (struct frame_info *next_frame, + void **this_cache, + int regnum, int *optimizedp, + enum lval_type *lvalp, CORE_ADDR *addrp, + int *realnump, void *valuep) +{ + struct mips_frame_cache *info = mips_mdebug_frame_cache (next_frame, + this_cache); + trad_frame_get_prev_register (next_frame, info->saved_regs, regnum, + optimizedp, lvalp, addrp, realnump, valuep); +} + +static const struct frame_unwind mips_mdebug_frame_unwind = +{ + NORMAL_FRAME, + mips_mdebug_frame_this_id, + mips_mdebug_frame_prev_register +}; + +static const struct frame_unwind * +mips_mdebug_frame_sniffer (struct frame_info *next_frame) +{ + CORE_ADDR pc = frame_pc_unwind (next_frame); + CORE_ADDR startaddr = 0; + mips_extra_func_info_t proc_desc; + int kernel_trap; + + /* Don't use this on MIPS16. */ + if (mips_pc_is_mips16 (pc)) + return NULL; + + /* Only use the mdebug frame unwinder on mdebug frames where all the + registers have been saved. Leave hard cases such as no mdebug or + in prologue for the heuristic unwinders. */ + + proc_desc = non_heuristic_proc_desc (pc, &startaddr); + if (proc_desc == NULL) + return NULL; + + /* Not sure exactly what kernel_trap means, but if it means the + kernel saves the registers without a prologue doing it, we better + not examine the prologue to see whether registers have been saved + yet. */ + kernel_trap = PROC_REG_MASK (proc_desc) & 1; + if (kernel_trap) + return &mips_mdebug_frame_unwind; + + /* In any frame other than the innermost or a frame interrupted by a + signal, we assume that all registers have been saved. This + assumes that all register saves in a function happen before the + first function call. */ + if (!in_prologue (pc, PROC_LOW_ADDR (proc_desc))) + return &mips_mdebug_frame_unwind; + + return NULL; +} + +static CORE_ADDR +mips_mdebug_frame_base_address (struct frame_info *next_frame, + void **this_cache) +{ + struct mips_frame_cache *info = mips_mdebug_frame_cache (next_frame, + this_cache); + return info->base; +} + +static const struct frame_base mips_mdebug_frame_base = { + &mips_mdebug_frame_unwind, + mips_mdebug_frame_base_address, + mips_mdebug_frame_base_address, + mips_mdebug_frame_base_address +}; + +static const struct frame_base * +mips_mdebug_frame_base_sniffer (struct frame_info *next_frame) +{ + if (mips_mdebug_frame_sniffer (next_frame) != NULL) + return &mips_mdebug_frame_base; + else + return NULL; +} + +void +mips_mdebug_append_sniffers (struct gdbarch *gdbarch) +{ + frame_unwind_append_sniffer (gdbarch, mips_mdebug_frame_sniffer); + frame_base_append_sniffer (gdbarch, mips_mdebug_frame_base_sniffer); +} + + +extern void _initialize_mips_mdebug_tdep (void); +void +_initialize_mips_mdebug_tdep (void) +{ + mips_pdr_data = register_objfile_data (); +} -- cgit v1.1