binutils-gdb/gdb/moxie-tdep.c

533 lines
14 KiB
C

/* Target-dependent code for Moxie.
Copyright (C) 2009 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 "frame.h"
#include "frame-unwind.h"
#include "frame-base.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "gdbcmd.h"
#include "gdbcore.h"
#include "gdb_string.h"
#include "value.h"
#include "inferior.h"
#include "symfile.h"
#include "objfiles.h"
#include "osabi.h"
#include "language.h"
#include "arch-utils.h"
#include "regcache.h"
#include "trad-frame.h"
#include "dis-asm.h"
#include "gdb_assert.h"
#include "moxie-tdep.h"
/* Local functions. */
extern void _initialize_moxie_tdep (void);
/* Use an invalid address value as 'not available' marker. */
enum { REG_UNAVAIL = (CORE_ADDR) -1 };
struct moxie_frame_cache
{
/* Base address. */
CORE_ADDR base;
CORE_ADDR pc;
LONGEST framesize;
CORE_ADDR saved_regs[MOXIE_NUM_REGS];
CORE_ADDR saved_sp;
};
/* Implement the "frame_align" gdbarch method. */
static CORE_ADDR
moxie_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp)
{
/* Align to the size of an instruction (so that they can safely be
pushed onto the stack. */
return sp & ~1;
}
/* Implement the "breakpoint_from_pc" gdbarch method. */
const static unsigned char *
moxie_breakpoint_from_pc (struct gdbarch *gdbarch,
CORE_ADDR *pcptr, int *lenptr)
{
static unsigned char breakpoint[] = { 0x35, 0x00 };
*lenptr = sizeof (breakpoint);
return breakpoint;
}
/* Moxie register names. */
char *moxie_register_names[] = {
"$fp", "$sp", "$r0", "$r1", "$r2",
"$r3", "$r4", "$r5", "$r6", "$r7",
"$r8", "$r9", "$r10", "$r11", "$r12",
"$r13", "$pc", "$cc" };
/* Implement the "register_name" gdbarch method. */
static const char *
moxie_register_name (struct gdbarch *gdbarch, int reg_nr)
{
if (reg_nr < 0)
return NULL;
if (reg_nr >= MOXIE_NUM_REGS)
return NULL;
return moxie_register_names[reg_nr];
}
/* Implement the "register_type" gdbarch method. */
static struct type *
moxie_register_type (struct gdbarch *gdbarch, int reg_nr)
{
if (reg_nr == MOXIE_PC_REGNUM)
return builtin_type (gdbarch)->builtin_func_ptr;
else if (reg_nr == MOXIE_SP_REGNUM || reg_nr == MOXIE_FP_REGNUM)
return builtin_type (gdbarch)->builtin_data_ptr;
else
return builtin_type_int32;
}
/* Write into appropriate registers a function return value
of type TYPE, given in virtual format. */
static void
moxie_store_return_value (struct type *type, struct regcache *regcache,
const void *valbuf)
{
CORE_ADDR regval;
int len = TYPE_LENGTH (type);
/* Things always get returned in RET1_REGNUM, RET2_REGNUM. */
regval = extract_unsigned_integer (valbuf, len > 4 ? 4 : len);
regcache_cooked_write_unsigned (regcache, RET1_REGNUM, regval);
if (len > 4)
{
regval = extract_unsigned_integer ((gdb_byte *) valbuf + 4, len - 4);
regcache_cooked_write_unsigned (regcache, RET1_REGNUM + 1, regval);
}
}
/* Decode the instructions within the given address range. Decide
when we must have reached the end of the function prologue. If a
frame_info pointer is provided, fill in its saved_regs etc.
Returns the address of the first instruction after the prologue. */
static CORE_ADDR
moxie_analyze_prologue (CORE_ADDR start_addr, CORE_ADDR end_addr,
struct moxie_frame_cache *cache,
struct frame_info *this_frame)
{
CORE_ADDR next_addr;
ULONGEST inst, inst2;
LONGEST offset;
int regnum;
/* Record where the jsra instruction saves the PC and FP. */
cache->saved_regs[MOXIE_PC_REGNUM] = -4;
cache->saved_regs[MOXIE_FP_REGNUM] = 0;
cache->framesize = 0;
if (start_addr >= end_addr)
return end_addr;
for (next_addr = start_addr; next_addr < end_addr; )
{
inst = read_memory_unsigned_integer (next_addr, 2);
/* Match "push $rN" where N is between 2 and 13 inclusive. */
if (inst >= 0x0614 && inst <= 0x061f)
{
regnum = inst & 0x000f;
cache->framesize += 4;
cache->saved_regs[regnum] = cache->framesize;
next_addr += 2;
}
/* Optional stack allocation for args and local vars <= 4
byte. */
else if (inst == 0x01f0) /* ldi.l $r12, X */
{
offset = read_memory_integer (next_addr + 2, 4);
inst2 = read_memory_unsigned_integer (next_addr + 6, 2);
if (inst2 == 0x051f) /* add.l $sp, $r12 */
{
cache->framesize += offset;
}
return (next_addr + 8);
}
else /* This is not a prologue instruction. */
break;
}
return next_addr;
}
/* Find the end of function prologue. */
static CORE_ADDR
moxie_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
{
CORE_ADDR func_addr = 0, func_end = 0;
char *func_name;
/* See if we can determine the end of the prologue via the symbol table.
If so, then return either PC, or the PC after the prologue, whichever
is greater. */
if (find_pc_partial_function (pc, &func_name, &func_addr, &func_end))
{
CORE_ADDR post_prologue_pc
= skip_prologue_using_sal (gdbarch, func_addr);
if (post_prologue_pc != 0)
return max (pc, post_prologue_pc);
else
{
/* Can't determine prologue from the symbol table, need to examine
instructions. */
struct symtab_and_line sal;
struct symbol *sym;
struct moxie_frame_cache cache;
CORE_ADDR plg_end;
memset (&cache, 0, sizeof cache);
plg_end = moxie_analyze_prologue (func_addr,
func_end, &cache, NULL);
/* Found a function. */
sym = lookup_symbol (func_name, NULL, VAR_DOMAIN, NULL);
/* Don't use line number debug info for assembly source
files. */
if (sym && SYMBOL_LANGUAGE (sym) != language_asm)
{
sal = find_pc_line (func_addr, 0);
if (sal.end && sal.end < func_end)
{
/* Found a line number, use it as end of
prologue. */
return sal.end;
}
}
/* No useable line symbol. Use result of prologue parsing
method. */
return plg_end;
}
}
/* No function symbol -- just return the PC. */
return (CORE_ADDR) pc;
}
struct moxie_unwind_cache
{
/* The previous frame's inner most stack address. Used as this
frame ID's stack_addr. */
CORE_ADDR prev_sp;
/* The frame's base, optionally used by the high-level debug info. */
CORE_ADDR base;
int size;
/* How far the SP and r13 (FP) have been offset from the start of
the stack frame (as defined by the previous frame's stack
pointer). */
LONGEST sp_offset;
LONGEST r13_offset;
int uses_frame;
/* Table indicating the location of each and every register. */
struct trad_frame_saved_reg *saved_regs;
};
/* Implement the "read_pc" gdbarch method. */
static CORE_ADDR
moxie_read_pc (struct regcache *regcache)
{
ULONGEST pc;
regcache_cooked_read_unsigned (regcache, MOXIE_PC_REGNUM, &pc);
return pc;
}
/* Implement the "write_pc" gdbarch method. */
static void
moxie_write_pc (struct regcache *regcache, CORE_ADDR val)
{
regcache_cooked_write_unsigned (regcache, MOXIE_PC_REGNUM, val);
}
/* Implement the "unwind_pc" gdbarch method. */
static CORE_ADDR
moxie_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame)
{
return frame_unwind_register_unsigned (next_frame, MOXIE_SP_REGNUM);
}
/* Given a return value in `regbuf' with a type `valtype',
extract and copy its value into `valbuf'. */
static void
moxie_extract_return_value (struct type *type, struct regcache *regcache,
void *dst)
{
bfd_byte *valbuf = dst;
int len = TYPE_LENGTH (type);
ULONGEST tmp;
/* By using store_unsigned_integer we avoid having to do
anything special for small big-endian values. */
regcache_cooked_read_unsigned (regcache, RET1_REGNUM, &tmp);
store_unsigned_integer (valbuf, (len > 4 ? len - 4 : len), tmp);
/* Ignore return values more than 8 bytes in size because the moxie
returns anything more than 8 bytes in the stack. */
if (len > 4)
{
regcache_cooked_read_unsigned (regcache, RET1_REGNUM + 1, &tmp);
store_unsigned_integer (valbuf + len - 4, 4, tmp);
}
}
/* Implement the "return_value" gdbarch method. */
static enum return_value_convention
moxie_return_value (struct gdbarch *gdbarch, struct type *func_type,
struct type *valtype, struct regcache *regcache,
gdb_byte *readbuf, const gdb_byte *writebuf)
{
if (TYPE_LENGTH (valtype) > 8)
return RETURN_VALUE_STRUCT_CONVENTION;
else
{
if (readbuf != NULL)
moxie_extract_return_value (valtype, regcache, readbuf);
if (writebuf != NULL)
moxie_store_return_value (valtype, regcache, writebuf);
return RETURN_VALUE_REGISTER_CONVENTION;
}
}
/* Allocate and initialize a moxie_frame_cache object. */
static struct moxie_frame_cache *
moxie_alloc_frame_cache (void)
{
struct moxie_frame_cache *cache;
int i;
cache = FRAME_OBSTACK_ZALLOC (struct moxie_frame_cache);
cache->base = 0;
cache->saved_sp = 0;
cache->pc = 0;
cache->framesize = 0;
for (i = 0; i < MOXIE_NUM_REGS; ++i)
cache->saved_regs[i] = REG_UNAVAIL;
return cache;
}
/* Populate a moxie_frame_cache object for this_frame. */
static struct moxie_frame_cache *
moxie_frame_cache (struct frame_info *this_frame, void **this_cache)
{
struct moxie_frame_cache *cache;
CORE_ADDR current_pc;
int i;
if (*this_cache)
return *this_cache;
cache = moxie_alloc_frame_cache ();
*this_cache = cache;
cache->base = get_frame_register_unsigned (this_frame, MOXIE_FP_REGNUM);
if (cache->base == 0)
return cache;
cache->pc = get_frame_func (this_frame);
current_pc = get_frame_pc (this_frame);
if (cache->pc)
moxie_analyze_prologue (cache->pc, current_pc, cache, this_frame);
cache->saved_sp = cache->base - cache->framesize;
for (i = 0; i < MOXIE_NUM_REGS; ++i)
if (cache->saved_regs[i] != REG_UNAVAIL)
cache->saved_regs[i] = cache->base - cache->saved_regs[i];
return cache;
}
/* Implement the "unwind_pc" gdbarch method. */
static CORE_ADDR
moxie_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
{
return frame_unwind_register_unsigned (next_frame, MOXIE_PC_REGNUM);
}
/* Given a GDB frame, determine the address of the calling function's
frame. This will be used to create a new GDB frame struct. */
static void
moxie_frame_this_id (struct frame_info *this_frame,
void **this_prologue_cache, struct frame_id *this_id)
{
struct moxie_frame_cache *cache = moxie_frame_cache (this_frame,
this_prologue_cache);
/* This marks the outermost frame. */
if (cache->base == 0)
return;
*this_id = frame_id_build (cache->saved_sp, cache->pc);
}
/* Get the value of register regnum in the previous stack frame. */
static struct value *
moxie_frame_prev_register (struct frame_info *this_frame,
void **this_prologue_cache, int regnum)
{
struct moxie_frame_cache *cache = moxie_frame_cache (this_frame,
this_prologue_cache);
gdb_assert (regnum >= 0);
if (regnum == MOXIE_SP_REGNUM && cache->saved_sp)
return frame_unwind_got_constant (this_frame, regnum, cache->saved_sp);
if (regnum < MOXIE_NUM_REGS && cache->saved_regs[regnum] != REG_UNAVAIL)
return frame_unwind_got_memory (this_frame, regnum,
cache->saved_regs[regnum]);
return frame_unwind_got_register (this_frame, regnum, regnum);
}
static const struct frame_unwind moxie_frame_unwind = {
NORMAL_FRAME,
moxie_frame_this_id,
moxie_frame_prev_register,
NULL,
default_frame_sniffer
};
/* Return the base address of this_frame. */
static CORE_ADDR
moxie_frame_base_address (struct frame_info *this_frame, void **this_cache)
{
struct moxie_frame_cache *cache = moxie_frame_cache (this_frame,
this_cache);
return cache->base;
}
static const struct frame_base moxie_frame_base = {
&moxie_frame_unwind,
moxie_frame_base_address,
moxie_frame_base_address,
moxie_frame_base_address
};
static struct frame_id
moxie_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
{
CORE_ADDR sp = get_frame_register_unsigned (this_frame, MOXIE_SP_REGNUM);
return frame_id_build (sp, get_frame_pc (this_frame));
}
/* Allocate and initialize the moxie gdbarch object. */
static struct gdbarch *
moxie_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
{
struct gdbarch *gdbarch;
struct gdbarch_tdep *tdep;
/* If there is already a candidate, use it. */
arches = gdbarch_list_lookup_by_info (arches, &info);
if (arches != NULL)
return arches->gdbarch;
/* Allocate space for the new architecture. */
tdep = XMALLOC (struct gdbarch_tdep);
gdbarch = gdbarch_alloc (&info, tdep);
set_gdbarch_read_pc (gdbarch, moxie_read_pc);
set_gdbarch_write_pc (gdbarch, moxie_write_pc);
set_gdbarch_unwind_sp (gdbarch, moxie_unwind_sp);
set_gdbarch_num_regs (gdbarch, MOXIE_NUM_REGS);
set_gdbarch_sp_regnum (gdbarch, MOXIE_SP_REGNUM);
set_gdbarch_register_name (gdbarch, moxie_register_name);
set_gdbarch_register_type (gdbarch, moxie_register_type);
set_gdbarch_return_value (gdbarch, moxie_return_value);
set_gdbarch_skip_prologue (gdbarch, moxie_skip_prologue);
set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
set_gdbarch_breakpoint_from_pc (gdbarch, moxie_breakpoint_from_pc);
set_gdbarch_frame_align (gdbarch, moxie_frame_align);
frame_base_set_default (gdbarch, &moxie_frame_base);
/* Methods for saving / extracting a dummy frame's ID. The ID's
stack address must match the SP value returned by
PUSH_DUMMY_CALL, and saved by generic_save_dummy_frame_tos. */
set_gdbarch_dummy_id (gdbarch, moxie_dummy_id);
set_gdbarch_unwind_pc (gdbarch, moxie_unwind_pc);
set_gdbarch_print_insn (gdbarch, print_insn_moxie);
/* Hook in ABI-specific overrides, if they have been registered. */
gdbarch_init_osabi (info, gdbarch);
/* Hook in the default unwinders. */
frame_unwind_append_unwinder (gdbarch, &moxie_frame_unwind);
/* Support simple overlay manager. */
set_gdbarch_overlay_update (gdbarch, simple_overlay_update);
return gdbarch;
}
/* Register this machine's init routine. */
void
_initialize_moxie_tdep (void)
{
register_gdbarch_init (bfd_arch_moxie, moxie_gdbarch_init);
}