441 lines
13 KiB
C
441 lines
13 KiB
C
/* Print VAX instructions for GDB, the GNU debugger.
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Copyright 1986, 1989, 1991, 1992, 1995, 1996, 1998, 1999, 2000,
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2002, 2003, 2004 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "symtab.h"
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#include "opcode/vax.h"
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#include "gdbcore.h"
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#include "inferior.h"
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#include "regcache.h"
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#include "frame.h"
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#include "frame-base.h"
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#include "frame-unwind.h"
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#include "trad-frame.h"
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#include "value.h"
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#include "arch-utils.h"
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#include "gdb_string.h"
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#include "osabi.h"
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#include "dis-asm.h"
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#include "vax-tdep.h"
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/* Return the name of register REGNUM. */
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static const char *
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vax_register_name (int regnum)
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{
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static char *register_names[] =
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{
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"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
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"r8", "r9", "r10", "r11", "ap", "fp", "sp", "pc",
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"ps",
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};
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if (regnum >= 0 && regnum < ARRAY_SIZE (register_names))
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return register_names[regnum];
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return NULL;
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}
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/* Return the GDB type object for the "standard" data type of data in
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register REGNUM. */
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static struct type *
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vax_register_type (struct gdbarch *gdbarch, int regnum)
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{
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return builtin_type_int;
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}
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static void
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vax_push_dummy_frame (void)
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{
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CORE_ADDR sp = read_register (SP_REGNUM);
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int regnum;
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sp = push_word (sp, 0); /* arglist */
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for (regnum = 11; regnum >= 0; regnum--)
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sp = push_word (sp, read_register (regnum));
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sp = push_word (sp, read_register (PC_REGNUM));
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sp = push_word (sp, read_register (VAX_FP_REGNUM));
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sp = push_word (sp, read_register (VAX_AP_REGNUM));
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sp = push_word (sp, (read_register (PS_REGNUM) & 0xffef) + 0x2fff0000);
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sp = push_word (sp, 0);
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write_register (SP_REGNUM, sp);
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write_register (VAX_FP_REGNUM, sp);
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write_register (VAX_AP_REGNUM, sp + (17 * 4));
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}
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static void
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vax_pop_frame (void)
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{
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CORE_ADDR fp = read_register (VAX_FP_REGNUM);
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int regnum;
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int regmask = read_memory_integer (fp + 4, 4);
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write_register (PS_REGNUM,
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(regmask & 0xffff)
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| (read_register (PS_REGNUM) & 0xffff0000));
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write_register (PC_REGNUM, read_memory_integer (fp + 16, 4));
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write_register (VAX_FP_REGNUM, read_memory_integer (fp + 12, 4));
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write_register (VAX_AP_REGNUM, read_memory_integer (fp + 8, 4));
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fp += 16;
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for (regnum = 0; regnum < 12; regnum++)
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if (regmask & (0x10000 << regnum))
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write_register (regnum, read_memory_integer (fp += 4, 4));
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fp = fp + 4 + ((regmask >> 30) & 3);
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if (regmask & 0x20000000)
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{
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regnum = read_memory_integer (fp, 4);
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fp += (regnum + 1) * 4;
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}
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write_register (SP_REGNUM, fp);
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flush_cached_frames ();
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}
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/* The VAX call dummy sequence:
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calls #69, @#32323232
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bpt
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It is 8 bytes long. The address and argc are patched by
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vax_fix_call_dummy(). */
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static LONGEST vax_call_dummy_words[] = { 0x329f69fb, 0x03323232 };
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static int sizeof_vax_call_dummy_words = sizeof(vax_call_dummy_words);
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static void
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vax_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
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struct value **args, struct type *type, int gcc_p)
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{
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dummy[1] = nargs;
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store_unsigned_integer (dummy + 3, 4, fun);
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}
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static void
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vax_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
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{
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write_register (1, addr);
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}
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static void
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vax_extract_return_value (struct type *valtype, char *regbuf, char *valbuf)
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{
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memcpy (valbuf, regbuf + DEPRECATED_REGISTER_BYTE (0), TYPE_LENGTH (valtype));
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}
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static void
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vax_store_return_value (struct type *valtype, char *valbuf)
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{
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deprecated_write_register_bytes (0, valbuf, TYPE_LENGTH (valtype));
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}
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/* Use the program counter to determine the contents and size of a
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breakpoint instruction. Return a pointer to a string of bytes that
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encode a breakpoint instruction, store the length of the string in
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*LEN and optionally adjust *PC to point to the correct memory
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location for inserting the breakpoint. */
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static const unsigned char *
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vax_breakpoint_from_pc (CORE_ADDR *pc, int *len)
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{
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static unsigned char break_insn[] = { 3 };
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*len = sizeof (break_insn);
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return break_insn;
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}
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/* Advance PC across any function entry prologue instructions
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to reach some "real" code. */
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static CORE_ADDR
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vax_skip_prologue (CORE_ADDR pc)
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{
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int op = (unsigned char) read_memory_integer (pc, 1);
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if (op == 0x11)
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pc += 2; /* skip brb */
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if (op == 0x31)
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pc += 3; /* skip brw */
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if (op == 0xC2
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&& ((unsigned char) read_memory_integer (pc + 2, 1)) == 0x5E)
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pc += 3; /* skip subl2 */
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if (op == 0x9E
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&& ((unsigned char) read_memory_integer (pc + 1, 1)) == 0xAE
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&& ((unsigned char) read_memory_integer (pc + 3, 1)) == 0x5E)
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pc += 4; /* skip movab */
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if (op == 0x9E
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&& ((unsigned char) read_memory_integer (pc + 1, 1)) == 0xCE
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&& ((unsigned char) read_memory_integer (pc + 4, 1)) == 0x5E)
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pc += 5; /* skip movab */
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if (op == 0x9E
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&& ((unsigned char) read_memory_integer (pc + 1, 1)) == 0xEE
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&& ((unsigned char) read_memory_integer (pc + 6, 1)) == 0x5E)
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pc += 7; /* skip movab */
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return pc;
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}
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/* Unwinding the stack is relatively easy since the VAX has a
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dedicated frame pointer, and frames are set up automatically as the
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result of a function call. Most of the relevant information can be
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inferred from the documentation of the Procedure Call Instructions
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in the VAX MACRO and Instruction Set Reference Manual. */
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struct vax_frame_cache
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{
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/* Base address. */
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CORE_ADDR base;
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/* Table of saved registers. */
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struct trad_frame_saved_reg *saved_regs;
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};
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struct vax_frame_cache *
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vax_frame_cache (struct frame_info *next_frame, void **this_cache)
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{
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struct vax_frame_cache *cache;
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CORE_ADDR addr;
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ULONGEST mask;
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int regnum;
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if (*this_cache)
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return *this_cache;
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/* Allocate a new cache. */
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cache = FRAME_OBSTACK_ZALLOC (struct vax_frame_cache);
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cache->saved_regs = trad_frame_alloc_saved_regs (next_frame);
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/* The frame pointer is used as the base for the frame. */
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cache->base = frame_unwind_register_unsigned (next_frame, VAX_FP_REGNUM);
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if (cache->base == 0)
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return cache;
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/* The register save mask and control bits determine the layout of
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the stack frame. */
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mask = get_frame_memory_unsigned (next_frame, cache->base + 4, 4) >> 16;
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/* These are always saved. */
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cache->saved_regs[VAX_PC_REGNUM].addr = cache->base + 16;
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cache->saved_regs[VAX_FP_REGNUM].addr = cache->base + 12;
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cache->saved_regs[VAX_AP_REGNUM].addr = cache->base + 8;
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cache->saved_regs[VAX_PS_REGNUM].addr = cache->base + 4;
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/* Scan the register save mask and record the location of the saved
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registers. */
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addr = cache->base + 20;
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for (regnum = 0; regnum < VAX_AP_REGNUM; regnum++)
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{
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if (mask & (1 << regnum))
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{
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cache->saved_regs[regnum].addr = addr;
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addr += 4;
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}
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}
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/* The CALLS/CALLG flag determines whether this frame has a General
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Argument List or a Stack Argument List. */
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if (mask & (1 << 13))
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{
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ULONGEST numarg;
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/* This is a procedure with Stack Argument List. Adjust the
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stack address for the arguments thet were pushed onto the
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stack. The return instruction will automatically pop the
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arguments from the stack. */
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numarg = get_frame_memory_unsigned (next_frame, addr, 1);
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addr += 4 + numarg * 4;
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}
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/* Bits 1:0 of the stack pointer were saved in the control bits. */
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trad_frame_set_value (cache->saved_regs, VAX_SP_REGNUM, addr + (mask >> 14));
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return cache;
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}
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static void
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vax_frame_this_id (struct frame_info *next_frame, void **this_cache,
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struct frame_id *this_id)
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{
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struct vax_frame_cache *cache = vax_frame_cache (next_frame, this_cache);
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/* This marks the outermost frame. */
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if (cache->base == 0)
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return;
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(*this_id) = frame_id_build (cache->base, frame_pc_unwind (next_frame));
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}
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static void
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vax_frame_prev_register (struct frame_info *next_frame, void **this_cache,
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int regnum, int *optimizedp,
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enum lval_type *lvalp, CORE_ADDR *addrp,
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int *realnump, void *valuep)
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{
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struct vax_frame_cache *cache = vax_frame_cache (next_frame, this_cache);
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trad_frame_prev_register (next_frame, cache->saved_regs, regnum,
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optimizedp, lvalp, addrp, realnump, valuep);
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}
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static const struct frame_unwind vax_frame_unwind =
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{
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NORMAL_FRAME,
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vax_frame_this_id,
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vax_frame_prev_register
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};
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static const struct frame_unwind *
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vax_frame_sniffer (struct frame_info *next_frame)
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{
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return &vax_frame_unwind;
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}
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static CORE_ADDR
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vax_frame_base_address (struct frame_info *next_frame, void **this_cache)
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{
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struct vax_frame_cache *cache = vax_frame_cache (next_frame, this_cache);
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return cache->base;
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}
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static CORE_ADDR
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vax_frame_args_address (struct frame_info *next_frame, void **this_cache)
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{
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return frame_unwind_register_unsigned (next_frame, VAX_AP_REGNUM);
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}
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static const struct frame_base vax_frame_base =
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{
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&vax_frame_unwind,
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vax_frame_base_address,
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vax_frame_base_address,
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vax_frame_args_address
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};
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/* Return number of arguments for FRAME. */
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static int
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vax_frame_num_args (struct frame_info *frame)
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{
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CORE_ADDR args;
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/* Assume that the argument pointer for the outermost frame is
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hosed, as is the case on NetBSD/vax ELF. */
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if (get_frame_base (frame) == 0)
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return 0;
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args = get_frame_register_unsigned (frame, VAX_AP_REGNUM);
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return get_frame_memory_unsigned (frame, args, 1);
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}
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static CORE_ADDR
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vax_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
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{
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return frame_unwind_register_unsigned (next_frame, VAX_PC_REGNUM);
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}
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/* Initialize the current architecture based on INFO. If possible, re-use an
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architecture from ARCHES, which is a list of architectures already created
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during this debugging session.
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Called e.g. at program startup, when reading a core file, and when reading
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a binary file. */
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static struct gdbarch *
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vax_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
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{
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struct gdbarch *gdbarch;
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/* If there is already a candidate, use it. */
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arches = gdbarch_list_lookup_by_info (arches, &info);
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if (arches != NULL)
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return arches->gdbarch;
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gdbarch = gdbarch_alloc (&info, NULL);
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/* Register info */
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set_gdbarch_num_regs (gdbarch, VAX_NUM_REGS);
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set_gdbarch_register_name (gdbarch, vax_register_name);
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set_gdbarch_register_type (gdbarch, vax_register_type);
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set_gdbarch_sp_regnum (gdbarch, VAX_SP_REGNUM);
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set_gdbarch_pc_regnum (gdbarch, VAX_PC_REGNUM);
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set_gdbarch_ps_regnum (gdbarch, VAX_PS_REGNUM);
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/* Frame and stack info */
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set_gdbarch_skip_prologue (gdbarch, vax_skip_prologue);
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set_gdbarch_frame_num_args (gdbarch, vax_frame_num_args);
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set_gdbarch_frame_args_skip (gdbarch, 4);
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/* Stack grows downward. */
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set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
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/* Return value info */
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set_gdbarch_deprecated_store_struct_return (gdbarch, vax_store_struct_return);
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set_gdbarch_deprecated_extract_return_value (gdbarch, vax_extract_return_value);
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set_gdbarch_deprecated_store_return_value (gdbarch, vax_store_return_value);
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/* Call dummy info */
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set_gdbarch_deprecated_push_dummy_frame (gdbarch, vax_push_dummy_frame);
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set_gdbarch_deprecated_pop_frame (gdbarch, vax_pop_frame);
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set_gdbarch_call_dummy_location (gdbarch, ON_STACK);
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set_gdbarch_deprecated_call_dummy_words (gdbarch, vax_call_dummy_words);
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set_gdbarch_deprecated_sizeof_call_dummy_words (gdbarch, sizeof_vax_call_dummy_words);
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set_gdbarch_deprecated_fix_call_dummy (gdbarch, vax_fix_call_dummy);
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set_gdbarch_deprecated_call_dummy_breakpoint_offset (gdbarch, 7);
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set_gdbarch_deprecated_use_generic_dummy_frames (gdbarch, 0);
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set_gdbarch_deprecated_pc_in_call_dummy (gdbarch, deprecated_pc_in_call_dummy_on_stack);
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/* Breakpoint info */
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set_gdbarch_breakpoint_from_pc (gdbarch, vax_breakpoint_from_pc);
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/* Misc info */
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set_gdbarch_function_start_offset (gdbarch, 2);
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set_gdbarch_believe_pcc_promotion (gdbarch, 1);
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/* Should be using push_dummy_call. */
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set_gdbarch_deprecated_dummy_write_sp (gdbarch, deprecated_write_sp);
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set_gdbarch_unwind_pc (gdbarch, vax_unwind_pc);
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frame_base_set_default (gdbarch, &vax_frame_base);
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/* Hook in ABI-specific overrides, if they have been registered. */
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gdbarch_init_osabi (info, gdbarch);
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frame_unwind_append_sniffer (gdbarch, vax_frame_sniffer);
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set_gdbarch_print_insn (gdbarch, print_insn_vax);
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return (gdbarch);
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}
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extern initialize_file_ftype _initialize_vax_tdep; /* -Wmissing-prototypes */
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void
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_initialize_vax_tdep (void)
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{
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gdbarch_register (bfd_arch_vax, vax_gdbarch_init, NULL);
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}
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