/* Target-dependent code for the ALPHA architecture, for GDB, the GNU Debugger.
- Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002
- Free Software Foundation, Inc.
+
+ Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
+ 2003, 2005, 2006, 2007, 2008, 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 2 of the License, or
+ 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,
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. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
+#include "doublest.h"
#include "frame.h"
+#include "frame-unwind.h"
+#include "frame-base.h"
+#include "dwarf2-frame.h"
#include "inferior.h"
#include "symtab.h"
#include "value.h"
#include "gdb_string.h"
#include "linespec.h"
#include "regcache.h"
-#include "doublest.h"
+#include "reggroups.h"
+#include "arch-utils.h"
+#include "osabi.h"
+#include "block.h"
+#include "infcall.h"
+#include "trad-frame.h"
+
+#include "elf-bfd.h"
+
+#include "alpha-tdep.h"
+
+\f
+/* Return the name of the REGNO register.
-struct frame_extra_info
+ An empty name corresponds to a register number that used to
+ be used for a virtual register. That virtual register has
+ been removed, but the index is still reserved to maintain
+ compatibility with existing remote alpha targets. */
+
+static const char *
+alpha_register_name (struct gdbarch *gdbarch, int regno)
+{
+ static const char * const register_names[] =
{
- alpha_extra_func_info_t proc_desc;
- int localoff;
- int pc_reg;
+ "v0", "t0", "t1", "t2", "t3", "t4", "t5", "t6",
+ "t7", "s0", "s1", "s2", "s3", "s4", "s5", "fp",
+ "a0", "a1", "a2", "a3", "a4", "a5", "t8", "t9",
+ "t10", "t11", "ra", "t12", "at", "gp", "sp", "zero",
+ "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
+ "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",
+ "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",
+ "f24", "f25", "f26", "f27", "f28", "f29", "f30", "fpcr",
+ "pc", "", "unique"
};
-/* FIXME: Some of this code should perhaps be merged with mips-tdep.c. */
+ if (regno < 0)
+ return NULL;
+ if (regno >= ARRAY_SIZE(register_names))
+ return NULL;
+ return register_names[regno];
+}
-/* Prototypes for local functions. */
+static int
+alpha_cannot_fetch_register (struct gdbarch *gdbarch, int regno)
+{
+ return (regno == ALPHA_ZERO_REGNUM
+ || strlen (alpha_register_name (gdbarch, regno)) == 0);
+}
-static void alpha_find_saved_regs (struct frame_info *);
+static int
+alpha_cannot_store_register (struct gdbarch *gdbarch, int regno)
+{
+ return (regno == ALPHA_ZERO_REGNUM
+ || strlen (alpha_register_name (gdbarch, regno)) == 0);
+}
-static alpha_extra_func_info_t push_sigtramp_desc (CORE_ADDR low_addr);
+static struct type *
+alpha_register_type (struct gdbarch *gdbarch, int regno)
+{
+ if (regno == ALPHA_SP_REGNUM || regno == ALPHA_GP_REGNUM)
+ return builtin_type (gdbarch)->builtin_data_ptr;
+ if (regno == ALPHA_PC_REGNUM)
+ return builtin_type (gdbarch)->builtin_func_ptr;
-static CORE_ADDR read_next_frame_reg (struct frame_info *, int);
+ /* Don't need to worry about little vs big endian until
+ some jerk tries to port to alpha-unicosmk. */
+ if (regno >= ALPHA_FP0_REGNUM && regno < ALPHA_FP0_REGNUM + 31)
+ return builtin_type_ieee_double;
-static CORE_ADDR heuristic_proc_start (CORE_ADDR);
+ return builtin_type_int64;
+}
-static alpha_extra_func_info_t heuristic_proc_desc (CORE_ADDR,
- CORE_ADDR,
- struct frame_info *);
+/* Is REGNUM a member of REGGROUP? */
-static alpha_extra_func_info_t find_proc_desc (CORE_ADDR,
- struct frame_info *);
+static int
+alpha_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
+ struct reggroup *group)
+{
+ /* Filter out any registers eliminated, but whose regnum is
+ reserved for backward compatibility, e.g. the vfp. */
+ if (gdbarch_register_name (gdbarch, regnum) == NULL
+ || *gdbarch_register_name (gdbarch, regnum) == '\0')
+ return 0;
-#if 0
-static int alpha_in_lenient_prologue (CORE_ADDR, CORE_ADDR);
-#endif
+ if (group == all_reggroup)
+ return 1;
-static void reinit_frame_cache_sfunc (char *, int, struct cmd_list_element *);
+ /* Zero should not be saved or restored. Technically it is a general
+ register (just as $f31 would be a float if we represented it), but
+ there's no point displaying it during "info regs", so leave it out
+ of all groups except for "all". */
+ if (regnum == ALPHA_ZERO_REGNUM)
+ return 0;
-static CORE_ADDR after_prologue (CORE_ADDR pc,
- alpha_extra_func_info_t proc_desc);
+ /* All other registers are saved and restored. */
+ if (group == save_reggroup || group == restore_reggroup)
+ return 1;
-static int alpha_in_prologue (CORE_ADDR pc,
- alpha_extra_func_info_t proc_desc);
+ /* All other groups are non-overlapping. */
-static int alpha_about_to_return (CORE_ADDR pc);
+ /* Since this is really a PALcode memory slot... */
+ if (regnum == ALPHA_UNIQUE_REGNUM)
+ return group == system_reggroup;
-void _initialize_alpha_tdep (void);
+ /* Force the FPCR to be considered part of the floating point state. */
+ if (regnum == ALPHA_FPCR_REGNUM)
+ return group == float_reggroup;
-/* Heuristic_proc_start may hunt through the text section for a long
- time across a 2400 baud serial line. Allows the user to limit this
- search. */
-static unsigned int heuristic_fence_post = 0;
-/* *INDENT-OFF* */
-/* Layout of a stack frame on the alpha:
-
- | |
- pdr members: | 7th ... nth arg, |
- | `pushed' by caller. |
- | |
-----------------|-------------------------------|<-- old_sp == vfp
- ^ ^ ^ ^ | |
- | | | | | |
- | |localoff | Copies of 1st .. 6th |
- | | | | | argument if necessary. |
- | | | v | |
- | | | --- |-------------------------------|<-- FRAME_LOCALS_ADDRESS
- | | | | |
- | | | | Locals and temporaries. |
- | | | | |
- | | | |-------------------------------|
- | | | | |
- |-fregoffset | Saved float registers. |
- | | | | F9 |
- | | | | . |
- | | | | . |
- | | | | F2 |
- | | v | |
- | | -------|-------------------------------|
- | | | |
- | | | Saved registers. |
- | | | S6 |
- |-regoffset | . |
- | | | . |
- | | | S0 |
- | | | pdr.pcreg |
- | v | |
- | ----------|-------------------------------|
- | | |
- frameoffset | Argument build area, gets |
- | | 7th ... nth arg for any |
- | | called procedure. |
- v | |
- -------------|-------------------------------|<-- sp
- | |
-*/
-/* *INDENT-ON* */
-
-
-
-#define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) /* least address */
-/* These next two fields are kind of being hijacked. I wonder if
- iline is too small for the values it needs to hold, if GDB is
- running on a 32-bit host. */
-#define PROC_HIGH_ADDR(proc) ((proc)->pdr.iline) /* upper address bound */
-#define PROC_DUMMY_FRAME(proc) ((proc)->pdr.cbLineOffset) /*CALL_DUMMY frame */
-#define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset)
-#define PROC_FRAME_REG(proc) ((proc)->pdr.framereg)
-#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)
-#define PROC_LOCALOFF(proc) ((proc)->pdr.localoff)
-#define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym)
-#define _PROC_MAGIC_ 0x0F0F0F0F
-#define PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym == _PROC_MAGIC_)
-#define SET_PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym = _PROC_MAGIC_)
-
-struct linked_proc_info
- {
- struct alpha_extra_func_info info;
- struct linked_proc_info *next;
- }
- *linked_proc_desc_table = NULL;
-\f
-int
-alpha_osf_in_sigtramp (CORE_ADDR pc, char *func_name)
-{
- return (func_name != NULL && STREQ ("__sigtramp", func_name));
+ if (regnum >= ALPHA_FP0_REGNUM && regnum < ALPHA_FP0_REGNUM + 31)
+ return group == float_reggroup;
+ else
+ return group == general_reggroup;
}
-/* Under GNU/Linux, signal handler invocations can be identified by the
- designated code sequence that is used to return from a signal
- handler. In particular, the return address of a signal handler
- points to the following sequence (the first instruction is quadword
- aligned):
-
- bis $30,$30,$16
- addq $31,0x67,$0
- call_pal callsys
-
- Each instruction has a unique encoding, so we simply attempt to
- match the instruction the pc is pointing to with any of the above
- instructions. If there is a hit, we know the offset to the start
- of the designated sequence and can then check whether we really are
- executing in a designated sequence. If not, -1 is returned,
- otherwise the offset from the start of the desingated sequence is
- returned.
-
- There is a slight chance of false hits: code could jump into the
- middle of the designated sequence, in which case there is no
- guarantee that we are in the middle of a sigreturn syscall. Don't
- think this will be a problem in praxis, though.
- */
-
-#ifndef TM_LINUXALPHA_H
-/* HACK: Provide a prototype when compiling this file for non
- linuxalpha targets. */
-long alpha_linux_sigtramp_offset (CORE_ADDR pc);
-#endif
-long
-alpha_linux_sigtramp_offset (CORE_ADDR pc)
-{
- unsigned int i[3], w;
- long off;
-
- if (read_memory_nobpt (pc, (char *) &w, 4) != 0)
- return -1;
+/* The following represents exactly the conversion performed by
+ the LDS instruction. This applies to both single-precision
+ floating point and 32-bit integers. */
- off = -1;
- switch (w)
+static void
+alpha_lds (void *out, const void *in)
+{
+ ULONGEST mem = extract_unsigned_integer (in, 4);
+ ULONGEST frac = (mem >> 0) & 0x7fffff;
+ ULONGEST sign = (mem >> 31) & 1;
+ ULONGEST exp_msb = (mem >> 30) & 1;
+ ULONGEST exp_low = (mem >> 23) & 0x7f;
+ ULONGEST exp, reg;
+
+ exp = (exp_msb << 10) | exp_low;
+ if (exp_msb)
{
- case 0x47de0410:
- off = 0;
- break; /* bis $30,$30,$16 */
- case 0x43ecf400:
- off = 4;
- break; /* addq $31,0x67,$0 */
- case 0x00000083:
- off = 8;
- break; /* call_pal callsys */
- default:
- return -1;
+ if (exp_low == 0x7f)
+ exp = 0x7ff;
}
- pc -= off;
- if (pc & 0x7)
+ else
{
- /* designated sequence is not quadword aligned */
- return -1;
+ if (exp_low != 0x00)
+ exp |= 0x380;
}
- if (read_memory_nobpt (pc, (char *) i, sizeof (i)) != 0)
- return -1;
-
- if (i[0] == 0x47de0410 && i[1] == 0x43ecf400 && i[2] == 0x00000083)
- return off;
-
- return -1;
+ reg = (sign << 63) | (exp << 52) | (frac << 29);
+ store_unsigned_integer (out, 8, reg);
}
-\f
-/* Under OSF/1, the __sigtramp routine is frameless and has a frame
- size of zero, but we are able to backtrace through it. */
-CORE_ADDR
-alpha_osf_skip_sigtramp_frame (struct frame_info *frame, CORE_ADDR pc)
+/* Similarly, this represents exactly the conversion performed by
+ the STS instruction. */
+
+static void
+alpha_sts (void *out, const void *in)
{
- char *name;
- find_pc_partial_function (pc, &name, (CORE_ADDR *) NULL, (CORE_ADDR *) NULL);
- if (IN_SIGTRAMP (pc, name))
- return frame->frame;
- else
- return 0;
+ ULONGEST reg, mem;
+
+ reg = extract_unsigned_integer (in, 8);
+ mem = ((reg >> 32) & 0xc0000000) | ((reg >> 29) & 0x3fffffff);
+ store_unsigned_integer (out, 4, mem);
}
-\f
-/* Dynamically create a signal-handler caller procedure descriptor for
- the signal-handler return code starting at address LOW_ADDR. The
- descriptor is added to the linked_proc_desc_table. */
+/* The alpha needs a conversion between register and memory format if the
+ register is a floating point register and memory format is float, as the
+ register format must be double or memory format is an integer with 4
+ bytes or less, as the representation of integers in floating point
+ registers is different. */
-static alpha_extra_func_info_t
-push_sigtramp_desc (CORE_ADDR low_addr)
+static int
+alpha_convert_register_p (struct gdbarch *gdbarch, int regno, struct type *type)
{
- struct linked_proc_info *link;
- alpha_extra_func_info_t proc_desc;
-
- link = (struct linked_proc_info *)
- xmalloc (sizeof (struct linked_proc_info));
- link->next = linked_proc_desc_table;
- linked_proc_desc_table = link;
-
- proc_desc = &link->info;
-
- proc_desc->numargs = 0;
- PROC_LOW_ADDR (proc_desc) = low_addr;
- PROC_HIGH_ADDR (proc_desc) = low_addr + 3 * 4;
- PROC_DUMMY_FRAME (proc_desc) = 0;
- PROC_FRAME_OFFSET (proc_desc) = 0x298; /* sizeof(struct sigcontext_struct) */
- PROC_FRAME_REG (proc_desc) = SP_REGNUM;
- PROC_REG_MASK (proc_desc) = 0xffff;
- PROC_FREG_MASK (proc_desc) = 0xffff;
- PROC_PC_REG (proc_desc) = 26;
- PROC_LOCALOFF (proc_desc) = 0;
- SET_PROC_DESC_IS_DYN_SIGTRAMP (proc_desc);
- return (proc_desc);
+ return (regno >= ALPHA_FP0_REGNUM && regno < ALPHA_FP0_REGNUM + 31
+ && TYPE_LENGTH (type) != 8);
}
-\f
-char *
-alpha_register_name (int regno)
+static void
+alpha_register_to_value (struct frame_info *frame, int regnum,
+ struct type *valtype, gdb_byte *out)
{
- static char *register_names[] =
- {
- "v0", "t0", "t1", "t2", "t3", "t4", "t5", "t6",
- "t7", "s0", "s1", "s2", "s3", "s4", "s5", "fp",
- "a0", "a1", "a2", "a3", "a4", "a5", "t8", "t9",
- "t10", "t11", "ra", "t12", "at", "gp", "sp", "zero",
- "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
- "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",
- "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",
- "f24", "f25", "f26", "f27", "f28", "f29", "f30", "fpcr",
- "pc", "vfp",
- };
+ gdb_byte in[MAX_REGISTER_SIZE];
- if (regno < 0)
- return (NULL);
- if (regno >= (sizeof(register_names) / sizeof(*register_names)))
- return (NULL);
- return (register_names[regno]);
+ frame_register_read (frame, regnum, in);
+ switch (TYPE_LENGTH (valtype))
+ {
+ case 4:
+ alpha_sts (out, in);
+ break;
+ default:
+ error (_("Cannot retrieve value from floating point register"));
+ }
}
-int
-alpha_cannot_fetch_register (int regno)
+static void
+alpha_value_to_register (struct frame_info *frame, int regnum,
+ struct type *valtype, const gdb_byte *in)
{
- return (regno == FP_REGNUM || regno == ZERO_REGNUM);
-}
+ gdb_byte out[MAX_REGISTER_SIZE];
-int
-alpha_cannot_store_register (int regno)
-{
- return (regno == FP_REGNUM || regno == ZERO_REGNUM);
+ switch (TYPE_LENGTH (valtype))
+ {
+ case 4:
+ alpha_lds (out, in);
+ break;
+ default:
+ error (_("Cannot store value in floating point register"));
+ }
+ put_frame_register (frame, regnum, out);
}
-int
-alpha_register_convertible (int regno)
-{
- return (regno >= FP0_REGNUM && regno <= FP0_REGNUM + 31);
-}
\f
+/* The alpha passes the first six arguments in the registers, the rest on
+ the stack. The register arguments are stored in ARG_REG_BUFFER, and
+ then moved into the register file; this simplifies the passing of a
+ large struct which extends from the registers to the stack, plus avoids
+ three ptrace invocations per word.
-/* Guaranteed to set frame->saved_regs to some values (it never leaves it
- NULL). */
+ We don't bother tracking which register values should go in integer
+ regs or fp regs; we load the same values into both.
-static void
-alpha_find_saved_regs (struct frame_info *frame)
+ If the called function is returning a structure, the address of the
+ structure to be returned is passed as a hidden first argument. */
+
+static CORE_ADDR
+alpha_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
+ struct regcache *regcache, CORE_ADDR bp_addr,
+ int nargs, struct value **args, CORE_ADDR sp,
+ int struct_return, CORE_ADDR struct_addr)
{
- int ireg;
- CORE_ADDR reg_position;
- unsigned long mask;
- alpha_extra_func_info_t proc_desc;
- int returnreg;
-
- frame_saved_regs_zalloc (frame);
-
- /* If it is the frame for __sigtramp, the saved registers are located
- in a sigcontext structure somewhere on the stack. __sigtramp
- passes a pointer to the sigcontext structure on the stack.
- If the stack layout for __sigtramp changes, or if sigcontext offsets
- change, we might have to update this code. */
-#ifndef SIGFRAME_PC_OFF
-#define SIGFRAME_PC_OFF (2 * 8)
-#define SIGFRAME_REGSAVE_OFF (4 * 8)
-#define SIGFRAME_FPREGSAVE_OFF (SIGFRAME_REGSAVE_OFF + 32 * 8 + 8)
-#endif
- if (frame->signal_handler_caller)
+ int i;
+ int accumulate_size = struct_return ? 8 : 0;
+ struct alpha_arg
{
- CORE_ADDR sigcontext_addr;
+ gdb_byte *contents;
+ int len;
+ int offset;
+ };
+ struct alpha_arg *alpha_args
+ = (struct alpha_arg *) alloca (nargs * sizeof (struct alpha_arg));
+ struct alpha_arg *m_arg;
+ gdb_byte arg_reg_buffer[ALPHA_REGISTER_SIZE * ALPHA_NUM_ARG_REGS];
+ int required_arg_regs;
+ CORE_ADDR func_addr = find_function_addr (function, NULL);
- sigcontext_addr = SIGCONTEXT_ADDR (frame);
- for (ireg = 0; ireg < 32; ireg++)
- {
- reg_position = sigcontext_addr + SIGFRAME_REGSAVE_OFF + ireg * 8;
- frame->saved_regs[ireg] = reg_position;
- }
- for (ireg = 0; ireg < 32; ireg++)
+ /* The ABI places the address of the called function in T12. */
+ regcache_cooked_write_signed (regcache, ALPHA_T12_REGNUM, func_addr);
+
+ /* Set the return address register to point to the entry point
+ of the program, where a breakpoint lies in wait. */
+ regcache_cooked_write_signed (regcache, ALPHA_RA_REGNUM, bp_addr);
+
+ /* Lay out the arguments in memory. */
+ for (i = 0, m_arg = alpha_args; i < nargs; i++, m_arg++)
+ {
+ struct value *arg = args[i];
+ struct type *arg_type = check_typedef (value_type (arg));
+
+ /* Cast argument to long if necessary as the compiler does it too. */
+ switch (TYPE_CODE (arg_type))
{
- reg_position = sigcontext_addr + SIGFRAME_FPREGSAVE_OFF + ireg * 8;
- frame->saved_regs[FP0_REGNUM + ireg] = reg_position;
- }
- frame->saved_regs[PC_REGNUM] = sigcontext_addr + SIGFRAME_PC_OFF;
- return;
- }
+ case TYPE_CODE_INT:
+ case TYPE_CODE_BOOL:
+ case TYPE_CODE_CHAR:
+ case TYPE_CODE_RANGE:
+ case TYPE_CODE_ENUM:
+ if (TYPE_LENGTH (arg_type) == 4)
+ {
+ /* 32-bit values must be sign-extended to 64 bits
+ even if the base data type is unsigned. */
+ arg_type = builtin_type_int32;
+ arg = value_cast (arg_type, arg);
+ }
+ if (TYPE_LENGTH (arg_type) < ALPHA_REGISTER_SIZE)
+ {
+ arg_type = builtin_type_int64;
+ arg = value_cast (arg_type, arg);
+ }
+ break;
- proc_desc = frame->extra_info->proc_desc;
- if (proc_desc == NULL)
- /* I'm not sure how/whether this can happen. Normally when we can't
- find a proc_desc, we "synthesize" one using heuristic_proc_desc
- and set the saved_regs right away. */
- return;
+ case TYPE_CODE_FLT:
+ /* "float" arguments loaded in registers must be passed in
+ register format, aka "double". */
+ if (accumulate_size < sizeof (arg_reg_buffer)
+ && TYPE_LENGTH (arg_type) == 4)
+ {
+ arg_type = builtin_type_ieee_double;
+ arg = value_cast (arg_type, arg);
+ }
+ /* Tru64 5.1 has a 128-bit long double, and passes this by
+ invisible reference. No one else uses this data type. */
+ else if (TYPE_LENGTH (arg_type) == 16)
+ {
+ /* Allocate aligned storage. */
+ sp = (sp & -16) - 16;
- /* Fill in the offsets for the registers which gen_mask says
- were saved. */
+ /* Write the real data into the stack. */
+ write_memory (sp, value_contents (arg), 16);
- reg_position = frame->frame + PROC_REG_OFFSET (proc_desc);
- mask = PROC_REG_MASK (proc_desc);
+ /* Construct the indirection. */
+ arg_type = lookup_pointer_type (arg_type);
+ arg = value_from_pointer (arg_type, sp);
+ }
+ break;
- returnreg = PROC_PC_REG (proc_desc);
+ case TYPE_CODE_COMPLEX:
+ /* ??? The ABI says that complex values are passed as two
+ separate scalar values. This distinction only matters
+ for complex float. However, GCC does not implement this. */
- /* Note that RA is always saved first, regardless of its actual
- register number. */
- if (mask & (1 << returnreg))
- {
- frame->saved_regs[returnreg] = reg_position;
- reg_position += 8;
- mask &= ~(1 << returnreg); /* Clear bit for RA so we
- don't save again later. */
- }
+ /* Tru64 5.1 has a 128-bit long double, and passes this by
+ invisible reference. */
+ if (TYPE_LENGTH (arg_type) == 32)
+ {
+ /* Allocate aligned storage. */
+ sp = (sp & -16) - 16;
- for (ireg = 0; ireg <= 31; ++ireg)
- if (mask & (1 << ireg))
- {
- frame->saved_regs[ireg] = reg_position;
- reg_position += 8;
- }
+ /* Write the real data into the stack. */
+ write_memory (sp, value_contents (arg), 32);
- /* Fill in the offsets for the registers which float_mask says
- were saved. */
+ /* Construct the indirection. */
+ arg_type = lookup_pointer_type (arg_type);
+ arg = value_from_pointer (arg_type, sp);
+ }
+ break;
- reg_position = frame->frame + PROC_FREG_OFFSET (proc_desc);
- mask = PROC_FREG_MASK (proc_desc);
+ default:
+ break;
+ }
+ m_arg->len = TYPE_LENGTH (arg_type);
+ m_arg->offset = accumulate_size;
+ accumulate_size = (accumulate_size + m_arg->len + 7) & ~7;
+ m_arg->contents = value_contents_writeable (arg);
+ }
- for (ireg = 0; ireg <= 31; ++ireg)
- if (mask & (1 << ireg))
- {
- frame->saved_regs[FP0_REGNUM + ireg] = reg_position;
- reg_position += 8;
- }
+ /* Determine required argument register loads, loading an argument register
+ is expensive as it uses three ptrace calls. */
+ required_arg_regs = accumulate_size / 8;
+ if (required_arg_regs > ALPHA_NUM_ARG_REGS)
+ required_arg_regs = ALPHA_NUM_ARG_REGS;
- frame->saved_regs[PC_REGNUM] = frame->saved_regs[returnreg];
-}
+ /* Make room for the arguments on the stack. */
+ if (accumulate_size < sizeof(arg_reg_buffer))
+ accumulate_size = 0;
+ else
+ accumulate_size -= sizeof(arg_reg_buffer);
+ sp -= accumulate_size;
-void
-alpha_frame_init_saved_regs (struct frame_info *fi)
-{
- if (fi->saved_regs == NULL)
- alpha_find_saved_regs (fi);
- fi->saved_regs[SP_REGNUM] = fi->frame;
-}
+ /* Keep sp aligned to a multiple of 16 as the ABI requires. */
+ sp &= ~15;
-static CORE_ADDR
-read_next_frame_reg (struct frame_info *fi, int regno)
-{
- for (; fi; fi = fi->next)
+ /* `Push' arguments on the stack. */
+ for (i = nargs; m_arg--, --i >= 0;)
{
- /* We have to get the saved sp from the sigcontext
- if it is a signal handler frame. */
- if (regno == SP_REGNUM && !fi->signal_handler_caller)
- return fi->frame;
- else
+ gdb_byte *contents = m_arg->contents;
+ int offset = m_arg->offset;
+ int len = m_arg->len;
+
+ /* Copy the bytes destined for registers into arg_reg_buffer. */
+ if (offset < sizeof(arg_reg_buffer))
{
- if (fi->saved_regs == NULL)
- alpha_find_saved_regs (fi);
- if (fi->saved_regs[regno])
- return read_memory_integer (fi->saved_regs[regno], 8);
+ if (offset + len <= sizeof(arg_reg_buffer))
+ {
+ memcpy (arg_reg_buffer + offset, contents, len);
+ continue;
+ }
+ else
+ {
+ int tlen = sizeof(arg_reg_buffer) - offset;
+ memcpy (arg_reg_buffer + offset, contents, tlen);
+ offset += tlen;
+ contents += tlen;
+ len -= tlen;
+ }
}
+
+ /* Everything else goes to the stack. */
+ write_memory (sp + offset - sizeof(arg_reg_buffer), contents, len);
}
- return read_register (regno);
-}
+ if (struct_return)
+ store_unsigned_integer (arg_reg_buffer, ALPHA_REGISTER_SIZE, struct_addr);
-CORE_ADDR
-alpha_frame_saved_pc (struct frame_info *frame)
-{
- alpha_extra_func_info_t proc_desc = frame->extra_info->proc_desc;
- /* We have to get the saved pc from the sigcontext
- if it is a signal handler frame. */
- int pcreg = frame->signal_handler_caller ? PC_REGNUM
- : frame->extra_info->pc_reg;
+ /* Load the argument registers. */
+ for (i = 0; i < required_arg_regs; i++)
+ {
+ regcache_cooked_write (regcache, ALPHA_A0_REGNUM + i,
+ arg_reg_buffer + i*ALPHA_REGISTER_SIZE);
+ regcache_cooked_write (regcache, ALPHA_FPA0_REGNUM + i,
+ arg_reg_buffer + i*ALPHA_REGISTER_SIZE);
+ }
- if (proc_desc && PROC_DESC_IS_DUMMY (proc_desc))
- return read_memory_integer (frame->frame - 8, 8);
+ /* Finally, update the stack pointer. */
+ regcache_cooked_write_signed (regcache, ALPHA_SP_REGNUM, sp);
- return read_next_frame_reg (frame, pcreg);
+ return sp;
}
-CORE_ADDR
-alpha_saved_pc_after_call (struct frame_info *frame)
+/* Extract from REGCACHE the value about to be returned from a function
+ and copy it into VALBUF. */
+
+static void
+alpha_extract_return_value (struct type *valtype, struct regcache *regcache,
+ gdb_byte *valbuf)
{
- CORE_ADDR pc = frame->pc;
- CORE_ADDR tmp;
- alpha_extra_func_info_t proc_desc;
- int pcreg;
+ int length = TYPE_LENGTH (valtype);
+ gdb_byte raw_buffer[ALPHA_REGISTER_SIZE];
+ ULONGEST l;
- /* Skip over shared library trampoline if necessary. */
- tmp = SKIP_TRAMPOLINE_CODE (pc);
- if (tmp != 0)
- pc = tmp;
+ switch (TYPE_CODE (valtype))
+ {
+ case TYPE_CODE_FLT:
+ switch (length)
+ {
+ case 4:
+ regcache_cooked_read (regcache, ALPHA_FP0_REGNUM, raw_buffer);
+ alpha_sts (valbuf, raw_buffer);
+ break;
- proc_desc = find_proc_desc (pc, frame->next);
- pcreg = proc_desc ? PROC_PC_REG (proc_desc) : RA_REGNUM;
+ case 8:
+ regcache_cooked_read (regcache, ALPHA_FP0_REGNUM, valbuf);
+ break;
- if (frame->signal_handler_caller)
- return alpha_frame_saved_pc (frame);
- else
- return read_register (pcreg);
-}
+ case 16:
+ regcache_cooked_read_unsigned (regcache, ALPHA_V0_REGNUM, &l);
+ read_memory (l, valbuf, 16);
+ break;
+ default:
+ internal_error (__FILE__, __LINE__, _("unknown floating point width"));
+ }
+ break;
-static struct alpha_extra_func_info temp_proc_desc;
-static CORE_ADDR temp_saved_regs[NUM_REGS];
+ case TYPE_CODE_COMPLEX:
+ switch (length)
+ {
+ case 8:
+ /* ??? This isn't correct wrt the ABI, but it's what GCC does. */
+ regcache_cooked_read (regcache, ALPHA_FP0_REGNUM, valbuf);
+ break;
-/* Nonzero if instruction at PC is a return instruction. "ret
- $zero,($ra),1" on alpha. */
+ case 16:
+ regcache_cooked_read (regcache, ALPHA_FP0_REGNUM, valbuf);
+ regcache_cooked_read (regcache, ALPHA_FP0_REGNUM + 1, valbuf + 8);
+ break;
-static int
-alpha_about_to_return (CORE_ADDR pc)
-{
- return read_memory_integer (pc, 4) == 0x6bfa8001;
-}
+ case 32:
+ regcache_cooked_read_signed (regcache, ALPHA_V0_REGNUM, &l);
+ read_memory (l, valbuf, 32);
+ break;
+ default:
+ internal_error (__FILE__, __LINE__, _("unknown floating point width"));
+ }
+ break;
+ default:
+ /* Assume everything else degenerates to an integer. */
+ regcache_cooked_read_unsigned (regcache, ALPHA_V0_REGNUM, &l);
+ store_unsigned_integer (valbuf, length, l);
+ break;
+ }
+}
-/* This fencepost looks highly suspicious to me. Removing it also
- seems suspicious as it could affect remote debugging across serial
- lines. */
+/* Insert the given value into REGCACHE as if it was being
+ returned by a function. */
-static CORE_ADDR
-heuristic_proc_start (CORE_ADDR pc)
+static void
+alpha_store_return_value (struct type *valtype, struct regcache *regcache,
+ const gdb_byte *valbuf)
{
- CORE_ADDR start_pc = pc;
- CORE_ADDR fence = start_pc - heuristic_fence_post;
+ int length = TYPE_LENGTH (valtype);
+ gdb_byte raw_buffer[ALPHA_REGISTER_SIZE];
+ ULONGEST l;
- if (start_pc == 0)
- return 0;
+ switch (TYPE_CODE (valtype))
+ {
+ case TYPE_CODE_FLT:
+ switch (length)
+ {
+ case 4:
+ alpha_lds (raw_buffer, valbuf);
+ regcache_cooked_write (regcache, ALPHA_FP0_REGNUM, raw_buffer);
+ break;
- if (heuristic_fence_post == UINT_MAX
- || fence < VM_MIN_ADDRESS)
- fence = VM_MIN_ADDRESS;
-
- /* search back for previous return */
- for (start_pc -= 4;; start_pc -= 4)
- if (start_pc < fence)
- {
- /* It's not clear to me why we reach this point when
- stop_soon_quietly, but with this test, at least we
- don't print out warnings for every child forked (eg, on
- decstation). 22apr93 rich@cygnus.com. */
- if (!stop_soon_quietly)
- {
- static int blurb_printed = 0;
-
- if (fence == VM_MIN_ADDRESS)
- warning ("Hit beginning of text section without finding");
- else
- warning ("Hit heuristic-fence-post without finding");
-
- warning ("enclosing function for address 0x%s", paddr_nz (pc));
- if (!blurb_printed)
- {
- printf_filtered ("\
-This warning occurs if you are debugging a function without any symbols\n\
-(for example, in a stripped executable). In that case, you may wish to\n\
-increase the size of the search with the `set heuristic-fence-post' command.\n\
-\n\
-Otherwise, you told GDB there was a function where there isn't one, or\n\
-(more likely) you have encountered a bug in GDB.\n");
- blurb_printed = 1;
- }
- }
-
- return 0;
- }
- else if (alpha_about_to_return (start_pc))
- break;
+ case 8:
+ regcache_cooked_write (regcache, ALPHA_FP0_REGNUM, valbuf);
+ break;
- start_pc += 4; /* skip return */
- return start_pc;
-}
+ case 16:
+ /* FIXME: 128-bit long doubles are returned like structures:
+ by writing into indirect storage provided by the caller
+ as the first argument. */
+ error (_("Cannot set a 128-bit long double return value."));
-static alpha_extra_func_info_t
-heuristic_proc_desc (CORE_ADDR start_pc, CORE_ADDR limit_pc,
- struct frame_info *next_frame)
-{
- CORE_ADDR sp = read_next_frame_reg (next_frame, SP_REGNUM);
- CORE_ADDR cur_pc;
- int frame_size;
- int has_frame_reg = 0;
- unsigned long reg_mask = 0;
- int pcreg = -1;
+ default:
+ internal_error (__FILE__, __LINE__, _("unknown floating point width"));
+ }
+ break;
- if (start_pc == 0)
- return NULL;
- memset (&temp_proc_desc, '\0', sizeof (temp_proc_desc));
- memset (&temp_saved_regs, '\0', SIZEOF_FRAME_SAVED_REGS);
- PROC_LOW_ADDR (&temp_proc_desc) = start_pc;
+ case TYPE_CODE_COMPLEX:
+ switch (length)
+ {
+ case 8:
+ /* ??? This isn't correct wrt the ABI, but it's what GCC does. */
+ regcache_cooked_write (regcache, ALPHA_FP0_REGNUM, valbuf);
+ break;
- if (start_pc + 200 < limit_pc)
- limit_pc = start_pc + 200;
- frame_size = 0;
- for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += 4)
- {
- char buf[4];
- unsigned long word;
- int status;
+ case 16:
+ regcache_cooked_write (regcache, ALPHA_FP0_REGNUM, valbuf);
+ regcache_cooked_write (regcache, ALPHA_FP0_REGNUM + 1, valbuf + 8);
+ break;
- status = read_memory_nobpt (cur_pc, buf, 4);
- if (status)
- memory_error (status, cur_pc);
- word = extract_unsigned_integer (buf, 4);
+ case 32:
+ /* FIXME: 128-bit long doubles are returned like structures:
+ by writing into indirect storage provided by the caller
+ as the first argument. */
+ error (_("Cannot set a 128-bit long double return value."));
- if ((word & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */
- {
- if (word & 0x8000)
- frame_size += (-word) & 0xffff;
- else
- /* Exit loop if a positive stack adjustment is found, which
- usually means that the stack cleanup code in the function
- epilogue is reached. */
- break;
- }
- else if ((word & 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */
- && (word & 0xffff0000) != 0xb7fe0000) /* reg != $zero */
- {
- int reg = (word & 0x03e00000) >> 21;
- reg_mask |= 1 << reg;
- temp_saved_regs[reg] = sp + (short) word;
-
- /* Starting with OSF/1-3.2C, the system libraries are shipped
- without local symbols, but they still contain procedure
- descriptors without a symbol reference. GDB is currently
- unable to find these procedure descriptors and uses
- heuristic_proc_desc instead.
- As some low level compiler support routines (__div*, __add*)
- use a non-standard return address register, we have to
- add some heuristics to determine the return address register,
- or stepping over these routines will fail.
- Usually the return address register is the first register
- saved on the stack, but assembler optimization might
- rearrange the register saves.
- So we recognize only a few registers (t7, t9, ra) within
- the procedure prologue as valid return address registers.
- If we encounter a return instruction, we extract the
- the return address register from it.
-
- FIXME: Rewriting GDB to access the procedure descriptors,
- e.g. via the minimal symbol table, might obviate this hack. */
- if (pcreg == -1
- && cur_pc < (start_pc + 80)
- && (reg == T7_REGNUM || reg == T9_REGNUM || reg == RA_REGNUM))
- pcreg = reg;
+ default:
+ internal_error (__FILE__, __LINE__, _("unknown floating point width"));
}
- else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */
- pcreg = (word >> 16) & 0x1f;
- else if (word == 0x47de040f) /* bis sp,sp fp */
- has_frame_reg = 1;
+ break;
+
+ default:
+ /* Assume everything else degenerates to an integer. */
+ /* 32-bit values must be sign-extended to 64 bits
+ even if the base data type is unsigned. */
+ if (length == 4)
+ valtype = builtin_type_int32;
+ l = unpack_long (valtype, valbuf);
+ regcache_cooked_write_unsigned (regcache, ALPHA_V0_REGNUM, l);
+ break;
}
- if (pcreg == -1)
- {
- /* If we haven't found a valid return address register yet,
- keep searching in the procedure prologue. */
- while (cur_pc < (limit_pc + 80) && cur_pc < (start_pc + 80))
- {
- char buf[4];
- unsigned long word;
+}
- if (read_memory_nobpt (cur_pc, buf, 4))
- break;
- cur_pc += 4;
- word = extract_unsigned_integer (buf, 4);
+static enum return_value_convention
+alpha_return_value (struct gdbarch *gdbarch, struct type *func_type,
+ struct type *type, struct regcache *regcache,
+ gdb_byte *readbuf, const gdb_byte *writebuf)
+{
+ enum type_code code = TYPE_CODE (type);
- if ((word & 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */
- && (word & 0xffff0000) != 0xb7fe0000) /* reg != $zero */
- {
- int reg = (word & 0x03e00000) >> 21;
- if (reg == T7_REGNUM || reg == T9_REGNUM || reg == RA_REGNUM)
- {
- pcreg = reg;
- break;
- }
- }
- else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */
- {
- pcreg = (word >> 16) & 0x1f;
- break;
- }
+ if ((code == TYPE_CODE_STRUCT
+ || code == TYPE_CODE_UNION
+ || code == TYPE_CODE_ARRAY)
+ && gdbarch_tdep (gdbarch)->return_in_memory (type))
+ {
+ if (readbuf)
+ {
+ ULONGEST addr;
+ regcache_raw_read_unsigned (regcache, ALPHA_V0_REGNUM, &addr);
+ read_memory (addr, readbuf, TYPE_LENGTH (type));
}
+
+ return RETURN_VALUE_ABI_RETURNS_ADDRESS;
}
- if (has_frame_reg)
- PROC_FRAME_REG (&temp_proc_desc) = GCC_FP_REGNUM;
- else
- PROC_FRAME_REG (&temp_proc_desc) = SP_REGNUM;
- PROC_FRAME_OFFSET (&temp_proc_desc) = frame_size;
- PROC_REG_MASK (&temp_proc_desc) = reg_mask;
- PROC_PC_REG (&temp_proc_desc) = (pcreg == -1) ? RA_REGNUM : pcreg;
- PROC_LOCALOFF (&temp_proc_desc) = 0; /* XXX - bogus */
- return &temp_proc_desc;
+ if (readbuf)
+ alpha_extract_return_value (type, regcache, readbuf);
+ if (writebuf)
+ alpha_store_return_value (type, regcache, writebuf);
+
+ return RETURN_VALUE_REGISTER_CONVENTION;
}
-/* This returns the PC of the first inst after the prologue. If we can't
- find the prologue, then return 0. */
+static int
+alpha_return_in_memory_always (struct type *type)
+{
+ return 1;
+}
+\f
+static const gdb_byte *
+alpha_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pc, int *len)
+{
+ static const gdb_byte break_insn[] = { 0x80, 0, 0, 0 }; /* call_pal bpt */
-static CORE_ADDR
-after_prologue (CORE_ADDR pc, alpha_extra_func_info_t proc_desc)
+ *len = sizeof(break_insn);
+ return break_insn;
+}
+
+\f
+/* This returns the PC of the first insn after the prologue.
+ If we can't find the prologue, then return 0. */
+
+CORE_ADDR
+alpha_after_prologue (CORE_ADDR pc)
{
struct symtab_and_line sal;
CORE_ADDR func_addr, func_end;
- if (!proc_desc)
- proc_desc = find_proc_desc (pc, NULL);
-
- if (proc_desc)
- {
- if (PROC_DESC_IS_DYN_SIGTRAMP (proc_desc))
- return PROC_LOW_ADDR (proc_desc); /* "prologue" is in kernel */
-
- /* If function is frameless, then we need to do it the hard way. I
- strongly suspect that frameless always means prologueless... */
- if (PROC_FRAME_REG (proc_desc) == SP_REGNUM
- && PROC_FRAME_OFFSET (proc_desc) == 0)
- return 0;
- }
-
if (!find_pc_partial_function (pc, NULL, &func_addr, &func_end))
- return 0; /* Unknown */
+ return 0;
sal = find_pc_line (func_addr, 0);
-
if (sal.end < func_end)
return sal.end;
/* The line after the prologue is after the end of the function. In this
case, tell the caller to find the prologue the hard way. */
-
return 0;
}
-/* Return non-zero if we *might* be in a function prologue. Return zero if we
- are definitively *not* in a function prologue. */
+/* Read an instruction from memory at PC, looking through breakpoints. */
-static int
-alpha_in_prologue (CORE_ADDR pc, alpha_extra_func_info_t proc_desc)
+unsigned int
+alpha_read_insn (CORE_ADDR pc)
{
- CORE_ADDR after_prologue_pc;
+ gdb_byte buf[ALPHA_INSN_SIZE];
+ int status;
- after_prologue_pc = after_prologue (pc, proc_desc);
-
- if (after_prologue_pc == 0
- || pc < after_prologue_pc)
- return 1;
- else
- return 0;
+ status = target_read_memory (pc, buf, sizeof (buf));
+ if (status)
+ memory_error (status, pc);
+ return extract_unsigned_integer (buf, sizeof (buf));
}
-static alpha_extra_func_info_t
-find_proc_desc (CORE_ADDR pc, struct frame_info *next_frame)
+/* To skip prologues, I use this predicate. Returns either PC itself
+ if the code at PC does not look like a function prologue; otherwise
+ returns an address that (if we're lucky) follows the prologue. If
+ LENIENT, then we must skip everything which is involved in setting
+ up the frame (it's OK to skip more, just so long as we don't skip
+ anything which might clobber the registers which are being saved. */
+
+static CORE_ADDR
+alpha_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
{
- alpha_extra_func_info_t proc_desc;
- struct block *b;
- struct symbol *sym;
- CORE_ADDR startaddr;
-
- /* Try to get the proc_desc from the linked call dummy proc_descs
- if the pc is in the call dummy.
- This is hairy. In the case of nested dummy calls we have to find the
- right proc_desc, but we might not yet know the frame for the dummy
- as it will be contained in the proc_desc we are searching for.
- So we have to find the proc_desc whose frame is closest to the current
- stack pointer. */
-
- if (PC_IN_CALL_DUMMY (pc, 0, 0))
- {
- struct linked_proc_info *link;
- CORE_ADDR sp = read_next_frame_reg (next_frame, SP_REGNUM);
- alpha_extra_func_info_t found_proc_desc = NULL;
- long min_distance = LONG_MAX;
+ unsigned long inst;
+ int offset;
+ CORE_ADDR post_prologue_pc;
+ gdb_byte buf[ALPHA_INSN_SIZE];
- for (link = linked_proc_desc_table; link; link = link->next)
- {
- long distance = (CORE_ADDR) PROC_DUMMY_FRAME (&link->info) - sp;
- if (distance > 0 && distance < min_distance)
- {
- min_distance = distance;
- found_proc_desc = &link->info;
- }
- }
- if (found_proc_desc != NULL)
- return found_proc_desc;
- }
+ /* Silently return the unaltered pc upon memory errors.
+ This could happen on OSF/1 if decode_line_1 tries to skip the
+ prologue for quickstarted shared library functions when the
+ shared library is not yet mapped in.
+ Reading target memory is slow over serial lines, so we perform
+ this check only if the target has shared libraries (which all
+ Alpha targets do). */
+ if (target_read_memory (pc, buf, sizeof (buf)))
+ return pc;
- b = block_for_pc (pc);
+ /* 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. */
- find_pc_partial_function (pc, NULL, &startaddr, NULL);
- if (b == NULL)
- sym = NULL;
- else
- {
- 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. */
- sym = NULL;
- else
- sym = lookup_symbol (MIPS_EFI_SYMBOL_NAME, b, LABEL_NAMESPACE,
- 0, NULL);
- }
+ post_prologue_pc = alpha_after_prologue (pc);
+ if (post_prologue_pc != 0)
+ return max (pc, post_prologue_pc);
- /* If we never found a PDR for this function in symbol reading, then
- examine prologues to find the information. */
- if (sym && ((mips_extra_func_info_t) SYMBOL_VALUE (sym))->pdr.framereg == -1)
- sym = NULL;
+ /* Can't determine prologue from the symbol table, need to examine
+ instructions. */
- if (sym)
- {
- /* IF this is the topmost frame AND
- * (this proc does not have debugging information OR
- * the PC is in the procedure prologue)
- * THEN create a "heuristic" proc_desc (by analyzing
- * the actual code) to replace the "official" proc_desc.
- */
- proc_desc = (alpha_extra_func_info_t) SYMBOL_VALUE (sym);
- if (next_frame == NULL)
- {
- if (PROC_DESC_IS_DUMMY (proc_desc) || alpha_in_prologue (pc, proc_desc))
- {
- alpha_extra_func_info_t found_heuristic =
- heuristic_proc_desc (PROC_LOW_ADDR (proc_desc),
- pc, next_frame);
- if (found_heuristic)
- {
- PROC_LOCALOFF (found_heuristic) =
- PROC_LOCALOFF (proc_desc);
- PROC_PC_REG (found_heuristic) = PROC_PC_REG (proc_desc);
- proc_desc = found_heuristic;
- }
- }
- }
- }
- else
+ /* Skip the typical prologue instructions. These are the stack adjustment
+ instruction and the instructions that save registers on the stack
+ or in the gcc frame. */
+ for (offset = 0; offset < 100; offset += ALPHA_INSN_SIZE)
{
- long offset;
-
- /* Is linked_proc_desc_table really necessary? It only seems to be used
- by procedure call dummys. However, the procedures being called ought
- to have their own proc_descs, and even if they don't,
- heuristic_proc_desc knows how to create them! */
-
- register struct linked_proc_info *link;
- for (link = linked_proc_desc_table; link; link = link->next)
- if (PROC_LOW_ADDR (&link->info) <= pc
- && PROC_HIGH_ADDR (&link->info) > pc)
- return &link->info;
-
- /* If PC is inside a dynamically generated sigtramp handler,
- create and push a procedure descriptor for that code: */
- offset = DYNAMIC_SIGTRAMP_OFFSET (pc);
- if (offset >= 0)
- return push_sigtramp_desc (pc - offset);
-
- /* If heuristic_fence_post is non-zero, determine the procedure
- start address by examining the instructions.
- This allows us to find the start address of static functions which
- have no symbolic information, as startaddr would have been set to
- the preceding global function start address by the
- find_pc_partial_function call above. */
- if (startaddr == 0 || heuristic_fence_post != 0)
- startaddr = heuristic_proc_start (pc);
-
- proc_desc =
- heuristic_proc_desc (startaddr, pc, next_frame);
+ inst = alpha_read_insn (pc + offset);
+
+ if ((inst & 0xffff0000) == 0x27bb0000) /* ldah $gp,n($t12) */
+ continue;
+ if ((inst & 0xffff0000) == 0x23bd0000) /* lda $gp,n($gp) */
+ continue;
+ if ((inst & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */
+ continue;
+ if ((inst & 0xffe01fff) == 0x43c0153e) /* subq $sp,n,$sp */
+ continue;
+
+ if (((inst & 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */
+ || (inst & 0xfc1f0000) == 0x9c1e0000) /* stt reg,n($sp) */
+ && (inst & 0x03e00000) != 0x03e00000) /* reg != $zero */
+ continue;
+
+ if (inst == 0x47de040f) /* bis sp,sp,fp */
+ continue;
+ if (inst == 0x47fe040f) /* bis zero,sp,fp */
+ continue;
+
+ break;
}
- return proc_desc;
+ return pc + offset;
}
-alpha_extra_func_info_t cached_proc_desc;
+\f
+/* Figure out where the longjmp will land.
+ We expect the first arg to be a pointer to the jmp_buf structure from
+ which we extract the PC (JB_PC) that we will land at. The PC is copied
+ into the "pc". This routine returns true on success. */
-CORE_ADDR
-alpha_frame_chain (struct frame_info *frame)
+static int
+alpha_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
{
- alpha_extra_func_info_t proc_desc;
- CORE_ADDR saved_pc = FRAME_SAVED_PC (frame);
+ struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (frame));
+ CORE_ADDR jb_addr;
+ gdb_byte raw_buffer[ALPHA_REGISTER_SIZE];
- if (saved_pc == 0 || inside_entry_file (saved_pc))
- return 0;
+ jb_addr = get_frame_register_unsigned (frame, ALPHA_A0_REGNUM);
- proc_desc = find_proc_desc (saved_pc, frame);
- if (!proc_desc)
+ if (target_read_memory (jb_addr + (tdep->jb_pc * tdep->jb_elt_size),
+ raw_buffer, tdep->jb_elt_size))
return 0;
- cached_proc_desc = proc_desc;
-
- /* Fetch the frame pointer for a dummy frame from the procedure
- descriptor. */
- if (PROC_DESC_IS_DUMMY (proc_desc))
- return (CORE_ADDR) PROC_DUMMY_FRAME (proc_desc);
-
- /* If no frame pointer and frame size is zero, we must be at end
- of stack (or otherwise hosed). If we don't check frame size,
- we loop forever if we see a zero size frame. */
- if (PROC_FRAME_REG (proc_desc) == SP_REGNUM
- && PROC_FRAME_OFFSET (proc_desc) == 0
- /* The previous frame from a sigtramp frame might be frameless
- and have frame size zero. */
- && !frame->signal_handler_caller)
- return FRAME_PAST_SIGTRAMP_FRAME (frame, saved_pc);
- else
- return read_next_frame_reg (frame, PROC_FRAME_REG (proc_desc))
- + PROC_FRAME_OFFSET (proc_desc);
+ *pc = extract_unsigned_integer (raw_buffer, tdep->jb_elt_size);
+ return 1;
}
-void
-alpha_print_extra_frame_info (struct frame_info *fi)
+\f
+/* Frame unwinder for signal trampolines. We use alpha tdep bits that
+ describe the location and shape of the sigcontext structure. After
+ that, all registers are in memory, so it's easy. */
+/* ??? Shouldn't we be able to do this generically, rather than with
+ OSABI data specific to Alpha? */
+
+struct alpha_sigtramp_unwind_cache
+{
+ CORE_ADDR sigcontext_addr;
+};
+
+static struct alpha_sigtramp_unwind_cache *
+alpha_sigtramp_frame_unwind_cache (struct frame_info *this_frame,
+ void **this_prologue_cache)
{
- if (fi
- && fi->extra_info
- && fi->extra_info->proc_desc
- && fi->extra_info->proc_desc->pdr.framereg < NUM_REGS)
- printf_filtered (" frame pointer is at %s+%s\n",
- REGISTER_NAME (fi->extra_info->proc_desc->pdr.framereg),
- paddr_d (fi->extra_info->proc_desc->pdr.frameoffset));
+ struct alpha_sigtramp_unwind_cache *info;
+ struct gdbarch_tdep *tdep;
+
+ if (*this_prologue_cache)
+ return *this_prologue_cache;
+
+ info = FRAME_OBSTACK_ZALLOC (struct alpha_sigtramp_unwind_cache);
+ *this_prologue_cache = info;
+
+ tdep = gdbarch_tdep (get_frame_arch (this_frame));
+ info->sigcontext_addr = tdep->sigcontext_addr (this_frame);
+
+ return info;
}
-void
-alpha_init_extra_frame_info (int fromleaf, struct frame_info *frame)
+/* Return the address of REGNUM in a sigtramp frame. Since this is
+ all arithmetic, it doesn't seem worthwhile to cache it. */
+
+static CORE_ADDR
+alpha_sigtramp_register_address (struct gdbarch *gdbarch,
+ CORE_ADDR sigcontext_addr, int regnum)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ if (regnum >= 0 && regnum < 32)
+ return sigcontext_addr + tdep->sc_regs_offset + regnum * 8;
+ else if (regnum >= ALPHA_FP0_REGNUM && regnum < ALPHA_FP0_REGNUM + 32)
+ return sigcontext_addr + tdep->sc_fpregs_offset + regnum * 8;
+ else if (regnum == ALPHA_PC_REGNUM)
+ return sigcontext_addr + tdep->sc_pc_offset;
+
+ return 0;
+}
+
+/* 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
+alpha_sigtramp_frame_this_id (struct frame_info *this_frame,
+ void **this_prologue_cache,
+ struct frame_id *this_id)
{
- /* Use proc_desc calculated in frame_chain */
- alpha_extra_func_info_t proc_desc =
- frame->next ? cached_proc_desc : find_proc_desc (frame->pc, frame->next);
-
- frame->extra_info = (struct frame_extra_info *)
- frame_obstack_alloc (sizeof (struct frame_extra_info));
-
- frame->saved_regs = NULL;
- frame->extra_info->localoff = 0;
- frame->extra_info->pc_reg = RA_REGNUM;
- frame->extra_info->proc_desc = proc_desc == &temp_proc_desc ? 0 : proc_desc;
- if (proc_desc)
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ struct alpha_sigtramp_unwind_cache *info
+ = alpha_sigtramp_frame_unwind_cache (this_frame, this_prologue_cache);
+ CORE_ADDR stack_addr, code_addr;
+
+ /* If the OSABI couldn't locate the sigcontext, give up. */
+ if (info->sigcontext_addr == 0)
+ return;
+
+ /* If we have dynamic signal trampolines, find their start.
+ If we do not, then we must assume there is a symbol record
+ that can provide the start address. */
+ if (tdep->dynamic_sigtramp_offset)
{
- /* Get the locals offset and the saved pc register from the
- procedure descriptor, they are valid even if we are in the
- middle of the prologue. */
- frame->extra_info->localoff = PROC_LOCALOFF (proc_desc);
- frame->extra_info->pc_reg = PROC_PC_REG (proc_desc);
-
- /* Fixup frame-pointer - only needed for top frame */
-
- /* Fetch the frame pointer for a dummy frame from the procedure
- descriptor. */
- if (PROC_DESC_IS_DUMMY (proc_desc))
- frame->frame = (CORE_ADDR) PROC_DUMMY_FRAME (proc_desc);
-
- /* This may not be quite right, if proc has a real frame register.
- Get the value of the frame relative sp, procedure might have been
- interrupted by a signal at it's very start. */
- else if (frame->pc == PROC_LOW_ADDR (proc_desc)
- && !PROC_DESC_IS_DYN_SIGTRAMP (proc_desc))
- frame->frame = read_next_frame_reg (frame->next, SP_REGNUM);
+ int offset;
+ code_addr = get_frame_pc (this_frame);
+ offset = tdep->dynamic_sigtramp_offset (code_addr);
+ if (offset >= 0)
+ code_addr -= offset;
else
- frame->frame = read_next_frame_reg (frame->next, PROC_FRAME_REG (proc_desc))
- + PROC_FRAME_OFFSET (proc_desc);
-
- if (proc_desc == &temp_proc_desc)
- {
- char *name;
-
- /* Do not set the saved registers for a sigtramp frame,
- alpha_find_saved_registers will do that for us.
- We can't use frame->signal_handler_caller, it is not yet set. */
- find_pc_partial_function (frame->pc, &name,
- (CORE_ADDR *) NULL, (CORE_ADDR *) NULL);
- if (!IN_SIGTRAMP (frame->pc, name))
- {
- frame->saved_regs = (CORE_ADDR *)
- frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS);
- memcpy (frame->saved_regs, temp_saved_regs,
- SIZEOF_FRAME_SAVED_REGS);
- frame->saved_regs[PC_REGNUM]
- = frame->saved_regs[RA_REGNUM];
- }
- }
+ code_addr = 0;
}
-}
+ else
+ code_addr = get_frame_func (this_frame);
-CORE_ADDR
-alpha_frame_locals_address (struct frame_info *fi)
-{
- return (fi->frame - fi->extra_info->localoff);
+ /* The stack address is trivially read from the sigcontext. */
+ stack_addr = alpha_sigtramp_register_address (gdbarch, info->sigcontext_addr,
+ ALPHA_SP_REGNUM);
+ stack_addr = get_frame_memory_unsigned (this_frame, stack_addr,
+ ALPHA_REGISTER_SIZE);
+
+ *this_id = frame_id_build (stack_addr, code_addr);
}
-CORE_ADDR
-alpha_frame_args_address (struct frame_info *fi)
+/* Retrieve the value of REGNUM in FRAME. Don't give up! */
+
+static struct value *
+alpha_sigtramp_frame_prev_register (struct frame_info *this_frame,
+ void **this_prologue_cache, int regnum)
{
- return (fi->frame - (ALPHA_NUM_ARG_REGS * 8));
+ struct alpha_sigtramp_unwind_cache *info
+ = alpha_sigtramp_frame_unwind_cache (this_frame, this_prologue_cache);
+ CORE_ADDR addr;
+
+ if (info->sigcontext_addr != 0)
+ {
+ /* All integer and fp registers are stored in memory. */
+ addr = alpha_sigtramp_register_address (get_frame_arch (this_frame),
+ info->sigcontext_addr, regnum);
+ if (addr != 0)
+ return frame_unwind_got_memory (this_frame, regnum, addr);
+ }
+
+ /* This extra register may actually be in the sigcontext, but our
+ current description of it in alpha_sigtramp_frame_unwind_cache
+ doesn't include it. Too bad. Fall back on whatever's in the
+ outer frame. */
+ return frame_unwind_got_register (this_frame, regnum, regnum);
}
-/* ALPHA stack frames are almost impenetrable. When execution stops,
- we basically have to look at symbol information for the function
- that we stopped in, which tells us *which* register (if any) is
- the base of the frame pointer, and what offset from that register
- the frame itself is at.
+static int
+alpha_sigtramp_frame_sniffer (const struct frame_unwind *self,
+ struct frame_info *this_frame,
+ void **this_prologue_cache)
+{
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ CORE_ADDR pc = get_frame_pc (this_frame);
+ char *name;
- This presents a problem when trying to examine a stack in memory
- (that isn't executing at the moment), using the "frame" command. We
- don't have a PC, nor do we have any registers except SP.
+ /* NOTE: cagney/2004-04-30: Do not copy/clone this code. Instead
+ look at tramp-frame.h and other simplier per-architecture
+ sigtramp unwinders. */
- This routine takes two arguments, SP and PC, and tries to make the
- cached frames look as if these two arguments defined a frame on the
- cache. This allows the rest of info frame to extract the important
- arguments without difficulty. */
+ /* We shouldn't even bother to try if the OSABI didn't register a
+ sigcontext_addr handler or pc_in_sigtramp hander. */
+ if (gdbarch_tdep (gdbarch)->sigcontext_addr == NULL)
+ return 0;
+ if (gdbarch_tdep (gdbarch)->pc_in_sigtramp == NULL)
+ return 0;
-struct frame_info *
-setup_arbitrary_frame (int argc, CORE_ADDR *argv)
-{
- if (argc != 2)
- error ("ALPHA frame specifications require two arguments: sp and pc");
+ /* Otherwise we should be in a signal frame. */
+ find_pc_partial_function (pc, &name, NULL, NULL);
+ if (gdbarch_tdep (gdbarch)->pc_in_sigtramp (pc, name))
+ return 1;
- return create_new_frame (argv[0], argv[1]);
+ return 0;
}
-/* The alpha passes the first six arguments in the registers, the rest on
- the stack. The register arguments are eventually transferred to the
- argument transfer area immediately below the stack by the called function
- anyway. So we `push' at least six arguments on the stack, `reload' the
- argument registers and then adjust the stack pointer to point past the
- sixth argument. This algorithm simplifies the passing of a large struct
- which extends from the registers to the stack.
- If the called function is returning a structure, the address of the
- structure to be returned is passed as a hidden first argument. */
+static const struct frame_unwind alpha_sigtramp_frame_unwind = {
+ SIGTRAMP_FRAME,
+ alpha_sigtramp_frame_this_id,
+ alpha_sigtramp_frame_prev_register,
+ NULL,
+ alpha_sigtramp_frame_sniffer
+};
-CORE_ADDR
-alpha_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
- int struct_return, CORE_ADDR struct_addr)
-{
- int i;
- int accumulate_size = struct_return ? 8 : 0;
- int arg_regs_size = ALPHA_NUM_ARG_REGS * 8;
- struct alpha_arg
- {
- char *contents;
- int len;
- int offset;
- };
- struct alpha_arg *alpha_args =
- (struct alpha_arg *) alloca (nargs * sizeof (struct alpha_arg));
- register struct alpha_arg *m_arg;
- char raw_buffer[sizeof (CORE_ADDR)];
- int required_arg_regs;
+\f
+
+/* Heuristic_proc_start may hunt through the text section for a long
+ time across a 2400 baud serial line. Allows the user to limit this
+ search. */
+static unsigned int heuristic_fence_post = 0;
- for (i = 0, m_arg = alpha_args; i < nargs; i++, m_arg++)
+/* Attempt to locate the start of the function containing PC. We assume that
+ the previous function ends with an about_to_return insn. Not foolproof by
+ any means, since gcc is happy to put the epilogue in the middle of a
+ function. But we're guessing anyway... */
+
+static CORE_ADDR
+alpha_heuristic_proc_start (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ CORE_ADDR last_non_nop = pc;
+ CORE_ADDR fence = pc - heuristic_fence_post;
+ CORE_ADDR orig_pc = pc;
+ CORE_ADDR func;
+ struct inferior *inf;
+
+ if (pc == 0)
+ return 0;
+
+ /* First see if we can find the start of the function from minimal
+ symbol information. This can succeed with a binary that doesn't
+ have debug info, but hasn't been stripped. */
+ func = get_pc_function_start (pc);
+ if (func)
+ return func;
+
+ if (heuristic_fence_post == UINT_MAX
+ || fence < tdep->vm_min_address)
+ fence = tdep->vm_min_address;
+
+ /* Search back for previous return; also stop at a 0, which might be
+ seen for instance before the start of a code section. Don't include
+ nops, since this usually indicates padding between functions. */
+ for (pc -= ALPHA_INSN_SIZE; pc >= fence; pc -= ALPHA_INSN_SIZE)
{
- struct value *arg = args[i];
- struct type *arg_type = check_typedef (VALUE_TYPE (arg));
- /* Cast argument to long if necessary as the compiler does it too. */
- switch (TYPE_CODE (arg_type))
+ unsigned int insn = alpha_read_insn (pc);
+ switch (insn)
{
- case TYPE_CODE_INT:
- case TYPE_CODE_BOOL:
- case TYPE_CODE_CHAR:
- case TYPE_CODE_RANGE:
- case TYPE_CODE_ENUM:
- if (TYPE_LENGTH (arg_type) < TYPE_LENGTH (builtin_type_long))
- {
- arg_type = builtin_type_long;
- arg = value_cast (arg_type, arg);
- }
+ case 0: /* invalid insn */
+ case 0x6bfa8001: /* ret $31,($26),1 */
+ return last_non_nop;
+
+ case 0x2ffe0000: /* unop: ldq_u $31,0($30) */
+ case 0x47ff041f: /* nop: bis $31,$31,$31 */
break;
+
default:
+ last_non_nop = pc;
break;
}
- m_arg->len = TYPE_LENGTH (arg_type);
- m_arg->offset = accumulate_size;
- accumulate_size = (accumulate_size + m_arg->len + 7) & ~7;
- m_arg->contents = VALUE_CONTENTS (arg);
}
- /* Determine required argument register loads, loading an argument register
- is expensive as it uses three ptrace calls. */
- required_arg_regs = accumulate_size / 8;
- if (required_arg_regs > ALPHA_NUM_ARG_REGS)
- required_arg_regs = ALPHA_NUM_ARG_REGS;
-
- /* Make room for the arguments on the stack. */
- if (accumulate_size < arg_regs_size)
- accumulate_size = arg_regs_size;
- sp -= accumulate_size;
-
- /* Keep sp aligned to a multiple of 16 as the compiler does it too. */
- sp &= ~15;
+ inf = current_inferior ();
- /* `Push' arguments on the stack. */
- for (i = nargs; m_arg--, --i >= 0;)
- write_memory (sp + m_arg->offset, m_arg->contents, m_arg->len);
- if (struct_return)
+ /* It's not clear to me why we reach this point when stopping quietly,
+ but with this test, at least we don't print out warnings for every
+ child forked (eg, on decstation). 22apr93 rich@cygnus.com. */
+ if (inf->stop_soon == NO_STOP_QUIETLY)
{
- store_address (raw_buffer, sizeof (CORE_ADDR), struct_addr);
- write_memory (sp, raw_buffer, sizeof (CORE_ADDR));
- }
+ static int blurb_printed = 0;
- /* Load the argument registers. */
- for (i = 0; i < required_arg_regs; i++)
- {
- LONGEST val;
+ if (fence == tdep->vm_min_address)
+ warning (_("Hit beginning of text section without finding \
+enclosing function for address 0x%s"), paddr_nz (orig_pc));
+ else
+ warning (_("Hit heuristic-fence-post without finding \
+enclosing function for address 0x%s"), paddr_nz (orig_pc));
- val = read_memory_integer (sp + i * 8, 8);
- write_register (A0_REGNUM + i, val);
- write_register (FPA0_REGNUM + i, val);
+ if (!blurb_printed)
+ {
+ printf_filtered (_("\
+This warning occurs if you are debugging a function without any symbols\n\
+(for example, in a stripped executable). In that case, you may wish to\n\
+increase the size of the search with the `set heuristic-fence-post' command.\n\
+\n\
+Otherwise, you told GDB there was a function where there isn't one, or\n\
+(more likely) you have encountered a bug in GDB.\n"));
+ blurb_printed = 1;
+ }
}
- return sp + arg_regs_size;
-}
-
-void
-alpha_push_dummy_frame (void)
-{
- int ireg;
- struct linked_proc_info *link;
- alpha_extra_func_info_t proc_desc;
- CORE_ADDR sp = read_register (SP_REGNUM);
- CORE_ADDR save_address;
- char raw_buffer[MAX_REGISTER_RAW_SIZE];
- unsigned long mask;
-
- link = (struct linked_proc_info *) xmalloc (sizeof (struct linked_proc_info));
- link->next = linked_proc_desc_table;
- linked_proc_desc_table = link;
-
- proc_desc = &link->info;
-
- /*
- * The registers we must save are all those not preserved across
- * procedure calls.
- * In addition, we must save the PC and RA.
- *
- * Dummy frame layout:
- * (high memory)
- * Saved PC
- * Saved F30
- * ...
- * Saved F0
- * Saved R29
- * ...
- * Saved R0
- * Saved R26 (RA)
- * Parameter build area
- * (low memory)
- */
-
-/* MASK(i,j) == (1<<i) + (1<<(i+1)) + ... + (1<<j)). Assume i<=j<31. */
-#define MASK(i,j) ((((LONGEST)1 << ((j)+1)) - 1) ^ (((LONGEST)1 << (i)) - 1))
-#define GEN_REG_SAVE_MASK (MASK(0,8) | MASK(16,29))
-#define GEN_REG_SAVE_COUNT 24
-#define FLOAT_REG_SAVE_MASK (MASK(0,1) | MASK(10,30))
-#define FLOAT_REG_SAVE_COUNT 23
- /* The special register is the PC as we have no bit for it in the save masks.
- alpha_frame_saved_pc knows where the pc is saved in a dummy frame. */
-#define SPECIAL_REG_SAVE_COUNT 1
-
- PROC_REG_MASK (proc_desc) = GEN_REG_SAVE_MASK;
- PROC_FREG_MASK (proc_desc) = FLOAT_REG_SAVE_MASK;
- /* PROC_REG_OFFSET is the offset from the dummy frame to the saved RA,
- but keep SP aligned to a multiple of 16. */
- PROC_REG_OFFSET (proc_desc) =
- -((8 * (SPECIAL_REG_SAVE_COUNT
- + GEN_REG_SAVE_COUNT
- + FLOAT_REG_SAVE_COUNT)
- + 15) & ~15);
- PROC_FREG_OFFSET (proc_desc) =
- PROC_REG_OFFSET (proc_desc) + 8 * GEN_REG_SAVE_COUNT;
-
- /* Save general registers.
- The return address register is the first saved register, all other
- registers follow in ascending order.
- The PC is saved immediately below the SP. */
- save_address = sp + PROC_REG_OFFSET (proc_desc);
- store_address (raw_buffer, 8, read_register (RA_REGNUM));
- write_memory (save_address, raw_buffer, 8);
- save_address += 8;
- mask = PROC_REG_MASK (proc_desc) & 0xffffffffL;
- for (ireg = 0; mask; ireg++, mask >>= 1)
- if (mask & 1)
- {
- if (ireg == RA_REGNUM)
- continue;
- store_address (raw_buffer, 8, read_register (ireg));
- write_memory (save_address, raw_buffer, 8);
- save_address += 8;
- }
-
- store_address (raw_buffer, 8, read_register (PC_REGNUM));
- write_memory (sp - 8, raw_buffer, 8);
-
- /* Save floating point registers. */
- save_address = sp + PROC_FREG_OFFSET (proc_desc);
- mask = PROC_FREG_MASK (proc_desc) & 0xffffffffL;
- for (ireg = 0; mask; ireg++, mask >>= 1)
- if (mask & 1)
- {
- store_address (raw_buffer, 8, read_register (ireg + FP0_REGNUM));
- write_memory (save_address, raw_buffer, 8);
- save_address += 8;
- }
-
- /* Set and save the frame address for the dummy.
- This is tricky. The only registers that are suitable for a frame save
- are those that are preserved across procedure calls (s0-s6). But if
- a read system call is interrupted and then a dummy call is made
- (see testsuite/gdb.t17/interrupt.exp) the dummy call hangs till the read
- is satisfied. Then it returns with the s0-s6 registers set to the values
- on entry to the read system call and our dummy frame pointer would be
- destroyed. So we save the dummy frame in the proc_desc and handle the
- retrieval of the frame pointer of a dummy specifically. The frame register
- is set to the virtual frame (pseudo) register, it's value will always
- be read as zero and will help us to catch any errors in the dummy frame
- retrieval code. */
- PROC_DUMMY_FRAME (proc_desc) = sp;
- PROC_FRAME_REG (proc_desc) = FP_REGNUM;
- PROC_FRAME_OFFSET (proc_desc) = 0;
- sp += PROC_REG_OFFSET (proc_desc);
- write_register (SP_REGNUM, sp);
-
- PROC_LOW_ADDR (proc_desc) = CALL_DUMMY_ADDRESS ();
- PROC_HIGH_ADDR (proc_desc) = PROC_LOW_ADDR (proc_desc) + 4;
-
- SET_PROC_DESC_IS_DUMMY (proc_desc);
- PROC_PC_REG (proc_desc) = RA_REGNUM;
+ return 0;
}
-void
-alpha_pop_frame (void)
+/* Fallback alpha frame unwinder. Uses instruction scanning and knows
+ something about the traditional layout of alpha stack frames. */
+
+struct alpha_heuristic_unwind_cache
+{
+ CORE_ADDR vfp;
+ CORE_ADDR start_pc;
+ struct trad_frame_saved_reg *saved_regs;
+ int return_reg;
+};
+
+static struct alpha_heuristic_unwind_cache *
+alpha_heuristic_frame_unwind_cache (struct frame_info *this_frame,
+ void **this_prologue_cache,
+ CORE_ADDR start_pc)
{
- register int regnum;
- struct frame_info *frame = get_current_frame ();
- CORE_ADDR new_sp = frame->frame;
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ struct alpha_heuristic_unwind_cache *info;
+ ULONGEST val;
+ CORE_ADDR limit_pc, cur_pc;
+ int frame_reg, frame_size, return_reg, reg;
- alpha_extra_func_info_t proc_desc = frame->extra_info->proc_desc;
+ if (*this_prologue_cache)
+ return *this_prologue_cache;
- /* we need proc_desc to know how to restore the registers;
- if it is NULL, construct (a temporary) one */
- if (proc_desc == NULL)
- proc_desc = find_proc_desc (frame->pc, frame->next);
+ info = FRAME_OBSTACK_ZALLOC (struct alpha_heuristic_unwind_cache);
+ *this_prologue_cache = info;
+ info->saved_regs = trad_frame_alloc_saved_regs (this_frame);
- /* Question: should we copy this proc_desc and save it in
- frame->proc_desc? If we do, who will free it?
- For now, we don't save a copy... */
+ limit_pc = get_frame_pc (this_frame);
+ if (start_pc == 0)
+ start_pc = alpha_heuristic_proc_start (gdbarch, limit_pc);
+ info->start_pc = start_pc;
- write_register (PC_REGNUM, FRAME_SAVED_PC (frame));
- if (frame->saved_regs == NULL)
- alpha_find_saved_regs (frame);
- if (proc_desc)
- {
- for (regnum = 32; --regnum >= 0;)
- if (PROC_REG_MASK (proc_desc) & (1 << regnum))
- write_register (regnum,
- read_memory_integer (frame->saved_regs[regnum],
- 8));
- for (regnum = 32; --regnum >= 0;)
- if (PROC_FREG_MASK (proc_desc) & (1 << regnum))
- write_register (regnum + FP0_REGNUM,
- read_memory_integer (frame->saved_regs[regnum + FP0_REGNUM], 8));
- }
- write_register (SP_REGNUM, new_sp);
- flush_cached_frames ();
+ frame_reg = ALPHA_SP_REGNUM;
+ frame_size = 0;
+ return_reg = -1;
- if (proc_desc && (PROC_DESC_IS_DUMMY (proc_desc)
- || PROC_DESC_IS_DYN_SIGTRAMP (proc_desc)))
+ /* If we've identified a likely place to start, do code scanning. */
+ if (start_pc != 0)
{
- struct linked_proc_info *pi_ptr, *prev_ptr;
+ /* Limit the forward search to 50 instructions. */
+ if (start_pc + 200 < limit_pc)
+ limit_pc = start_pc + 200;
- for (pi_ptr = linked_proc_desc_table, prev_ptr = NULL;
- pi_ptr != NULL;
- prev_ptr = pi_ptr, pi_ptr = pi_ptr->next)
+ for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += ALPHA_INSN_SIZE)
{
- if (&pi_ptr->info == proc_desc)
- break;
+ unsigned int word = alpha_read_insn (cur_pc);
+
+ if ((word & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */
+ {
+ if (word & 0x8000)
+ {
+ /* Consider only the first stack allocation instruction
+ to contain the static size of the frame. */
+ if (frame_size == 0)
+ frame_size = (-word) & 0xffff;
+ }
+ else
+ {
+ /* Exit loop if a positive stack adjustment is found, which
+ usually means that the stack cleanup code in the function
+ epilogue is reached. */
+ break;
+ }
+ }
+ else if ((word & 0xfc1f0000) == 0xb41e0000) /* stq reg,n($sp) */
+ {
+ reg = (word & 0x03e00000) >> 21;
+
+ /* Ignore this instruction if we have already encountered
+ an instruction saving the same register earlier in the
+ function code. The current instruction does not tell
+ us where the original value upon function entry is saved.
+ All it says is that the function we are scanning reused
+ that register for some computation of its own, and is now
+ saving its result. */
+ if (trad_frame_addr_p(info->saved_regs, reg))
+ continue;
+
+ if (reg == 31)
+ continue;
+
+ /* Do not compute the address where the register was saved yet,
+ because we don't know yet if the offset will need to be
+ relative to $sp or $fp (we can not compute the address
+ relative to $sp if $sp is updated during the execution of
+ the current subroutine, for instance when doing some alloca).
+ So just store the offset for the moment, and compute the
+ address later when we know whether this frame has a frame
+ pointer or not. */
+ /* Hack: temporarily add one, so that the offset is non-zero
+ and we can tell which registers have save offsets below. */
+ info->saved_regs[reg].addr = (word & 0xffff) + 1;
+
+ /* Starting with OSF/1-3.2C, the system libraries are shipped
+ without local symbols, but they still contain procedure
+ descriptors without a symbol reference. GDB is currently
+ unable to find these procedure descriptors and uses
+ heuristic_proc_desc instead.
+ As some low level compiler support routines (__div*, __add*)
+ use a non-standard return address register, we have to
+ add some heuristics to determine the return address register,
+ or stepping over these routines will fail.
+ Usually the return address register is the first register
+ saved on the stack, but assembler optimization might
+ rearrange the register saves.
+ So we recognize only a few registers (t7, t9, ra) within
+ the procedure prologue as valid return address registers.
+ If we encounter a return instruction, we extract the
+ the return address register from it.
+
+ FIXME: Rewriting GDB to access the procedure descriptors,
+ e.g. via the minimal symbol table, might obviate this hack. */
+ if (return_reg == -1
+ && cur_pc < (start_pc + 80)
+ && (reg == ALPHA_T7_REGNUM
+ || reg == ALPHA_T9_REGNUM
+ || reg == ALPHA_RA_REGNUM))
+ return_reg = reg;
+ }
+ else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */
+ return_reg = (word >> 16) & 0x1f;
+ else if (word == 0x47de040f) /* bis sp,sp,fp */
+ frame_reg = ALPHA_GCC_FP_REGNUM;
+ else if (word == 0x47fe040f) /* bis zero,sp,fp */
+ frame_reg = ALPHA_GCC_FP_REGNUM;
}
- if (pi_ptr == NULL)
- error ("Can't locate dummy extra frame info\n");
+ /* If we haven't found a valid return address register yet, keep
+ searching in the procedure prologue. */
+ if (return_reg == -1)
+ {
+ while (cur_pc < (limit_pc + 80) && cur_pc < (start_pc + 80))
+ {
+ unsigned int word = alpha_read_insn (cur_pc);
- if (prev_ptr != NULL)
- prev_ptr->next = pi_ptr->next;
- else
- linked_proc_desc_table = pi_ptr->next;
+ if ((word & 0xfc1f0000) == 0xb41e0000) /* stq reg,n($sp) */
+ {
+ reg = (word & 0x03e00000) >> 21;
+ if (reg == ALPHA_T7_REGNUM
+ || reg == ALPHA_T9_REGNUM
+ || reg == ALPHA_RA_REGNUM)
+ {
+ return_reg = reg;
+ break;
+ }
+ }
+ else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */
+ {
+ return_reg = (word >> 16) & 0x1f;
+ break;
+ }
- xfree (pi_ptr);
+ cur_pc += ALPHA_INSN_SIZE;
+ }
+ }
}
-}
-\f
-/* To skip prologues, I use this predicate. Returns either PC itself
- if the code at PC does not look like a function prologue; otherwise
- returns an address that (if we're lucky) follows the prologue. If
- LENIENT, then we must skip everything which is involved in setting
- up the frame (it's OK to skip more, just so long as we don't skip
- anything which might clobber the registers which are being saved.
- Currently we must not skip more on the alpha, but we might need the
- lenient stuff some day. */
-CORE_ADDR
-alpha_skip_prologue (CORE_ADDR pc, int lenient)
-{
- unsigned long inst;
- int offset;
- CORE_ADDR post_prologue_pc;
- char buf[4];
+ /* Failing that, do default to the customary RA. */
+ if (return_reg == -1)
+ return_reg = ALPHA_RA_REGNUM;
+ info->return_reg = return_reg;
-#ifdef GDB_TARGET_HAS_SHARED_LIBS
- /* Silently return the unaltered pc upon memory errors.
- This could happen on OSF/1 if decode_line_1 tries to skip the
- prologue for quickstarted shared library functions when the
- shared library is not yet mapped in.
- Reading target memory is slow over serial lines, so we perform
- this check only if the target has shared libraries. */
- if (target_read_memory (pc, buf, 4))
- return pc;
-#endif
+ val = get_frame_register_unsigned (this_frame, frame_reg);
+ info->vfp = val + frame_size;
- /* 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. */
+ /* Convert offsets to absolute addresses. See above about adding
+ one to the offsets to make all detected offsets non-zero. */
+ for (reg = 0; reg < ALPHA_NUM_REGS; ++reg)
+ if (trad_frame_addr_p(info->saved_regs, reg))
+ info->saved_regs[reg].addr += val - 1;
- post_prologue_pc = after_prologue (pc, NULL);
+ /* The stack pointer of the previous frame is computed by popping
+ the current stack frame. */
+ if (!trad_frame_addr_p (info->saved_regs, ALPHA_SP_REGNUM))
+ trad_frame_set_value (info->saved_regs, ALPHA_SP_REGNUM, info->vfp);
- if (post_prologue_pc != 0)
- return max (pc, post_prologue_pc);
+ return info;
+}
- /* Can't determine prologue from the symbol table, need to examine
- instructions. */
+/* Given a GDB frame, determine the address of the calling function's
+ frame. This will be used to create a new GDB frame struct. */
- /* Skip the typical prologue instructions. These are the stack adjustment
- instruction and the instructions that save registers on the stack
- or in the gcc frame. */
- for (offset = 0; offset < 100; offset += 4)
- {
- int status;
+static void
+alpha_heuristic_frame_this_id (struct frame_info *this_frame,
+ void **this_prologue_cache,
+ struct frame_id *this_id)
+{
+ struct alpha_heuristic_unwind_cache *info
+ = alpha_heuristic_frame_unwind_cache (this_frame, this_prologue_cache, 0);
- status = read_memory_nobpt (pc + offset, buf, 4);
- if (status)
- memory_error (status, pc + offset);
- inst = extract_unsigned_integer (buf, 4);
+ *this_id = frame_id_build (info->vfp, info->start_pc);
+}
- /* The alpha has no delay slots. But let's keep the lenient stuff,
- we might need it for something else in the future. */
- if (lenient && 0)
- continue;
+/* Retrieve the value of REGNUM in FRAME. Don't give up! */
- if ((inst & 0xffff0000) == 0x27bb0000) /* ldah $gp,n($t12) */
- continue;
- if ((inst & 0xffff0000) == 0x23bd0000) /* lda $gp,n($gp) */
- continue;
- if ((inst & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */
- continue;
- if ((inst & 0xffe01fff) == 0x43c0153e) /* subq $sp,n,$sp */
- continue;
+static struct value *
+alpha_heuristic_frame_prev_register (struct frame_info *this_frame,
+ void **this_prologue_cache, int regnum)
+{
+ struct alpha_heuristic_unwind_cache *info
+ = alpha_heuristic_frame_unwind_cache (this_frame, this_prologue_cache, 0);
+
+ /* The PC of the previous frame is stored in the link register of
+ the current frame. Frob regnum so that we pull the value from
+ the correct place. */
+ if (regnum == ALPHA_PC_REGNUM)
+ regnum = info->return_reg;
+
+ return trad_frame_get_prev_register (this_frame, info->saved_regs, regnum);
+}
- if ((inst & 0xfc1f0000) == 0xb41e0000
- && (inst & 0xffff0000) != 0xb7fe0000)
- continue; /* stq reg,n($sp) */
- /* reg != $zero */
- if ((inst & 0xfc1f0000) == 0x9c1e0000
- && (inst & 0xffff0000) != 0x9ffe0000)
- continue; /* stt reg,n($sp) */
- /* reg != $zero */
- if (inst == 0x47de040f) /* bis sp,sp,fp */
- continue;
+static const struct frame_unwind alpha_heuristic_frame_unwind = {
+ NORMAL_FRAME,
+ alpha_heuristic_frame_this_id,
+ alpha_heuristic_frame_prev_register,
+ NULL,
+ default_frame_sniffer
+};
- break;
- }
- return pc + offset;
+static CORE_ADDR
+alpha_heuristic_frame_base_address (struct frame_info *this_frame,
+ void **this_prologue_cache)
+{
+ struct alpha_heuristic_unwind_cache *info
+ = alpha_heuristic_frame_unwind_cache (this_frame, this_prologue_cache, 0);
+
+ return info->vfp;
}
-#if 0
-/* Is address PC in the prologue (loosely defined) for function at
- STARTADDR? */
+static const struct frame_base alpha_heuristic_frame_base = {
+ &alpha_heuristic_frame_unwind,
+ alpha_heuristic_frame_base_address,
+ alpha_heuristic_frame_base_address,
+ alpha_heuristic_frame_base_address
+};
-static int
-alpha_in_lenient_prologue (CORE_ADDR startaddr, CORE_ADDR pc)
+/* Just like reinit_frame_cache, but with the right arguments to be
+ callable as an sfunc. Used by the "set heuristic-fence-post" command. */
+
+static void
+reinit_frame_cache_sfunc (char *args, int from_tty, struct cmd_list_element *c)
{
- CORE_ADDR end_prologue = alpha_skip_prologue (startaddr, 1);
- return pc >= startaddr && pc < end_prologue;
+ reinit_frame_cache ();
}
-#endif
-
-/* The alpha needs a conversion between register and memory format if
- the register is a floating point register and
- memory format is float, as the register format must be double
- or
- memory format is an integer with 4 bytes or less, as the representation
- of integers in floating point registers is different. */
-void
-alpha_register_convert_to_virtual (int regnum, struct type *valtype,
- char *raw_buffer, char *virtual_buffer)
-{
- if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum))
- {
- memcpy (virtual_buffer, raw_buffer, REGISTER_VIRTUAL_SIZE (regnum));
- return;
- }
- if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
- {
- double d = extract_floating (raw_buffer, REGISTER_RAW_SIZE (regnum));
- store_floating (virtual_buffer, TYPE_LENGTH (valtype), d);
- }
- else if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4)
- {
- ULONGEST l;
- l = extract_unsigned_integer (raw_buffer, REGISTER_RAW_SIZE (regnum));
- l = ((l >> 32) & 0xc0000000) | ((l >> 29) & 0x3fffffff);
- store_unsigned_integer (virtual_buffer, TYPE_LENGTH (valtype), l);
- }
- else
- error ("Cannot retrieve value from floating point register");
-}
+\f
+/* Assuming NEXT_FRAME->prev is a dummy, return the frame ID of that
+ dummy frame. The frame ID's base needs to match the TOS value
+ saved by save_dummy_frame_tos(), and the PC match the dummy frame's
+ breakpoint. */
-void
-alpha_register_convert_to_raw (struct type *valtype, int regnum,
- char *virtual_buffer, char *raw_buffer)
+static struct frame_id
+alpha_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
{
- if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum))
- {
- memcpy (raw_buffer, virtual_buffer, REGISTER_RAW_SIZE (regnum));
- return;
- }
+ ULONGEST base;
+ base = get_frame_register_unsigned (this_frame, ALPHA_SP_REGNUM);
+ return frame_id_build (base, get_frame_pc (this_frame));
+}
- if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
- {
- double d = extract_floating (virtual_buffer, TYPE_LENGTH (valtype));
- store_floating (raw_buffer, REGISTER_RAW_SIZE (regnum), d);
- }
- else if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4)
- {
- ULONGEST l;
- if (TYPE_UNSIGNED (valtype))
- l = extract_unsigned_integer (virtual_buffer, TYPE_LENGTH (valtype));
- else
- l = extract_signed_integer (virtual_buffer, TYPE_LENGTH (valtype));
- l = ((l & 0xc0000000) << 32) | ((l & 0x3fffffff) << 29);
- store_unsigned_integer (raw_buffer, REGISTER_RAW_SIZE (regnum), l);
- }
- else
- error ("Cannot store value in floating point register");
+static CORE_ADDR
+alpha_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
+{
+ ULONGEST pc;
+ pc = frame_unwind_register_unsigned (next_frame, ALPHA_PC_REGNUM);
+ return pc;
}
-/* Given a return value in `regbuf' with a type `valtype',
- extract and copy its value into `valbuf'. */
+\f
+/* Helper routines for alpha*-nat.c files to move register sets to and
+ from core files. The UNIQUE pointer is allowed to be NULL, as most
+ targets don't supply this value in their core files. */
void
-alpha_extract_return_value (struct type *valtype,
- char regbuf[REGISTER_BYTES], char *valbuf)
+alpha_supply_int_regs (struct regcache *regcache, int regno,
+ const void *r0_r30, const void *pc, const void *unique)
{
- if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
- alpha_register_convert_to_virtual (FP0_REGNUM, valtype,
- regbuf + REGISTER_BYTE (FP0_REGNUM),
- valbuf);
- else
- memcpy (valbuf, regbuf + REGISTER_BYTE (V0_REGNUM), TYPE_LENGTH (valtype));
-}
+ const gdb_byte *regs = r0_r30;
+ int i;
+
+ for (i = 0; i < 31; ++i)
+ if (regno == i || regno == -1)
+ regcache_raw_supply (regcache, i, regs + i * 8);
-/* Given a return value in `regbuf' with a type `valtype',
- write its value into the appropriate register. */
+ if (regno == ALPHA_ZERO_REGNUM || regno == -1)
+ regcache_raw_supply (regcache, ALPHA_ZERO_REGNUM, NULL);
+
+ if (regno == ALPHA_PC_REGNUM || regno == -1)
+ regcache_raw_supply (regcache, ALPHA_PC_REGNUM, pc);
+
+ if (regno == ALPHA_UNIQUE_REGNUM || regno == -1)
+ regcache_raw_supply (regcache, ALPHA_UNIQUE_REGNUM, unique);
+}
void
-alpha_store_return_value (struct type *valtype, char *valbuf)
+alpha_fill_int_regs (const struct regcache *regcache,
+ int regno, void *r0_r30, void *pc, void *unique)
{
- char raw_buffer[MAX_REGISTER_RAW_SIZE];
- int regnum = V0_REGNUM;
- int length = TYPE_LENGTH (valtype);
+ gdb_byte *regs = r0_r30;
+ int i;
- if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
- {
- regnum = FP0_REGNUM;
- length = REGISTER_RAW_SIZE (regnum);
- alpha_register_convert_to_raw (valtype, regnum, valbuf, raw_buffer);
- }
- else
- memcpy (raw_buffer, valbuf, length);
+ for (i = 0; i < 31; ++i)
+ if (regno == i || regno == -1)
+ regcache_raw_collect (regcache, i, regs + i * 8);
- write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, length);
-}
+ if (regno == ALPHA_PC_REGNUM || regno == -1)
+ regcache_raw_collect (regcache, ALPHA_PC_REGNUM, pc);
-/* Just like reinit_frame_cache, but with the right arguments to be
- callable as an sfunc. */
+ if (unique && (regno == ALPHA_UNIQUE_REGNUM || regno == -1))
+ regcache_raw_collect (regcache, ALPHA_UNIQUE_REGNUM, unique);
+}
-static void
-reinit_frame_cache_sfunc (char *args, int from_tty, struct cmd_list_element *c)
+void
+alpha_supply_fp_regs (struct regcache *regcache, int regno,
+ const void *f0_f30, const void *fpcr)
{
- reinit_frame_cache ();
-}
+ const gdb_byte *regs = f0_f30;
+ int i;
-/* This is the definition of CALL_DUMMY_ADDRESS. It's a heuristic that is used
- to find a convenient place in the text segment to stick a breakpoint to
- detect the completion of a target function call (ala call_function_by_hand).
- */
+ for (i = ALPHA_FP0_REGNUM; i < ALPHA_FP0_REGNUM + 31; ++i)
+ if (regno == i || regno == -1)
+ regcache_raw_supply (regcache, i,
+ regs + (i - ALPHA_FP0_REGNUM) * 8);
-CORE_ADDR
-alpha_call_dummy_address (void)
+ if (regno == ALPHA_FPCR_REGNUM || regno == -1)
+ regcache_raw_supply (regcache, ALPHA_FPCR_REGNUM, fpcr);
+}
+
+void
+alpha_fill_fp_regs (const struct regcache *regcache,
+ int regno, void *f0_f30, void *fpcr)
{
- CORE_ADDR entry;
- struct minimal_symbol *sym;
+ gdb_byte *regs = f0_f30;
+ int i;
- entry = entry_point_address ();
+ for (i = ALPHA_FP0_REGNUM; i < ALPHA_FP0_REGNUM + 31; ++i)
+ if (regno == i || regno == -1)
+ regcache_raw_collect (regcache, i,
+ regs + (i - ALPHA_FP0_REGNUM) * 8);
+
+ if (regno == ALPHA_FPCR_REGNUM || regno == -1)
+ regcache_raw_collect (regcache, ALPHA_FPCR_REGNUM, fpcr);
+}
- if (entry != 0)
- return entry;
+\f
- sym = lookup_minimal_symbol ("_Prelude", NULL, symfile_objfile);
+/* Return nonzero if the G_floating register value in REG is equal to
+ zero for FP control instructions. */
+
+static int
+fp_register_zero_p (LONGEST reg)
+{
+ /* Check that all bits except the sign bit are zero. */
+ const LONGEST zero_mask = ((LONGEST) 1 << 63) ^ -1;
- if (!sym || MSYMBOL_TYPE (sym) != mst_text)
- return 0;
- else
- return SYMBOL_VALUE_ADDRESS (sym) + 4;
+ return ((reg & zero_mask) == 0);
}
-int
-alpha_use_struct_convention (int gcc_p, struct type *type)
+/* Return the value of the sign bit for the G_floating register
+ value held in REG. */
+
+static int
+fp_register_sign_bit (LONGEST reg)
{
- /* Structures are returned by ref in extra arg0. */
- return 1;
+ const LONGEST sign_mask = (LONGEST) 1 << 63;
+
+ return ((reg & sign_mask) != 0);
}
/* alpha_software_single_step() is called just before we want to resume
the inferior, if we want to single-step it but there is no hardware
or kernel single-step support (NetBSD on Alpha, for example). We find
- the target of the coming instruction and breakpoint it.
-
- single_step is also called just after the inferior stops. If we had
- set up a simulated single-step, we undo our damage. */
+ the target of the coming instruction and breakpoint it. */
static CORE_ADDR
-alpha_next_pc (CORE_ADDR pc)
+alpha_next_pc (struct frame_info *frame, CORE_ADDR pc)
{
unsigned int insn;
unsigned int op;
+ int regno;
int offset;
LONGEST rav;
- insn = read_memory_unsigned_integer (pc, sizeof (insn));
+ insn = alpha_read_insn (pc);
/* Opcode is top 6 bits. */
op = (insn >> 26) & 0x3f;
{
/* Jump format: target PC is:
RB & ~3 */
- return (read_register ((insn >> 16) & 0x1f) & ~3);
+ return (get_frame_register_unsigned (frame, (insn >> 16) & 0x1f) & ~3);
}
if ((op & 0x30) == 0x30)
offset = (insn & 0x001fffff);
if (offset & 0x00100000)
offset |= 0xffe00000;
- offset *= 4;
- return (pc + 4 + offset);
+ offset *= ALPHA_INSN_SIZE;
+ return (pc + ALPHA_INSN_SIZE + offset);
}
/* Need to determine if branch is taken; read RA. */
- rav = (LONGEST) read_register ((insn >> 21) & 0x1f);
+ regno = (insn >> 21) & 0x1f;
+ switch (op)
+ {
+ case 0x31: /* FBEQ */
+ case 0x36: /* FBGE */
+ case 0x37: /* FBGT */
+ case 0x33: /* FBLE */
+ case 0x32: /* FBLT */
+ case 0x35: /* FBNE */
+ regno += gdbarch_fp0_regnum (get_frame_arch (frame));
+ }
+
+ rav = get_frame_register_signed (frame, regno);
+
switch (op)
{
case 0x38: /* BLBC */
if (rav >= 0)
goto branch_taken;
break;
+
+ /* Floating point branches. */
+
+ case 0x31: /* FBEQ */
+ if (fp_register_zero_p (rav))
+ goto branch_taken;
+ break;
+ case 0x36: /* FBGE */
+ if (fp_register_sign_bit (rav) == 0 || fp_register_zero_p (rav))
+ goto branch_taken;
+ break;
+ case 0x37: /* FBGT */
+ if (fp_register_sign_bit (rav) == 0 && ! fp_register_zero_p (rav))
+ goto branch_taken;
+ break;
+ case 0x33: /* FBLE */
+ if (fp_register_sign_bit (rav) == 1 || fp_register_zero_p (rav))
+ goto branch_taken;
+ break;
+ case 0x32: /* FBLT */
+ if (fp_register_sign_bit (rav) == 1 && ! fp_register_zero_p (rav))
+ goto branch_taken;
+ break;
+ case 0x35: /* FBNE */
+ if (! fp_register_zero_p (rav))
+ goto branch_taken;
+ break;
}
}
/* Not a branch or branch not taken; target PC is:
pc + 4 */
- return (pc + 4);
+ return (pc + ALPHA_INSN_SIZE);
}
-void
-alpha_software_single_step (enum target_signal sig, int insert_breakpoints_p)
+int
+alpha_software_single_step (struct frame_info *frame)
{
- static CORE_ADDR next_pc;
- typedef char binsn_quantum[BREAKPOINT_MAX];
- static binsn_quantum break_mem;
- CORE_ADDR pc;
+ CORE_ADDR pc, next_pc;
- if (insert_breakpoints_p)
- {
- pc = read_pc ();
- next_pc = alpha_next_pc (pc);
+ pc = get_frame_pc (frame);
+ next_pc = alpha_next_pc (frame, pc);
- target_insert_breakpoint (next_pc, break_mem);
- }
- else
+ insert_single_step_breakpoint (next_pc);
+ return 1;
+}
+
+\f
+/* Initialize the current architecture based on INFO. If possible, re-use an
+ architecture from ARCHES, which is a list of architectures already created
+ during this debugging session.
+
+ Called e.g. at program startup, when reading a core file, and when reading
+ a binary file. */
+
+static struct gdbarch *
+alpha_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
+{
+ struct gdbarch_tdep *tdep;
+ struct gdbarch *gdbarch;
+
+ /* Try to determine the ABI of the object we are loading. */
+ if (info.abfd != NULL && info.osabi == GDB_OSABI_UNKNOWN)
{
- target_remove_breakpoint (next_pc, break_mem);
- write_pc (next_pc);
+ /* If it's an ECOFF file, assume it's OSF/1. */
+ if (bfd_get_flavour (info.abfd) == bfd_target_ecoff_flavour)
+ info.osabi = GDB_OSABI_OSF1;
}
+
+ /* Find a candidate among extant architectures. */
+ arches = gdbarch_list_lookup_by_info (arches, &info);
+ if (arches != NULL)
+ return arches->gdbarch;
+
+ tdep = xmalloc (sizeof (struct gdbarch_tdep));
+ gdbarch = gdbarch_alloc (&info, tdep);
+
+ /* Lowest text address. This is used by heuristic_proc_start()
+ to decide when to stop looking. */
+ tdep->vm_min_address = (CORE_ADDR) 0x120000000LL;
+
+ tdep->dynamic_sigtramp_offset = NULL;
+ tdep->sigcontext_addr = NULL;
+ tdep->sc_pc_offset = 2 * 8;
+ tdep->sc_regs_offset = 4 * 8;
+ tdep->sc_fpregs_offset = tdep->sc_regs_offset + 32 * 8 + 8;
+
+ tdep->jb_pc = -1; /* longjmp support not enabled by default */
+
+ tdep->return_in_memory = alpha_return_in_memory_always;
+
+ /* Type sizes */
+ set_gdbarch_short_bit (gdbarch, 16);
+ set_gdbarch_int_bit (gdbarch, 32);
+ set_gdbarch_long_bit (gdbarch, 64);
+ set_gdbarch_long_long_bit (gdbarch, 64);
+ set_gdbarch_float_bit (gdbarch, 32);
+ set_gdbarch_double_bit (gdbarch, 64);
+ set_gdbarch_long_double_bit (gdbarch, 64);
+ set_gdbarch_ptr_bit (gdbarch, 64);
+
+ /* Register info */
+ set_gdbarch_num_regs (gdbarch, ALPHA_NUM_REGS);
+ set_gdbarch_sp_regnum (gdbarch, ALPHA_SP_REGNUM);
+ set_gdbarch_pc_regnum (gdbarch, ALPHA_PC_REGNUM);
+ set_gdbarch_fp0_regnum (gdbarch, ALPHA_FP0_REGNUM);
+
+ set_gdbarch_register_name (gdbarch, alpha_register_name);
+ set_gdbarch_register_type (gdbarch, alpha_register_type);
+
+ set_gdbarch_cannot_fetch_register (gdbarch, alpha_cannot_fetch_register);
+ set_gdbarch_cannot_store_register (gdbarch, alpha_cannot_store_register);
+
+ set_gdbarch_convert_register_p (gdbarch, alpha_convert_register_p);
+ set_gdbarch_register_to_value (gdbarch, alpha_register_to_value);
+ set_gdbarch_value_to_register (gdbarch, alpha_value_to_register);
+
+ set_gdbarch_register_reggroup_p (gdbarch, alpha_register_reggroup_p);
+
+ /* Prologue heuristics. */
+ set_gdbarch_skip_prologue (gdbarch, alpha_skip_prologue);
+
+ /* Disassembler. */
+ set_gdbarch_print_insn (gdbarch, print_insn_alpha);
+
+ /* Call info. */
+
+ set_gdbarch_return_value (gdbarch, alpha_return_value);
+
+ /* Settings for calling functions in the inferior. */
+ set_gdbarch_push_dummy_call (gdbarch, alpha_push_dummy_call);
+
+ /* Methods for saving / extracting a dummy frame's ID. */
+ set_gdbarch_dummy_id (gdbarch, alpha_dummy_id);
+
+ /* Return the unwound PC value. */
+ set_gdbarch_unwind_pc (gdbarch, alpha_unwind_pc);
+
+ set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
+ set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
+
+ set_gdbarch_breakpoint_from_pc (gdbarch, alpha_breakpoint_from_pc);
+ set_gdbarch_decr_pc_after_break (gdbarch, ALPHA_INSN_SIZE);
+ set_gdbarch_cannot_step_breakpoint (gdbarch, 1);
+
+ /* Hook in ABI-specific overrides, if they have been registered. */
+ gdbarch_init_osabi (info, gdbarch);
+
+ /* Now that we have tuned the configuration, set a few final things
+ based on what the OS ABI has told us. */
+
+ if (tdep->jb_pc >= 0)
+ set_gdbarch_get_longjmp_target (gdbarch, alpha_get_longjmp_target);
+
+ frame_unwind_append_unwinder (gdbarch, &alpha_sigtramp_frame_unwind);
+ frame_unwind_append_unwinder (gdbarch, &alpha_heuristic_frame_unwind);
+
+ frame_base_set_default (gdbarch, &alpha_heuristic_frame_base);
+
+ return gdbarch;
+}
+
+void
+alpha_dwarf2_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+ dwarf2_append_unwinders (gdbarch);
+ frame_base_append_sniffer (gdbarch, dwarf2_frame_base_sniffer);
}
+extern initialize_file_ftype _initialize_alpha_tdep; /* -Wmissing-prototypes */
+
void
_initialize_alpha_tdep (void)
{
struct cmd_list_element *c;
- tm_print_insn = print_insn_alpha;
+ gdbarch_register (bfd_arch_alpha, alpha_gdbarch_init, NULL);
/* Let the user set the fence post for heuristic_proc_start. */
/* We really would like to have both "0" and "unlimited" work, but
command.c doesn't deal with that. So make it a var_zinteger
because the user can always use "999999" or some such for unlimited. */
- c = add_set_cmd ("heuristic-fence-post", class_support, var_zinteger,
- (char *) &heuristic_fence_post,
- "\
-Set the distance searched for the start of a function.\n\
-If you are debugging a stripped executable, GDB needs to search through the\n\
-program for the start of a function. This command sets the distance of the\n\
-search. The only need to set it is when debugging a stripped executable.",
- &setlist);
/* We need to throw away the frame cache when we set this, since it
might change our ability to get backtraces. */
- c->function.sfunc = reinit_frame_cache_sfunc;
- add_show_from_set (c, &showlist);
+ add_setshow_zinteger_cmd ("heuristic-fence-post", class_support,
+ &heuristic_fence_post, _("\
+Set the distance searched for the start of a function."), _("\
+Show the distance searched for the start of a function."), _("\
+If you are debugging a stripped executable, GDB needs to search through the\n\
+program for the start of a function. This command sets the distance of the\n\
+search. The only need to set it is when debugging a stripped executable."),
+ reinit_frame_cache_sfunc,
+ NULL, /* FIXME: i18n: The distance searched for the start of a function is \"%d\". */
+ &setlist, &showlist);
}