/* Target-dependent code for the ALPHA architecture, for GDB, the GNU Debugger.
- Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001
+ Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
Free Software Foundation, Inc.
This file is part of GDB.
#include "defs.h"
#include "frame.h"
+#include "frame-unwind.h"
+#include "frame-base.h"
#include "inferior.h"
#include "symtab.h"
#include "value.h"
#include "linespec.h"
#include "regcache.h"
#include "doublest.h"
+#include "arch-utils.h"
+#include "osabi.h"
+#include "block.h"
-/* FIXME: Some of this code should perhaps be merged with mips-tdep.c. */
+#include "elf-bfd.h"
-/* Prototypes for local functions. */
+#include "alpha-tdep.h"
-static alpha_extra_func_info_t push_sigtramp_desc (CORE_ADDR low_addr);
+\f
+static const char *
+alpha_register_name (int regno)
+{
+ static const char * const 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", "", "unique"
+ };
+
+ if (regno < 0)
+ return NULL;
+ if (regno >= (sizeof(register_names) / sizeof(*register_names)))
+ return NULL;
+ return register_names[regno];
+}
-static CORE_ADDR read_next_frame_reg (struct frame_info *, int);
+static int
+alpha_cannot_fetch_register (int regno)
+{
+ return regno == ALPHA_ZERO_REGNUM;
+}
-static CORE_ADDR heuristic_proc_start (CORE_ADDR);
+static int
+alpha_cannot_store_register (int regno)
+{
+ return regno == ALPHA_ZERO_REGNUM;
+}
-static alpha_extra_func_info_t heuristic_proc_desc (CORE_ADDR,
- CORE_ADDR,
- struct frame_info *);
+static int
+alpha_register_convertible (int regno)
+{
+ return (regno >= FP0_REGNUM && regno <= FP0_REGNUM + 31);
+}
-static alpha_extra_func_info_t find_proc_desc (CORE_ADDR,
- struct frame_info *);
+static struct type *
+alpha_register_virtual_type (int regno)
+{
+ return ((regno >= FP0_REGNUM && regno < (FP0_REGNUM+31))
+ ? builtin_type_double : builtin_type_long);
+}
-#if 0
-static int alpha_in_lenient_prologue (CORE_ADDR, CORE_ADDR);
-#endif
+static int
+alpha_register_byte (int regno)
+{
+ return (regno * 8);
+}
-static void reinit_frame_cache_sfunc (char *, int, struct cmd_list_element *);
+static int
+alpha_register_raw_size (int regno)
+{
+ return 8;
+}
-static CORE_ADDR after_prologue (CORE_ADDR pc,
- alpha_extra_func_info_t proc_desc);
+static int
+alpha_register_virtual_size (int regno)
+{
+ return 8;
+}
-static int alpha_in_prologue (CORE_ADDR pc,
- alpha_extra_func_info_t proc_desc);
+/* 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 int alpha_about_to_return (CORE_ADDR pc);
+static 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;
+ }
-void _initialize_alpha_tdep (void);
+ if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
+ {
+ double d = deprecated_extract_floating (raw_buffer, REGISTER_RAW_SIZE (regnum));
+ deprecated_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");
+}
+
+static void
+alpha_register_convert_to_raw (struct type *valtype, int regnum,
+ char *virtual_buffer, char *raw_buffer)
+{
+ if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum))
+ {
+ memcpy (raw_buffer, virtual_buffer, REGISTER_RAW_SIZE (regnum));
+ return;
+ }
+
+ if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
+ {
+ double d = deprecated_extract_floating (virtual_buffer, TYPE_LENGTH (valtype));
+ deprecated_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");
+}
-/* 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
+/* 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.
-/* 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)
+ We don't bother tracking which register values should go in integer
+ regs or fp regs; we load the same values into both.
+
+ 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, CORE_ADDR func_addr,
+ struct regcache *regcache, CORE_ADDR bp_addr,
+ int nargs, struct value **args, CORE_ADDR sp,
+ int struct_return, CORE_ADDR struct_addr)
{
- unsigned int i[3], w;
- long off;
+ int i;
+ int accumulate_size = struct_return ? 8 : 0;
+ 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 arg_reg_buffer[ALPHA_REGISTER_SIZE * ALPHA_NUM_ARG_REGS];
+ int required_arg_regs;
- if (read_memory_nobpt (pc, (char *) &w, 4) != 0)
- return -1;
+ /* The ABI places the address of the called function in T12. */
+ regcache_cooked_write_signed (regcache, ALPHA_T12_REGNUM, func_addr);
- off = -1;
- switch (w)
+ /* 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++)
{
- 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;
+ 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))
+ {
+ 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);
+ }
+ break;
+ 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_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;
+
+ /* Write the real data into the stack. */
+ write_memory (sp, VALUE_CONTENTS (arg), 16);
+
+ /* Construct the indirection. */
+ arg_type = lookup_pointer_type (arg_type);
+ arg = value_from_pointer (arg_type, sp);
+ }
+ break;
+ 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 (arg);
}
- pc -= off;
- if (pc & 0x7)
+
+ /* 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 < sizeof(arg_reg_buffer))
+ accumulate_size = 0;
+ else
+ accumulate_size -= sizeof(arg_reg_buffer);
+ sp -= accumulate_size;
+
+ /* Keep sp aligned to a multiple of 16 as the ABI requires. */
+ sp &= ~15;
+
+ /* `Push' arguments on the stack. */
+ for (i = nargs; m_arg--, --i >= 0;)
{
- /* designated sequence is not quadword aligned */
- return -1;
+ char *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 (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);
}
+ if (struct_return)
+ store_unsigned_integer (arg_reg_buffer, ALPHA_REGISTER_SIZE, struct_addr);
- if (read_memory_nobpt (pc, (char *) i, sizeof (i)) != 0)
- return -1;
+ /* 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 (i[0] == 0x47de0410 && i[1] == 0x43ecf400 && i[2] == 0x00000083)
- return off;
+ /* Finally, update the stack pointer. */
+ regcache_cooked_write_signed (regcache, ALPHA_SP_REGNUM, sp);
- return -1;
+ return sp;
}
-\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)
+/* Given a return value in `regbuf' with a type `valtype',
+ extract and copy its value into `valbuf'. */
+
+static void
+alpha_extract_return_value (struct type *valtype,
+ char regbuf[ALPHA_REGISTER_BYTES], char *valbuf)
{
- char *name;
- find_pc_partial_function (pc, &name, (CORE_ADDR *) NULL, (CORE_ADDR *) NULL);
- if (IN_SIGTRAMP (pc, name))
- return frame->frame;
+ if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
+ alpha_register_convert_to_virtual (FP0_REGNUM, valtype,
+ regbuf + REGISTER_BYTE (FP0_REGNUM),
+ valbuf);
else
- return 0;
+ memcpy (valbuf, regbuf + REGISTER_BYTE (ALPHA_V0_REGNUM),
+ TYPE_LENGTH (valtype));
}
-\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. */
+/* Given a return value in `regbuf' with a type `valtype',
+ write its value into the appropriate register. */
-static alpha_extra_func_info_t
-push_sigtramp_desc (CORE_ADDR low_addr)
+static void
+alpha_store_return_value (struct type *valtype, char *valbuf)
{
- 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);
+ char raw_buffer[ALPHA_REGISTER_SIZE];
+ int regnum = ALPHA_V0_REGNUM;
+ int length = TYPE_LENGTH (valtype);
+
+ if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
+ {
+ regnum = FP0_REGNUM;
+ length = ALPHA_REGISTER_SIZE;
+ alpha_register_convert_to_raw (valtype, regnum, valbuf, raw_buffer);
+ }
+ else
+ memcpy (raw_buffer, valbuf, length);
+
+ deprecated_write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, length);
}
-\f
-/* Guaranteed to set frame->saved_regs to some values (it never leaves it
- NULL). */
+static int
+alpha_use_struct_convention (int gcc_p, struct type *type)
+{
+ /* Structures are returned by ref in extra arg0. */
+ return 1;
+}
-void
-alpha_find_saved_regs (struct frame_info *frame)
+static void
+alpha_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
{
- 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)
- {
- CORE_ADDR sigcontext_addr;
+ /* Store the address of the place in which to copy the structure the
+ subroutine will return. Handled by alpha_push_arguments. */
+}
- 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++)
- {
- 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;
- }
+static CORE_ADDR
+alpha_extract_struct_value_address (char *regbuf)
+{
+ return (extract_unsigned_integer (regbuf + REGISTER_BYTE (ALPHA_V0_REGNUM),
+ REGISTER_RAW_SIZE (ALPHA_V0_REGNUM)));
+}
- proc_desc = frame->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;
+\f
+static const unsigned char *
+alpha_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr)
+{
+ static const unsigned char alpha_breakpoint[] =
+ { 0x80, 0, 0, 0 }; /* call_pal bpt */
- /* Fill in the offsets for the registers which gen_mask says
- were saved. */
+ *lenptr = sizeof(alpha_breakpoint);
+ return (alpha_breakpoint);
+}
- reg_position = frame->frame + PROC_REG_OFFSET (proc_desc);
- mask = PROC_REG_MASK (proc_desc);
+\f
+/* This returns the PC of the first insn after the prologue.
+ If we can't find the prologue, then return 0. */
- returnreg = PROC_PC_REG (proc_desc);
+CORE_ADDR
+alpha_after_prologue (CORE_ADDR pc)
+{
+ struct symtab_and_line sal;
+ CORE_ADDR func_addr, func_end;
- /* 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. */
- }
+ if (!find_pc_partial_function (pc, NULL, &func_addr, &func_end))
+ return 0;
- for (ireg = 0; ireg <= 31; ++ireg)
- if (mask & (1 << ireg))
- {
- frame->saved_regs[ireg] = reg_position;
- reg_position += 8;
- }
+ sal = find_pc_line (func_addr, 0);
+ if (sal.end < func_end)
+ return sal.end;
- /* Fill in the offsets for the registers which float_mask says
- were saved. */
+ /* 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;
+}
- reg_position = frame->frame + PROC_FREG_OFFSET (proc_desc);
- mask = PROC_FREG_MASK (proc_desc);
+/* Read an instruction from memory at PC, looking through breakpoints. */
- for (ireg = 0; ireg <= 31; ++ireg)
- if (mask & (1 << ireg))
- {
- frame->saved_regs[FP0_REGNUM + ireg] = reg_position;
- reg_position += 8;
- }
+unsigned int
+alpha_read_insn (CORE_ADDR pc)
+{
+ char buf[4];
+ int status;
- frame->saved_regs[PC_REGNUM] = frame->saved_regs[returnreg];
+ status = read_memory_nobpt (pc, buf, 4);
+ if (status)
+ memory_error (status, pc);
+ return extract_unsigned_integer (buf, 4);
}
+/* 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
-read_next_frame_reg (struct frame_info *fi, int regno)
+alpha_skip_prologue (CORE_ADDR pc)
{
- for (; fi; fi = fi->next)
+ unsigned long inst;
+ int offset;
+ CORE_ADDR post_prologue_pc;
+ char buf[4];
+
+ /* 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, 4))
+ return 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. */
+
+ post_prologue_pc = alpha_after_prologue (pc);
+ if (post_prologue_pc != 0)
+ return max (pc, post_prologue_pc);
+
+ /* Can't determine prologue from the symbol table, need to examine
+ instructions. */
+
+ /* 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)
{
- /* 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
- {
- if (fi->saved_regs == NULL)
- alpha_find_saved_regs (fi);
- if (fi->saved_regs[regno])
- return read_memory_integer (fi->saved_regs[regno], 8);
- }
+ 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 read_register (regno);
+ return pc + offset;
}
-CORE_ADDR
-alpha_frame_saved_pc (struct frame_info *frame)
+\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. */
+
+static int
+alpha_get_longjmp_target (CORE_ADDR *pc)
{
- alpha_extra_func_info_t proc_desc = frame->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->pc_reg;
+ struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+ CORE_ADDR jb_addr;
+ char raw_buffer[ALPHA_REGISTER_SIZE];
+
+ jb_addr = read_register (ALPHA_A0_REGNUM);
- if (proc_desc && PROC_DESC_IS_DUMMY (proc_desc))
- return read_memory_integer (frame->frame - 8, 8);
+ if (target_read_memory (jb_addr + (tdep->jb_pc * tdep->jb_elt_size),
+ raw_buffer, tdep->jb_elt_size))
+ return 0;
- return read_next_frame_reg (frame, pcreg);
+ *pc = extract_unsigned_integer (raw_buffer, tdep->jb_elt_size);
+ return 1;
}
-CORE_ADDR
-alpha_saved_pc_after_call (struct frame_info *frame)
+\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 pc = frame->pc;
- CORE_ADDR tmp;
- alpha_extra_func_info_t proc_desc;
- int pcreg;
+ CORE_ADDR sigcontext_addr;
+};
+
+static struct alpha_sigtramp_unwind_cache *
+alpha_sigtramp_frame_unwind_cache (struct frame_info *next_frame,
+ void **this_prologue_cache)
+{
+ 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;
- /* Skip over shared library trampoline if necessary. */
- tmp = SKIP_TRAMPOLINE_CODE (pc);
- if (tmp != 0)
- pc = tmp;
+ tdep = gdbarch_tdep (current_gdbarch);
+ info->sigcontext_addr = tdep->sigcontext_addr (next_frame);
- proc_desc = find_proc_desc (pc, frame->next);
- pcreg = proc_desc ? PROC_PC_REG (proc_desc) : RA_REGNUM;
+ return info;
+}
+
+/* Return the address of REGNO in a sigtramp frame. Since this is all
+ arithmetic, it doesn't seem worthwhile to cache it. */
- if (frame->signal_handler_caller)
- return alpha_frame_saved_pc (frame);
+#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
+
+static CORE_ADDR
+alpha_sigtramp_register_address (CORE_ADDR sigcontext_addr, unsigned int regno)
+{
+ if (regno < 32)
+ return sigcontext_addr + SIGFRAME_REGSAVE_OFF + regno * 8;
+ if (regno >= FP0_REGNUM && regno < FP0_REGNUM + 32)
+ return sigcontext_addr + SIGFRAME_FPREGSAVE_OFF + regno * 8;
+ if (regno == PC_REGNUM)
+ return sigcontext_addr + SIGFRAME_PC_OFF;
+
+ 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 *next_frame,
+ void **this_prologue_cache,
+ struct frame_id *this_id)
+{
+ struct alpha_sigtramp_unwind_cache *info
+ = alpha_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache);
+ struct gdbarch_tdep *tdep;
+ 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. */
+ tdep = gdbarch_tdep (current_gdbarch);
+ if (tdep->dynamic_sigtramp_offset)
+ {
+ int offset;
+ code_addr = frame_pc_unwind (next_frame);
+ offset = tdep->dynamic_sigtramp_offset (code_addr);
+ if (offset >= 0)
+ code_addr -= offset;
+ else
+ code_addr = 0;
+ }
else
- return read_register (pcreg);
+ code_addr = frame_func_unwind (next_frame);
+
+ /* The stack address is trivially read from the sigcontext. */
+ stack_addr = alpha_sigtramp_register_address (info->sigcontext_addr,
+ ALPHA_SP_REGNUM);
+ stack_addr = read_memory_unsigned_integer (stack_addr, ALPHA_REGISTER_SIZE);
+
+ *this_id = frame_id_build (stack_addr, code_addr);
}
+/* Retrieve the value of REGNUM in FRAME. Don't give up! */
-static struct alpha_extra_func_info temp_proc_desc;
-static struct frame_saved_regs temp_saved_regs;
+static void
+alpha_sigtramp_frame_prev_register (struct frame_info *next_frame,
+ void **this_prologue_cache,
+ int regnum, int *optimizedp,
+ enum lval_type *lvalp, CORE_ADDR *addrp,
+ int *realnump, void *bufferp)
+{
+ struct alpha_sigtramp_unwind_cache *info
+ = alpha_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache);
+ CORE_ADDR addr;
-/* Nonzero if instruction at PC is a return instruction. "ret
- $zero,($ra),1" on alpha. */
+ if (info->sigcontext_addr != 0)
+ {
+ /* All integer and fp registers are stored in memory. */
+ addr = alpha_sigtramp_register_address (info->sigcontext_addr, regnum);
+ if (addr != 0)
+ {
+ *optimizedp = 0;
+ *lvalp = lval_memory;
+ *addrp = addr;
+ *realnump = -1;
+ if (bufferp != NULL)
+ read_memory (addr, bufferp, ALPHA_REGISTER_SIZE);
+ return;
+ }
+ }
-static int
-alpha_about_to_return (CORE_ADDR pc)
+ /* 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. */
+ frame_register (next_frame, regnum, optimizedp, lvalp, addrp,
+ realnump, bufferp);
+}
+
+static const struct frame_unwind alpha_sigtramp_frame_unwind = {
+ SIGTRAMP_FRAME,
+ alpha_sigtramp_frame_this_id,
+ alpha_sigtramp_frame_prev_register
+};
+
+static const struct frame_unwind *
+alpha_sigtramp_frame_p (CORE_ADDR pc)
{
- return read_memory_integer (pc, 4) == 0x6bfa8001;
+ char *name;
+
+ /* We shouldn't even bother to try if the OSABI didn't register
+ a sigcontext_addr handler. */
+ if (!gdbarch_tdep (current_gdbarch)->sigcontext_addr)
+ return NULL;
+
+ /* Otherwise we should be in a signal frame. */
+ find_pc_partial_function (pc, &name, NULL, NULL);
+ if (PC_IN_SIGTRAMP (pc, name))
+ return &alpha_sigtramp_frame_unwind;
+
+ return NULL;
}
+\f
+/* 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 *saved_regs;
+ CORE_ADDR vfp;
+ CORE_ADDR start_pc;
+ int return_reg;
+};
+/* 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;
-/* This fencepost looks highly suspicious to me. Removing it also
- seems suspicious as it could affect remote debugging across serial
- lines. */
+/* 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
-heuristic_proc_start (CORE_ADDR pc)
+alpha_heuristic_proc_start (CORE_ADDR pc)
{
- CORE_ADDR start_pc = pc;
- CORE_ADDR fence = start_pc - heuristic_fence_post;
+ struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+ CORE_ADDR last_non_nop = pc;
+ CORE_ADDR fence = pc - heuristic_fence_post;
+ CORE_ADDR orig_pc = pc;
+ CORE_ADDR func;
- if (start_pc == 0)
+ 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 < 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
- 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 ("\
+ || 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 -= 4; pc >= fence; pc -= 4)
+ {
+ unsigned int insn = alpha_read_insn (pc);
+ switch (insn)
+ {
+ 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;
+ }
+ }
+
+ /* 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
+ if (stop_soon == NO_STOP_QUIETLY)
+ {
+ static int blurb_printed = 0;
+
+ if (fence == tdep->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 (orig_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;
+ blurb_printed = 1;
+ }
+ }
- start_pc += 4; /* skip return */
- return start_pc;
+ return 0;
}
-static alpha_extra_func_info_t
-heuristic_proc_desc (CORE_ADDR start_pc, CORE_ADDR limit_pc,
- struct frame_info *next_frame)
+static struct alpha_heuristic_unwind_cache *
+alpha_heuristic_frame_unwind_cache (struct frame_info *next_frame,
+ void **this_prologue_cache,
+ CORE_ADDR start_pc)
{
- 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;
+ struct alpha_heuristic_unwind_cache *info;
+ ULONGEST val;
+ CORE_ADDR limit_pc, cur_pc;
+ int frame_reg, frame_size, return_reg, reg;
+
+ if (*this_prologue_cache)
+ return *this_prologue_cache;
+ info = FRAME_OBSTACK_ZALLOC (struct alpha_heuristic_unwind_cache);
+ *this_prologue_cache = info;
+ info->saved_regs = frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS);
+
+ limit_pc = frame_pc_unwind (next_frame);
if (start_pc == 0)
- return NULL;
- memset (&temp_proc_desc, '\0', sizeof (temp_proc_desc));
- memset (&temp_saved_regs, '\0', sizeof (struct frame_saved_regs));
- PROC_LOW_ADDR (&temp_proc_desc) = start_pc;
+ start_pc = alpha_heuristic_proc_start (limit_pc);
+ info->start_pc = start_pc;
- if (start_pc + 200 < limit_pc)
- limit_pc = start_pc + 200;
+ frame_reg = ALPHA_SP_REGNUM;
frame_size = 0;
- for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += 4)
- {
- char buf[4];
- unsigned long word;
- int status;
-
- status = read_memory_nobpt (cur_pc, buf, 4);
- if (status)
- memory_error (status, cur_pc);
- word = extract_unsigned_integer (buf, 4);
+ return_reg = -1;
- 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.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;
- }
- 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;
- }
- if (pcreg == -1)
+ /* If we've identified a likely place to start, do code scanning. */
+ if (start_pc != 0)
{
- /* 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;
+ /* Limit the forward search to 50 instructions. */
+ if (start_pc + 200 < limit_pc)
+ limit_pc = start_pc + 200;
- if (read_memory_nobpt (cur_pc, buf, 4))
- break;
- cur_pc += 4;
- word = extract_unsigned_integer (buf, 4);
+ for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += 4)
+ {
+ unsigned int word = alpha_read_insn (cur_pc);
- if ((word & 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */
- && (word & 0xffff0000) != 0xb7fe0000) /* reg != $zero */
+ if ((word & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */
{
- int reg = (word & 0x03e00000) >> 21;
- if (reg == T7_REGNUM || reg == T9_REGNUM || reg == RA_REGNUM)
+ if (word & 0x8000)
{
- pcreg = reg;
+ /* 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 & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */
+ else if ((word & 0xfc1f0000) == 0xb41e0000) /* stq reg,n($sp) */
{
- pcreg = (word >> 16) & 0x1f;
- break;
+ reg = (word & 0x03e00000) >> 21;
+
+ 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] = (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 (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;
-}
-/* This returns the PC of the first inst after the prologue. If we can't
- find the prologue, then return 0. */
-
-static CORE_ADDR
-after_prologue (CORE_ADDR pc, alpha_extra_func_info_t proc_desc)
-{
- struct symtab_and_line sal;
- CORE_ADDR func_addr, func_end;
+ /* 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 (!proc_desc)
- proc_desc = find_proc_desc (pc, NULL);
+ 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;
+ }
- 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;
+ cur_pc += 4;
+ }
+ }
}
- if (!find_pc_partial_function (pc, NULL, &func_addr, &func_end))
- return 0; /* Unknown */
+ /* Failing that, do default to the customary RA. */
+ if (return_reg == -1)
+ return_reg = ALPHA_RA_REGNUM;
+ info->return_reg = return_reg;
- sal = find_pc_line (func_addr, 0);
-
- if (sal.end < func_end)
- return sal.end;
+ frame_unwind_unsigned_register (next_frame, frame_reg, &val);
+ info->vfp = val + frame_size;
- /* 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. */
+ /* 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 (info->saved_regs[reg])
+ info->saved_regs[reg] += val - 1;
- return 0;
+ return info;
}
-/* Return non-zero if we *might* be in a function prologue. Return zero if we
- are definitively *not* in a function prologue. */
+/* 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 int
-alpha_in_prologue (CORE_ADDR pc, alpha_extra_func_info_t proc_desc)
+static void
+alpha_heuristic_frame_this_id (struct frame_info *next_frame,
+ void **this_prologue_cache,
+ struct frame_id *this_id)
{
- CORE_ADDR after_prologue_pc;
+ struct alpha_heuristic_unwind_cache *info
+ = alpha_heuristic_frame_unwind_cache (next_frame, this_prologue_cache, 0);
- after_prologue_pc = after_prologue (pc, proc_desc);
+ /* This is meant to halt the backtrace at "_start". Make sure we
+ don't halt it at a generic dummy frame. */
+ if (inside_entry_file (info->start_pc))
+ return;
- if (after_prologue_pc == 0
- || pc < after_prologue_pc)
- return 1;
- else
- return 0;
+ *this_id = frame_id_build (info->vfp, info->start_pc);
}
-static alpha_extra_func_info_t
-find_proc_desc (CORE_ADDR pc, struct frame_info *next_frame)
-{
- 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;
-
- 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;
- }
-
- b = block_for_pc (pc);
+/* Retrieve the value of REGNUM in FRAME. Don't give up! */
- 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);
- }
-
- /* 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;
-
- if (sym)
+static void
+alpha_heuristic_frame_prev_register (struct frame_info *next_frame,
+ void **this_prologue_cache,
+ int regnum, int *optimizedp,
+ enum lval_type *lvalp, CORE_ADDR *addrp,
+ int *realnump, void *bufferp)
+{
+ struct alpha_heuristic_unwind_cache *info
+ = alpha_heuristic_frame_unwind_cache (next_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;
+
+ /* For all registers known to be saved in the current frame,
+ do the obvious and pull the value out. */
+ if (info->saved_regs[regnum])
{
- /* 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;
- }
- }
- }
+ *optimizedp = 0;
+ *lvalp = lval_memory;
+ *addrp = info->saved_regs[regnum];
+ *realnump = -1;
+ if (bufferp != NULL)
+ read_memory (*addrp, bufferp, ALPHA_REGISTER_SIZE);
+ return;
}
- else
+
+ /* The stack pointer of the previous frame is computed by popping
+ the current stack frame. */
+ if (regnum == ALPHA_SP_REGNUM)
{
- 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);
+ *optimizedp = 0;
+ *lvalp = not_lval;
+ *addrp = 0;
+ *realnump = -1;
+ if (bufferp != NULL)
+ store_unsigned_integer (bufferp, ALPHA_REGISTER_SIZE, info->vfp);
+ return;
}
- return proc_desc;
+
+ /* Otherwise assume the next frame has the same register value. */
+ frame_register (next_frame, regnum, optimizedp, lvalp, addrp,
+ realnump, bufferp);
}
-alpha_extra_func_info_t cached_proc_desc;
+static const struct frame_unwind alpha_heuristic_frame_unwind = {
+ NORMAL_FRAME,
+ alpha_heuristic_frame_this_id,
+ alpha_heuristic_frame_prev_register
+};
-CORE_ADDR
-alpha_frame_chain (struct frame_info *frame)
+static const struct frame_unwind *
+alpha_heuristic_frame_p (CORE_ADDR pc)
{
- alpha_extra_func_info_t proc_desc;
- CORE_ADDR saved_pc = FRAME_SAVED_PC (frame);
-
- if (saved_pc == 0 || inside_entry_file (saved_pc))
- return 0;
+ return &alpha_heuristic_frame_unwind;
+}
- proc_desc = find_proc_desc (saved_pc, frame);
- if (!proc_desc)
- return 0;
+static CORE_ADDR
+alpha_heuristic_frame_base_address (struct frame_info *next_frame,
+ void **this_prologue_cache)
+{
+ struct alpha_heuristic_unwind_cache *info
+ = alpha_heuristic_frame_unwind_cache (next_frame, this_prologue_cache, 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);
+ return info->vfp;
}
-void
-init_extra_frame_info (struct frame_info *frame)
-{
- /* 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->saved_regs = NULL;
- frame->localoff = 0;
- frame->pc_reg = RA_REGNUM;
- frame->proc_desc = proc_desc == &temp_proc_desc ? 0 : proc_desc;
- if (proc_desc)
- {
- /* 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->localoff = PROC_LOCALOFF (proc_desc);
- frame->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);
- else
- frame->frame = read_next_frame_reg (frame->next, PROC_FRAME_REG (proc_desc))
- + PROC_FRAME_OFFSET (proc_desc);
+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
+};
- 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.regs, SIZEOF_FRAME_SAVED_REGS);
- frame->saved_regs[PC_REGNUM]
- = frame->saved_regs[RA_REGNUM];
- }
- }
- }
+/* 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)
+{
+ reinit_frame_cache ();
}
+\f
/* 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
arguments without difficulty. */
struct frame_info *
-setup_arbitrary_frame (int argc, CORE_ADDR *argv)
+alpha_setup_arbitrary_frame (int argc, CORE_ADDR *argv)
{
if (argc != 2)
error ("ALPHA frame specifications require two arguments: sp and pc");
return create_new_frame (argv[0], argv[1]);
}
-/* 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. */
+/* 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. */
-CORE_ADDR
-alpha_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
- int struct_return, CORE_ADDR struct_addr)
+static struct frame_id
+alpha_unwind_dummy_id (struct gdbarch *gdbarch, struct frame_info *next_frame)
{
- 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;
-
- 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))
- {
- 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);
- }
- break;
- 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 (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;
-
- /* `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)
- {
- store_address (raw_buffer, sizeof (CORE_ADDR), struct_addr);
- write_memory (sp, raw_buffer, sizeof (CORE_ADDR));
- }
-
- /* Load the argument registers. */
- for (i = 0; i < required_arg_regs; i++)
- {
- LONGEST val;
-
- val = read_memory_integer (sp + i * 8, 8);
- write_register (A0_REGNUM + i, val);
- write_register (FPA0_REGNUM + i, val);
- }
-
- return sp + arg_regs_size;
+ ULONGEST base;
+ frame_unwind_unsigned_register (next_frame, ALPHA_SP_REGNUM, &base);
+ return frame_id_build (base, frame_pc_unwind (next_frame));
}
-void
-alpha_push_dummy_frame (void)
+static CORE_ADDR
+alpha_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
{
- 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;
+ ULONGEST pc;
+ frame_unwind_unsigned_register (next_frame, ALPHA_PC_REGNUM, &pc);
+ return pc;
}
-void
-alpha_pop_frame (void)
-{
- register int regnum;
- struct frame_info *frame = get_current_frame ();
- CORE_ADDR new_sp = frame->frame;
+\f
+/* 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.
- alpha_extra_func_info_t proc_desc = frame->proc_desc;
+ single_step is also called just after the inferior stops. If we had
+ set up a simulated single-step, we undo our damage. */
+
+static CORE_ADDR
+alpha_next_pc (CORE_ADDR pc)
+{
+ unsigned int insn;
+ unsigned int op;
+ int offset;
+ LONGEST rav;
- /* 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);
+ insn = read_memory_unsigned_integer (pc, sizeof (insn));
- /* 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... */
+ /* Opcode is top 6 bits. */
+ op = (insn >> 26) & 0x3f;
- write_register (PC_REGNUM, FRAME_SAVED_PC (frame));
- if (frame->saved_regs == NULL)
- alpha_find_saved_regs (frame);
- if (proc_desc)
+ if (op == 0x1a)
{
- 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));
+ /* Jump format: target PC is:
+ RB & ~3 */
+ return (read_register ((insn >> 16) & 0x1f) & ~3);
}
- write_register (SP_REGNUM, new_sp);
- flush_cached_frames ();
- if (proc_desc && (PROC_DESC_IS_DUMMY (proc_desc)
- || PROC_DESC_IS_DYN_SIGTRAMP (proc_desc)))
+ if ((op & 0x30) == 0x30)
{
- struct linked_proc_info *pi_ptr, *prev_ptr;
-
- for (pi_ptr = linked_proc_desc_table, prev_ptr = NULL;
- pi_ptr != NULL;
- prev_ptr = pi_ptr, pi_ptr = pi_ptr->next)
+ /* Branch format: target PC is:
+ (new PC) + (4 * sext(displacement)) */
+ if (op == 0x30 || /* BR */
+ op == 0x34) /* BSR */
{
- if (&pi_ptr->info == proc_desc)
- break;
+ branch_taken:
+ offset = (insn & 0x001fffff);
+ if (offset & 0x00100000)
+ offset |= 0xffe00000;
+ offset *= 4;
+ return (pc + 4 + offset);
}
- if (pi_ptr == NULL)
- error ("Can't locate dummy extra frame info\n");
-
- if (prev_ptr != NULL)
- prev_ptr->next = pi_ptr->next;
- else
- linked_proc_desc_table = pi_ptr->next;
+ /* Need to determine if branch is taken; read RA. */
+ rav = (LONGEST) read_register ((insn >> 21) & 0x1f);
+ switch (op)
+ {
+ case 0x38: /* BLBC */
+ if ((rav & 1) == 0)
+ goto branch_taken;
+ break;
+ case 0x3c: /* BLBS */
+ if (rav & 1)
+ goto branch_taken;
+ break;
+ case 0x39: /* BEQ */
+ if (rav == 0)
+ goto branch_taken;
+ break;
+ case 0x3d: /* BNE */
+ if (rav != 0)
+ goto branch_taken;
+ break;
+ case 0x3a: /* BLT */
+ if (rav < 0)
+ goto branch_taken;
+ break;
+ case 0x3b: /* BLE */
+ if (rav <= 0)
+ goto branch_taken;
+ break;
+ case 0x3f: /* BGT */
+ if (rav > 0)
+ goto branch_taken;
+ break;
+ case 0x3e: /* BGE */
+ if (rav >= 0)
+ goto branch_taken;
+ break;
- xfree (pi_ptr);
+ /* ??? Missing floating-point branches. */
+ }
}
+
+ /* Not a branch or branch not taken; target PC is:
+ pc + 4 */
+ return (pc + 4);
}
-\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)
+void
+alpha_software_single_step (enum target_signal sig, int insert_breakpoints_p)
{
- unsigned long inst;
- int offset;
- CORE_ADDR post_prologue_pc;
- char buf[4];
+ static CORE_ADDR next_pc;
+ typedef char binsn_quantum[BREAKPOINT_MAX];
+ static binsn_quantum break_mem;
+ CORE_ADDR pc;
-#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
+ if (insert_breakpoints_p)
+ {
+ pc = read_pc ();
+ next_pc = alpha_next_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. */
+ target_insert_breakpoint (next_pc, break_mem);
+ }
+ else
+ {
+ target_remove_breakpoint (next_pc, break_mem);
+ write_pc (next_pc);
+ }
+}
- post_prologue_pc = after_prologue (pc, NULL);
+\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.
- if (post_prologue_pc != 0)
- return max (pc, post_prologue_pc);
+ Called e.g. at program startup, when reading a core file, and when reading
+ a binary file. */
- /* Can't determine prologue from the symbol table, need to examine
- instructions. */
+static struct gdbarch *
+alpha_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
+{
+ struct gdbarch_tdep *tdep;
+ struct gdbarch *gdbarch;
- /* 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)
+ /* Try to determine the ABI of the object we are loading. */
+ if (info.abfd != NULL && info.osabi == GDB_OSABI_UNKNOWN)
{
- int status;
+ /* 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;
+ }
- status = read_memory_nobpt (pc + offset, buf, 4);
- if (status)
- memory_error (status, pc + offset);
- inst = extract_unsigned_integer (buf, 4);
+ /* Find a candidate among extant architectures. */
+ arches = gdbarch_list_lookup_by_info (arches, &info);
+ if (arches != NULL)
+ return arches->gdbarch;
- /* 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;
+ tdep = xmalloc (sizeof (struct gdbarch_tdep));
+ gdbarch = gdbarch_alloc (&info, tdep);
- 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;
+ /* Lowest text address. This is used by heuristic_proc_start()
+ to decide when to stop looking. */
+ tdep->vm_min_address = (CORE_ADDR) 0x120000000;
- 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;
+ tdep->dynamic_sigtramp_offset = NULL;
+ tdep->sigcontext_addr = NULL;
- break;
- }
- return pc + offset;
-}
+ tdep->jb_pc = -1; /* longjmp support not enabled by default */
-#if 0
-/* Is address PC in the prologue (loosely defined) for function at
- STARTADDR? */
+ /* 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);
-static int
-alpha_in_lenient_prologue (CORE_ADDR startaddr, CORE_ADDR pc)
-{
- CORE_ADDR end_prologue = alpha_skip_prologue (startaddr, 1);
- return pc >= startaddr && pc < end_prologue;
-}
-#endif
+ /* 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);
-/* 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;
- }
+ set_gdbarch_register_name (gdbarch, alpha_register_name);
+ set_gdbarch_register_byte (gdbarch, alpha_register_byte);
+ set_gdbarch_register_raw_size (gdbarch, alpha_register_raw_size);
+ set_gdbarch_register_virtual_size (gdbarch, alpha_register_virtual_size);
+ set_gdbarch_register_virtual_type (gdbarch, alpha_register_virtual_type);
- 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");
-}
+ set_gdbarch_cannot_fetch_register (gdbarch, alpha_cannot_fetch_register);
+ set_gdbarch_cannot_store_register (gdbarch, alpha_cannot_store_register);
-void
-alpha_register_convert_to_raw (struct type *valtype, int regnum,
- char *virtual_buffer, char *raw_buffer)
-{
- if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum))
- {
- memcpy (raw_buffer, virtual_buffer, REGISTER_RAW_SIZE (regnum));
- return;
- }
+ set_gdbarch_register_convertible (gdbarch, alpha_register_convertible);
+ set_gdbarch_register_convert_to_virtual (gdbarch,
+ alpha_register_convert_to_virtual);
+ set_gdbarch_register_convert_to_raw (gdbarch, alpha_register_convert_to_raw);
- 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");
-}
+ /* Prologue heuristics. */
+ set_gdbarch_skip_prologue (gdbarch, alpha_skip_prologue);
-/* Given a return value in `regbuf' with a type `valtype',
- extract and copy its value into `valbuf'. */
+ /* Call info. */
+ set_gdbarch_frame_num_args (gdbarch, frame_num_args_unknown);
+ set_gdbarch_frameless_function_invocation (gdbarch,
+ generic_frameless_function_invocation_not);
-void
-alpha_extract_return_value (struct type *valtype,
- char regbuf[REGISTER_BYTES], char *valbuf)
-{
- 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));
-}
+ set_gdbarch_use_struct_convention (gdbarch, alpha_use_struct_convention);
+ set_gdbarch_deprecated_extract_return_value (gdbarch, alpha_extract_return_value);
+ set_gdbarch_deprecated_store_struct_return (gdbarch, alpha_store_struct_return);
+ set_gdbarch_deprecated_store_return_value (gdbarch, alpha_store_return_value);
+ set_gdbarch_deprecated_extract_struct_value_address (gdbarch,
+ alpha_extract_struct_value_address);
-/* Given a return value in `regbuf' with a type `valtype',
- write its value into the appropriate register. */
+ /* Settings for calling functions in the inferior. */
+ set_gdbarch_push_dummy_call (gdbarch, alpha_push_dummy_call);
-void
-alpha_store_return_value (struct type *valtype, char *valbuf)
-{
- char raw_buffer[MAX_REGISTER_RAW_SIZE];
- int regnum = V0_REGNUM;
- int length = TYPE_LENGTH (valtype);
+ /* Methods for saving / extracting a dummy frame's ID. */
+ set_gdbarch_unwind_dummy_id (gdbarch, alpha_unwind_dummy_id);
+ set_gdbarch_save_dummy_frame_tos (gdbarch, generic_save_dummy_frame_tos);
- 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);
+ /* Return the unwound PC value. */
+ set_gdbarch_unwind_pc (gdbarch, alpha_unwind_pc);
- write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, length);
-}
+ set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
+ set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
-/* Just like reinit_frame_cache, but with the right arguments to be
- callable as an sfunc. */
+ set_gdbarch_breakpoint_from_pc (gdbarch, alpha_breakpoint_from_pc);
+ set_gdbarch_decr_pc_after_break (gdbarch, 4);
-static void
-reinit_frame_cache_sfunc (char *args, int from_tty, struct cmd_list_element *c)
-{
- reinit_frame_cache ();
-}
+ set_gdbarch_function_start_offset (gdbarch, 0);
+ set_gdbarch_frame_args_skip (gdbarch, 0);
-/* 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).
- */
+ /* Hook in ABI-specific overrides, if they have been registered. */
+ gdbarch_init_osabi (info, gdbarch);
-CORE_ADDR
-alpha_call_dummy_address (void)
-{
- CORE_ADDR entry;
- struct minimal_symbol *sym;
+ /* Now that we have tuned the configuration, set a few final things
+ based on what the OS ABI has told us. */
- entry = entry_point_address ();
+ if (tdep->jb_pc >= 0)
+ set_gdbarch_get_longjmp_target (gdbarch, alpha_get_longjmp_target);
- if (entry != 0)
- return entry;
+ frame_unwind_append_predicate (gdbarch, alpha_sigtramp_frame_p);
+ frame_unwind_append_predicate (gdbarch, alpha_heuristic_frame_p);
- sym = lookup_minimal_symbol ("_Prelude", NULL, symfile_objfile);
+ frame_base_set_default (gdbarch, &alpha_heuristic_frame_base);
- if (!sym || MSYMBOL_TYPE (sym) != mst_text)
- return 0;
- else
- return SYMBOL_VALUE_ADDRESS (sym) + 4;
+ return gdbarch;
}
void
{
struct cmd_list_element *c;
- tm_print_insn = print_insn_alpha;
+ gdbarch_register (bfd_arch_alpha, alpha_gdbarch_init, NULL);
+ deprecated_tm_print_insn = print_insn_alpha;
/* Let the user set the fence post for heuristic_proc_start. */
&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;
+ set_cmd_sfunc (c, reinit_frame_cache_sfunc);
add_show_from_set (c, &showlist);
}
projects / binutils.git / blobdiff