static int is_branch PARAMS ((unsigned long));
static int inst_saves_gr PARAMS ((unsigned long));
static int inst_saves_fr PARAMS ((unsigned long));
+static int pc_in_interrupt_handler PARAMS ((CORE_ADDR));
+static int pc_in_linker_stub PARAMS ((CORE_ADDR));
+static int compare_unwind_entries PARAMS ((struct unwind_table_entry *,
+ struct unwind_table_entry *));
+static void read_unwind_info PARAMS ((struct objfile *));
+static void internalize_unwinds PARAMS ((struct objfile *,
+ struct unwind_table_entry *,
+ asection *, unsigned int,
+ unsigned int));
\f
/* Routines to extract various sized constants out of hppa
(word & 0x1) << 16, 17) << 2;
}
\f
+
+/* Compare the start address for two unwind entries returning 1 if
+ the first address is larger than the second, -1 if the second is
+ larger than the first, and zero if they are equal. */
+
+static int
+compare_unwind_entries (a, b)
+ struct unwind_table_entry *a;
+ struct unwind_table_entry *b;
+{
+ if (a->region_start > b->region_start)
+ return 1;
+ else if (a->region_start < b->region_start)
+ return -1;
+ else
+ return 0;
+}
+
+static void
+internalize_unwinds (objfile, table, section, entries, size)
+ struct objfile *objfile;
+ struct unwind_table_entry *table;
+ asection *section;
+ unsigned int entries, size;
+{
+ /* We will read the unwind entries into temporary memory, then
+ fill in the actual unwind table. */
+ if (size > 0)
+ {
+ unsigned long tmp;
+ unsigned i;
+ char *buf = alloca (size);
+
+ bfd_get_section_contents (objfile->obfd, section, buf, 0, size);
+
+ /* Now internalize the information being careful to handle host/target
+ endian issues. */
+ for (i = 0; i < entries; i++)
+ {
+ table[i].region_start = bfd_get_32 (objfile->obfd,
+ (bfd_byte *)buf);
+ buf += 4;
+ table[i].region_end = bfd_get_32 (objfile->obfd, (bfd_byte *)buf);
+ buf += 4;
+ tmp = bfd_get_32 (objfile->obfd, (bfd_byte *)buf);
+ buf += 4;
+ table[i].Cannot_unwind = (tmp >> 31) & 0x1;;
+ table[i].Millicode = (tmp >> 30) & 0x1;
+ table[i].Millicode_save_sr0 = (tmp >> 29) & 0x1;
+ table[i].Region_description = (tmp >> 27) & 0x3;
+ table[i].reserved1 = (tmp >> 26) & 0x1;
+ table[i].Entry_SR = (tmp >> 25) & 0x1;
+ table[i].Entry_FR = (tmp >> 21) & 0xf;
+ table[i].Entry_GR = (tmp >> 16) & 0x1f;
+ table[i].Args_stored = (tmp >> 15) & 0x1;
+ table[i].Variable_Frame = (tmp >> 14) & 0x1;
+ table[i].Separate_Package_Body = (tmp >> 13) & 0x1;
+ table[i].Frame_Extension_Millicode = (tmp >> 12 ) & 0x1;
+ table[i].Stack_Overflow_Check = (tmp >> 11) & 0x1;
+ table[i].Two_Instruction_SP_Increment = (tmp >> 10) & 0x1;
+ table[i].Ada_Region = (tmp >> 9) & 0x1;
+ table[i].reserved2 = (tmp >> 5) & 0xf;
+ table[i].Save_SP = (tmp >> 4) & 0x1;
+ table[i].Save_RP = (tmp >> 3) & 0x1;
+ table[i].Save_MRP_in_frame = (tmp >> 2) & 0x1;
+ table[i].extn_ptr_defined = (tmp >> 1) & 0x1;
+ table[i].Cleanup_defined = tmp & 0x1;
+ tmp = bfd_get_32 (objfile->obfd, (bfd_byte *)buf);
+ buf += 4;
+ table[i].MPE_XL_interrupt_marker = (tmp >> 31) & 0x1;
+ table[i].HP_UX_interrupt_marker = (tmp >> 30) & 0x1;
+ table[i].Large_frame = (tmp >> 29) & 0x1;
+ table[i].reserved4 = (tmp >> 27) & 0x3;
+ table[i].Total_frame_size = tmp & 0x7ffffff;
+ }
+ }
+}
+
+/* Read in the backtrace information stored in the `$UNWIND_START$' section of
+ the object file. This info is used mainly by find_unwind_entry() to find
+ out the stack frame size and frame pointer used by procedures. We put
+ everything on the psymbol obstack in the objfile so that it automatically
+ gets freed when the objfile is destroyed. */
+
+static void
+read_unwind_info (objfile)
+ struct objfile *objfile;
+{
+ asection *unwind_sec, *elf_unwind_sec, *stub_unwind_sec;
+ unsigned unwind_size, elf_unwind_size, stub_unwind_size, total_size;
+ unsigned index, unwind_entries, elf_unwind_entries;
+ unsigned stub_entries, total_entries;
+ struct obj_unwind_info *ui;
+
+ ui = obstack_alloc (&objfile->psymbol_obstack,
+ sizeof (struct obj_unwind_info));
+
+ ui->table = NULL;
+ ui->cache = NULL;
+ ui->last = -1;
+
+ /* Get hooks to all unwind sections. Note there is no linker-stub unwind
+ section in ELF at the moment. */
+ unwind_sec = bfd_get_section_by_name (objfile->obfd, "$UNWIND_START$");
+ elf_unwind_sec = bfd_get_section_by_name (objfile->obfd, ".hppa_unwind");
+ stub_unwind_sec = bfd_get_section_by_name (objfile->obfd, "$UNWIND_END$");
+
+ /* Get sizes and unwind counts for all sections. */
+ if (unwind_sec)
+ {
+ unwind_size = bfd_section_size (objfile->obfd, unwind_sec);
+ unwind_entries = unwind_size / UNWIND_ENTRY_SIZE;
+ }
+ else
+ {
+ unwind_size = 0;
+ unwind_entries = 0;
+ }
+
+ if (elf_unwind_sec)
+ {
+ elf_unwind_size = bfd_section_size (objfile->obfd, elf_unwind_sec);
+ elf_unwind_entries = elf_unwind_size / UNWIND_ENTRY_SIZE;
+ }
+ else
+ {
+ elf_unwind_size = 0;
+ elf_unwind_entries = 0;
+ }
+
+ if (stub_unwind_sec)
+ {
+ stub_unwind_size = bfd_section_size (objfile->obfd, stub_unwind_sec);
+ stub_entries = stub_unwind_size / STUB_UNWIND_ENTRY_SIZE;
+ }
+ else
+ {
+ stub_unwind_size = 0;
+ stub_entries = 0;
+ }
+
+ /* Compute total number of unwind entries and their total size. */
+ total_entries = unwind_entries + elf_unwind_entries + stub_entries;
+ total_size = total_entries * sizeof (struct unwind_table_entry);
+
+ /* Allocate memory for the unwind table. */
+ ui->table = obstack_alloc (&objfile->psymbol_obstack, total_size);
+ ui->last = total_entries - 1;
+
+ /* Internalize the standard unwind entries. */
+ index = 0;
+ internalize_unwinds (objfile, &ui->table[index], unwind_sec,
+ unwind_entries, unwind_size);
+ index += unwind_entries;
+ internalize_unwinds (objfile, &ui->table[index], elf_unwind_sec,
+ elf_unwind_entries, elf_unwind_size);
+ index += elf_unwind_entries;
+
+ /* Now internalize the stub unwind entries. */
+ if (stub_unwind_size > 0)
+ {
+ unsigned int i;
+ char *buf = alloca (stub_unwind_size);
+
+ /* Read in the stub unwind entries. */
+ bfd_get_section_contents (objfile->obfd, stub_unwind_sec, buf,
+ 0, stub_unwind_size);
+
+ /* Now convert them into regular unwind entries. */
+ for (i = 0; i < stub_entries; i++, index++)
+ {
+ /* Clear out the next unwind entry. */
+ memset (&ui->table[index], 0, sizeof (struct unwind_table_entry));
+
+ /* Convert offset & size into region_start and region_end.
+ Stuff away the stub type into "reserved" fields. */
+ ui->table[index].region_start = bfd_get_32 (objfile->obfd,
+ (bfd_byte *) buf);
+ buf += 4;
+ ui->table[index].stub_type = bfd_get_8 (objfile->obfd,
+ (bfd_byte *) buf);
+ buf += 2;
+ ui->table[index].region_end
+ = ui->table[index].region_start + 4 *
+ (bfd_get_16 (objfile->obfd, (bfd_byte *) buf) - 1);
+ buf += 2;
+ }
+
+ }
+
+ /* Unwind table needs to be kept sorted. */
+ qsort (ui->table, total_entries, sizeof (struct unwind_table_entry),
+ compare_unwind_entries);
+
+ /* Keep a pointer to the unwind information. */
+ objfile->obj_private = (PTR) ui;
+}
+
/* Lookup the unwind (stack backtrace) info for the given PC. We search all
of the objfiles seeking the unwind table entry for this PC. Each objfile
contains a sorted list of struct unwind_table_entry. Since we do a binary
ui = OBJ_UNWIND_INFO (objfile);
if (!ui)
- continue;
+ {
+ read_unwind_info (objfile);
+ ui = OBJ_UNWIND_INFO (objfile);
+ }
/* First, check the cache */
return NULL;
}
+/* Called to determine if PC is in an interrupt handler of some
+ kind. */
+
+static int
+pc_in_interrupt_handler (pc)
+ CORE_ADDR pc;
+{
+ struct unwind_table_entry *u;
+ struct minimal_symbol *msym_us;
+
+ u = find_unwind_entry (pc);
+ if (!u)
+ return 0;
+
+ /* Oh joys. HPUX sets the interrupt bit for _sigreturn even though
+ its frame isn't a pure interrupt frame. Deal with this. */
+ msym_us = lookup_minimal_symbol_by_pc (pc);
+
+ return u->HP_UX_interrupt_marker && !IN_SIGTRAMP (pc, SYMBOL_NAME (msym_us));
+}
+
/* Called when no unwind descriptor was found for PC. Returns 1 if it
appears that PC is in a linker stub. */
-static int pc_in_linker_stub PARAMS ((CORE_ADDR));
static int
pc_in_linker_stub (pc)
/* Return size of frame, or -1 if we should use a frame pointer. */
int
-find_proc_framesize(pc)
+find_proc_framesize (pc)
CORE_ADDR pc;
{
struct unwind_table_entry *u;
+ struct minimal_symbol *msym_us;
u = find_unwind_entry (pc);
return -1;
}
- if (u->Save_SP)
- /* If this bit is set, it means there is a frame pointer and we should
- use it. */
+ msym_us = lookup_minimal_symbol_by_pc (pc);
+
+ /* If Save_SP is set, and we're not in an interrupt or signal caller,
+ then we have a frame pointer. Use it. */
+ if (u->Save_SP && !pc_in_interrupt_handler (pc)
+ && !IN_SIGTRAMP (pc, SYMBOL_NAME (msym_us)))
return -1;
return u->Total_frame_size << 3;
if (u->Save_RP)
return -20;
+ else if (u->stub_type != 0)
+ {
+ switch (u->stub_type)
+ {
+ case EXPORT:
+ return -24;
+ case PARAMETER_RELOCATION:
+ return -8;
+ default:
+ return 0;
+ }
+ }
else
return 0;
}
u = find_unwind_entry (frame->pc);
if (u == 0)
- return frameless_look_for_prologue (frame);
+ return 0;
- return (u->Total_frame_size == 0);
+ return (u->Total_frame_size == 0 && u->stub_type == 0);
}
CORE_ADDR
FRAME frame;
{
CORE_ADDR pc = get_frame_pc (frame);
+ struct unwind_table_entry *u;
+
+ /* BSD, HPUX & OSF1 all lay out the hardware state in the same manner
+ at the base of the frame in an interrupt handler. Registers within
+ are saved in the exact same order as GDB numbers registers. How
+ convienent. */
+ if (pc_in_interrupt_handler (pc))
+ return read_memory_integer (frame->frame + PC_REGNUM * 4, 4) & ~0x3;
+
+ /* Deal with signal handler caller frames too. */
+ if (frame->signal_handler_caller)
+ {
+ CORE_ADDR rp;
+ FRAME_SAVED_PC_IN_SIGTRAMP (frame, &rp);
+ return rp;
+ }
+restart:
if (frameless_function_invocation (frame))
{
int ret_regnum;
ret_regnum = find_return_regnum (pc);
- return read_register (ret_regnum) & ~0x3;
+ /* If the next frame is an interrupt frame or a signal
+ handler caller, then we need to look in the saved
+ register area to get the return pointer (the values
+ in the registers may not correspond to anything useful). */
+ if (frame->next
+ && (frame->next->signal_handler_caller
+ || pc_in_interrupt_handler (frame->next->pc)))
+ {
+ struct frame_info *fi;
+ struct frame_saved_regs saved_regs;
+
+ fi = get_frame_info (frame->next);
+ get_frame_saved_regs (fi, &saved_regs);
+ if (read_memory_integer (saved_regs.regs[FLAGS_REGNUM] & 0x2, 4))
+ pc = read_memory_integer (saved_regs.regs[31], 4) & ~0x3;
+ else
+ pc = read_memory_integer (saved_regs.regs[RP_REGNUM], 4) & ~0x3;
+ }
+ else
+ pc = read_register (ret_regnum) & ~0x3;
}
else
{
int rp_offset = rp_saved (pc);
- if (rp_offset == 0)
- return read_register (RP_REGNUM) & ~0x3;
+ /* Similar to code in frameless function case. If the next
+ frame is a signal or interrupt handler, then dig the right
+ information out of the saved register info. */
+ if (rp_offset == 0
+ && frame->next
+ && (frame->next->signal_handler_caller
+ || pc_in_interrupt_handler (frame->next->pc)))
+ {
+ struct frame_info *fi;
+ struct frame_saved_regs saved_regs;
+
+ fi = get_frame_info (frame->next);
+ get_frame_saved_regs (fi, &saved_regs);
+ if (read_memory_integer (saved_regs.regs[FLAGS_REGNUM] & 0x2, 4))
+ pc = read_memory_integer (saved_regs.regs[31], 4) & ~0x3;
+ else
+ pc = read_memory_integer (saved_regs.regs[RP_REGNUM], 4) & ~0x3;
+ }
+ else if (rp_offset == 0)
+ pc = read_register (RP_REGNUM) & ~0x3;
else
- return read_memory_integer (frame->frame + rp_offset, 4) & ~0x3;
+ pc = read_memory_integer (frame->frame + rp_offset, 4) & ~0x3;
}
+
+ /* If PC is inside a linker stub, then dig out the address the stub
+ will return to. */
+ u = find_unwind_entry (pc);
+ if (u && u->stub_type != 0)
+ goto restart;
+
+ return pc;
}
\f
/* We need to correct the PC and the FP for the outermost frame when we are
{
int my_framesize, caller_framesize;
struct unwind_table_entry *u;
+ CORE_ADDR frame_base;
+
+ /* Handle HPUX, BSD, and OSF1 style interrupt frames first. These
+ are easy; at *sp we have a full save state strucutre which we can
+ pull the old stack pointer from. Also see frame_saved_pc for
+ code to dig a saved PC out of the save state structure. */
+ if (pc_in_interrupt_handler (frame->pc))
+ frame_base = read_memory_integer (frame->frame + SP_REGNUM * 4, 4);
+ else if (frame->signal_handler_caller)
+ {
+ FRAME_BASE_BEFORE_SIGTRAMP (frame, &frame_base);
+ }
+ else
+ frame_base = frame->frame;
/* Get frame sizes for the current frame and the frame of the
caller. */
/* If caller does not have a frame pointer, then its frame
can be found at current_frame - caller_framesize. */
if (caller_framesize != -1)
- return frame->frame - caller_framesize;
+ return frame_base - caller_framesize;
/* Both caller and callee have frame pointers and are GCC compiled
(SAVE_SP bit in unwind descriptor is on for both functions.
The previous frame pointer is found at the top of the current frame. */
if (caller_framesize == -1 && my_framesize == -1)
- return read_memory_integer (frame->frame, 4);
+ return read_memory_integer (frame_base, 4);
/* Caller has a frame pointer, but callee does not. This is a little
more difficult as GCC and HP C lay out locals and callee register save
/* Entry_GR specifies the number of callee-saved general registers
saved in the stack. It starts at %r3, so %r3 would be 1. */
- if (u->Entry_GR >= 1 || u->Save_SP)
+ if (u->Entry_GR >= 1 || u->Save_SP
+ || frame->signal_handler_caller
+ || pc_in_interrupt_handler (frame->pc))
break;
else
frame = frame->next;
{
/* We may have walked down the chain into a function with a frame
pointer. */
- if (u->Save_SP)
+ if (u->Save_SP
+ && !frame->signal_handler_caller
+ && !pc_in_interrupt_handler (frame->pc))
return read_memory_integer (frame->frame, 4);
/* %r3 was saved somewhere in the stack. Dig it out. */
else
{
struct minimal_symbol *msym_us;
struct minimal_symbol *msym_start;
- struct unwind_table_entry *u;
+ struct unwind_table_entry *u, *next_u = NULL;
+ FRAME next;
if (!chain)
return 0;
u = find_unwind_entry (thisframe->pc);
+ if (u == NULL)
+ return 1;
+
/* We can't just check that the same of msym_us is "_start", because
someone idiotically decided that they were going to make a Ltext_end
symbol with the same address. This Ltext_end symbol is totally
&& SYMBOL_VALUE_ADDRESS (msym_us) == SYMBOL_VALUE_ADDRESS (msym_start))
return 0;
- if (u == NULL)
- return 1;
+ next = get_next_frame (thisframe);
+ if (next)
+ next_u = find_unwind_entry (next->pc);
- if (u->Save_SP || u->Total_frame_size)
+ /* If this frame does not save SP, has no stack, isn't a stub,
+ and doesn't "call" an interrupt routine or signal handler caller,
+ then its not valid. */
+ if (u->Save_SP || u->Total_frame_size || u->stub_type != 0
+ || (thisframe->next && thisframe->next->signal_handler_caller)
+ || (next_u && next_u->HP_UX_interrupt_marker))
return 1;
if (pc_in_linker_stub (thisframe->pc))
fp = fi->frame;
get_frame_saved_regs (fi, &fsr);
+#ifndef NO_PC_SPACE_QUEUE_RESTORE
if (fsr.regs[IPSW_REGNUM]) /* Restoring a call dummy frame */
restore_pc_queue (&fsr);
+#endif
for (regnum = 31; regnum > 0; regnum--)
if (fsr.regs[regnum])
/* Else use the value in %rp to set the new PC. */
else
- target_write_pc (read_register (RP_REGNUM));
+ target_write_pc (read_register (RP_REGNUM), 0);
write_register (FP_REGNUM, read_memory_integer (fp, 4));
}
}
target_terminal_ours ();
- fetch_inferior_registers (-1);
+ (current_target->to_fetch_registers) (-1);
return 1;
}
CORE_ADDR
hppa_push_arguments (nargs, args, sp, struct_return, struct_addr)
int nargs;
- value *args;
+ value_ptr *args;
CORE_ADDR sp;
int struct_return;
CORE_ADDR struct_addr;
CORE_ADDR pc;
CORE_ADDR fun;
int nargs;
- value *args;
+ value_ptr *args;
struct type *type;
int gcc_p;
{
CORE_ADDR dyncall_addr, sr4export_addr;
struct minimal_symbol *msymbol;
int flags = read_register (FLAGS_REGNUM);
+ struct unwind_table_entry *u;
msymbol = lookup_minimal_symbol ("$$dyncall", (struct objfile *) NULL);
if (msymbol == NULL)
dyncall_addr = SYMBOL_VALUE_ADDRESS (msymbol);
+ /* FUN could be a procedure label, in which case we have to get
+ its real address and the value of its GOT/DP. */
+ if (fun & 0x2)
+ {
+ /* Get the GOT/DP value for the target function. It's
+ at *(fun+4). Note the call dummy is *NOT* allowed to
+ trash %r19 before calling the target function. */
+ write_register (19, read_memory_integer ((fun & ~0x3) + 4, 4));
+
+ /* Now get the real address for the function we are calling, it's
+ at *fun. */
+ fun = (CORE_ADDR) read_memory_integer (fun & ~0x3, 4);
+ }
+
+ /* If we are calling an import stub (eg calling into a dynamic library)
+ then have sr4export call the magic __d_plt_call routine which is linked
+ in from end.o. (You can't use _sr4export to call the import stub as
+ the value in sp-24 will get fried and you end up returning to the
+ wrong location. You can't call the import stub directly as the code
+ to bind the PLT entry to a function can't return to a stack address.) */
+ u = find_unwind_entry (fun);
+ if (u && u->stub_type == IMPORT)
+ {
+ CORE_ADDR new_fun;
+ msymbol = lookup_minimal_symbol ("__d_plt_call", (struct objfile *) NULL);
+ if (msymbol == NULL)
+ error ("Can't find an address for __d_plt_call trampoline");
+
+ /* This is where sr4export will jump to. */
+ new_fun = SYMBOL_VALUE_ADDRESS (msymbol);
+
+ /* We have to store the address of the stub in __shlib_funcptr. */
+ msymbol = lookup_minimal_symbol ("__shlib_funcptr",
+ (struct objfile *)NULL);
+ if (msymbol == NULL)
+ error ("Can't find an address for __shlib_funcptr");
+
+ target_write_memory (SYMBOL_VALUE_ADDRESS (msymbol), (char *)&fun, 4);
+ fun = new_fun;
+
+ }
+
+ /* We still need sr4export's address too. */
msymbol = lookup_minimal_symbol ("_sr4export", (struct objfile *) NULL);
if (msymbol == NULL)
error ("Can't find an address for _sr4export trampoline");
/* Get the PC from %r31 if currently in a syscall. Also mask out privilege
bits. */
CORE_ADDR
-target_read_pc ()
+target_read_pc (pid)
+ int pid;
{
int flags = read_register (FLAGS_REGNUM);
/* Write out the PC. If currently in a syscall, then also write the new
PC value into %r31. */
void
-target_write_pc (v)
+target_write_pc (v, pid)
CORE_ADDR v;
+ int pid;
{
int flags = read_register (FLAGS_REGNUM);
unsigned char raw_buffer[MAX_REGISTER_RAW_SIZE];
unsigned char virtual_buffer[MAX_REGISTER_VIRTUAL_SIZE];
- /* Get the data in raw format. */
+ /* Get 32bits of data. */
read_relative_register_raw_bytes (i, raw_buffer);
- /* Convert raw data to virtual format if necessary. */
-#ifdef REGISTER_CONVERTIBLE
- if (REGISTER_CONVERTIBLE (i))
- {
- REGISTER_CONVERT_TO_VIRTUAL (i, REGISTER_VIRTUAL_TYPE (i),
- raw_buffer, virtual_buffer);
- }
- else
-#endif
- memcpy (virtual_buffer, raw_buffer,
- REGISTER_VIRTUAL_SIZE (i));
+ /* Put it in the buffer. No conversions are ever necessary. */
+ memcpy (virtual_buffer, raw_buffer, REGISTER_RAW_SIZE (i));
fputs_filtered (reg_names[i], gdb_stdout);
- print_spaces_filtered (15 - strlen (reg_names[i]), gdb_stdout);
+ print_spaces_filtered (8 - strlen (reg_names[i]), gdb_stdout);
+ fputs_filtered ("(single precision) ", gdb_stdout);
val_print (REGISTER_VIRTUAL_TYPE (i), virtual_buffer, 0, gdb_stdout, 0,
1, 0, Val_pretty_default);
printf_filtered ("\n");
+
+ /* If "i" is even, then this register can also be a double-precision
+ FP register. Dump it out as such. */
+ if ((i % 2) == 0)
+ {
+ /* Get the data in raw format for the 2nd half. */
+ read_relative_register_raw_bytes (i + 1, raw_buffer);
+
+ /* Copy it into the appropriate part of the virtual buffer. */
+ memcpy (virtual_buffer + REGISTER_RAW_SIZE (i), raw_buffer,
+ REGISTER_RAW_SIZE (i));
+
+ /* Dump it as a double. */
+ fputs_filtered (reg_names[i], gdb_stdout);
+ print_spaces_filtered (8 - strlen (reg_names[i]), gdb_stdout);
+ fputs_filtered ("(double precision) ", gdb_stdout);
+
+ val_print (builtin_type_double, virtual_buffer, 0, gdb_stdout, 0,
+ 1, 0, Val_pretty_default);
+ printf_filtered ("\n");
+ }
}
-/* Function calls that pass into a new compilation unit must pass through a
- small piece of code that does long format (`external' in HPPA parlance)
- jumps. We figure out where the trampoline is going to end up, and return
- the PC of the final destination. If we aren't in a trampoline, we just
- return NULL.
+/* Figure out if PC is in a trampoline, and if so find out where
+ the trampoline will jump to. If not in a trampoline, return zero.
+
+ Simple code examination probably is not a good idea since the code
+ sequences in trampolines can also appear in user code.
- For computed calls, we just extract the new PC from r22. */
+ We use unwinds and information from the minimal symbol table to
+ determine when we're in a trampoline. This won't work for ELF
+ (yet) since it doesn't create stub unwind entries. Whether or
+ not ELF will create stub unwinds or normal unwinds for linker
+ stubs is still being debated.
+
+ This should handle simple calls through dyncall or sr4export,
+ long calls, argument relocation stubs, and dyncall/sr4export
+ calling an argument relocation stub. It even handles some stubs
+ used in dynamic executables. */
CORE_ADDR
skip_trampoline_code (pc, name)
CORE_ADDR pc;
char *name;
{
- long inst0, inst1;
+ long orig_pc = pc;
+ long prev_inst, curr_inst, loc;
static CORE_ADDR dyncall = 0;
+ static CORE_ADDR sr4export = 0;
struct minimal_symbol *msym;
+ struct unwind_table_entry *u;
-/* FIXME XXX - dyncall must be initialized whenever we get a new exec file */
+/* FIXME XXX - dyncall and sr4export must be initialized whenever we get a
+ new exec file */
if (!dyncall)
{
dyncall = -1;
}
+ if (!sr4export)
+ {
+ msym = lookup_minimal_symbol ("_sr4export", NULL);
+ if (msym)
+ sr4export = SYMBOL_VALUE_ADDRESS (msym);
+ else
+ sr4export = -1;
+ }
+
+ /* Addresses passed to dyncall may *NOT* be the actual address
+ of the funtion. So we may have to do something special. */
if (pc == dyncall)
- return (CORE_ADDR)(read_register (22) & ~0x3);
+ {
+ pc = (CORE_ADDR) read_register (22);
- inst0 = read_memory_integer (pc, 4);
- inst1 = read_memory_integer (pc+4, 4);
+ /* If bit 30 (counting from the left) is on, then pc is the address of
+ the PLT entry for this function, not the address of the function
+ itself. Bit 31 has meaning too, but only for MPE. */
+ if (pc & 0x2)
+ pc = (CORE_ADDR) read_memory_integer (pc & ~0x3, 4);
+ }
+ else if (pc == sr4export)
+ pc = (CORE_ADDR) (read_register (22));
- if ( (inst0 & 0xffe00000) == 0x20200000 /* ldil xxx, r1 */
- && (inst1 & 0xffe0e002) == 0xe0202002) /* be,n yyy(sr4, r1) */
- pc = extract_21 (inst0) + extract_17 (inst1);
- else
- pc = (CORE_ADDR)NULL;
+ /* Get the unwind descriptor corresponding to PC, return zero
+ if no unwind was found. */
+ u = find_unwind_entry (pc);
+ if (!u)
+ return 0;
- return pc;
+ /* If this isn't a linker stub, then return now. */
+ if (u->stub_type == 0)
+ return orig_pc == pc ? 0 : pc & ~0x3;
+
+ /* It's a stub. Search for a branch and figure out where it goes.
+ Note we have to handle multi insn branch sequences like ldil;ble.
+ Most (all?) other branches can be determined by examining the contents
+ of certain registers and the stack. */
+ loc = pc;
+ curr_inst = 0;
+ prev_inst = 0;
+ while (1)
+ {
+ /* Make sure we haven't walked outside the range of this stub. */
+ if (u != find_unwind_entry (loc))
+ {
+ warning ("Unable to find branch in linker stub");
+ return orig_pc == pc ? 0 : pc & ~0x3;
+ }
+
+ prev_inst = curr_inst;
+ curr_inst = read_memory_integer (loc, 4);
+
+ /* Does it look like a branch external using %r1? Then it's the
+ branch from the stub to the actual function. */
+ if ((curr_inst & 0xffe0e000) == 0xe0202000)
+ {
+ /* Yup. See if the previous instruction loaded
+ a value into %r1. If so compute and return the jump address. */
+ if ((prev_inst & 0xffe0e000) == 0x20202000)
+ return (extract_21 (prev_inst) + extract_17 (curr_inst)) & ~0x3;
+ else
+ {
+ warning ("Unable to find ldil X,%%r1 before ble Y(%%sr4,%%r1).");
+ return orig_pc == pc ? 0 : pc & ~0x3;
+ }
+ }
+
+ /* Does it look like bl X,%rp or bl X,%r0? Another way to do a
+ branch from the stub to the actual function. */
+ else if ((curr_inst & 0xffe0e000) == 0xe8400000
+ || (curr_inst & 0xffe0e000) == 0xe8000000)
+ return (loc + extract_17 (curr_inst) + 8) & ~0x3;
+
+ /* Does it look like bv (rp)? Note this depends on the
+ current stack pointer being the same as the stack
+ pointer in the stub itself! This is a branch on from the
+ stub back to the original caller. */
+ else if ((curr_inst & 0xffe0e000) == 0xe840c000)
+ {
+ /* Yup. See if the previous instruction loaded
+ rp from sp - 8. */
+ if (prev_inst == 0x4bc23ff1)
+ return (read_memory_integer
+ (read_register (SP_REGNUM) - 8, 4)) & ~0x3;
+ else
+ {
+ warning ("Unable to find restore of %%rp before bv (%%rp).");
+ return orig_pc == pc ? 0 : pc & ~0x3;
+ }
+ }
+
+ /* What about be,n 0(sr0,%rp)? It's just another way we return to
+ the original caller from the stub. Used in dynamic executables. */
+ else if (curr_inst == 0xe0400002)
+ {
+ /* The value we jump to is sitting in sp - 24. But that's
+ loaded several instructions before the be instruction.
+ I guess we could check for the previous instruction being
+ mtsp %r1,%sr0 if we want to do sanity checking. */
+ return (read_memory_integer
+ (read_register (SP_REGNUM) - 24, 4)) & ~0x3;
+ }
+
+ /* Haven't found the branch yet, but we're still in the stub.
+ Keep looking. */
+ loc += 4;
+ }
}
/* For the given instruction (INST), return any adjustment it makes
be in the prologue. */
CORE_ADDR
-skip_prologue(pc)
+skip_prologue (pc)
CORE_ADDR pc;
{
char buf[4];
u = find_unwind_entry (pc);
if (!u)
- return 0;
+ return pc;
+
+ /* If we are not at the beginning of a function, then return now. */
+ if ((pc & ~0x3) != u->region_start)
+ return pc;
/* This is how much of a frame adjustment we need to account for. */
stack_remaining = u->Total_frame_size << 3;
+ 6 * 4)))
find_dummy_frame_regs (frame_info, frame_saved_regs);
+ /* Interrupt handlers are special too. They lay out the register
+ state in the exact same order as the register numbers in GDB. */
+ if (pc_in_interrupt_handler (frame_info->pc))
+ {
+ for (i = 0; i < NUM_REGS; i++)
+ {
+ /* SP is a little special. */
+ if (i == SP_REGNUM)
+ frame_saved_regs->regs[SP_REGNUM]
+ = read_memory_integer (frame_info->frame + SP_REGNUM * 4, 4);
+ else
+ frame_saved_regs->regs[i] = frame_info->frame + i * 4;
+ }
+ return;
+ }
+
+ /* Handle signal handler callers. */
+ if (frame_info->signal_handler_caller)
+ {
+ FRAME_FIND_SAVED_REGS_IN_SIGTRAMP (frame_info, frame_saved_regs);
+ return;
+ }
+
/* Get the starting address of the function referred to by the PC
saved in frame_info. */
pc = get_pc_function_start (frame_info->pc);
for (i = 12; i < u->Entry_FR + 12; i++)
save_fr |= (1 << i);
+ /* The frame always represents the value of %sp at entry to the
+ current function (and is thus equivalent to the "saved" stack
+ pointer. */
+ frame_saved_regs->regs[SP_REGNUM] = frame_info->frame;
+
/* Loop until we find everything of interest or hit a branch.
For unoptimized GCC code and for any HP CC code this will never ever
frame_saved_regs->regs[RP_REGNUM] = frame_info->frame - 20;
}
- /* This is the only way we save SP into the stack. At this time
- the HP compilers never bother to save SP into the stack. */
+ /* Just note that we found the save of SP into the stack. The
+ value for frame_saved_regs was computed above. */
if ((inst & 0xffffc000) == 0x6fc10000)
- {
- save_sp = 0;
- frame_saved_regs->regs[SP_REGNUM] = frame_info->frame;
- }
+ save_sp = 0;
/* Account for general and floating-point register saves. */
reg = inst_saves_gr (inst);
projects / binutils.git / blobdiff