/* Target-dependent code for the ALPHA architecture, for GDB, the GNU Debugger.
- Copyright 1993, 1994 Free Software Foundation, Inc.
+ Copyright 1993, 94, 95, 96, 97, 1998 Free Software Foundation, Inc.
This file is part of GDB.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
-Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "frame.h"
#include "gdbcmd.h"
#include "gdbcore.h"
#include "dis-asm.h"
+#include "symfile.h"
+#include "objfiles.h"
+#include "gdb_string.h"
/* FIXME: Some of this code should perhaps be merged with mips-tdep.c. */
-#define VM_MIN_ADDRESS (CORE_ADDR)0x120000000
-\f
+/* Prototypes for local functions. */
-/* Forward declarations. */
+static alpha_extra_func_info_t push_sigtramp_desc PARAMS ((CORE_ADDR low_addr));
-static CORE_ADDR
-read_next_frame_reg PARAMS ((FRAME, int));
+static CORE_ADDR read_next_frame_reg PARAMS ((struct frame_info *, int));
-static CORE_ADDR
-heuristic_proc_start PARAMS ((CORE_ADDR));
+static CORE_ADDR heuristic_proc_start PARAMS ((CORE_ADDR));
-static alpha_extra_func_info_t
-heuristic_proc_desc PARAMS ((CORE_ADDR, CORE_ADDR, FRAME));
+static alpha_extra_func_info_t heuristic_proc_desc PARAMS ((CORE_ADDR,
+ CORE_ADDR,
+ struct frame_info *));
-static alpha_extra_func_info_t
-find_proc_desc PARAMS ((CORE_ADDR, FRAME));
+static alpha_extra_func_info_t find_proc_desc PARAMS ((CORE_ADDR,
+ struct frame_info *));
-static int
-alpha_in_lenient_prologue PARAMS ((CORE_ADDR, CORE_ADDR));
+#if 0
+static int alpha_in_lenient_prologue PARAMS ((CORE_ADDR, CORE_ADDR));
+#endif
-static void
-reinit_frame_cache_sfunc PARAMS ((char *, int, struct cmd_list_element *));
+static void reinit_frame_cache_sfunc PARAMS ((char *, int,
+ struct cmd_list_element *));
+
+static CORE_ADDR after_prologue PARAMS ((CORE_ADDR pc,
+ alpha_extra_func_info_t proc_desc));
+
+static int alpha_in_prologue PARAMS ((CORE_ADDR pc,
+ alpha_extra_func_info_t proc_desc));
/* 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
} *linked_proc_desc_table = NULL;
\f
-#define READ_FRAME_REG(fi, regno) read_next_frame_reg((fi)->next, regno)
+/* 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.
+*/
-static CORE_ADDR
-read_next_frame_reg(fi, regno)
- FRAME fi;
- int regno;
+long
+alpha_linux_sigtramp_offset (CORE_ADDR pc)
{
- /* If it is the frame for sigtramp we have a pointer to the sigcontext
- on the stack.
- If the stack layout for __sigtramp changes or if sigcontext offsets
- change we might have to update this code. */
+ unsigned int i[3], w;
+ long off;
+
+ if (read_memory_nobpt(pc, (char *) &w, 4) != 0)
+ return -1;
+
+ off = -1;
+ switch (w)
+ {
+ 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;
+ }
+ pc -= off;
+ if (pc & 0x7)
+ {
+ /* designated sequence is not quadword aligned */
+ return -1;
+ }
+
+ if (read_memory_nobpt(pc, (char *) i, sizeof(i)) != 0)
+ return -1;
+
+ if (i[0] == 0x47de0410 && i[1] == 0x43ecf400 && i[2] == 0x00000083)
+ return off;
+
+ return -1;
+}
+
+\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 (frame, pc)
+ struct frame_info *frame;
+ CORE_ADDR pc;
+{
+ char *name;
+ find_pc_partial_function (pc, &name, (CORE_ADDR *)NULL, (CORE_ADDR *)NULL);
+ if (IN_SIGTRAMP (pc, name))
+ return frame->frame;
+ else
+ return 0;
+}
+
+\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. */
+
+static alpha_extra_func_info_t
+push_sigtramp_desc (low_addr)
+ CORE_ADDR low_addr;
+{
+ 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);
+}
+
+\f
+/* Guaranteed to set frame->saved_regs to some values (it never leaves it
+ NULL). */
+
+void
+alpha_find_saved_regs (frame)
+ struct frame_info *frame;
+{
+ 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
- for (; fi; fi = fi->next)
+ if (frame->signal_handler_caller)
{
- if (fi->signal_handler_caller)
+ CORE_ADDR sigcontext_addr;
+
+ 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++)
{
- int offset;
- CORE_ADDR sigcontext_addr = read_memory_integer(fi->frame, 8);
-
- if (regno == PC_REGNUM)
- offset = SIGFRAME_PC_OFF;
- else if (regno < 32)
- offset = SIGFRAME_REGSAVE_OFF + regno * 8;
- else
- return 0;
- return read_memory_integer(sigcontext_addr + offset, 8);
- }
- else if (regno == SP_REGNUM)
+ 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;
+ }
+
+ 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;
+
+ /* Fill in the offsets for the registers which gen_mask says
+ were saved. */
+
+ reg_position = frame->frame + PROC_REG_OFFSET (proc_desc);
+ mask = PROC_REG_MASK (proc_desc);
+
+ returnreg = PROC_PC_REG (proc_desc);
+
+ /* 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. */
+ }
+
+ for (ireg = 0; ireg <= 31 ; ++ireg)
+ if (mask & (1 << ireg))
+ {
+ frame->saved_regs[ireg] = reg_position;
+ reg_position += 8;
+ }
+
+ /* Fill in the offsets for the registers which float_mask says
+ were saved. */
+
+ reg_position = frame->frame + PROC_FREG_OFFSET (proc_desc);
+ mask = PROC_FREG_MASK (proc_desc);
+
+ for (ireg = 0; ireg <= 31 ; ++ireg)
+ if (mask & (1 << ireg))
+ {
+ frame->saved_regs[FP0_REGNUM+ireg] = reg_position;
+ reg_position += 8;
+ }
+
+ frame->saved_regs[PC_REGNUM] = frame->saved_regs[returnreg];
+}
+
+static CORE_ADDR
+read_next_frame_reg(fi, regno)
+ struct frame_info *fi;
+ int regno;
+{
+ for (; fi; fi = fi->next)
+ {
+ /* 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->regs[regno])
- return read_memory_integer(fi->saved_regs->regs[regno], 8);
+ 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);
+ }
}
return read_register(regno);
}
CORE_ADDR
alpha_frame_saved_pc(frame)
- FRAME frame;
+ struct frame_info *frame;
{
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
- : (proc_desc ? PROC_PC_REG(proc_desc) : RA_REGNUM);
+ int pcreg = frame->signal_handler_caller ? PC_REGNUM : frame->pc_reg;
if (proc_desc && PROC_DESC_IS_DUMMY(proc_desc))
return read_memory_integer(frame->frame - 8, 8);
CORE_ADDR
alpha_saved_pc_after_call (frame)
- FRAME frame;
+ struct frame_info *frame;
{
- alpha_extra_func_info_t proc_desc = find_proc_desc (frame->pc, frame->next);
- int pcreg = proc_desc ? PROC_PC_REG (proc_desc) : RA_REGNUM;
+ CORE_ADDR pc = frame->pc;
+ CORE_ADDR tmp;
+ alpha_extra_func_info_t proc_desc;
+ int pcreg;
+
+ /* Skip over shared library trampoline if necessary. */
+ tmp = SKIP_TRAMPOLINE_CODE (pc);
+ if (tmp != 0)
+ pc = tmp;
+
+ proc_desc = find_proc_desc (pc, frame->next);
+ pcreg = proc_desc ? PROC_PC_REG (proc_desc) : RA_REGNUM;
- return read_register (pcreg);
+ if (frame->signal_handler_caller)
+ return alpha_frame_saved_pc (frame);
+ else
+ return read_register (pcreg);
}
static struct alpha_extra_func_info temp_proc_desc;
static struct frame_saved_regs temp_saved_regs;
+/* Nonzero if instruction at PC is a return instruction. "ret
+ $zero,($ra),1" on alpha. */
+
+static int
+alpha_about_to_return (pc)
+ CORE_ADDR pc;
+{
+ return read_memory_integer (pc, 4) == 0x6bfa8001;
+}
+
+
+
/* This fencepost looks highly suspicious to me. Removing it also
seems suspicious as it could affect remote debugging across serial
lines. */
return 0;
}
- else if (ABOUT_TO_RETURN(start_pc))
- break;
+ else if (alpha_about_to_return (start_pc))
+ break;
start_pc += 4; /* skip return */
return start_pc;
static alpha_extra_func_info_t
heuristic_proc_desc(start_pc, limit_pc, next_frame)
CORE_ADDR start_pc, limit_pc;
- FRAME next_frame;
+ struct frame_info *next_frame;
{
- CORE_ADDR sp = next_frame ? next_frame->frame : read_register (SP_REGNUM);
+ 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;
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;
+ 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;
if (start_pc + 200 < limit_pc)
limit_pc = start_pc + 200;
word = extract_unsigned_integer (buf, 4);
if ((word & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */
- frame_size += (-word) & 0xffff;
+ {
+ 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 != $zero */
{
int reg = (word & 0x03e00000) >> 21;
reg_mask |= 1 << reg;
temp_saved_regs.regs[reg] = sp + (short)word;
+
+ /* Starting with OSF/1-3.2C, the system libraries are shipped
+ without local symbols, but they still contain procedure
+ descriptors without a symbol reference. GDB is currently
+ unable to find these procedure descriptors and uses
+ heuristic_proc_desc instead.
+ As some low level compiler support routines (__div*, __add*)
+ use a non-standard return address register, we have to
+ add some heuristics to determine the return address register,
+ or stepping over these routines will fail.
+ Usually the return address register is the first register
+ saved on the stack, but assembler optimization might
+ rearrange the register saves.
+ So we recognize only a few registers (t7, t9, ra) within
+ the procedure prologue as valid return address registers.
+ If we encounter a return instruction, we extract the
+ the return address register from it.
+
+ FIXME: Rewriting GDB to access the procedure descriptors,
+ e.g. via the minimal symbol table, might obviate this hack. */
+ if (pcreg == -1
+ && cur_pc < (start_pc + 80)
+ && (reg == T7_REGNUM || reg == T9_REGNUM || reg == RA_REGNUM))
+ pcreg = reg;
}
+ else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */
+ pcreg = (word >> 16) & 0x1f;
else if (word == 0x47de040f) /* bis sp,sp fp */
has_frame_reg = 1;
}
+ if (pcreg == -1)
+ {
+ /* If we haven't found a valid return address register yet,
+ keep searching in the procedure prologue. */
+ while (cur_pc < (limit_pc + 80) && cur_pc < (start_pc + 80))
+ {
+ char buf[4];
+ unsigned long word;
+
+ if (read_memory_nobpt (cur_pc, buf, 4))
+ break;
+ cur_pc += 4;
+ word = extract_unsigned_integer (buf, 4);
+
+ if ((word & 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */
+ && (word & 0xffff0000) != 0xb7fe0000) /* reg != $zero */
+ {
+ int reg = (word & 0x03e00000) >> 21;
+ if (reg == T7_REGNUM || reg == T9_REGNUM || reg == RA_REGNUM)
+ {
+ pcreg = reg;
+ break;
+ }
+ }
+ else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */
+ {
+ pcreg = (word >> 16) & 0x1f;
+ break;
+ }
+ }
+ }
+
if (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) = RA_REGNUM;
+ 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 (pc, proc_desc)
+ CORE_ADDR pc;
+ alpha_extra_func_info_t proc_desc;
+{
+ struct symtab_and_line sal;
+ CORE_ADDR func_addr, func_end;
+
+ if (!proc_desc)
+ proc_desc = find_proc_desc (pc, NULL);
+
+ if (proc_desc)
+ {
+ if (PROC_DESC_IS_DYN_SIGTRAMP (proc_desc))
+ return PROC_LOW_ADDR (proc_desc); /* "prologue" is in kernel */
+
+ /* If function is frameless, then we need to do it the hard way. I
+ strongly suspect that frameless always means prologueless... */
+ if (PROC_FRAME_REG (proc_desc) == SP_REGNUM
+ && PROC_FRAME_OFFSET (proc_desc) == 0)
+ return 0;
+ }
+
+ if (!find_pc_partial_function (pc, NULL, &func_addr, &func_end))
+ return 0; /* Unknown */
+
+ sal = find_pc_line (func_addr, 0);
+
+ if (sal.end < func_end)
+ return sal.end;
+
+ /* The line after the prologue is after the end of the function. In this
+ case, tell the caller to find the prologue the hard way. */
+
+ return 0;
+}
+
+/* Return non-zero if we *might* be in a function prologue. Return zero if we
+ are definitively *not* in a function prologue. */
+
+static int
+alpha_in_prologue (pc, proc_desc)
+ CORE_ADDR pc;
+ alpha_extra_func_info_t proc_desc;
+{
+ CORE_ADDR after_prologue_pc;
+
+ after_prologue_pc = after_prologue (pc, proc_desc);
+
+ if (after_prologue_pc == 0
+ || pc < after_prologue_pc)
+ return 1;
+ else
+ return 0;
+}
+
static alpha_extra_func_info_t
-find_proc_desc(pc, next_frame)
+find_proc_desc (pc, next_frame)
CORE_ADDR pc;
- FRAME next_frame;
+ struct frame_info *next_frame;
{
alpha_extra_func_info_t proc_desc;
struct block *b;
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 = next_frame ? next_frame->frame : read_register (SP_REGNUM);
+ 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;
}
b = block_for_pc(pc);
+
find_pc_partial_function (pc, NULL, &startaddr, NULL);
if (b == NULL)
sym = NULL;
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)
{
- /* IF (this is the topmost frame OR a frame interrupted by a signal)
- * AND (this proc does not have debugging information OR
+ /* 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 || next_frame->signal_handler_caller) {
- struct symtab_and_line val;
- struct symbol *proc_symbol =
- PROC_DESC_IS_DUMMY(proc_desc) ? 0 : PROC_SYMBOL(proc_desc);
-
- if (proc_symbol) {
- val = find_pc_line (BLOCK_START
- (SYMBOL_BLOCK_VALUE(proc_symbol)),
- 0);
- val.pc = val.end ? val.end : pc;
- }
- if (!proc_symbol || pc < val.pc) {
+ 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);
+ heuristic_proc_desc (PROC_LOW_ADDR (proc_desc),
+ pc, next_frame);
if (found_heuristic)
{
- /* The call to heuristic_proc_desc determines
- which registers have been saved so far and if the
- frame is already set up.
- The heuristic algorithm doesn't work well for other
- information in the procedure descriptor, so copy
- it from the found procedure descriptor. */
- PROC_LOCALOFF(found_heuristic) = PROC_LOCALOFF(proc_desc);
- PROC_PC_REG(found_heuristic) = PROC_PC_REG(proc_desc);
+ PROC_LOCALOFF (found_heuristic) =
+ PROC_LOCALOFF (proc_desc);
+ PROC_PC_REG (found_heuristic) = PROC_PC_REG (proc_desc);
proc_desc = found_heuristic;
}
- }
- }
+ }
+ }
}
else
{
- if (startaddr == 0)
+ 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 =
alpha_extra_func_info_t cached_proc_desc;
-FRAME_ADDR
+CORE_ADDR
alpha_frame_chain(frame)
- FRAME frame;
+ struct frame_info *frame;
{
alpha_extra_func_info_t proc_desc;
CORE_ADDR saved_pc = FRAME_SAVED_PC(frame);
/* Fetch the frame pointer for a dummy frame from the procedure
descriptor. */
if (PROC_DESC_IS_DUMMY(proc_desc))
- return (FRAME_ADDR) PROC_DUMMY_FRAME(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,
/* The previous frame from a sigtramp frame might be frameless
and have frame size zero. */
&& !frame->signal_handler_caller)
- {
- /* The alpha __sigtramp routine is frameless and has a frame size
- of zero, but we are able to backtrace through it. */
- char *name;
- find_pc_partial_function (saved_pc, &name,
- (CORE_ADDR *)NULL, (CORE_ADDR *)NULL);
- if (IN_SIGTRAMP (saved_pc, name))
- return frame->frame;
- else
- return 0;
- }
+ 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);
}
void
-init_extra_frame_info(fci)
- struct frame_info *fci;
+init_extra_frame_info (frame)
+ struct frame_info *frame;
{
- extern struct obstack frame_cache_obstack;
/* Use proc_desc calculated in frame_chain */
alpha_extra_func_info_t proc_desc =
- fci->next ? cached_proc_desc : find_proc_desc(fci->pc, fci->next);
+ frame->next ? cached_proc_desc : find_proc_desc(frame->pc, frame->next);
- fci->saved_regs = (struct frame_saved_regs*)
- obstack_alloc (&frame_cache_obstack, sizeof(struct frame_saved_regs));
- memset (fci->saved_regs, 0, sizeof (struct frame_saved_regs));
- fci->proc_desc =
- proc_desc == &temp_proc_desc ? 0 : proc_desc;
+ 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)
{
- int ireg;
- CORE_ADDR reg_position;
- unsigned long mask;
- int returnreg;
-
- /* Get the locals offset from the procedure descriptor, it is valid
- even if we are in the middle of the prologue. */
- fci->localoff = PROC_LOCALOFF(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))
- fci->frame = (FRAME_ADDR) PROC_DUMMY_FRAME(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 (fci->pc == PROC_LOW_ADDR(proc_desc))
- fci->frame = READ_FRAME_REG(fci, SP_REGNUM);
+ 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
- fci->frame = READ_FRAME_REG(fci, PROC_FRAME_REG(proc_desc))
- + PROC_FRAME_OFFSET(proc_desc);
-
- /* If this is the innermost frame, and we are still in the
- prologue (loosely defined), then the registers may not have
- been saved yet. */
- if (fci->next == NULL
- && !PROC_DESC_IS_DUMMY(proc_desc)
- && alpha_in_lenient_prologue (PROC_LOW_ADDR (proc_desc), fci->pc))
- {
- /* Can't just say that the registers are not saved, because they
- might get clobbered halfway through the prologue.
- heuristic_proc_desc already has the right code to figure out
- exactly what has been saved, so use it. As far as I know we
- could be doing this (as we do on the 68k, for example)
- regardless of whether we are in the prologue; I'm leaving in
- the check for being in the prologue only out of conservatism
- (I'm not sure whether heuristic_proc_desc handles all cases,
- for example).
-
- This stuff is ugly (and getting uglier by the minute). Probably
- the best way to clean it up is to ignore the proc_desc's from
- the symbols altogher, and get all the information we need by
- examining the prologue (provided we can make the prologue
- examining code good enough to get all the cases...). */
- proc_desc =
- heuristic_proc_desc (PROC_LOW_ADDR (proc_desc),
- fci->pc,
- fci->next);
- }
+ frame->frame = read_next_frame_reg (frame->next, PROC_FRAME_REG (proc_desc))
+ + PROC_FRAME_OFFSET (proc_desc);
if (proc_desc == &temp_proc_desc)
- *fci->saved_regs = temp_saved_regs;
- else
{
- /* Find which general-purpose registers were saved.
- The return address register is the first saved register,
- the other registers follow in ascending order. */
- reg_position = fci->frame + PROC_REG_OFFSET(proc_desc);
- mask = PROC_REG_MASK(proc_desc) & 0xffffffffL;
- returnreg = PROC_PC_REG(proc_desc);
- if (mask & (1 << returnreg))
+ 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))
{
- fci->saved_regs->regs[returnreg] = reg_position;
- reg_position += 8;
+ 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];
}
- for (ireg = 0; mask; ireg++, mask >>= 1)
- if (mask & 1)
- {
- if (ireg == returnreg)
- continue;
- fci->saved_regs->regs[ireg] = reg_position;
- reg_position += 8;
- }
- /* find which floating-point registers were saved */
- reg_position = fci->frame + PROC_FREG_OFFSET(proc_desc);
- mask = PROC_FREG_MASK(proc_desc) & 0xffffffffL;
- for (ireg = 0; mask; ireg++, mask >>= 1)
- if (mask & 1)
- {
- fci->saved_regs->regs[FP0_REGNUM+ireg] = reg_position;
- reg_position += 8;
- }
}
-
- fci->saved_regs->regs[PC_REGNUM] = fci->saved_regs->regs[PROC_PC_REG(proc_desc)];
}
}
cache. This allows the rest of info frame to extract the important
arguments without difficulty. */
-FRAME
+struct frame_info *
setup_arbitrary_frame (argc, argv)
int argc;
- FRAME_ADDR *argv;
+ CORE_ADDR *argv;
{
if (argc != 2)
error ("ALPHA frame specifications require two arguments: sp and pc");
for (i = 0, m_arg = alpha_args; i < nargs; i++, m_arg++)
{
- value_ptr arg = value_arg_coerce (args[i]);
+ value_ptr arg = args[i];
+ struct type *arg_type = check_typedef (VALUE_TYPE (arg));
/* Cast argument to long if necessary as the compiler does it too. */
- if (TYPE_LENGTH (VALUE_TYPE (arg)) < TYPE_LENGTH (builtin_type_long))
- arg = value_cast (builtin_type_long, arg);
- m_arg->len = TYPE_LENGTH (VALUE_TYPE (arg));
+ 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);
alpha_push_dummy_frame()
{
int ireg;
- struct linked_proc_info *link = (struct linked_proc_info*)
- xmalloc(sizeof (struct linked_proc_info));
- alpha_extra_func_info_t proc_desc = &link->info;
+ 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
*/
/* MASK(i,j) == (1<<i) + (1<<(i+1)) + ... + (1<<j)). Assume i<=j<31. */
-#define MASK(i,j) (((1L << ((j)+1)) - 1) ^ ((1L << (i)) - 1))
+#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))
sp += PROC_REG_OFFSET(proc_desc);
write_register (SP_REGNUM, sp);
- PROC_LOW_ADDR(proc_desc) = entry_point_address ();
+ 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);
alpha_pop_frame()
{
register int regnum;
- FRAME frame = get_current_frame ();
+ struct frame_info *frame = get_current_frame ();
CORE_ADDR new_sp = frame->frame;
alpha_extra_func_info_t proc_desc = frame->proc_desc;
write_register (PC_REGNUM, FRAME_SAVED_PC(frame));
+ if (frame->saved_regs == NULL)
+ alpha_find_saved_regs (frame);
if (proc_desc)
{
for (regnum = 32; --regnum >= 0; )
if (PROC_REG_MASK(proc_desc) & (1 << regnum))
write_register (regnum,
- read_memory_integer (frame->saved_regs->regs[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->regs[regnum + FP0_REGNUM], 8));
+ read_memory_integer (frame->saved_regs[regnum + FP0_REGNUM], 8));
}
write_register (SP_REGNUM, new_sp);
flush_cached_frames ();
- /* We let init_extra_frame_info figure out the frame pointer */
- set_current_frame (create_new_frame (0, read_pc ()));
- if (proc_desc && PROC_DESC_IS_DUMMY(proc_desc))
+ if (proc_desc && (PROC_DESC_IS_DUMMY(proc_desc)
+ || PROC_DESC_IS_DYN_SIGTRAMP (proc_desc)))
{
struct linked_proc_info *pi_ptr, *prev_ptr;
{
unsigned long inst;
int offset;
+ CORE_ADDR post_prologue_pc;
+ char buf[4];
+
+#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
+
+ /* 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 = after_prologue (pc, NULL);
+
+ 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)
{
- char buf[4];
int status;
status = read_memory_nobpt (pc + offset, buf, 4);
return pc + offset;
}
+#if 0
/* Is address PC in the prologue (loosely defined) for function at
STARTADDR? */
CORE_ADDR end_prologue = alpha_skip_prologue (startaddr, 1);
return pc >= startaddr && pc < end_prologue;
}
+#endif
/* The alpha needs a conversion between register and memory format if
the register is a floating point register and
}
else if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4)
{
- unsigned LONGEST l;
+ 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 if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4)
{
- unsigned LONGEST l;
+ ULONGEST l;
if (TYPE_UNSIGNED (valtype))
l = extract_unsigned_integer (virtual_buffer, TYPE_LENGTH (valtype));
else
/* Given a return value in `regbuf' with a type `valtype',
extract and copy its value into `valbuf'. */
+
void
alpha_extract_return_value (valtype, regbuf, valbuf)
struct type *valtype;
char regbuf[REGISTER_BYTES];
char *valbuf;
{
- int regnum;
-
- regnum = TYPE_CODE (valtype) == TYPE_CODE_FLT ? FP0_REGNUM : V0_REGNUM;
-
- memcpy (valbuf, regbuf + REGISTER_BYTE (regnum), TYPE_LENGTH (valtype));
+ 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));
}
/* Given a return value in `regbuf' with a type `valtype',
write its value into the appropriate register. */
+
void
alpha_store_return_value (valtype, valbuf)
struct type *valtype;
char *valbuf;
{
- int regnum;
char raw_buffer[MAX_REGISTER_RAW_SIZE];
+ int regnum = V0_REGNUM;
+ int length = TYPE_LENGTH (valtype);
- regnum = TYPE_CODE (valtype) == TYPE_CODE_FLT ? FP0_REGNUM : V0_REGNUM;
- memcpy(raw_buffer, valbuf, TYPE_LENGTH (valtype));
-
- write_register_bytes(REGISTER_BYTE (regnum), raw_buffer, TYPE_LENGTH (valtype));
-}
-
-/* Print the instruction at address MEMADDR in debugged memory,
- on STREAM. Returns length of the instruction, in bytes. */
-
-int
-print_insn (memaddr, stream)
- CORE_ADDR memaddr;
- GDB_FILE *stream;
-{
- disassemble_info info;
-
- GDB_INIT_DISASSEMBLE_INFO(info, stream);
+ 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 print_insn_alpha (memaddr, &info);
+ write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, length);
}
/* Just like reinit_frame_cache, but with the right arguments to be
callable as an sfunc. */
+
static void
reinit_frame_cache_sfunc (args, from_tty, c)
char *args;
reinit_frame_cache ();
}
+/* 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).
+ */
+
+CORE_ADDR
+alpha_call_dummy_address ()
+{
+ CORE_ADDR entry;
+ struct minimal_symbol *sym;
+
+ entry = entry_point_address ();
+
+ if (entry != 0)
+ return entry;
+
+ sym = lookup_minimal_symbol ("_Prelude", NULL, symfile_objfile);
+
+ if (!sym || MSYMBOL_TYPE (sym) != mst_text)
+ return 0;
+ else
+ return SYMBOL_VALUE_ADDRESS (sym) + 4;
+}
+
void
_initialize_alpha_tdep ()
{
struct cmd_list_element *c;
+ tm_print_insn = print_insn_alpha;
+
/* Let the user set the fence post for heuristic_proc_start. */
/* We really would like to have both "0" and "unlimited" work, but