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authorPeter Schauer <Peter.Schauer@mytum.de>1993-10-05 19:44:57 +0000
committerPeter Schauer <Peter.Schauer@mytum.de>1993-10-05 19:44:57 +0000
commitcef4c2e7a5f2d3426a8255f74b6c7f4e795fd9a4 (patch)
tree89bc0058548c4a5ef634989a13e0a9ce0f51e3a0 /gdb/alpha-tdep.c
parenta72e9833652c3a2e3c616b75522f7dfb462533e6 (diff)
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Changes to support alpha OSF/1 in native mode.
* alpha-nat.c, alpha-tdep.c, config/alpha/alpha-osf1.mt, config/alpha/nm-alpha.h, config/alpha/tm-alpha.h, osfsolib.c: New files. * Makefile.in: Add new files and dependencies. * configure.in: Add alpha target. * config/alpha/alpha-osf1.mh (NATDEPFILES): Add osfsolib.o * config/alpha/alpha-osf1.mh (MH_CFLAGS): Remove, we can handle shared libraries now. * config/alpha/xm-alpha.h: Cleanup, get MAKEVA_* defines right. * defs.h (CORE_ADDR): Make its type overridable via CORE_ADDR_TYPE, provide `unsigned int' default. * breakpoint.c (breakpoint_auto_delete): Delete only if we really stopped for the breakpoint. * stabsread.c, stabsread.h (define_symbol): Change valu parameter to a CORE_ADDR. * stabsread.c (read_range_type): Handle the case where the lower bound overflows and the upper doesn't and the range is legal. * infrun.c (resume): Do not step a breakpoint instruction if CANNOT_STEP_BREAKPOINT is defined. * inferior.h (CALL_DUMMY_LOCATION): New variant AT_ENTRY_POINT. Now that we have the bp_call_dummy breakpoint the call dummy code is no longer needed. PUSH_DUMMY_FRAME, PUSH_ARGUMENTS and FIX_CALL_DUMMY can be used to set up everything for the dummy. The breakpoint for the dummy is set at the entry point and thats it. * blockframe.c (inside_entry_file, inside_entry_func): Do not stop backtraces if pc is in the call dummy at the entry point. * infcmd.c (run_stack_dummy): Handle AT_ENTRY_POINT case. Use the expected breakpoint pc when setting up the frame for set_momentary_breakpoint. * symfile.c (entry_point_address): New function for AT_ENTRY_POINT support. * valops.c (call_function_by_hand): Handle AT_ENTRY_POINT case.
Diffstat (limited to 'gdb/alpha-tdep.c')
-rw-r--r--gdb/alpha-tdep.c987
1 files changed, 987 insertions, 0 deletions
diff --git a/gdb/alpha-tdep.c b/gdb/alpha-tdep.c
new file mode 100644
index 0000000..57e098f
--- /dev/null
+++ b/gdb/alpha-tdep.c
@@ -0,0 +1,987 @@
+/* Target-dependent code for the ALPHA architecture, for GDB, the GNU Debugger.
+ Copyright 1993 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "defs.h"
+#include "frame.h"
+#include "inferior.h"
+#include "symtab.h"
+#include "value.h"
+#include "gdbcmd.h"
+#include "gdbcore.h"
+#include "dis-asm.h"
+
+/* FIXME: Some of this code should perhaps be merged with mips-tdep.c. */
+
+#define VM_MIN_ADDRESS (CORE_ADDR)0x120000000
+
+
+/* Forward declarations. */
+
+static CORE_ADDR
+read_next_frame_reg PARAMS ((FRAME, int));
+
+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
+find_proc_desc PARAMS ((CORE_ADDR, FRAME));
+
+static int
+alpha_in_lenient_prologue PARAMS ((CORE_ADDR, CORE_ADDR));
+
+static void
+reinit_frame_cache_sfunc PARAMS ((char *, int, struct cmd_list_element *));
+
+void
+_initialize_alpha_tdep PARAMS ((void));
+
+/* 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;
+
+/* 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_ARGS_ADDRESS,
+ | | | | | 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
+ | |
+*/
+
+#define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) /* least address */
+#define PROC_HIGH_ADDR(proc) ((proc)->pdr.iline) /* upper address bound */
+#define PROC_DUMMY_FRAME(proc) ((proc)->pdr.iopt) /* frame for CALL_DUMMY */
+#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;
+
+
+#define READ_FRAME_REG(fi, regno) read_next_frame_reg((fi)->next, regno)
+
+static CORE_ADDR
+read_next_frame_reg(fi, regno)
+ FRAME fi;
+ int regno;
+{
+ /* 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. */
+#ifndef SIGFRAME_PC_OFF
+#define SIGFRAME_PC_OFF (2 * 8)
+#define SIGFRAME_REGSAVE_OFF (4 * 8)
+#endif
+ for (; fi; fi = fi->next)
+ {
+ if (fi->signal_handler_caller)
+ {
+ 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)
+ return fi->frame;
+ else if (fi->saved_regs->regs[regno])
+ return read_memory_integer(fi->saved_regs->regs[regno], 8);
+ }
+ return read_register(regno);
+}
+
+CORE_ADDR
+alpha_frame_saved_pc(frame)
+ FRAME frame;
+{
+ alpha_extra_func_info_t proc_desc = frame->proc_desc;
+ int pcreg = proc_desc ? PROC_PC_REG(proc_desc) : RA_REGNUM;
+
+ if (proc_desc && PROC_DESC_IS_DUMMY(proc_desc))
+ return read_memory_integer(frame->frame - 8, 8);
+
+ return read_next_frame_reg(frame, pcreg);
+}
+
+CORE_ADDR
+alpha_saved_pc_after_call (frame)
+ FRAME 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;
+
+ return read_register (pcreg);
+}
+
+
+static struct alpha_extra_func_info temp_proc_desc;
+static struct frame_saved_regs temp_saved_regs;
+
+/* This fencepost looks highly suspicious to me. Removing it also
+ seems suspicious as it could affect remote debugging across serial
+ lines. */
+
+static CORE_ADDR
+heuristic_proc_start(pc)
+ CORE_ADDR pc;
+{
+ CORE_ADDR start_pc = pc;
+ CORE_ADDR fence = start_pc - heuristic_fence_post;
+
+ if (start_pc == 0) return 0;
+
+ if (heuristic_fence_post == UINT_MAX
+ || fence < VM_MIN_ADDRESS)
+ fence = VM_MIN_ADDRESS;
+
+ /* search back for previous return */
+ for (start_pc -= 4; ; start_pc -= 4)
+ if (start_pc < fence)
+ {
+ /* It's not clear to me why we reach this point when
+ stop_soon_quietly, but with this test, at least we
+ don't print out warnings for every child forked (eg, on
+ decstation). 22apr93 rich@cygnus.com. */
+ if (!stop_soon_quietly)
+ {
+ static int blurb_printed = 0;
+
+ if (fence == VM_MIN_ADDRESS)
+ warning("Hit beginning of text section without finding");
+ else
+ warning("Hit heuristic-fence-post without finding");
+
+ warning("enclosing function for address 0x%lx", 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 (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;
+{
+ CORE_ADDR sp = next_frame ? next_frame->frame : read_register (SP_REGNUM);
+ CORE_ADDR cur_pc;
+ int frame_size;
+ int has_frame_reg = 0;
+ unsigned long reg_mask = 0;
+
+ 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;
+
+ if (start_pc + 200 < limit_pc)
+ limit_pc = start_pc + 200;
+ frame_size = 0;
+ for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += 4)
+ {
+ char buf[4];
+ unsigned long word;
+ int status;
+
+ status = read_memory_nobpt (cur_pc, buf, 4);
+ if (status)
+ memory_error (status, cur_pc);
+ word = extract_unsigned_integer (buf, 4);
+
+ if ((word & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */
+ frame_size += (-word) & 0xffff;
+ 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;
+ }
+ else if (word == 0x47de040f) /* bis sp,sp fp */
+ has_frame_reg = 1;
+ }
+ 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;
+ return &temp_proc_desc;
+}
+
+static alpha_extra_func_info_t
+find_proc_desc(pc, next_frame)
+ CORE_ADDR pc;
+ FRAME 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 = next_frame ? next_frame->frame : read_register (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);
+ 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 (sym)
+ {
+ /* IF (this is the topmost frame OR a frame interrupted by a signal)
+ * 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) {
+ alpha_extra_func_info_t found_heuristic =
+ 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_desc = found_heuristic;
+ }
+ }
+ }
+ }
+ else
+ {
+ if (startaddr == 0)
+ startaddr = heuristic_proc_start (pc);
+
+ proc_desc =
+ heuristic_proc_desc (startaddr, pc, next_frame);
+ }
+ return proc_desc;
+}
+
+alpha_extra_func_info_t cached_proc_desc;
+
+FRAME_ADDR
+alpha_frame_chain(frame)
+ FRAME frame;
+{
+ 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;
+
+ proc_desc = find_proc_desc(saved_pc, frame);
+ if (!proc_desc)
+ return 0;
+
+ cached_proc_desc = proc_desc;
+
+ /* Fetch the frame pointer for a dummy frame from the procedure
+ descriptor. */
+ if (PROC_DESC_IS_DUMMY(proc_desc))
+ return (FRAME_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 alpha __sigtramp routine is frameless and has a frame size
+ of zero. Luckily it is the only procedure which has PC_REGNUM
+ as PROC_PC_REG. */
+ && PROC_PC_REG (proc_desc) != PC_REGNUM
+ /* The previous frame from a sigtramp frame might be frameless
+ and have frame size zero. */
+ && !frame->signal_handler_caller)
+ return 0;
+ 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;
+{
+ 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);
+
+ 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;
+ 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);
+
+ /* FIXME: This is a kludge for gcc-2.4.5.
+ gcc-2.4.5 builds frames for the alpha in a peculiar way.
+ It uses $fp as a frame register (which seems to be identical to $sp
+ in all procedures that do not use alloca).
+ It has the arguments and the locals above the frame register, if
+ there are few arguments then the locals are above the arguments,
+ otherwise the arguments are above the local.
+ Frame offsets for arguments and locals are relative to $fp and always
+ positive.
+ If we want to stay compatible with the native cc compiler we have
+ to set localoff to frameoffset so that FRAME_ARGS_ADDRESS and
+ FRAME_LOCALS_ADDRESS point to the right place in the frame.
+ Please note that the setting of localoff in the compiler won't work
+ as localoff is only 8 bits wide (which is enough for cc as it needs
+ at most number_of_arg_regs * 8 == 48). */
+ if (PROC_FRAME_REG(proc_desc) == GCC_FP_REGNUM)
+ fci->localoff = PROC_FRAME_OFFSET(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);
+ /* 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
+ 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);
+ }
+
+ 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))
+ {
+ fci->saved_regs->regs[returnreg] = reg_position;
+ reg_position += 8;
+ }
+ 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)];
+ }
+}
+
+/* ALPHA stack frames are almost impenetrable. When execution stops,
+ we basically have to look at symbol information for the function
+ that we stopped in, which tells us *which* register (if any) is
+ the base of the frame pointer, and what offset from that register
+ the frame itself is at.
+
+ This presents a problem when trying to examine a stack in memory
+ (that isn't executing at the moment), using the "frame" command. We
+ don't have a PC, nor do we have any registers except SP.
+
+ This routine takes two arguments, SP and PC, and tries to make the
+ cached frames look as if these two arguments defined a frame on the
+ cache. This allows the rest of info frame to extract the important
+ arguments without difficulty. */
+
+FRAME
+setup_arbitrary_frame (argc, argv)
+ int argc;
+ FRAME_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. */
+
+#define NUM_ARG_REGS 6
+
+CORE_ADDR
+alpha_push_arguments (nargs, args, sp, struct_return, struct_addr)
+ int nargs;
+ value *args;
+ CORE_ADDR sp;
+ int struct_return;
+ CORE_ADDR struct_addr;
+{
+ register i;
+ int accumulate_size = struct_return ? 8 : 0;
+ int arg_regs_size = 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++)
+ {
+ value arg = value_arg_coerce (args[i]);
+ /* 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));
+ 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 > NUM_ARG_REGS)
+ required_arg_regs = 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;
+}
+
+void
+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;
+ CORE_ADDR sp = read_register (SP_REGNUM);
+ CORE_ADDR save_address;
+ char raw_buffer[MAX_REGISTER_RAW_SIZE];
+ unsigned long mask;
+
+ link->next = linked_proc_desc_table;
+ linked_proc_desc_table = link;
+
+ /*
+ * 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) (((1L << ((j)+1)) - 1) ^ ((1L << (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) = entry_point_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;
+}
+
+void
+alpha_pop_frame()
+{
+ register int regnum;
+ FRAME 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 (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],
+ 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));
+ }
+ 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))
+ {
+ 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)
+ {
+ if (&pi_ptr->info == proc_desc)
+ break;
+ }
+
+ 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;
+
+ free (pi_ptr);
+ }
+}
+
+/* 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 the lenient
+ stuff some day. */
+
+CORE_ADDR
+alpha_skip_prologue (pc, lenient)
+ CORE_ADDR pc;
+ int lenient;
+{
+ unsigned long inst;
+ int offset;
+
+ /* 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);
+ if (status)
+ memory_error (status, pc + offset);
+ inst = extract_unsigned_integer (buf, 4);
+
+ /* 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;
+
+ 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;
+ else if ((inst & 0xfc1f0000) == 0xb41e0000
+ && (inst & 0xffff0000) != 0xb7fe0000)
+ continue; /* stq reg,n($sp) */
+ /* reg != $zero */
+ else if ((inst & 0xfc1f0000) == 0x9c1e0000
+ && (inst & 0xffff0000) != 0x9ffe0000)
+ continue; /* stt reg,n($sp) */
+ /* reg != $zero */
+ else if (inst == 0x47de040f) /* bis sp,sp,fp */
+ continue;
+ else
+ break;
+ }
+ return pc + offset;
+}
+
+/* Is address PC in the prologue (loosely defined) for function at
+ STARTADDR? */
+
+static int
+alpha_in_lenient_prologue (startaddr, pc)
+ CORE_ADDR startaddr;
+ CORE_ADDR pc;
+{
+ CORE_ADDR end_prologue = alpha_skip_prologue (startaddr, 1);
+ return pc >= startaddr && pc < end_prologue;
+}
+
+/* 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));
+}
+
+/* Given a return value in `regbuf' with a type `valtype',
+ write it's 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];
+
+ 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;
+ FILE *stream;
+{
+ disassemble_info info;
+
+ GDB_INIT_DISASSEMBLE_INFO(info, stream);
+
+ return print_insn_alpha (memaddr, &info);
+}
+
+/* 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;
+ int from_tty;
+ struct cmd_list_element *c;
+{
+ reinit_frame_cache ();
+}
+
+void
+_initialize_alpha_tdep ()
+{
+ struct cmd_list_element *c;
+
+ /* Let the user set the fence post for heuristic_proc_start. */
+
+ /* We really would like to have both "0" and "unlimited" work, but
+ command.c doesn't deal with that. So make it a var_zinteger
+ because the user can always use "999999" or some such for unlimited. */
+ c = add_set_cmd ("heuristic-fence-post", class_support, var_zinteger,
+ (char *) &heuristic_fence_post,
+ "\
+Set the distance searched for the start of a function.\n\
+If you are debugging a stripped executable, GDB needs to search through the\n\
+program for the start of a function. This command sets the distance of the\n\
+search. The only need to set it is when debugging a stripped executable.",
+ &setlist);
+ /* We need to throw away the frame cache when we set this, since it
+ might change our ability to get backtraces. */
+ c->function.sfunc = reinit_frame_cache_sfunc;
+ add_show_from_set (c, &showlist);
+}