| /* Target-dependent code for the ALPHA architecture, for GDB, the GNU Debugger. |
| Copyright 1993, 94, 95, 96, 97, 1998 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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" |
| #include "symfile.h" |
| #include "objfiles.h" |
| #include "gdb_string.h" |
| |
| /* FIXME: Some of this code should perhaps be merged with mips-tdep.c. */ |
| |
| /* Prototypes for local functions. */ |
| |
| static alpha_extra_func_info_t push_sigtramp_desc PARAMS ((CORE_ADDR low_addr)); |
| |
| static CORE_ADDR read_next_frame_reg PARAMS ((struct frame_info *, int)); |
| |
| static CORE_ADDR heuristic_proc_start PARAMS ((CORE_ADDR)); |
| |
| 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, |
| struct frame_info *)); |
| |
| #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 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)); |
| |
| static int alpha_about_to_return PARAMS ((CORE_ADDR pc)); |
| |
| 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_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 */ |
| /* These next two fields are kind of being hijacked. I wonder if |
| iline is too small for the values it needs to hold, if GDB is |
| running on a 32-bit host. */ |
| #define PROC_HIGH_ADDR(proc) ((proc)->pdr.iline) /* upper address bound */ |
| #define PROC_DUMMY_FRAME(proc) ((proc)->pdr.cbLineOffset) /*CALL_DUMMY frame */ |
| #define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset) |
| #define PROC_FRAME_REG(proc) ((proc)->pdr.framereg) |
| #define PROC_REG_MASK(proc) ((proc)->pdr.regmask) |
| #define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask) |
| #define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset) |
| #define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset) |
| #define PROC_PC_REG(proc) ((proc)->pdr.pcreg) |
| #define PROC_LOCALOFF(proc) ((proc)->pdr.localoff) |
| #define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym) |
| #define _PROC_MAGIC_ 0x0F0F0F0F |
| #define PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym == _PROC_MAGIC_) |
| #define SET_PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym = _PROC_MAGIC_) |
| |
| struct linked_proc_info |
| { |
| struct alpha_extra_func_info info; |
| struct linked_proc_info *next; |
| } *linked_proc_desc_table = NULL; |
| |
| |
| /* Under GNU/Linux, signal handler invocations can be identified by the |
| designated code sequence that is used to return from a signal |
| handler. In particular, the return address of a signal handler |
| points to the following sequence (the first instruction is quadword |
| aligned): |
| |
| bis $30,$30,$16 |
| addq $31,0x67,$0 |
| call_pal callsys |
| |
| Each instruction has a unique encoding, so we simply attempt to |
| match the instruction the pc is pointing to with any of the above |
| instructions. If there is a hit, we know the offset to the start |
| of the designated sequence and can then check whether we really are |
| executing in a designated sequence. If not, -1 is returned, |
| otherwise the offset from the start of the desingated sequence is |
| returned. |
| |
| There is a slight chance of false hits: code could jump into the |
| middle of the designated sequence, in which case there is no |
| guarantee that we are in the middle of a sigreturn syscall. Don't |
| think this will be a problem in praxis, though. |
| */ |
| |
| #ifndef TM_LINUXALPHA_H |
| /* HACK: Provide a prototype when compiling this file for non |
| linuxalpha targets. */ |
| long alpha_linux_sigtramp_offset PARAMS ((CORE_ADDR pc)); |
| #endif |
| long |
| alpha_linux_sigtramp_offset (pc) |
| CORE_ADDR pc; |
| { |
| 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; |
| } |
| |
| |
| /* 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; |
| } |
| |
| |
| /* 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); |
| } |
| |
| |
| /* 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 |
| if (frame->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++) |
| { |
| 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 == 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) |
| 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 : frame->pc_reg; |
| |
| 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) |
| struct frame_info *frame; |
| { |
| 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; |
| |
| 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. */ |
| |
| 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 (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; |
| struct frame_info *next_frame; |
| { |
| CORE_ADDR sp = read_next_frame_reg (next_frame, SP_REGNUM); |
| CORE_ADDR cur_pc; |
| int frame_size; |
| int has_frame_reg = 0; |
| unsigned long reg_mask = 0; |
| int pcreg = -1; |
| |
| 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) */ |
| { |
| 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) = (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) |
| CORE_ADDR pc; |
| struct frame_info *next_frame; |
| { |
| alpha_extra_func_info_t proc_desc; |
| struct block *b; |
| struct symbol *sym; |
| CORE_ADDR startaddr; |
| |
| /* Try to get the proc_desc from the linked call dummy proc_descs |
| if the pc is in the call dummy. |
| This is hairy. In the case of nested dummy calls we have to find the |
| right proc_desc, but we might not yet know the frame for the dummy |
| as it will be contained in the proc_desc we are searching for. |
| So we have to find the proc_desc whose frame is closest to the current |
| stack pointer. */ |
| |
| if (PC_IN_CALL_DUMMY (pc, 0, 0)) |
| { |
| struct linked_proc_info *link; |
| CORE_ADDR sp = read_next_frame_reg (next_frame, SP_REGNUM); |
| alpha_extra_func_info_t found_proc_desc = NULL; |
| long min_distance = LONG_MAX; |
| |
| for (link = linked_proc_desc_table; link; link = link->next) |
| { |
| long distance = (CORE_ADDR) PROC_DUMMY_FRAME (&link->info) - sp; |
| if (distance > 0 && distance < min_distance) |
| { |
| min_distance = distance; |
| found_proc_desc = &link->info; |
| } |
| } |
| if (found_proc_desc != NULL) |
| return found_proc_desc; |
| } |
| |
| b = block_for_pc(pc); |
| |
| find_pc_partial_function (pc, NULL, &startaddr, NULL); |
| if (b == NULL) |
| sym = NULL; |
| else |
| { |
| if (startaddr > BLOCK_START (b)) |
| /* This is the "pathological" case referred to in a comment in |
| print_frame_info. It might be better to move this check into |
| symbol reading. */ |
| sym = NULL; |
| else |
| sym = lookup_symbol (MIPS_EFI_SYMBOL_NAME, b, LABEL_NAMESPACE, |
| 0, NULL); |
| } |
| |
| /* If we never found a PDR for this function in symbol reading, then |
| examine prologues to find the information. */ |
| if (sym && ((mips_extra_func_info_t) SYMBOL_VALUE (sym))->pdr.framereg == -1) |
| sym = NULL; |
| |
| if (sym) |
| { |
| /* IF this is the topmost frame AND |
| * (this proc does not have debugging information OR |
| * the PC is in the procedure prologue) |
| * THEN create a "heuristic" proc_desc (by analyzing |
| * the actual code) to replace the "official" proc_desc. |
| */ |
| proc_desc = (alpha_extra_func_info_t)SYMBOL_VALUE(sym); |
| if (next_frame == NULL) |
| { |
| if (PROC_DESC_IS_DUMMY (proc_desc) || alpha_in_prologue (pc, proc_desc)) |
| { |
| alpha_extra_func_info_t found_heuristic = |
| heuristic_proc_desc (PROC_LOW_ADDR (proc_desc), |
| pc, next_frame); |
| if (found_heuristic) |
| { |
| PROC_LOCALOFF (found_heuristic) = |
| PROC_LOCALOFF (proc_desc); |
| PROC_PC_REG (found_heuristic) = PROC_PC_REG (proc_desc); |
| proc_desc = found_heuristic; |
| } |
| } |
| } |
| } |
| else |
| { |
| long offset; |
| |
| /* Is linked_proc_desc_table really necessary? It only seems to be used |
| by procedure call dummys. However, the procedures being called ought |
| to have their own proc_descs, and even if they don't, |
| heuristic_proc_desc knows how to create them! */ |
| |
| register struct linked_proc_info *link; |
| for (link = linked_proc_desc_table; link; link = link->next) |
| if (PROC_LOW_ADDR(&link->info) <= pc |
| && PROC_HIGH_ADDR(&link->info) > pc) |
| return &link->info; |
| |
| /* If PC is inside a dynamically generated sigtramp handler, |
| create and push a procedure descriptor for that code: */ |
| offset = DYNAMIC_SIGTRAMP_OFFSET (pc); |
| if (offset >= 0) |
| return push_sigtramp_desc (pc - offset); |
| |
| /* If heuristic_fence_post is non-zero, determine the procedure |
| start address by examining the instructions. |
| This allows us to find the start address of static functions which |
| have no symbolic information, as startaddr would have been set to |
| the preceding global function start address by the |
| find_pc_partial_function call above. */ |
| if (startaddr == 0 || heuristic_fence_post != 0) |
| startaddr = heuristic_proc_start (pc); |
| |
| proc_desc = |
| heuristic_proc_desc (startaddr, pc, next_frame); |
| } |
| return proc_desc; |
| } |
| |
| alpha_extra_func_info_t cached_proc_desc; |
| |
| CORE_ADDR |
| alpha_frame_chain(frame) |
| struct frame_info *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 (CORE_ADDR) PROC_DUMMY_FRAME(proc_desc); |
| |
| /* If no frame pointer and frame size is zero, we must be at end |
| of stack (or otherwise hosed). If we don't check frame size, |
| we loop forever if we see a zero size frame. */ |
| if (PROC_FRAME_REG (proc_desc) == SP_REGNUM |
| && PROC_FRAME_OFFSET (proc_desc) == 0 |
| /* The previous frame from a sigtramp frame might be frameless |
| and have frame size zero. */ |
| && !frame->signal_handler_caller) |
| return FRAME_PAST_SIGTRAMP_FRAME (frame, saved_pc); |
| else |
| return read_next_frame_reg(frame, PROC_FRAME_REG(proc_desc)) |
| + PROC_FRAME_OFFSET(proc_desc); |
| } |
| |
| void |
| init_extra_frame_info (frame) |
| struct frame_info *frame; |
| { |
| /* Use proc_desc calculated in frame_chain */ |
| alpha_extra_func_info_t proc_desc = |
| frame->next ? cached_proc_desc : find_proc_desc(frame->pc, frame->next); |
| |
| frame->saved_regs = NULL; |
| frame->localoff = 0; |
| frame->pc_reg = RA_REGNUM; |
| frame->proc_desc = proc_desc == &temp_proc_desc ? 0 : proc_desc; |
| if (proc_desc) |
| { |
| /* Get the locals offset and the saved pc register from the |
| procedure descriptor, they are valid even if we are in the |
| middle of the prologue. */ |
| frame->localoff = PROC_LOCALOFF(proc_desc); |
| frame->pc_reg = PROC_PC_REG(proc_desc); |
| |
| /* Fixup frame-pointer - only needed for top frame */ |
| |
| /* Fetch the frame pointer for a dummy frame from the procedure |
| descriptor. */ |
| if (PROC_DESC_IS_DUMMY(proc_desc)) |
| frame->frame = (CORE_ADDR) PROC_DUMMY_FRAME(proc_desc); |
| |
| /* This may not be quite right, if proc has a real frame register. |
| Get the value of the frame relative sp, procedure might have been |
| interrupted by a signal at it's very start. */ |
| else if (frame->pc == PROC_LOW_ADDR (proc_desc) |
| && !PROC_DESC_IS_DYN_SIGTRAMP (proc_desc)) |
| frame->frame = read_next_frame_reg (frame->next, SP_REGNUM); |
| else |
| frame->frame = read_next_frame_reg (frame->next, PROC_FRAME_REG (proc_desc)) |
| + PROC_FRAME_OFFSET (proc_desc); |
| |
| if (proc_desc == &temp_proc_desc) |
| { |
| char *name; |
| |
| /* Do not set the saved registers for a sigtramp frame, |
| alpha_find_saved_registers will do that for us. |
| We can't use frame->signal_handler_caller, it is not yet set. */ |
| find_pc_partial_function (frame->pc, &name, |
| (CORE_ADDR *)NULL,(CORE_ADDR *)NULL); |
| if (!IN_SIGTRAMP (frame->pc, name)) |
| { |
| frame->saved_regs = (CORE_ADDR*) |
| frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS); |
| memcpy (frame->saved_regs, temp_saved_regs.regs, SIZEOF_FRAME_SAVED_REGS); |
| frame->saved_regs[PC_REGNUM] |
| = frame->saved_regs[RA_REGNUM]; |
| } |
| } |
| } |
| } |
| |
| /* 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. */ |
| |
| struct frame_info * |
| setup_arbitrary_frame (argc, argv) |
| int argc; |
| CORE_ADDR *argv; |
| { |
| if (argc != 2) |
| error ("ALPHA frame specifications require two arguments: sp and pc"); |
| |
| return create_new_frame (argv[0], argv[1]); |
| } |
| |
| /* The alpha passes the first six arguments in the registers, the rest on |
| the stack. The register arguments are eventually transferred to the |
| argument transfer area immediately below the stack by the called function |
| anyway. So we `push' at least six arguments on the stack, `reload' the |
| argument registers and then adjust the stack pointer to point past the |
| sixth argument. This algorithm simplifies the passing of a large struct |
| which extends from the registers to the stack. |
| If the called function is returning a structure, the address of the |
| structure to be returned is passed as a hidden first argument. */ |
| |
| CORE_ADDR |
| alpha_push_arguments (nargs, args, sp, struct_return, struct_addr) |
| int nargs; |
| value_ptr *args; |
| CORE_ADDR sp; |
| int struct_return; |
| CORE_ADDR struct_addr; |
| { |
| int i; |
| int accumulate_size = struct_return ? 8 : 0; |
| int arg_regs_size = ALPHA_NUM_ARG_REGS * 8; |
| struct alpha_arg { char *contents; int len; int offset; }; |
| struct alpha_arg *alpha_args = |
| (struct alpha_arg*)alloca (nargs * sizeof (struct alpha_arg)); |
| register struct alpha_arg *m_arg; |
| char raw_buffer[sizeof (CORE_ADDR)]; |
| int required_arg_regs; |
| |
| for (i = 0, m_arg = alpha_args; i < nargs; i++, m_arg++) |
| { |
| 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. */ |
| switch (TYPE_CODE (arg_type)) |
| { |
| case TYPE_CODE_INT: |
| case TYPE_CODE_BOOL: |
| case TYPE_CODE_CHAR: |
| case TYPE_CODE_RANGE: |
| case TYPE_CODE_ENUM: |
| if (TYPE_LENGTH (arg_type) < TYPE_LENGTH (builtin_type_long)) |
| { |
| arg_type = builtin_type_long; |
| arg = value_cast (arg_type, arg); |
| } |
| break; |
| default: |
| break; |
| } |
| m_arg->len = TYPE_LENGTH (arg_type); |
| m_arg->offset = accumulate_size; |
| accumulate_size = (accumulate_size + m_arg->len + 7) & ~7; |
| m_arg->contents = VALUE_CONTENTS(arg); |
| } |
| |
| /* Determine required argument register loads, loading an argument register |
| is expensive as it uses three ptrace calls. */ |
| required_arg_regs = accumulate_size / 8; |
| if (required_arg_regs > ALPHA_NUM_ARG_REGS) |
| required_arg_regs = ALPHA_NUM_ARG_REGS; |
| |
| /* Make room for the arguments on the stack. */ |
| if (accumulate_size < arg_regs_size) |
| accumulate_size = arg_regs_size; |
| sp -= accumulate_size; |
| |
| /* Keep sp aligned to a multiple of 16 as the compiler does it too. */ |
| sp &= ~15; |
| |
| /* `Push' arguments on the stack. */ |
| for (i = nargs; m_arg--, --i >= 0; ) |
| write_memory(sp + m_arg->offset, m_arg->contents, m_arg->len); |
| if (struct_return) |
| { |
| store_address (raw_buffer, sizeof (CORE_ADDR), struct_addr); |
| write_memory (sp, raw_buffer, sizeof (CORE_ADDR)); |
| } |
| |
| /* Load the argument registers. */ |
| for (i = 0; i < required_arg_regs; i++) |
| { |
| LONGEST val; |
| |
| val = read_memory_integer (sp + i * 8, 8); |
| write_register (A0_REGNUM + i, val); |
| write_register (FPA0_REGNUM + i, val); |
| } |
| |
| return sp + arg_regs_size; |
| } |
| |
| void |
| alpha_push_dummy_frame() |
| { |
| int ireg; |
| struct linked_proc_info *link; |
| alpha_extra_func_info_t proc_desc; |
| CORE_ADDR sp = read_register (SP_REGNUM); |
| CORE_ADDR save_address; |
| char raw_buffer[MAX_REGISTER_RAW_SIZE]; |
| unsigned long mask; |
| |
| link = (struct linked_proc_info *) xmalloc(sizeof (struct linked_proc_info)); |
| link->next = linked_proc_desc_table; |
| linked_proc_desc_table = link; |
| |
| proc_desc = &link->info; |
| |
| /* |
| * The registers we must save are all those not preserved across |
| * procedure calls. |
| * In addition, we must save the PC and RA. |
| * |
| * Dummy frame layout: |
| * (high memory) |
| * Saved PC |
| * Saved F30 |
| * ... |
| * Saved F0 |
| * Saved R29 |
| * ... |
| * Saved R0 |
| * Saved R26 (RA) |
| * Parameter build area |
| * (low memory) |
| */ |
| |
| /* MASK(i,j) == (1<<i) + (1<<(i+1)) + ... + (1<<j)). Assume i<=j<31. */ |
| #define MASK(i,j) ((((LONGEST)1 << ((j)+1)) - 1) ^ (((LONGEST)1 << (i)) - 1)) |
| #define GEN_REG_SAVE_MASK (MASK(0,8) | MASK(16,29)) |
| #define GEN_REG_SAVE_COUNT 24 |
| #define FLOAT_REG_SAVE_MASK (MASK(0,1) | MASK(10,30)) |
| #define FLOAT_REG_SAVE_COUNT 23 |
| /* The special register is the PC as we have no bit for it in the save masks. |
| alpha_frame_saved_pc knows where the pc is saved in a dummy frame. */ |
| #define SPECIAL_REG_SAVE_COUNT 1 |
| |
| PROC_REG_MASK(proc_desc) = GEN_REG_SAVE_MASK; |
| PROC_FREG_MASK(proc_desc) = FLOAT_REG_SAVE_MASK; |
| /* PROC_REG_OFFSET is the offset from the dummy frame to the saved RA, |
| but keep SP aligned to a multiple of 16. */ |
| PROC_REG_OFFSET(proc_desc) = |
| - ((8 * (SPECIAL_REG_SAVE_COUNT |
| + GEN_REG_SAVE_COUNT |
| + FLOAT_REG_SAVE_COUNT) |
| + 15) & ~15); |
| PROC_FREG_OFFSET(proc_desc) = |
| PROC_REG_OFFSET(proc_desc) + 8 * GEN_REG_SAVE_COUNT; |
| |
| /* Save general registers. |
| The return address register is the first saved register, all other |
| registers follow in ascending order. |
| The PC is saved immediately below the SP. */ |
| save_address = sp + PROC_REG_OFFSET(proc_desc); |
| store_address (raw_buffer, 8, read_register (RA_REGNUM)); |
| write_memory (save_address, raw_buffer, 8); |
| save_address += 8; |
| mask = PROC_REG_MASK(proc_desc) & 0xffffffffL; |
| for (ireg = 0; mask; ireg++, mask >>= 1) |
| if (mask & 1) |
| { |
| if (ireg == RA_REGNUM) |
| continue; |
| store_address (raw_buffer, 8, read_register (ireg)); |
| write_memory (save_address, raw_buffer, 8); |
| save_address += 8; |
| } |
| |
| store_address (raw_buffer, 8, read_register (PC_REGNUM)); |
| write_memory (sp - 8, raw_buffer, 8); |
| |
| /* Save floating point registers. */ |
| save_address = sp + PROC_FREG_OFFSET(proc_desc); |
| mask = PROC_FREG_MASK(proc_desc) & 0xffffffffL; |
| for (ireg = 0; mask; ireg++, mask >>= 1) |
| if (mask & 1) |
| { |
| store_address (raw_buffer, 8, read_register (ireg + FP0_REGNUM)); |
| write_memory (save_address, raw_buffer, 8); |
| save_address += 8; |
| } |
| |
| /* Set and save the frame address for the dummy. |
| This is tricky. The only registers that are suitable for a frame save |
| are those that are preserved across procedure calls (s0-s6). But if |
| a read system call is interrupted and then a dummy call is made |
| (see testsuite/gdb.t17/interrupt.exp) the dummy call hangs till the read |
| is satisfied. Then it returns with the s0-s6 registers set to the values |
| on entry to the read system call and our dummy frame pointer would be |
| destroyed. So we save the dummy frame in the proc_desc and handle the |
| retrieval of the frame pointer of a dummy specifically. The frame register |
| is set to the virtual frame (pseudo) register, it's value will always |
| be read as zero and will help us to catch any errors in the dummy frame |
| retrieval code. */ |
| PROC_DUMMY_FRAME(proc_desc) = sp; |
| PROC_FRAME_REG(proc_desc) = FP_REGNUM; |
| PROC_FRAME_OFFSET(proc_desc) = 0; |
| sp += PROC_REG_OFFSET(proc_desc); |
| write_register (SP_REGNUM, sp); |
| |
| PROC_LOW_ADDR(proc_desc) = CALL_DUMMY_ADDRESS (); |
| PROC_HIGH_ADDR(proc_desc) = PROC_LOW_ADDR(proc_desc) + 4; |
| |
| SET_PROC_DESC_IS_DUMMY(proc_desc); |
| PROC_PC_REG(proc_desc) = RA_REGNUM; |
| } |
| |
| void |
| alpha_pop_frame() |
| { |
| register int regnum; |
| struct frame_info *frame = get_current_frame (); |
| CORE_ADDR new_sp = frame->frame; |
| |
| alpha_extra_func_info_t proc_desc = frame->proc_desc; |
| |
| /* we need proc_desc to know how to restore the registers; |
| if it is NULL, construct (a temporary) one */ |
| if (proc_desc == NULL) |
| proc_desc = find_proc_desc(frame->pc, frame->next); |
| |
| /* Question: should we copy this proc_desc and save it in |
| frame->proc_desc? If we do, who will free it? |
| For now, we don't save a copy... */ |
| |
| write_register (PC_REGNUM, FRAME_SAVED_PC(frame)); |
| if (frame->saved_regs == NULL) |
| alpha_find_saved_regs (frame); |
| if (proc_desc) |
| { |
| for (regnum = 32; --regnum >= 0; ) |
| if (PROC_REG_MASK(proc_desc) & (1 << regnum)) |
| write_register (regnum, |
| read_memory_integer (frame->saved_regs[regnum], |
| 8)); |
| for (regnum = 32; --regnum >= 0; ) |
| if (PROC_FREG_MASK(proc_desc) & (1 << regnum)) |
| write_register (regnum + FP0_REGNUM, |
| read_memory_integer (frame->saved_regs[regnum + FP0_REGNUM], 8)); |
| } |
| write_register (SP_REGNUM, new_sp); |
| flush_cached_frames (); |
| |
| if (proc_desc && (PROC_DESC_IS_DUMMY(proc_desc) |
| || PROC_DESC_IS_DYN_SIGTRAMP (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; |
| 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) |
| { |
| 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; |
| if ((inst & 0xffe01fff) == 0x43c0153e) /* subq $sp,n,$sp */ |
| continue; |
| |
| if ((inst & 0xfc1f0000) == 0xb41e0000 |
| && (inst & 0xffff0000) != 0xb7fe0000) |
| continue; /* stq reg,n($sp) */ |
| /* reg != $zero */ |
| if ((inst & 0xfc1f0000) == 0x9c1e0000 |
| && (inst & 0xffff0000) != 0x9ffe0000) |
| continue; /* stt reg,n($sp) */ |
| /* reg != $zero */ |
| if (inst == 0x47de040f) /* bis sp,sp,fp */ |
| continue; |
| |
| break; |
| } |
| return pc + offset; |
| } |
| |
| #if 0 |
| /* 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; |
| } |
| #endif |
| |
| /* The alpha needs a conversion between register and memory format if |
| the register is a floating point register and |
| memory format is float, as the register format must be double |
| or |
| memory format is an integer with 4 bytes or less, as the representation |
| of integers in floating point registers is different. */ |
| void |
| alpha_register_convert_to_virtual (regnum, valtype, raw_buffer, virtual_buffer) |
| int regnum; |
| struct type *valtype; |
| char *raw_buffer; |
| char *virtual_buffer; |
| { |
| if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum)) |
| { |
| memcpy (virtual_buffer, raw_buffer, REGISTER_VIRTUAL_SIZE (regnum)); |
| return; |
| } |
| |
| if (TYPE_CODE (valtype) == TYPE_CODE_FLT) |
| { |
| double d = extract_floating (raw_buffer, REGISTER_RAW_SIZE (regnum)); |
| store_floating (virtual_buffer, TYPE_LENGTH (valtype), d); |
| } |
| else if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4) |
| { |
| ULONGEST l; |
| l = extract_unsigned_integer (raw_buffer, REGISTER_RAW_SIZE (regnum)); |
| l = ((l >> 32) & 0xc0000000) | ((l >> 29) & 0x3fffffff); |
| store_unsigned_integer (virtual_buffer, TYPE_LENGTH (valtype), l); |
| } |
| else |
| error ("Cannot retrieve value from floating point register"); |
| } |
| |
| void |
| alpha_register_convert_to_raw (valtype, regnum, virtual_buffer, raw_buffer) |
| struct type *valtype; |
| int regnum; |
| char *virtual_buffer; |
| char *raw_buffer; |
| { |
| if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum)) |
| { |
| memcpy (raw_buffer, virtual_buffer, REGISTER_RAW_SIZE (regnum)); |
| return; |
| } |
| |
| if (TYPE_CODE (valtype) == TYPE_CODE_FLT) |
| { |
| double d = extract_floating (virtual_buffer, TYPE_LENGTH (valtype)); |
| store_floating (raw_buffer, REGISTER_RAW_SIZE (regnum), d); |
| } |
| else if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4) |
| { |
| ULONGEST l; |
| if (TYPE_UNSIGNED (valtype)) |
| l = extract_unsigned_integer (virtual_buffer, TYPE_LENGTH (valtype)); |
| else |
| l = extract_signed_integer (virtual_buffer, TYPE_LENGTH (valtype)); |
| l = ((l & 0xc0000000) << 32) | ((l & 0x3fffffff) << 29); |
| store_unsigned_integer (raw_buffer, REGISTER_RAW_SIZE (regnum), l); |
| } |
| else |
| error ("Cannot store value in floating point register"); |
| } |
| |
| /* 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; |
| { |
| 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; |
| { |
| char raw_buffer[MAX_REGISTER_RAW_SIZE]; |
| int regnum = V0_REGNUM; |
| int length = TYPE_LENGTH (valtype); |
| |
| 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); |
| |
| 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; |
| int from_tty; |
| struct cmd_list_element *c; |
| { |
| 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 |
| 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); |
| } |