| /* Target-dependent code for the Matsushita MN10200 for GDB, the GNU debugger. |
| Copyright 1997, 1998, 1999, 2000, 2001 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 "target.h" |
| #include "value.h" |
| #include "bfd.h" |
| #include "gdb_string.h" |
| #include "gdbcore.h" |
| #include "symfile.h" |
| #include "regcache.h" |
| |
| |
| /* Should call_function allocate stack space for a struct return? */ |
| int |
| mn10200_use_struct_convention (int gcc_p, struct type *type) |
| { |
| return (TYPE_NFIELDS (type) > 1 || TYPE_LENGTH (type) > 8); |
| } |
| /* *INDENT-OFF* */ |
| /* The main purpose of this file is dealing with prologues to extract |
| information about stack frames and saved registers. |
| |
| For reference here's how prologues look on the mn10200: |
| |
| With frame pointer: |
| mov fp,a0 |
| mov sp,fp |
| add <size>,sp |
| Register saves for d2, d3, a1, a2 as needed. Saves start |
| at fp - <size> + <outgoing_args_size> and work towards higher |
| addresses. Note that the saves are actually done off the stack |
| pointer in the prologue! This makes for smaller code and easier |
| prologue scanning as the displacement fields will unlikely |
| be more than 8 bits! |
| |
| Without frame pointer: |
| add <size>,sp |
| Register saves for d2, d3, a1, a2 as needed. Saves start |
| at sp + <outgoing_args_size> and work towards higher addresses. |
| |
| Out of line prologue: |
| add <local size>,sp -- optional |
| jsr __prologue |
| add <outgoing_size>,sp -- optional |
| |
| The stack pointer remains constant throughout the life of most |
| functions. As a result the compiler will usually omit the |
| frame pointer, so we must handle frame pointerless functions. */ |
| |
| /* Analyze the prologue to determine where registers are saved, |
| the end of the prologue, etc etc. Return the end of the prologue |
| scanned. |
| |
| We store into FI (if non-null) several tidbits of information: |
| |
| * stack_size -- size of this stack frame. Note that if we stop in |
| certain parts of the prologue/epilogue we may claim the size of the |
| current frame is zero. This happens when the current frame has |
| not been allocated yet or has already been deallocated. |
| |
| * fsr -- Addresses of registers saved in the stack by this frame. |
| |
| * status -- A (relatively) generic status indicator. It's a bitmask |
| with the following bits: |
| |
| MY_FRAME_IN_SP: The base of the current frame is actually in |
| the stack pointer. This can happen for frame pointerless |
| functions, or cases where we're stopped in the prologue/epilogue |
| itself. For these cases mn10200_analyze_prologue will need up |
| update fi->frame before returning or analyzing the register |
| save instructions. |
| |
| MY_FRAME_IN_FP: The base of the current frame is in the |
| frame pointer register ($a2). |
| |
| CALLER_A2_IN_A0: $a2 from the caller's frame is temporarily |
| in $a0. This can happen if we're stopped in the prologue. |
| |
| NO_MORE_FRAMES: Set this if the current frame is "start" or |
| if the first instruction looks like mov <imm>,sp. This tells |
| frame chain to not bother trying to unwind past this frame. */ |
| /* *INDENT-ON* */ |
| |
| |
| |
| |
| #define MY_FRAME_IN_SP 0x1 |
| #define MY_FRAME_IN_FP 0x2 |
| #define CALLER_A2_IN_A0 0x4 |
| #define NO_MORE_FRAMES 0x8 |
| |
| static CORE_ADDR |
| mn10200_analyze_prologue (struct frame_info *fi, CORE_ADDR pc) |
| { |
| CORE_ADDR func_addr, func_end, addr, stop; |
| CORE_ADDR stack_size = 0; |
| unsigned char buf[4]; |
| int status; |
| char *name; |
| int out_of_line_prologue = 0; |
| |
| /* Use the PC in the frame if it's provided to look up the |
| start of this function. */ |
| pc = (fi ? fi->pc : pc); |
| |
| /* Find the start of this function. */ |
| status = find_pc_partial_function (pc, &name, &func_addr, &func_end); |
| |
| /* Do nothing if we couldn't find the start of this function or if we're |
| stopped at the first instruction in the prologue. */ |
| if (status == 0) |
| return pc; |
| |
| /* If we're in start, then give up. */ |
| if (strcmp (name, "start") == 0) |
| { |
| if (fi) |
| fi->status = NO_MORE_FRAMES; |
| return pc; |
| } |
| |
| /* At the start of a function our frame is in the stack pointer. */ |
| if (fi) |
| fi->status = MY_FRAME_IN_SP; |
| |
| /* If we're physically on an RTS instruction, then our frame has already |
| been deallocated. |
| |
| fi->frame is bogus, we need to fix it. */ |
| if (fi && fi->pc + 1 == func_end) |
| { |
| status = target_read_memory (fi->pc, buf, 1); |
| if (status != 0) |
| { |
| if (fi->next == NULL) |
| fi->frame = read_sp (); |
| return fi->pc; |
| } |
| |
| if (buf[0] == 0xfe) |
| { |
| if (fi->next == NULL) |
| fi->frame = read_sp (); |
| return fi->pc; |
| } |
| } |
| |
| /* Similarly if we're stopped on the first insn of a prologue as our |
| frame hasn't been allocated yet. */ |
| if (fi && fi->pc == func_addr) |
| { |
| if (fi->next == NULL) |
| fi->frame = read_sp (); |
| return fi->pc; |
| } |
| |
| /* Figure out where to stop scanning. */ |
| stop = fi ? fi->pc : func_end; |
| |
| /* Don't walk off the end of the function. */ |
| stop = stop > func_end ? func_end : stop; |
| |
| /* Start scanning on the first instruction of this function. */ |
| addr = func_addr; |
| |
| status = target_read_memory (addr, buf, 2); |
| if (status != 0) |
| { |
| if (fi && fi->next == NULL && fi->status & MY_FRAME_IN_SP) |
| fi->frame = read_sp (); |
| return addr; |
| } |
| |
| /* First see if this insn sets the stack pointer; if so, it's something |
| we won't understand, so quit now. */ |
| if (buf[0] == 0xdf |
| || (buf[0] == 0xf4 && buf[1] == 0x77)) |
| { |
| if (fi) |
| fi->status = NO_MORE_FRAMES; |
| return addr; |
| } |
| |
| /* Now see if we have a frame pointer. |
| |
| Search for mov a2,a0 (0xf278) |
| then mov a3,a2 (0xf27e). */ |
| |
| if (buf[0] == 0xf2 && buf[1] == 0x78) |
| { |
| /* Our caller's $a2 will be found in $a0 now. Note it for |
| our callers. */ |
| if (fi) |
| fi->status |= CALLER_A2_IN_A0; |
| addr += 2; |
| if (addr >= stop) |
| { |
| /* We still haven't allocated our local stack. Handle this |
| as if we stopped on the first or last insn of a function. */ |
| if (fi && fi->next == NULL) |
| fi->frame = read_sp (); |
| return addr; |
| } |
| |
| status = target_read_memory (addr, buf, 2); |
| if (status != 0) |
| { |
| if (fi && fi->next == NULL) |
| fi->frame = read_sp (); |
| return addr; |
| } |
| if (buf[0] == 0xf2 && buf[1] == 0x7e) |
| { |
| addr += 2; |
| |
| /* Our frame pointer is valid now. */ |
| if (fi) |
| { |
| fi->status |= MY_FRAME_IN_FP; |
| fi->status &= ~MY_FRAME_IN_SP; |
| } |
| if (addr >= stop) |
| return addr; |
| } |
| else |
| { |
| if (fi && fi->next == NULL) |
| fi->frame = read_sp (); |
| return addr; |
| } |
| } |
| |
| /* Next we should allocate the local frame. |
| |
| Search for add imm8,a3 (0xd3XX) |
| or add imm16,a3 (0xf70bXXXX) |
| or add imm24,a3 (0xf467XXXXXX). |
| |
| If none of the above was found, then this prologue has |
| no stack, and therefore can't have any register saves, |
| so quit now. */ |
| status = target_read_memory (addr, buf, 2); |
| if (status != 0) |
| { |
| if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| fi->frame = read_sp (); |
| return addr; |
| } |
| if (buf[0] == 0xd3) |
| { |
| stack_size = extract_signed_integer (&buf[1], 1); |
| if (fi) |
| fi->stack_size = stack_size; |
| addr += 2; |
| if (addr >= stop) |
| { |
| if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| fi->frame = read_sp () - stack_size; |
| return addr; |
| } |
| } |
| else if (buf[0] == 0xf7 && buf[1] == 0x0b) |
| { |
| status = target_read_memory (addr + 2, buf, 2); |
| if (status != 0) |
| { |
| if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| fi->frame = read_sp (); |
| return addr; |
| } |
| stack_size = extract_signed_integer (buf, 2); |
| if (fi) |
| fi->stack_size = stack_size; |
| addr += 4; |
| if (addr >= stop) |
| { |
| if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| fi->frame = read_sp () - stack_size; |
| return addr; |
| } |
| } |
| else if (buf[0] == 0xf4 && buf[1] == 0x67) |
| { |
| status = target_read_memory (addr + 2, buf, 3); |
| if (status != 0) |
| { |
| if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| fi->frame = read_sp (); |
| return addr; |
| } |
| stack_size = extract_signed_integer (buf, 3); |
| if (fi) |
| fi->stack_size = stack_size; |
| addr += 5; |
| if (addr >= stop) |
| { |
| if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| fi->frame = read_sp () - stack_size; |
| return addr; |
| } |
| } |
| |
| /* Now see if we have a call to __prologue for an out of line |
| prologue. */ |
| status = target_read_memory (addr, buf, 2); |
| if (status != 0) |
| return addr; |
| |
| /* First check for 16bit pc-relative call to __prologue. */ |
| if (buf[0] == 0xfd) |
| { |
| CORE_ADDR temp; |
| status = target_read_memory (addr + 1, buf, 2); |
| if (status != 0) |
| { |
| if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| fi->frame = read_sp (); |
| return addr; |
| } |
| |
| /* Get the PC this instruction will branch to. */ |
| temp = (extract_signed_integer (buf, 2) + addr + 3) & 0xffffff; |
| |
| /* Get the name of the function at the target address. */ |
| status = find_pc_partial_function (temp, &name, NULL, NULL); |
| if (status == 0) |
| { |
| if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| fi->frame = read_sp (); |
| return addr; |
| } |
| |
| /* Note if it is an out of line prologue. */ |
| out_of_line_prologue = (strcmp (name, "__prologue") == 0); |
| |
| /* This sucks up 3 bytes of instruction space. */ |
| if (out_of_line_prologue) |
| addr += 3; |
| |
| if (addr >= stop) |
| { |
| if (fi && fi->next == NULL) |
| { |
| fi->stack_size -= 16; |
| fi->frame = read_sp () - fi->stack_size; |
| } |
| return addr; |
| } |
| } |
| /* Now check for the 24bit pc-relative call to __prologue. */ |
| else if (buf[0] == 0xf4 && buf[1] == 0xe1) |
| { |
| CORE_ADDR temp; |
| status = target_read_memory (addr + 2, buf, 3); |
| if (status != 0) |
| { |
| if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| fi->frame = read_sp (); |
| return addr; |
| } |
| |
| /* Get the PC this instruction will branch to. */ |
| temp = (extract_signed_integer (buf, 3) + addr + 5) & 0xffffff; |
| |
| /* Get the name of the function at the target address. */ |
| status = find_pc_partial_function (temp, &name, NULL, NULL); |
| if (status == 0) |
| { |
| if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| fi->frame = read_sp (); |
| return addr; |
| } |
| |
| /* Note if it is an out of line prologue. */ |
| out_of_line_prologue = (strcmp (name, "__prologue") == 0); |
| |
| /* This sucks up 5 bytes of instruction space. */ |
| if (out_of_line_prologue) |
| addr += 5; |
| |
| if (addr >= stop) |
| { |
| if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| { |
| fi->stack_size -= 16; |
| fi->frame = read_sp () - fi->stack_size; |
| } |
| return addr; |
| } |
| } |
| |
| /* Now actually handle the out of line prologue. */ |
| if (out_of_line_prologue) |
| { |
| int outgoing_args_size = 0; |
| |
| /* First adjust the stack size for this function. The out of |
| line prologue saves 4 registers (16bytes of data). */ |
| if (fi) |
| fi->stack_size -= 16; |
| |
| /* Update fi->frame if necessary. */ |
| if (fi && fi->next == NULL) |
| fi->frame = read_sp () - fi->stack_size; |
| |
| /* After the out of line prologue, there may be another |
| stack adjustment for the outgoing arguments. |
| |
| Search for add imm8,a3 (0xd3XX) |
| or add imm16,a3 (0xf70bXXXX) |
| or add imm24,a3 (0xf467XXXXXX). */ |
| |
| status = target_read_memory (addr, buf, 2); |
| if (status != 0) |
| { |
| if (fi) |
| { |
| fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; |
| fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; |
| fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; |
| fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; |
| } |
| return addr; |
| } |
| |
| if (buf[0] == 0xd3) |
| { |
| outgoing_args_size = extract_signed_integer (&buf[1], 1); |
| addr += 2; |
| } |
| else if (buf[0] == 0xf7 && buf[1] == 0x0b) |
| { |
| status = target_read_memory (addr + 2, buf, 2); |
| if (status != 0) |
| { |
| if (fi) |
| { |
| fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; |
| fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; |
| fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; |
| fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; |
| } |
| return addr; |
| } |
| outgoing_args_size = extract_signed_integer (buf, 2); |
| addr += 4; |
| } |
| else if (buf[0] == 0xf4 && buf[1] == 0x67) |
| { |
| status = target_read_memory (addr + 2, buf, 3); |
| if (status != 0) |
| { |
| if (fi && fi->next == NULL) |
| { |
| fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; |
| fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; |
| fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; |
| fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; |
| } |
| return addr; |
| } |
| outgoing_args_size = extract_signed_integer (buf, 3); |
| addr += 5; |
| } |
| else |
| outgoing_args_size = 0; |
| |
| /* Now that we know the size of the outgoing arguments, fix |
| fi->frame again if this is the innermost frame. */ |
| if (fi && fi->next == NULL) |
| fi->frame -= outgoing_args_size; |
| |
| /* Note the register save information and update the stack |
| size for this frame too. */ |
| if (fi) |
| { |
| fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; |
| fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; |
| fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; |
| fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; |
| fi->stack_size += outgoing_args_size; |
| } |
| /* There can be no more prologue insns, so return now. */ |
| return addr; |
| } |
| |
| /* At this point fi->frame needs to be correct. |
| |
| If MY_FRAME_IN_SP is set and we're the innermost frame, then we |
| need to fix fi->frame so that backtracing, find_frame_saved_regs, |
| etc work correctly. */ |
| if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP) != 0) |
| fi->frame = read_sp () - fi->stack_size; |
| |
| /* And last we have the register saves. These are relatively |
| simple because they're physically done off the stack pointer, |
| and thus the number of different instructions we need to |
| check is greatly reduced because we know the displacements |
| will be small. |
| |
| Search for movx d2,(X,a3) (0xf55eXX) |
| then movx d3,(X,a3) (0xf55fXX) |
| then mov a1,(X,a3) (0x5dXX) No frame pointer case |
| then mov a2,(X,a3) (0x5eXX) No frame pointer case |
| or mov a0,(X,a3) (0x5cXX) Frame pointer case. */ |
| |
| status = target_read_memory (addr, buf, 2); |
| if (status != 0) |
| return addr; |
| if (buf[0] == 0xf5 && buf[1] == 0x5e) |
| { |
| if (fi) |
| { |
| status = target_read_memory (addr + 2, buf, 1); |
| if (status != 0) |
| return addr; |
| fi->fsr.regs[2] = (fi->frame + stack_size |
| + extract_signed_integer (buf, 1)); |
| } |
| addr += 3; |
| if (addr >= stop) |
| return addr; |
| status = target_read_memory (addr, buf, 2); |
| if (status != 0) |
| return addr; |
| } |
| if (buf[0] == 0xf5 && buf[1] == 0x5f) |
| { |
| if (fi) |
| { |
| status = target_read_memory (addr + 2, buf, 1); |
| if (status != 0) |
| return addr; |
| fi->fsr.regs[3] = (fi->frame + stack_size |
| + extract_signed_integer (buf, 1)); |
| } |
| addr += 3; |
| if (addr >= stop) |
| return addr; |
| status = target_read_memory (addr, buf, 2); |
| if (status != 0) |
| return addr; |
| } |
| if (buf[0] == 0x5d) |
| { |
| if (fi) |
| { |
| status = target_read_memory (addr + 1, buf, 1); |
| if (status != 0) |
| return addr; |
| fi->fsr.regs[5] = (fi->frame + stack_size |
| + extract_signed_integer (buf, 1)); |
| } |
| addr += 2; |
| if (addr >= stop) |
| return addr; |
| status = target_read_memory (addr, buf, 2); |
| if (status != 0) |
| return addr; |
| } |
| if (buf[0] == 0x5e || buf[0] == 0x5c) |
| { |
| if (fi) |
| { |
| status = target_read_memory (addr + 1, buf, 1); |
| if (status != 0) |
| return addr; |
| fi->fsr.regs[6] = (fi->frame + stack_size |
| + extract_signed_integer (buf, 1)); |
| fi->status &= ~CALLER_A2_IN_A0; |
| } |
| addr += 2; |
| if (addr >= stop) |
| return addr; |
| return addr; |
| } |
| return addr; |
| } |
| |
| /* Function: frame_chain |
| Figure out and return the caller's frame pointer given current |
| frame_info struct. |
| |
| We don't handle dummy frames yet but we would probably just return the |
| stack pointer that was in use at the time the function call was made? */ |
| |
| CORE_ADDR |
| mn10200_frame_chain (struct frame_info *fi) |
| { |
| struct frame_info dummy_frame; |
| |
| /* Walk through the prologue to determine the stack size, |
| location of saved registers, end of the prologue, etc. */ |
| if (fi->status == 0) |
| mn10200_analyze_prologue (fi, (CORE_ADDR) 0); |
| |
| /* Quit now if mn10200_analyze_prologue set NO_MORE_FRAMES. */ |
| if (fi->status & NO_MORE_FRAMES) |
| return 0; |
| |
| /* Now that we've analyzed our prologue, determine the frame |
| pointer for our caller. |
| |
| If our caller has a frame pointer, then we need to |
| find the entry value of $a2 to our function. |
| |
| If CALLER_A2_IN_A0, then the chain is in $a0. |
| |
| If fsr.regs[6] is nonzero, then it's at the memory |
| location pointed to by fsr.regs[6]. |
| |
| Else it's still in $a2. |
| |
| If our caller does not have a frame pointer, then his |
| frame base is fi->frame + -caller's stack size + 4. */ |
| |
| /* The easiest way to get that info is to analyze our caller's frame. |
| |
| So we set up a dummy frame and call mn10200_analyze_prologue to |
| find stuff for us. */ |
| dummy_frame.pc = FRAME_SAVED_PC (fi); |
| dummy_frame.frame = fi->frame; |
| memset (dummy_frame.fsr.regs, '\000', sizeof dummy_frame.fsr.regs); |
| dummy_frame.status = 0; |
| dummy_frame.stack_size = 0; |
| mn10200_analyze_prologue (&dummy_frame, 0); |
| |
| if (dummy_frame.status & MY_FRAME_IN_FP) |
| { |
| /* Our caller has a frame pointer. So find the frame in $a2, $a0, |
| or in the stack. */ |
| if (fi->fsr.regs[6]) |
| return (read_memory_integer (fi->fsr.regs[FP_REGNUM], REGISTER_SIZE) |
| & 0xffffff); |
| else if (fi->status & CALLER_A2_IN_A0) |
| return read_register (4); |
| else |
| return read_register (FP_REGNUM); |
| } |
| else |
| { |
| /* Our caller does not have a frame pointer. So his frame starts |
| at the base of our frame (fi->frame) + <his size> + 4 (saved pc). */ |
| return fi->frame + -dummy_frame.stack_size + 4; |
| } |
| } |
| |
| /* Function: skip_prologue |
| Return the address of the first inst past the prologue of the function. */ |
| |
| CORE_ADDR |
| mn10200_skip_prologue (CORE_ADDR pc) |
| { |
| /* We used to check the debug symbols, but that can lose if |
| we have a null prologue. */ |
| return mn10200_analyze_prologue (NULL, pc); |
| } |
| |
| /* Function: pop_frame |
| This routine gets called when either the user uses the `return' |
| command, or the call dummy breakpoint gets hit. */ |
| |
| void |
| mn10200_pop_frame (struct frame_info *frame) |
| { |
| int regnum; |
| |
| if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)) |
| generic_pop_dummy_frame (); |
| else |
| { |
| write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); |
| |
| /* Restore any saved registers. */ |
| for (regnum = 0; regnum < NUM_REGS; regnum++) |
| if (frame->fsr.regs[regnum] != 0) |
| { |
| ULONGEST value; |
| |
| value = read_memory_unsigned_integer (frame->fsr.regs[regnum], |
| REGISTER_RAW_SIZE (regnum)); |
| write_register (regnum, value); |
| } |
| |
| /* Actually cut back the stack. */ |
| write_register (SP_REGNUM, FRAME_FP (frame)); |
| |
| /* Don't we need to set the PC?!? XXX FIXME. */ |
| } |
| |
| /* Throw away any cached frame information. */ |
| flush_cached_frames (); |
| } |
| |
| /* Function: push_arguments |
| Setup arguments for a call to the target. Arguments go in |
| order on the stack. */ |
| |
| CORE_ADDR |
| mn10200_push_arguments (int nargs, struct value **args, CORE_ADDR sp, |
| unsigned char struct_return, CORE_ADDR struct_addr) |
| { |
| int argnum = 0; |
| int len = 0; |
| int stack_offset = 0; |
| int regsused = struct_return ? 1 : 0; |
| |
| /* This should be a nop, but align the stack just in case something |
| went wrong. Stacks are two byte aligned on the mn10200. */ |
| sp &= ~1; |
| |
| /* Now make space on the stack for the args. |
| |
| XXX This doesn't appear to handle pass-by-invisible reference |
| arguments. */ |
| for (argnum = 0; argnum < nargs; argnum++) |
| { |
| int arg_length = (TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 1) & ~1; |
| |
| /* If we've used all argument registers, then this argument is |
| pushed. */ |
| if (regsused >= 2 || arg_length > 4) |
| { |
| regsused = 2; |
| len += arg_length; |
| } |
| /* We know we've got some arg register space left. If this argument |
| will fit entirely in regs, then put it there. */ |
| else if (arg_length <= 2 |
| || TYPE_CODE (VALUE_TYPE (args[argnum])) == TYPE_CODE_PTR) |
| { |
| regsused++; |
| } |
| else if (regsused == 0) |
| { |
| regsused = 2; |
| } |
| else |
| { |
| regsused = 2; |
| len += arg_length; |
| } |
| } |
| |
| /* Allocate stack space. */ |
| sp -= len; |
| |
| regsused = struct_return ? 1 : 0; |
| /* Push all arguments onto the stack. */ |
| for (argnum = 0; argnum < nargs; argnum++) |
| { |
| int len; |
| char *val; |
| |
| /* XXX Check this. What about UNIONS? */ |
| if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT |
| && TYPE_LENGTH (VALUE_TYPE (*args)) > 8) |
| { |
| /* XXX Wrong, we want a pointer to this argument. */ |
| len = TYPE_LENGTH (VALUE_TYPE (*args)); |
| val = (char *) VALUE_CONTENTS (*args); |
| } |
| else |
| { |
| len = TYPE_LENGTH (VALUE_TYPE (*args)); |
| val = (char *) VALUE_CONTENTS (*args); |
| } |
| |
| if (regsused < 2 |
| && (len <= 2 |
| || TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_PTR)) |
| { |
| write_register (regsused, extract_unsigned_integer (val, 4)); |
| regsused++; |
| } |
| else if (regsused == 0 && len == 4) |
| { |
| write_register (regsused, extract_unsigned_integer (val, 2)); |
| write_register (regsused + 1, extract_unsigned_integer (val + 2, 2)); |
| regsused = 2; |
| } |
| else |
| { |
| regsused = 2; |
| while (len > 0) |
| { |
| write_memory (sp + stack_offset, val, 2); |
| |
| len -= 2; |
| val += 2; |
| stack_offset += 2; |
| } |
| } |
| args++; |
| } |
| |
| return sp; |
| } |
| |
| /* Function: push_return_address (pc) |
| Set up the return address for the inferior function call. |
| Needed for targets where we don't actually execute a JSR/BSR instruction */ |
| |
| CORE_ADDR |
| mn10200_push_return_address (CORE_ADDR pc, CORE_ADDR sp) |
| { |
| unsigned char buf[4]; |
| |
| store_unsigned_integer (buf, 4, CALL_DUMMY_ADDRESS ()); |
| write_memory (sp - 4, buf, 4); |
| return sp - 4; |
| } |
| |
| /* Function: store_struct_return (addr,sp) |
| Store the structure value return address for an inferior function |
| call. */ |
| |
| CORE_ADDR |
| mn10200_store_struct_return (CORE_ADDR addr, CORE_ADDR sp) |
| { |
| /* The structure return address is passed as the first argument. */ |
| write_register (0, addr); |
| return sp; |
| } |
| |
| /* Function: frame_saved_pc |
| Find the caller of this frame. We do this by seeing if RP_REGNUM |
| is saved in the stack anywhere, otherwise we get it from the |
| registers. If the inner frame is a dummy frame, return its PC |
| instead of RP, because that's where "caller" of the dummy-frame |
| will be found. */ |
| |
| CORE_ADDR |
| mn10200_frame_saved_pc (struct frame_info *fi) |
| { |
| /* The saved PC will always be at the base of the current frame. */ |
| return (read_memory_integer (fi->frame, REGISTER_SIZE) & 0xffffff); |
| } |
| |
| /* Function: init_extra_frame_info |
| Setup the frame's frame pointer, pc, and frame addresses for saved |
| registers. Most of the work is done in mn10200_analyze_prologue(). |
| |
| Note that when we are called for the last frame (currently active frame), |
| that fi->pc and fi->frame will already be setup. However, fi->frame will |
| be valid only if this routine uses FP. For previous frames, fi-frame will |
| always be correct. mn10200_analyze_prologue will fix fi->frame if |
| it's not valid. |
| |
| We can be called with the PC in the call dummy under two circumstances. |
| First, during normal backtracing, second, while figuring out the frame |
| pointer just prior to calling the target function (see run_stack_dummy). */ |
| |
| void |
| mn10200_init_extra_frame_info (struct frame_info *fi) |
| { |
| if (fi->next) |
| fi->pc = FRAME_SAVED_PC (fi->next); |
| |
| memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); |
| fi->status = 0; |
| fi->stack_size = 0; |
| |
| mn10200_analyze_prologue (fi, 0); |
| } |
| |
| void |
| _initialize_mn10200_tdep (void) |
| { |
| tm_print_insn = print_insn_mn10200; |
| } |