| /* Target-dependent code for the Matsushita MN10300 for GDB, the GNU debugger. |
| |
| Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, |
| 2007, 2008 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 3 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, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "defs.h" |
| #include "arch-utils.h" |
| #include "dis-asm.h" |
| #include "gdbtypes.h" |
| #include "regcache.h" |
| #include "gdb_string.h" |
| #include "gdb_assert.h" |
| #include "gdbcore.h" /* for write_memory_unsigned_integer */ |
| #include "value.h" |
| #include "gdbtypes.h" |
| #include "frame.h" |
| #include "frame-unwind.h" |
| #include "frame-base.h" |
| #include "trad-frame.h" |
| #include "symtab.h" |
| #include "dwarf2-frame.h" |
| #include "osabi.h" |
| #include "infcall.h" |
| |
| #include "mn10300-tdep.h" |
| |
| /* Forward decl. */ |
| extern struct trad_frame_cache *mn10300_frame_unwind_cache (struct frame_info*, |
| void **); |
| |
| /* Compute the alignment required by a type. */ |
| |
| static int |
| mn10300_type_align (struct type *type) |
| { |
| int i, align = 1; |
| |
| switch (TYPE_CODE (type)) |
| { |
| case TYPE_CODE_INT: |
| case TYPE_CODE_ENUM: |
| case TYPE_CODE_SET: |
| case TYPE_CODE_RANGE: |
| case TYPE_CODE_CHAR: |
| case TYPE_CODE_BOOL: |
| case TYPE_CODE_FLT: |
| case TYPE_CODE_PTR: |
| case TYPE_CODE_REF: |
| return TYPE_LENGTH (type); |
| |
| case TYPE_CODE_COMPLEX: |
| return TYPE_LENGTH (type) / 2; |
| |
| case TYPE_CODE_STRUCT: |
| case TYPE_CODE_UNION: |
| for (i = 0; i < TYPE_NFIELDS (type); i++) |
| { |
| int falign = mn10300_type_align (TYPE_FIELD_TYPE (type, i)); |
| while (align < falign) |
| align <<= 1; |
| } |
| return align; |
| |
| case TYPE_CODE_ARRAY: |
| /* HACK! Structures containing arrays, even small ones, are not |
| elligible for returning in registers. */ |
| return 256; |
| |
| case TYPE_CODE_TYPEDEF: |
| return mn10300_type_align (check_typedef (type)); |
| |
| default: |
| internal_error (__FILE__, __LINE__, _("bad switch")); |
| } |
| } |
| |
| /* Should call_function allocate stack space for a struct return? */ |
| static int |
| mn10300_use_struct_convention (struct type *type) |
| { |
| /* Structures bigger than a pair of words can't be returned in |
| registers. */ |
| if (TYPE_LENGTH (type) > 8) |
| return 1; |
| |
| switch (TYPE_CODE (type)) |
| { |
| case TYPE_CODE_STRUCT: |
| case TYPE_CODE_UNION: |
| /* Structures with a single field are handled as the field |
| itself. */ |
| if (TYPE_NFIELDS (type) == 1) |
| return mn10300_use_struct_convention (TYPE_FIELD_TYPE (type, 0)); |
| |
| /* Structures with word or double-word size are passed in memory, as |
| long as they require at least word alignment. */ |
| if (mn10300_type_align (type) >= 4) |
| return 0; |
| |
| return 1; |
| |
| /* Arrays are addressable, so they're never returned in |
| registers. This condition can only hold when the array is |
| the only field of a struct or union. */ |
| case TYPE_CODE_ARRAY: |
| return 1; |
| |
| case TYPE_CODE_TYPEDEF: |
| return mn10300_use_struct_convention (check_typedef (type)); |
| |
| default: |
| return 0; |
| } |
| } |
| |
| static void |
| mn10300_store_return_value (struct gdbarch *gdbarch, struct type *type, |
| struct regcache *regcache, const void *valbuf) |
| { |
| int len = TYPE_LENGTH (type); |
| int reg, regsz; |
| |
| if (TYPE_CODE (type) == TYPE_CODE_PTR) |
| reg = 4; |
| else |
| reg = 0; |
| |
| regsz = register_size (gdbarch, reg); |
| |
| if (len <= regsz) |
| regcache_raw_write_part (regcache, reg, 0, len, valbuf); |
| else if (len <= 2 * regsz) |
| { |
| regcache_raw_write (regcache, reg, valbuf); |
| gdb_assert (regsz == register_size (gdbarch, reg + 1)); |
| regcache_raw_write_part (regcache, reg+1, 0, |
| len - regsz, (char *) valbuf + regsz); |
| } |
| else |
| internal_error (__FILE__, __LINE__, |
| _("Cannot store return value %d bytes long."), len); |
| } |
| |
| static void |
| mn10300_extract_return_value (struct gdbarch *gdbarch, struct type *type, |
| struct regcache *regcache, void *valbuf) |
| { |
| char buf[MAX_REGISTER_SIZE]; |
| int len = TYPE_LENGTH (type); |
| int reg, regsz; |
| |
| if (TYPE_CODE (type) == TYPE_CODE_PTR) |
| reg = 4; |
| else |
| reg = 0; |
| |
| regsz = register_size (gdbarch, reg); |
| if (len <= regsz) |
| { |
| regcache_raw_read (regcache, reg, buf); |
| memcpy (valbuf, buf, len); |
| } |
| else if (len <= 2 * regsz) |
| { |
| regcache_raw_read (regcache, reg, buf); |
| memcpy (valbuf, buf, regsz); |
| gdb_assert (regsz == register_size (gdbarch, reg + 1)); |
| regcache_raw_read (regcache, reg + 1, buf); |
| memcpy ((char *) valbuf + regsz, buf, len - regsz); |
| } |
| else |
| internal_error (__FILE__, __LINE__, |
| _("Cannot extract return value %d bytes long."), len); |
| } |
| |
| /* Determine, for architecture GDBARCH, how a return value of TYPE |
| should be returned. If it is supposed to be returned in registers, |
| and READBUF is non-zero, read the appropriate value from REGCACHE, |
| and copy it into READBUF. If WRITEBUF is non-zero, write the value |
| from WRITEBUF into REGCACHE. */ |
| |
| static enum return_value_convention |
| mn10300_return_value (struct gdbarch *gdbarch, struct type *type, |
| struct regcache *regcache, gdb_byte *readbuf, |
| const gdb_byte *writebuf) |
| { |
| if (mn10300_use_struct_convention (type)) |
| return RETURN_VALUE_STRUCT_CONVENTION; |
| |
| if (readbuf) |
| mn10300_extract_return_value (gdbarch, type, regcache, readbuf); |
| if (writebuf) |
| mn10300_store_return_value (gdbarch, type, regcache, writebuf); |
| |
| return RETURN_VALUE_REGISTER_CONVENTION; |
| } |
| |
| static char * |
| register_name (int reg, char **regs, long sizeof_regs) |
| { |
| if (reg < 0 || reg >= sizeof_regs / sizeof (regs[0])) |
| return NULL; |
| else |
| return regs[reg]; |
| } |
| |
| static const char * |
| mn10300_generic_register_name (struct gdbarch *gdbarch, int reg) |
| { |
| static char *regs[] = |
| { "d0", "d1", "d2", "d3", "a0", "a1", "a2", "a3", |
| "sp", "pc", "mdr", "psw", "lir", "lar", "", "", |
| "", "", "", "", "", "", "", "", |
| "", "", "", "", "", "", "", "fp" |
| }; |
| return register_name (reg, regs, sizeof regs); |
| } |
| |
| |
| static const char * |
| am33_register_name (struct gdbarch *gdbarch, int reg) |
| { |
| static char *regs[] = |
| { "d0", "d1", "d2", "d3", "a0", "a1", "a2", "a3", |
| "sp", "pc", "mdr", "psw", "lir", "lar", "", |
| "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", |
| "ssp", "msp", "usp", "mcrh", "mcrl", "mcvf", "", "", "" |
| }; |
| return register_name (reg, regs, sizeof regs); |
| } |
| |
| static const char * |
| am33_2_register_name (struct gdbarch *gdbarch, int reg) |
| { |
| static char *regs[] = |
| { |
| "d0", "d1", "d2", "d3", "a0", "a1", "a2", "a3", |
| "sp", "pc", "mdr", "psw", "lir", "lar", "mdrq", "r0", |
| "r1", "r2", "r3", "r4", "r5", "r6", "r7", "ssp", |
| "msp", "usp", "mcrh", "mcrl", "mcvf", "fpcr", "", "", |
| "fs0", "fs1", "fs2", "fs3", "fs4", "fs5", "fs6", "fs7", |
| "fs8", "fs9", "fs10", "fs11", "fs12", "fs13", "fs14", "fs15", |
| "fs16", "fs17", "fs18", "fs19", "fs20", "fs21", "fs22", "fs23", |
| "fs24", "fs25", "fs26", "fs27", "fs28", "fs29", "fs30", "fs31" |
| }; |
| return register_name (reg, regs, sizeof regs); |
| } |
| |
| static struct type * |
| mn10300_register_type (struct gdbarch *gdbarch, int reg) |
| { |
| return builtin_type_int; |
| } |
| |
| static CORE_ADDR |
| mn10300_read_pc (struct regcache *regcache) |
| { |
| ULONGEST val; |
| regcache_cooked_read_unsigned (regcache, E_PC_REGNUM, &val); |
| return val; |
| } |
| |
| static void |
| mn10300_write_pc (struct regcache *regcache, CORE_ADDR val) |
| { |
| regcache_cooked_write_unsigned (regcache, E_PC_REGNUM, val); |
| } |
| |
| /* The breakpoint instruction must be the same size as the smallest |
| instruction in the instruction set. |
| |
| The Matsushita mn10x00 processors have single byte instructions |
| so we need a single byte breakpoint. Matsushita hasn't defined |
| one, so we defined it ourselves. */ |
| |
| const static unsigned char * |
| mn10300_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *bp_addr, |
| int *bp_size) |
| { |
| static char breakpoint[] = {0xff}; |
| *bp_size = 1; |
| return breakpoint; |
| } |
| |
| /* Set offsets of saved registers. |
| This is a helper function for mn10300_analyze_prologue. */ |
| |
| static void |
| set_reg_offsets (struct frame_info *fi, |
| void **this_cache, |
| int movm_args, |
| int fpregmask, |
| int stack_extra_size, |
| int frame_in_fp) |
| { |
| struct gdbarch *gdbarch; |
| struct trad_frame_cache *cache; |
| int offset = 0; |
| CORE_ADDR base; |
| |
| if (fi == NULL || this_cache == NULL) |
| return; |
| |
| cache = mn10300_frame_unwind_cache (fi, this_cache); |
| if (cache == NULL) |
| return; |
| gdbarch = get_frame_arch (fi); |
| |
| if (frame_in_fp) |
| { |
| base = frame_unwind_register_unsigned (fi, E_A3_REGNUM); |
| } |
| else |
| { |
| base = frame_unwind_register_unsigned (fi, E_SP_REGNUM) |
| + stack_extra_size; |
| } |
| |
| trad_frame_set_this_base (cache, base); |
| |
| if (AM33_MODE (gdbarch) == 2) |
| { |
| /* If bit N is set in fpregmask, fsN is saved on the stack. |
| The floating point registers are saved in ascending order. |
| For example: fs16 <- Frame Pointer |
| fs17 Frame Pointer + 4 */ |
| if (fpregmask != 0) |
| { |
| int i; |
| for (i = 0; i < 32; i++) |
| { |
| if (fpregmask & (1 << i)) |
| { |
| trad_frame_set_reg_addr (cache, E_FS0_REGNUM + i, |
| base + offset); |
| offset += 4; |
| } |
| } |
| } |
| } |
| |
| |
| if (movm_args & movm_other_bit) |
| { |
| /* The `other' bit leaves a blank area of four bytes at the |
| beginning of its block of saved registers, making it 32 bytes |
| long in total. */ |
| trad_frame_set_reg_addr (cache, E_LAR_REGNUM, base + offset + 4); |
| trad_frame_set_reg_addr (cache, E_LIR_REGNUM, base + offset + 8); |
| trad_frame_set_reg_addr (cache, E_MDR_REGNUM, base + offset + 12); |
| trad_frame_set_reg_addr (cache, E_A0_REGNUM + 1, base + offset + 16); |
| trad_frame_set_reg_addr (cache, E_A0_REGNUM, base + offset + 20); |
| trad_frame_set_reg_addr (cache, E_D0_REGNUM + 1, base + offset + 24); |
| trad_frame_set_reg_addr (cache, E_D0_REGNUM, base + offset + 28); |
| offset += 32; |
| } |
| |
| if (movm_args & movm_a3_bit) |
| { |
| trad_frame_set_reg_addr (cache, E_A3_REGNUM, base + offset); |
| offset += 4; |
| } |
| if (movm_args & movm_a2_bit) |
| { |
| trad_frame_set_reg_addr (cache, E_A2_REGNUM, base + offset); |
| offset += 4; |
| } |
| if (movm_args & movm_d3_bit) |
| { |
| trad_frame_set_reg_addr (cache, E_D3_REGNUM, base + offset); |
| offset += 4; |
| } |
| if (movm_args & movm_d2_bit) |
| { |
| trad_frame_set_reg_addr (cache, E_D2_REGNUM, base + offset); |
| offset += 4; |
| } |
| if (AM33_MODE (gdbarch)) |
| { |
| if (movm_args & movm_exother_bit) |
| { |
| trad_frame_set_reg_addr (cache, E_MCVF_REGNUM, base + offset); |
| trad_frame_set_reg_addr (cache, E_MCRL_REGNUM, base + offset + 4); |
| trad_frame_set_reg_addr (cache, E_MCRH_REGNUM, base + offset + 8); |
| trad_frame_set_reg_addr (cache, E_MDRQ_REGNUM, base + offset + 12); |
| trad_frame_set_reg_addr (cache, E_E1_REGNUM, base + offset + 16); |
| trad_frame_set_reg_addr (cache, E_E0_REGNUM, base + offset + 20); |
| offset += 24; |
| } |
| if (movm_args & movm_exreg1_bit) |
| { |
| trad_frame_set_reg_addr (cache, E_E7_REGNUM, base + offset); |
| trad_frame_set_reg_addr (cache, E_E6_REGNUM, base + offset + 4); |
| trad_frame_set_reg_addr (cache, E_E5_REGNUM, base + offset + 8); |
| trad_frame_set_reg_addr (cache, E_E4_REGNUM, base + offset + 12); |
| offset += 16; |
| } |
| if (movm_args & movm_exreg0_bit) |
| { |
| trad_frame_set_reg_addr (cache, E_E3_REGNUM, base + offset); |
| trad_frame_set_reg_addr (cache, E_E2_REGNUM, base + offset + 4); |
| offset += 8; |
| } |
| } |
| /* The last (or first) thing on the stack will be the PC. */ |
| trad_frame_set_reg_addr (cache, E_PC_REGNUM, base + offset); |
| /* Save the SP in the 'traditional' way. |
| This will be the same location where the PC is saved. */ |
| trad_frame_set_reg_value (cache, E_SP_REGNUM, base + offset); |
| } |
| |
| /* The main purpose of this file is dealing with prologues to extract |
| information about stack frames and saved registers. |
| |
| In gcc/config/mn13000/mn10300.c, the expand_prologue prologue |
| function is pretty readable, and has a nice explanation of how the |
| prologue is generated. The prologues generated by that code will |
| have the following form (NOTE: the current code doesn't handle all |
| this!): |
| |
| + If this is an old-style varargs function, then its arguments |
| need to be flushed back to the stack: |
| |
| mov d0,(4,sp) |
| mov d1,(4,sp) |
| |
| + If we use any of the callee-saved registers, save them now. |
| |
| movm [some callee-saved registers],(sp) |
| |
| + If we have any floating-point registers to save: |
| |
| - Decrement the stack pointer to reserve space for the registers. |
| If the function doesn't need a frame pointer, we may combine |
| this with the adjustment that reserves space for the frame. |
| |
| add -SIZE, sp |
| |
| - Save the floating-point registers. We have two possible |
| strategies: |
| |
| . Save them at fixed offset from the SP: |
| |
| fmov fsN,(OFFSETN,sp) |
| fmov fsM,(OFFSETM,sp) |
| ... |
| |
| Note that, if OFFSETN happens to be zero, you'll get the |
| different opcode: fmov fsN,(sp) |
| |
| . Or, set a0 to the start of the save area, and then use |
| post-increment addressing to save the FP registers. |
| |
| mov sp, a0 |
| add SIZE, a0 |
| fmov fsN,(a0+) |
| fmov fsM,(a0+) |
| ... |
| |
| + If the function needs a frame pointer, we set it here. |
| |
| mov sp, a3 |
| |
| + Now we reserve space for the stack frame proper. This could be |
| merged into the `add -SIZE, sp' instruction for FP saves up |
| above, unless we needed to set the frame pointer in the previous |
| step, or the frame is so large that allocating the whole thing at |
| once would put the FP register save slots out of reach of the |
| addressing mode (128 bytes). |
| |
| add -SIZE, sp |
| |
| One day we might keep the stack pointer constant, that won't |
| change the code for prologues, but it will make the frame |
| pointerless case much more common. */ |
| |
| /* 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 mn10300_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 ($a3). |
| |
| 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. */ |
| |
| static CORE_ADDR |
| mn10300_analyze_prologue (struct gdbarch *gdbarch, struct frame_info *fi, |
| void **this_cache, |
| CORE_ADDR pc) |
| { |
| CORE_ADDR func_addr, func_end, addr, stop; |
| long stack_extra_size = 0; |
| int imm_size; |
| unsigned char buf[4]; |
| int status; |
| int movm_args = 0; |
| int fpregmask = 0; |
| char *name; |
| int frame_in_fp = 0; |
| |
| /* Use the PC in the frame if it's provided to look up the |
| start of this function. |
| |
| Note: kevinb/2003-07-16: We used to do the following here: |
| pc = (fi ? get_frame_pc (fi) : pc); |
| But this is (now) badly broken when called from analyze_dummy_frame(). |
| */ |
| if (fi) |
| { |
| pc = (pc ? pc : get_frame_pc (fi)); |
| } |
| |
| /* 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 |
| |
| MVS: comment went on to say "or if we're stopped at the first |
| instruction in the prologue" -- but code doesn't reflect that, |
| and I don't want to do that anyway. */ |
| if (status == 0) |
| { |
| addr = pc; |
| goto finish_prologue; |
| } |
| |
| /* If we're in start, then give up. */ |
| if (strcmp (name, "start") == 0) |
| { |
| addr = pc; |
| goto finish_prologue; |
| } |
| |
| /* Figure out where to stop scanning. */ |
| stop = 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; |
| |
| /* Suck in two bytes. */ |
| if (addr + 2 > stop || !safe_frame_unwind_memory (fi, addr, buf, 2)) |
| goto finish_prologue; |
| |
| /* First see if this insn sets the stack pointer from a register; if |
| so, it's probably the initialization of the stack pointer in _start, |
| so mark this as the bottom-most frame. */ |
| if (buf[0] == 0xf2 && (buf[1] & 0xf3) == 0xf0) |
| { |
| goto finish_prologue; |
| } |
| |
| /* Now look for movm [regs],sp, which saves the callee saved registers. |
| |
| At this time we don't know if fi->frame is valid, so we only note |
| that we encountered a movm instruction. Later, we'll set the entries |
| in fsr.regs as needed. */ |
| if (buf[0] == 0xcf) |
| { |
| /* Extract the register list for the movm instruction. */ |
| movm_args = buf[1]; |
| |
| addr += 2; |
| |
| /* Quit now if we're beyond the stop point. */ |
| if (addr >= stop) |
| goto finish_prologue; |
| |
| /* Get the next two bytes so the prologue scan can continue. */ |
| if (!safe_frame_unwind_memory (fi, addr, buf, 2)) |
| goto finish_prologue; |
| } |
| |
| /* Check for "mov pc, a2", an instruction found in optimized, position |
| independent code. Skip it if found. */ |
| if (buf[0] == 0xf0 && buf[1] == 0x2e) |
| { |
| addr += 2; |
| |
| /* Quit now if we're beyond the stop point. */ |
| if (addr >= stop) |
| goto finish_prologue; |
| |
| /* Get the next two bytes so the prologue scan can continue. */ |
| status = read_memory_nobpt (addr, buf, 2); |
| if (status != 0) |
| goto finish_prologue; |
| } |
| |
| if (AM33_MODE (gdbarch) == 2) |
| { |
| /* Determine if any floating point registers are to be saved. |
| Look for one of the following three prologue formats: |
| |
| [movm [regs],(sp)] [movm [regs],(sp)] [movm [regs],(sp)] |
| |
| add -SIZE,sp add -SIZE,sp add -SIZE,sp |
| fmov fs#,(sp) mov sp,a0/a1 mov sp,a0/a1 |
| fmov fs#,(#,sp) fmov fs#,(a0/a1+) add SIZE2,a0/a1 |
| ... ... fmov fs#,(a0/a1+) |
| ... ... ... |
| fmov fs#,(#,sp) fmov fs#,(a0/a1+) fmov fs#,(a0/a1+) |
| |
| [mov sp,a3] [mov sp,a3] |
| [add -SIZE2,sp] [add -SIZE2,sp] */ |
| |
| /* Remember the address at which we started in the event that we |
| don't ultimately find an fmov instruction. Once we're certain |
| that we matched one of the above patterns, we'll set |
| ``restore_addr'' to the appropriate value. Note: At one time |
| in the past, this code attempted to not adjust ``addr'' until |
| there was a fair degree of certainty that the pattern would be |
| matched. However, that code did not wait until an fmov instruction |
| was actually encountered. As a consequence, ``addr'' would |
| sometimes be advanced even when no fmov instructions were found. */ |
| CORE_ADDR restore_addr = addr; |
| int fmov_found = 0; |
| |
| /* First, look for add -SIZE,sp (i.e. add imm8,sp (0xf8feXX) |
| or add imm16,sp (0xfafeXXXX) |
| or add imm32,sp (0xfcfeXXXXXXXX)) */ |
| imm_size = 0; |
| if (buf[0] == 0xf8 && buf[1] == 0xfe) |
| imm_size = 1; |
| else if (buf[0] == 0xfa && buf[1] == 0xfe) |
| imm_size = 2; |
| else if (buf[0] == 0xfc && buf[1] == 0xfe) |
| imm_size = 4; |
| if (imm_size != 0) |
| { |
| /* An "add -#,sp" instruction has been found. "addr + 2 + imm_size" |
| is the address of the next instruction. Don't modify "addr" until |
| the next "floating point prologue" instruction is found. If this |
| is not a prologue that saves floating point registers we need to |
| be able to back out of this bit of code and continue with the |
| prologue analysis. */ |
| if (addr + 2 + imm_size < stop) |
| { |
| if (!safe_frame_unwind_memory (fi, addr + 2 + imm_size, buf, 3)) |
| goto finish_prologue; |
| if ((buf[0] & 0xfc) == 0x3c) |
| { |
| /* Occasionally, especially with C++ code, the "fmov" |
| instructions will be preceded by "mov sp,aN" |
| (aN => a0, a1, a2, or a3). |
| |
| This is a one byte instruction: mov sp,aN = 0011 11XX |
| where XX is the register number. |
| |
| Skip this instruction by incrementing addr. The "fmov" |
| instructions will have the form "fmov fs#,(aN+)" in this |
| case, but that will not necessitate a change in the |
| "fmov" parsing logic below. */ |
| |
| addr++; |
| |
| if ((buf[1] & 0xfc) == 0x20) |
| { |
| /* Occasionally, especially with C++ code compiled with |
| the -fomit-frame-pointer or -O3 options, the |
| "mov sp,aN" instruction will be followed by an |
| "add #,aN" instruction. This indicates the |
| "stack_size", the size of the portion of the stack |
| containing the arguments. This instruction format is: |
| add #,aN = 0010 00XX YYYY YYYY |
| where XX is the register number |
| YYYY YYYY is the constant. |
| Note the size of the stack (as a negative number) in |
| the frame info structure. */ |
| if (fi) |
| stack_extra_size += -buf[2]; |
| |
| addr += 2; |
| } |
| } |
| |
| if ((buf[0] & 0xfc) == 0x3c || |
| buf[0] == 0xf9 || buf[0] == 0xfb) |
| { |
| /* An "fmov" instruction has been found indicating that this |
| prologue saves floating point registers (or, as described |
| above, a "mov sp,aN" and possible "add #,aN" have been |
| found and we will assume an "fmov" follows). Process the |
| consecutive "fmov" instructions. */ |
| for (addr += 2 + imm_size;;addr += imm_size) |
| { |
| int regnum; |
| |
| /* Read the "fmov" instruction. */ |
| if (addr >= stop || |
| !safe_frame_unwind_memory (fi, addr, buf, 4)) |
| goto finish_prologue; |
| |
| if (buf[0] != 0xf9 && buf[0] != 0xfb) |
| break; |
| |
| /* An fmov instruction has just been seen. We can |
| now really commit to the pattern match. */ |
| |
| fmov_found = 1; |
| |
| /* Get the floating point register number from the |
| 2nd and 3rd bytes of the "fmov" instruction: |
| Machine Code: 0000 00X0 YYYY 0000 => |
| Regnum: 000X YYYY */ |
| regnum = (buf[1] & 0x02) << 3; |
| regnum |= ((buf[2] & 0xf0) >> 4) & 0x0f; |
| |
| /* Add this register number to the bit mask of floating |
| point registers that have been saved. */ |
| fpregmask |= 1 << regnum; |
| |
| /* Determine the length of this "fmov" instruction. |
| fmov fs#,(sp) => 3 byte instruction |
| fmov fs#,(#,sp) => 4 byte instruction */ |
| imm_size = (buf[0] == 0xf9) ? 3 : 4; |
| } |
| } |
| } |
| } |
| /* If no fmov instructions were found by the above sequence, reset |
| the state and pretend that the above bit of code never happened. */ |
| if (!fmov_found) |
| { |
| addr = restore_addr; |
| status = read_memory_nobpt (addr, buf, 2); |
| if (status != 0) |
| goto finish_prologue; |
| stack_extra_size = 0; |
| } |
| } |
| |
| /* Now see if we set up a frame pointer via "mov sp,a3" */ |
| if (buf[0] == 0x3f) |
| { |
| addr += 1; |
| |
| /* The frame pointer is now valid. */ |
| if (fi) |
| { |
| frame_in_fp = 1; |
| } |
| |
| /* Quit now if we're beyond the stop point. */ |
| if (addr >= stop) |
| goto finish_prologue; |
| |
| /* Get two more bytes so scanning can continue. */ |
| if (!safe_frame_unwind_memory (fi, addr, buf, 2)) |
| goto finish_prologue; |
| } |
| |
| /* Next we should allocate the local frame. No more prologue insns |
| are found after allocating the local frame. |
| |
| Search for add imm8,sp (0xf8feXX) |
| or add imm16,sp (0xfafeXXXX) |
| or add imm32,sp (0xfcfeXXXXXXXX). |
| |
| If none of the above was found, then this prologue has no |
| additional stack. */ |
| |
| imm_size = 0; |
| if (buf[0] == 0xf8 && buf[1] == 0xfe) |
| imm_size = 1; |
| else if (buf[0] == 0xfa && buf[1] == 0xfe) |
| imm_size = 2; |
| else if (buf[0] == 0xfc && buf[1] == 0xfe) |
| imm_size = 4; |
| |
| if (imm_size != 0) |
| { |
| /* Suck in imm_size more bytes, they'll hold the size of the |
| current frame. */ |
| if (!safe_frame_unwind_memory (fi, addr + 2, buf, imm_size)) |
| goto finish_prologue; |
| |
| /* Note the size of the stack. */ |
| stack_extra_size -= extract_signed_integer (buf, imm_size); |
| |
| /* We just consumed 2 + imm_size bytes. */ |
| addr += 2 + imm_size; |
| |
| /* No more prologue insns follow, so begin preparation to return. */ |
| goto finish_prologue; |
| } |
| /* Do the essentials and get out of here. */ |
| finish_prologue: |
| /* Note if/where callee saved registers were saved. */ |
| if (fi) |
| set_reg_offsets (fi, this_cache, movm_args, fpregmask, stack_extra_size, |
| frame_in_fp); |
| return addr; |
| } |
| |
| /* Function: skip_prologue |
| Return the address of the first inst past the prologue of the function. */ |
| |
| static CORE_ADDR |
| mn10300_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc) |
| { |
| return mn10300_analyze_prologue (gdbarch, NULL, NULL, pc); |
| } |
| |
| /* Simple frame_unwind_cache. |
| This finds the "extra info" for the frame. */ |
| struct trad_frame_cache * |
| mn10300_frame_unwind_cache (struct frame_info *next_frame, |
| void **this_prologue_cache) |
| { |
| struct gdbarch *gdbarch; |
| struct trad_frame_cache *cache; |
| CORE_ADDR pc, start, end; |
| void *cache_p; |
| |
| if (*this_prologue_cache) |
| return (*this_prologue_cache); |
| |
| gdbarch = get_frame_arch (next_frame); |
| cache_p = trad_frame_cache_zalloc (next_frame); |
| pc = gdbarch_unwind_pc (gdbarch, next_frame); |
| mn10300_analyze_prologue (gdbarch, next_frame, &cache_p, pc); |
| cache = cache_p; |
| |
| if (find_pc_partial_function (pc, NULL, &start, &end)) |
| trad_frame_set_id (cache, |
| frame_id_build (trad_frame_get_this_base (cache), |
| start)); |
| else |
| { |
| start = frame_func_unwind (next_frame, NORMAL_FRAME); |
| trad_frame_set_id (cache, |
| frame_id_build (trad_frame_get_this_base (cache), |
| start)); |
| } |
| |
| (*this_prologue_cache) = cache; |
| return cache; |
| } |
| |
| /* Here is a dummy implementation. */ |
| static struct frame_id |
| mn10300_unwind_dummy_id (struct gdbarch *gdbarch, |
| struct frame_info *next_frame) |
| { |
| return frame_id_build (frame_sp_unwind (next_frame), |
| frame_pc_unwind (next_frame)); |
| } |
| |
| /* Trad frame implementation. */ |
| static void |
| mn10300_frame_this_id (struct frame_info *next_frame, |
| void **this_prologue_cache, |
| struct frame_id *this_id) |
| { |
| struct trad_frame_cache *cache = |
| mn10300_frame_unwind_cache (next_frame, this_prologue_cache); |
| |
| trad_frame_get_id (cache, this_id); |
| } |
| |
| static void |
| mn10300_frame_prev_register (struct frame_info *next_frame, |
| void **this_prologue_cache, |
| int regnum, int *optimizedp, |
| enum lval_type *lvalp, CORE_ADDR *addrp, |
| int *realnump, gdb_byte *bufferp) |
| { |
| struct trad_frame_cache *cache = |
| mn10300_frame_unwind_cache (next_frame, this_prologue_cache); |
| |
| trad_frame_get_register (cache, next_frame, regnum, optimizedp, |
| lvalp, addrp, realnump, bufferp); |
| /* Or... |
| trad_frame_get_prev_register (next_frame, cache->prev_regs, regnum, |
| optimizedp, lvalp, addrp, realnump, bufferp); |
| */ |
| } |
| |
| static const struct frame_unwind mn10300_frame_unwind = { |
| NORMAL_FRAME, |
| mn10300_frame_this_id, |
| mn10300_frame_prev_register |
| }; |
| |
| static CORE_ADDR |
| mn10300_frame_base_address (struct frame_info *next_frame, |
| void **this_prologue_cache) |
| { |
| struct trad_frame_cache *cache = |
| mn10300_frame_unwind_cache (next_frame, this_prologue_cache); |
| |
| return trad_frame_get_this_base (cache); |
| } |
| |
| static const struct frame_unwind * |
| mn10300_frame_sniffer (struct frame_info *next_frame) |
| { |
| return &mn10300_frame_unwind; |
| } |
| |
| static const struct frame_base mn10300_frame_base = { |
| &mn10300_frame_unwind, |
| mn10300_frame_base_address, |
| mn10300_frame_base_address, |
| mn10300_frame_base_address |
| }; |
| |
| static CORE_ADDR |
| mn10300_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame) |
| { |
| ULONGEST pc; |
| |
| pc = frame_unwind_register_unsigned (next_frame, E_PC_REGNUM); |
| return pc; |
| } |
| |
| static CORE_ADDR |
| mn10300_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame) |
| { |
| ULONGEST sp; |
| |
| sp = frame_unwind_register_unsigned (next_frame, E_SP_REGNUM); |
| return sp; |
| } |
| |
| static void |
| mn10300_frame_unwind_init (struct gdbarch *gdbarch) |
| { |
| frame_unwind_append_sniffer (gdbarch, dwarf2_frame_sniffer); |
| frame_unwind_append_sniffer (gdbarch, mn10300_frame_sniffer); |
| frame_base_set_default (gdbarch, &mn10300_frame_base); |
| set_gdbarch_unwind_dummy_id (gdbarch, mn10300_unwind_dummy_id); |
| set_gdbarch_unwind_pc (gdbarch, mn10300_unwind_pc); |
| set_gdbarch_unwind_sp (gdbarch, mn10300_unwind_sp); |
| } |
| |
| /* Function: push_dummy_call |
| * |
| * Set up machine state for a target call, including |
| * function arguments, stack, return address, etc. |
| * |
| */ |
| |
| static CORE_ADDR |
| mn10300_push_dummy_call (struct gdbarch *gdbarch, |
| struct value *target_func, |
| struct regcache *regcache, |
| CORE_ADDR bp_addr, |
| int nargs, struct value **args, |
| CORE_ADDR sp, |
| int struct_return, |
| CORE_ADDR struct_addr) |
| { |
| const int push_size = register_size (gdbarch, E_PC_REGNUM); |
| int regs_used; |
| int len, arg_len; |
| int stack_offset = 0; |
| int argnum; |
| char *val, valbuf[MAX_REGISTER_SIZE]; |
| |
| /* This should be a nop, but align the stack just in case something |
| went wrong. Stacks are four byte aligned on the mn10300. */ |
| sp &= ~3; |
| |
| /* Now make space on the stack for the args. |
| |
| XXX This doesn't appear to handle pass-by-invisible reference |
| arguments. */ |
| regs_used = struct_return ? 1 : 0; |
| for (len = 0, argnum = 0; argnum < nargs; argnum++) |
| { |
| arg_len = (TYPE_LENGTH (value_type (args[argnum])) + 3) & ~3; |
| while (regs_used < 2 && arg_len > 0) |
| { |
| regs_used++; |
| arg_len -= push_size; |
| } |
| len += arg_len; |
| } |
| |
| /* Allocate stack space. */ |
| sp -= len; |
| |
| if (struct_return) |
| { |
| regs_used = 1; |
| regcache_cooked_write_unsigned (regcache, E_D0_REGNUM, struct_addr); |
| } |
| else |
| regs_used = 0; |
| |
| /* Push all arguments onto the stack. */ |
| for (argnum = 0; argnum < nargs; argnum++) |
| { |
| /* FIXME what about structs? Unions? */ |
| if (TYPE_CODE (value_type (*args)) == TYPE_CODE_STRUCT |
| && TYPE_LENGTH (value_type (*args)) > 8) |
| { |
| /* Change to pointer-to-type. */ |
| arg_len = push_size; |
| store_unsigned_integer (valbuf, push_size, |
| VALUE_ADDRESS (*args)); |
| val = &valbuf[0]; |
| } |
| else |
| { |
| arg_len = TYPE_LENGTH (value_type (*args)); |
| val = (char *) value_contents (*args); |
| } |
| |
| while (regs_used < 2 && arg_len > 0) |
| { |
| regcache_cooked_write_unsigned (regcache, regs_used, |
| extract_unsigned_integer (val, push_size)); |
| val += push_size; |
| arg_len -= push_size; |
| regs_used++; |
| } |
| |
| while (arg_len > 0) |
| { |
| write_memory (sp + stack_offset, val, push_size); |
| arg_len -= push_size; |
| val += push_size; |
| stack_offset += push_size; |
| } |
| |
| args++; |
| } |
| |
| /* Make space for the flushback area. */ |
| sp -= 8; |
| |
| /* Push the return address that contains the magic breakpoint. */ |
| sp -= 4; |
| write_memory_unsigned_integer (sp, push_size, bp_addr); |
| |
| /* The CPU also writes the return address always into the |
| MDR register on "call". */ |
| regcache_cooked_write_unsigned (regcache, E_MDR_REGNUM, bp_addr); |
| |
| /* Update $sp. */ |
| regcache_cooked_write_unsigned (regcache, E_SP_REGNUM, sp); |
| |
| /* On the mn10300, it's possible to move some of the stack adjustment |
| and saving of the caller-save registers out of the prologue and |
| into the call sites. (When using gcc, this optimization can |
| occur when using the -mrelax switch.) If this occurs, the dwarf2 |
| info will reflect this fact. We can test to see if this is the |
| case by creating a new frame using the current stack pointer and |
| the address of the function that we're about to call. We then |
| unwind SP and see if it's different than the SP of our newly |
| created frame. If the SP values are the same, the caller is not |
| expected to allocate any additional stack. On the other hand, if |
| the SP values are different, the difference determines the |
| additional stack that must be allocated. |
| |
| Note that we don't update the return value though because that's |
| the value of the stack just after pushing the arguments, but prior |
| to performing the call. This value is needed in order to |
| construct the frame ID of the dummy call. */ |
| { |
| CORE_ADDR func_addr = find_function_addr (target_func, NULL); |
| CORE_ADDR unwound_sp |
| = mn10300_unwind_sp (gdbarch, create_new_frame (sp, func_addr)); |
| if (sp != unwound_sp) |
| regcache_cooked_write_unsigned (regcache, E_SP_REGNUM, |
| sp - (unwound_sp - sp)); |
| } |
| |
| return sp; |
| } |
| |
| /* If DWARF2 is a register number appearing in Dwarf2 debug info, then |
| mn10300_dwarf2_reg_to_regnum (DWARF2) is the corresponding GDB |
| register number. Why don't Dwarf2 and GDB use the same numbering? |
| Who knows? But since people have object files lying around with |
| the existing Dwarf2 numbering, and other people have written stubs |
| to work with the existing GDB, neither of them can change. So we |
| just have to cope. */ |
| static int |
| mn10300_dwarf2_reg_to_regnum (struct gdbarch *gdbarch, int dwarf2) |
| { |
| /* This table is supposed to be shaped like the gdbarch_register_name |
| initializer in gcc/config/mn10300/mn10300.h. Registers which |
| appear in GCC's numbering, but have no counterpart in GDB's |
| world, are marked with a -1. */ |
| static int dwarf2_to_gdb[] = { |
| 0, 1, 2, 3, 4, 5, 6, 7, -1, 8, |
| 15, 16, 17, 18, 19, 20, 21, 22, |
| 32, 33, 34, 35, 36, 37, 38, 39, |
| 40, 41, 42, 43, 44, 45, 46, 47, |
| 48, 49, 50, 51, 52, 53, 54, 55, |
| 56, 57, 58, 59, 60, 61, 62, 63, |
| 9 |
| }; |
| |
| if (dwarf2 < 0 |
| || dwarf2 >= ARRAY_SIZE (dwarf2_to_gdb)) |
| { |
| warning (_("Bogus register number in debug info: %d"), dwarf2); |
| return -1; |
| } |
| |
| return dwarf2_to_gdb[dwarf2]; |
| } |
| |
| static struct gdbarch * |
| mn10300_gdbarch_init (struct gdbarch_info info, |
| struct gdbarch_list *arches) |
| { |
| struct gdbarch *gdbarch; |
| struct gdbarch_tdep *tdep; |
| int num_regs; |
| |
| arches = gdbarch_list_lookup_by_info (arches, &info); |
| if (arches != NULL) |
| return arches->gdbarch; |
| |
| tdep = xmalloc (sizeof (struct gdbarch_tdep)); |
| gdbarch = gdbarch_alloc (&info, tdep); |
| |
| switch (info.bfd_arch_info->mach) |
| { |
| case 0: |
| case bfd_mach_mn10300: |
| set_gdbarch_register_name (gdbarch, mn10300_generic_register_name); |
| tdep->am33_mode = 0; |
| num_regs = 32; |
| break; |
| case bfd_mach_am33: |
| set_gdbarch_register_name (gdbarch, am33_register_name); |
| tdep->am33_mode = 1; |
| num_regs = 32; |
| break; |
| case bfd_mach_am33_2: |
| set_gdbarch_register_name (gdbarch, am33_2_register_name); |
| tdep->am33_mode = 2; |
| num_regs = 64; |
| set_gdbarch_fp0_regnum (gdbarch, 32); |
| break; |
| default: |
| internal_error (__FILE__, __LINE__, |
| _("mn10300_gdbarch_init: Unknown mn10300 variant")); |
| break; |
| } |
| |
| /* Registers. */ |
| set_gdbarch_num_regs (gdbarch, num_regs); |
| set_gdbarch_register_type (gdbarch, mn10300_register_type); |
| set_gdbarch_skip_prologue (gdbarch, mn10300_skip_prologue); |
| set_gdbarch_read_pc (gdbarch, mn10300_read_pc); |
| set_gdbarch_write_pc (gdbarch, mn10300_write_pc); |
| set_gdbarch_pc_regnum (gdbarch, E_PC_REGNUM); |
| set_gdbarch_sp_regnum (gdbarch, E_SP_REGNUM); |
| set_gdbarch_dwarf2_reg_to_regnum (gdbarch, mn10300_dwarf2_reg_to_regnum); |
| |
| /* Stack unwinding. */ |
| set_gdbarch_inner_than (gdbarch, core_addr_lessthan); |
| /* Breakpoints. */ |
| set_gdbarch_breakpoint_from_pc (gdbarch, mn10300_breakpoint_from_pc); |
| /* decr_pc_after_break? */ |
| /* Disassembly. */ |
| set_gdbarch_print_insn (gdbarch, print_insn_mn10300); |
| |
| /* Stage 2 */ |
| set_gdbarch_return_value (gdbarch, mn10300_return_value); |
| |
| /* Stage 3 -- get target calls working. */ |
| set_gdbarch_push_dummy_call (gdbarch, mn10300_push_dummy_call); |
| /* set_gdbarch_return_value (store, extract) */ |
| |
| |
| mn10300_frame_unwind_init (gdbarch); |
| |
| /* Hook in ABI-specific overrides, if they have been registered. */ |
| gdbarch_init_osabi (info, gdbarch); |
| |
| return gdbarch; |
| } |
| |
| /* Dump out the mn10300 specific architecture information. */ |
| |
| static void |
| mn10300_dump_tdep (struct gdbarch *gdbarch, struct ui_file *file) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| fprintf_unfiltered (file, "mn10300_dump_tdep: am33_mode = %d\n", |
| tdep->am33_mode); |
| } |
| |
| void |
| _initialize_mn10300_tdep (void) |
| { |
| gdbarch_register (bfd_arch_mn10300, mn10300_gdbarch_init, mn10300_dump_tdep); |
| } |
| |