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Diffstat (limited to 'gdb/fr30-tdep.c')
| -rw-r--r-- | gdb/fr30-tdep.c | 552 |
1 files changed, 552 insertions, 0 deletions
diff --git a/gdb/fr30-tdep.c b/gdb/fr30-tdep.c new file mode 100644 index 00000000000..0d442dafa4d --- /dev/null +++ b/gdb/fr30-tdep.c @@ -0,0 +1,552 @@ +/* Target-dependent code for the Fujitsu FR30. + Copyright 1999, 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 "obstack.h" +#include "target.h" +#include "value.h" +#include "bfd.h" +#include "gdb_string.h" +#include "gdbcore.h" +#include "symfile.h" + +/* Function: pop_frame + This routine gets called when either the user uses the `return' + command, or the call dummy breakpoint gets hit. */ + +void +fr30_pop_frame () +{ + struct frame_info *frame = get_current_frame(); + int regnum; + CORE_ADDR sp = read_register(SP_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)); + + for (regnum = 0; regnum < NUM_REGS; regnum++) + if (frame->fsr.regs[regnum] != 0) { + write_register (regnum, + read_memory_unsigned_integer (frame->fsr.regs[regnum], + REGISTER_RAW_SIZE(regnum))); + } + write_register (SP_REGNUM, sp + frame->framesize); + } + flush_cached_frames (); +} + +/* Function: skip_prologue + Return the address of the first code past the prologue of the function. */ + +CORE_ADDR +fr30_skip_prologue(CORE_ADDR pc) +{ + CORE_ADDR func_addr, func_end; + + /* See what the symbol table says */ + + if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) + { + struct symtab_and_line sal; + + sal = find_pc_line (func_addr, 0); + + if (sal.line != 0 && sal.end < func_end) { + return sal.end; + } + } + +/* Either we didn't find the start of this function (nothing we can do), + or there's no line info, or the line after the prologue is after + the end of the function (there probably isn't a prologue). */ + + return pc; +} + + +/* Function: push_arguments + Setup arguments and RP for a call to the target. First four args + go in FIRST_ARGREG -> LAST_ARGREG, subsequent args go on stack... + Structs are passed by reference. XXX not right now Z.R. + 64 bit quantities (doubles and long longs) may be split between + the regs and the stack. + When calling a function that returns a struct, a pointer to the struct + is passed in as a secret first argument (always in FIRST_ARGREG). + + Stack space for the args has NOT been allocated: that job is up to us. +*/ + +CORE_ADDR +fr30_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 argreg; + int argnum; + int stack_offset; + struct stack_arg { + char *val; + int len; + int offset; + }; + struct stack_arg *stack_args = + (struct stack_arg*)alloca (nargs * sizeof (struct stack_arg)); + int nstack_args = 0; + + argreg = FIRST_ARGREG; + + /* the struct_return pointer occupies the first parameter-passing reg */ + if (struct_return) + write_register (argreg++, struct_addr); + + stack_offset = 0; + + /* Process args from left to right. Store as many as allowed in + registers, save the rest to be pushed on the stack */ + for(argnum = 0; argnum < nargs; argnum++) + { + char * val; + value_ptr arg = args[argnum]; + struct type * arg_type = check_typedef (VALUE_TYPE (arg)); + struct type * target_type = TYPE_TARGET_TYPE (arg_type); + int len = TYPE_LENGTH (arg_type); + enum type_code typecode = TYPE_CODE (arg_type); + CORE_ADDR regval; + int newarg; + + val = (char *) VALUE_CONTENTS (arg); + + { + /* Copy the argument to general registers or the stack in + register-sized pieces. Large arguments are split between + registers and stack. */ + while (len > 0) + { + if (argreg <= LAST_ARGREG) + { + int partial_len = len < REGISTER_SIZE ? len : REGISTER_SIZE; + regval = extract_address (val, partial_len); + + /* It's a simple argument being passed in a general + register. */ + write_register (argreg, regval); + argreg++; + len -= partial_len; + val += partial_len; + } + else + { + /* keep for later pushing */ + stack_args[nstack_args].val = val; + stack_args[nstack_args++].len = len; + break; + } + } + } + } + /* now do the real stack pushing, process args right to left */ + while(nstack_args--) + { + sp -= stack_args[nstack_args].len; + write_memory(sp, stack_args[nstack_args].val, + stack_args[nstack_args].len); + } + + /* Return adjusted stack pointer. */ + return sp; +} + +_initialize_fr30_tdep() +{ + extern int print_insn_fr30(bfd_vma, disassemble_info *); + + tm_print_insn = print_insn_fr30; +} + +/* Function: check_prologue_cache + Check if prologue for this frame's PC has already been scanned. + If it has, copy the relevant information about that prologue and + return non-zero. Otherwise do not copy anything and return zero. + + The information saved in the cache includes: + * the frame register number; + * the size of the stack frame; + * the offsets of saved regs (relative to the old SP); and + * the offset from the stack pointer to the frame pointer + + The cache contains only one entry, since this is adequate + for the typical sequence of prologue scan requests we get. + When performing a backtrace, GDB will usually ask to scan + the same function twice in a row (once to get the frame chain, + and once to fill in the extra frame information). +*/ + +static struct frame_info prologue_cache; + +static int +check_prologue_cache (fi) + struct frame_info * fi; +{ + int i; + + if (fi->pc == prologue_cache.pc) + { + fi->framereg = prologue_cache.framereg; + fi->framesize = prologue_cache.framesize; + fi->frameoffset = prologue_cache.frameoffset; + for (i = 0; i <= NUM_REGS; i++) + fi->fsr.regs[i] = prologue_cache.fsr.regs[i]; + return 1; + } + else + return 0; +} + + +/* Function: save_prologue_cache + Copy the prologue information from fi to the prologue cache. +*/ + +static void +save_prologue_cache (fi) + struct frame_info * fi; +{ + int i; + + prologue_cache.pc = fi->pc; + prologue_cache.framereg = fi->framereg; + prologue_cache.framesize = fi->framesize; + prologue_cache.frameoffset = fi->frameoffset; + + for (i = 0; i <= NUM_REGS; i++) { + prologue_cache.fsr.regs[i] = fi->fsr.regs[i]; + } +} + + +/* Function: scan_prologue + Scan the prologue of the function that contains PC, and record what + we find in PI. PI->fsr must be zeroed by the called. Returns the + pc after the prologue. Note that the addresses saved in pi->fsr + are actually just frame relative (negative offsets from the frame + pointer). This is because we don't know the actual value of the + frame pointer yet. In some circumstances, the frame pointer can't + be determined till after we have scanned the prologue. */ + +static void +fr30_scan_prologue (fi) + struct frame_info * fi; +{ + int sp_offset, fp_offset; + CORE_ADDR prologue_start, prologue_end, current_pc; + + /* Check if this function is already in the cache of frame information. */ + if (check_prologue_cache (fi)) + return; + + /* Assume there is no frame until proven otherwise. */ + fi->framereg = SP_REGNUM; + fi->framesize = 0; + fi->frameoffset = 0; + + /* Find the function prologue. If we can't find the function in + the symbol table, peek in the stack frame to find the PC. */ + if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end)) + { + /* Assume the prologue is everything between the first instruction + in the function and the first source line. */ + struct symtab_and_line sal = find_pc_line (prologue_start, 0); + + if (sal.line == 0) /* no line info, use current PC */ + prologue_end = fi->pc; + else if (sal.end < prologue_end) /* next line begins after fn end */ + prologue_end = sal.end; /* (probably means no prologue) */ + } + else + { + /* XXX Z.R. What now??? The following is entirely bogus */ + prologue_start = (read_memory_integer (fi->frame, 4) & 0x03fffffc) - 12; + prologue_end = prologue_start + 40; + } + + /* Now search the prologue looking for instructions that set up the + frame pointer, adjust the stack pointer, and save registers. */ + + sp_offset = fp_offset = 0; + for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 2) + { + unsigned int insn; + + insn = read_memory_unsigned_integer (current_pc, 2); + + if ((insn & 0xfe00) == 0x8e00) /* stm0 or stm1 */ + { + int reg, mask = insn & 0xff; + + /* scan in one sweep - create virtual 16-bit mask from either insn's mask */ + if((insn & 0x0100) == 0) + { + mask <<= 8; /* stm0 - move to upper byte in virtual mask */ + } + + /* Calculate offsets of saved registers (to be turned later into addresses). */ + for (reg = R4_REGNUM; reg <= R11_REGNUM; reg++) + if (mask & (1 << (15 - reg))) + { + sp_offset -= 4; + fi->fsr.regs[reg] = sp_offset; + } + } + else if((insn & 0xfff0) == 0x1700) /* st rx,@-r15 */ + { + int reg = insn & 0xf; + + sp_offset -= 4; + fi->fsr.regs[reg] = sp_offset; + } + else if((insn & 0xff00) == 0x0f00) /* enter */ + { + fp_offset = fi->fsr.regs[FP_REGNUM] = sp_offset - 4; + sp_offset -= 4 * (insn & 0xff); + fi->framereg = FP_REGNUM; + } + else if(insn == 0x1781) /* st rp,@-sp */ + { + sp_offset -= 4; + fi->fsr.regs[RP_REGNUM] = sp_offset; + } + else if(insn == 0x170e) /* st fp,@-sp */ + { + sp_offset -= 4; + fi->fsr.regs[FP_REGNUM] = sp_offset; + } + else if(insn == 0x8bfe) /* mov sp,fp */ + { + fi->framereg = FP_REGNUM; + } + else if((insn & 0xff00) == 0xa300) /* addsp xx */ + { + sp_offset += 4 * (signed char)(insn & 0xff); + } + else if((insn & 0xff0f) == 0x9b00 && /* ldi:20 xx,r0 */ + read_memory_unsigned_integer(current_pc+4, 2) + == 0xac0f) /* sub r0,sp */ + { + /* large stack adjustment */ + sp_offset -= (((insn & 0xf0) << 12) | read_memory_unsigned_integer(current_pc+2, 2)); + current_pc += 4; + } + else if(insn == 0x9f80 && /* ldi:32 xx,r0 */ + read_memory_unsigned_integer(current_pc+6, 2) + == 0xac0f) /* sub r0,sp */ + { + /* large stack adjustment */ + sp_offset -= + (read_memory_unsigned_integer(current_pc+2, 2) << 16 | + read_memory_unsigned_integer(current_pc+4, 2)); + current_pc += 6; + } + } + + /* The frame size is just the negative of the offset (from the original SP) + of the last thing thing we pushed on the stack. The frame offset is + [new FP] - [new SP]. */ + fi->framesize = -sp_offset; + fi->frameoffset = fp_offset - sp_offset; + + save_prologue_cache (fi); +} + +/* 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 scan_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 (since that is derived from fr30_frame_chain ()). + + 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 +fr30_init_extra_frame_info (fi) + struct frame_info * fi; +{ + int reg; + + if (fi->next) + fi->pc = FRAME_SAVED_PC (fi->next); + + memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); + + if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) + { + /* We need to setup fi->frame here because run_stack_dummy gets it wrong + by assuming it's always FP. */ + fi->frame = generic_read_register_dummy (fi->pc, fi->frame, SP_REGNUM); + fi->framesize = 0; + fi->frameoffset = 0; + return; + } + fr30_scan_prologue (fi); + + if (!fi->next) /* this is the innermost frame? */ + fi->frame = read_register (fi->framereg); + else /* not the innermost frame */ + /* If we have an FP, the callee saved it. */ + if (fi->framereg == FP_REGNUM) + if (fi->next->fsr.regs[fi->framereg] != 0) + fi->frame = read_memory_integer (fi->next->fsr.regs[fi->framereg], + 4); + /* Calculate actual addresses of saved registers using offsets determined + by fr30_scan_prologue. */ + for (reg = 0; reg < NUM_REGS; reg++) + if (fi->fsr.regs[reg] != 0) { + fi->fsr.regs[reg] += fi->frame + fi->framesize - fi->frameoffset; + } +} + +/* Function: find_callers_reg + Find REGNUM on the stack. Otherwise, it's in an active register. + One thing we might want to do here is to check REGNUM against the + clobber mask, and somehow flag it as invalid if it isn't saved on + the stack somewhere. This would provide a graceful failure mode + when trying to get the value of caller-saves registers for an inner + frame. */ + +CORE_ADDR +fr30_find_callers_reg (fi, regnum) + struct frame_info *fi; + int regnum; +{ + for (; fi; fi = fi->next) + if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) + return generic_read_register_dummy (fi->pc, fi->frame, regnum); + else if (fi->fsr.regs[regnum] != 0) + return read_memory_unsigned_integer (fi->fsr.regs[regnum], + REGISTER_RAW_SIZE(regnum)); + + return read_register (regnum); +} + + +/* Function: frame_chain + Figure out the frame prior to FI. Unfortunately, this involves + scanning the prologue of the caller, which will also be done + shortly by fr30_init_extra_frame_info. For the dummy frame, we + just return the stack pointer that was in use at the time the + function call was made. */ + + +CORE_ADDR +fr30_frame_chain (fi) + struct frame_info * fi; +{ + CORE_ADDR fn_start, callers_pc, fp; + struct frame_info caller_fi; + int framereg; + + /* is this a dummy frame? */ + if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) + return fi->frame; /* dummy frame same as caller's frame */ + + /* is caller-of-this a dummy frame? */ + callers_pc = FRAME_SAVED_PC(fi); /* find out who called us: */ + fp = fr30_find_callers_reg (fi, FP_REGNUM); + if (PC_IN_CALL_DUMMY (callers_pc, fp, fp)) + return fp; /* dummy frame's frame may bear no relation to ours */ + + if (find_pc_partial_function (fi->pc, 0, &fn_start, 0)) + if (fn_start == entry_point_address ()) + return 0; /* in _start fn, don't chain further */ + + framereg = fi->framereg; + + /* If the caller is the startup code, we're at the end of the chain. */ + if (find_pc_partial_function (callers_pc, 0, &fn_start, 0)) + if (fn_start == entry_point_address ()) + return 0; + + memset (& caller_fi, 0, sizeof (caller_fi)); + caller_fi.pc = callers_pc; + fr30_scan_prologue (& caller_fi); + framereg = caller_fi.framereg; + + /* If the caller used a frame register, return its value. + Otherwise, return the caller's stack pointer. */ + if (framereg == FP_REGNUM) + return fr30_find_callers_reg (fi, framereg); + else + return fi->frame + fi->framesize; +} + +/* 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 +fr30_frame_saved_pc (fi) + struct frame_info *fi; +{ + if (PC_IN_CALL_DUMMY(fi->pc, fi->frame, fi->frame)) + return generic_read_register_dummy(fi->pc, fi->frame, PC_REGNUM); + else + return fr30_find_callers_reg (fi, RP_REGNUM); +} + +/* Function: fix_call_dummy + Pokes the callee function's address into the CALL_DUMMY assembly stub. + Assumes that the CALL_DUMMY looks like this: + jarl <offset24>, r31 + trap + */ + +int +fr30_fix_call_dummy (dummy, sp, fun, nargs, args, type, gcc_p) + char *dummy; + CORE_ADDR sp; + CORE_ADDR fun; + int nargs; + value_ptr *args; + struct type *type; + int gcc_p; +{ + long offset24; + + offset24 = (long) fun - (long) entry_point_address (); + offset24 &= 0x3fffff; + offset24 |= 0xff800000; /* jarl <offset24>, r31 */ + + store_unsigned_integer ((unsigned int *)&dummy[2], 2, offset24 & 0xffff); + store_unsigned_integer ((unsigned int *)&dummy[0], 2, offset24 >> 16); + return 0; +} |