/* Target-dependent code for the Renesas RX for GDB, the GNU debugger. Copyright (C) 2008-2017 Free Software Foundation, Inc. Contributed by Red Hat, 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 . */ #include "defs.h" #include "arch-utils.h" #include "prologue-value.h" #include "target.h" #include "regcache.h" #include "opcode/rx.h" #include "dis-asm.h" #include "gdbtypes.h" #include "frame.h" #include "frame-unwind.h" #include "frame-base.h" #include "value.h" #include "gdbcore.h" #include "dwarf2-frame.h" #include "elf/rx.h" #include "elf-bfd.h" /* Certain important register numbers. */ enum { RX_SP_REGNUM = 0, RX_R1_REGNUM = 1, RX_R4_REGNUM = 4, RX_FP_REGNUM = 6, RX_R15_REGNUM = 15, RX_USP_REGNUM = 16, RX_PSW_REGNUM = 18, RX_PC_REGNUM = 19, RX_BPSW_REGNUM = 21, RX_BPC_REGNUM = 22, RX_FPSW_REGNUM = 24, RX_ACC_REGNUM = 25, RX_NUM_REGS = 26 }; /* RX frame types. */ enum rx_frame_type { RX_FRAME_TYPE_NORMAL, RX_FRAME_TYPE_EXCEPTION, RX_FRAME_TYPE_FAST_INTERRUPT }; /* Architecture specific data. */ struct gdbarch_tdep { /* The ELF header flags specify the multilib used. */ int elf_flags; /* Type of PSW and BPSW. */ struct type *rx_psw_type; /* Type of FPSW. */ struct type *rx_fpsw_type; }; /* This structure holds the results of a prologue analysis. */ struct rx_prologue { /* Frame type, either a normal frame or one of two types of exception frames. */ enum rx_frame_type frame_type; /* The offset from the frame base to the stack pointer --- always zero or negative. Calling this a "size" is a bit misleading, but given that the stack grows downwards, using offsets for everything keeps one from going completely sign-crazy: you never change anything's sign for an ADD instruction; always change the second operand's sign for a SUB instruction; and everything takes care of itself. */ int frame_size; /* Non-zero if this function has initialized the frame pointer from the stack pointer, zero otherwise. */ int has_frame_ptr; /* If has_frame_ptr is non-zero, this is the offset from the frame base to where the frame pointer points. This is always zero or negative. */ int frame_ptr_offset; /* The address of the first instruction at which the frame has been set up and the arguments are where the debug info says they are --- as best as we can tell. */ CORE_ADDR prologue_end; /* reg_offset[R] is the offset from the CFA at which register R is saved, or 1 if register R has not been saved. (Real values are always zero or negative.) */ int reg_offset[RX_NUM_REGS]; }; /* Implement the "register_name" gdbarch method. */ static const char * rx_register_name (struct gdbarch *gdbarch, int regnr) { static const char *const reg_names[] = { "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", "usp", "isp", "psw", "pc", "intb", "bpsw", "bpc", "fintv", "fpsw", "acc" }; return reg_names[regnr]; } /* Construct the flags type for PSW and BPSW. */ static struct type * rx_psw_type (struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->rx_psw_type == NULL) { tdep->rx_psw_type = arch_flags_type (gdbarch, "rx_psw_type", 4); append_flags_type_flag (tdep->rx_psw_type, 0, "C"); append_flags_type_flag (tdep->rx_psw_type, 1, "Z"); append_flags_type_flag (tdep->rx_psw_type, 2, "S"); append_flags_type_flag (tdep->rx_psw_type, 3, "O"); append_flags_type_flag (tdep->rx_psw_type, 16, "I"); append_flags_type_flag (tdep->rx_psw_type, 17, "U"); append_flags_type_flag (tdep->rx_psw_type, 20, "PM"); append_flags_type_flag (tdep->rx_psw_type, 24, "IPL0"); append_flags_type_flag (tdep->rx_psw_type, 25, "IPL1"); append_flags_type_flag (tdep->rx_psw_type, 26, "IPL2"); append_flags_type_flag (tdep->rx_psw_type, 27, "IPL3"); } return tdep->rx_psw_type; } /* Construct flags type for FPSW. */ static struct type * rx_fpsw_type (struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->rx_psw_type == NULL) { tdep->rx_fpsw_type = arch_flags_type (gdbarch, "rx_fpsw_type", 4); append_flags_type_flag (tdep->rx_fpsw_type, 0, "RM0"); append_flags_type_flag (tdep->rx_fpsw_type, 1, "RM1"); append_flags_type_flag (tdep->rx_fpsw_type, 2, "CV"); append_flags_type_flag (tdep->rx_fpsw_type, 3, "CO"); append_flags_type_flag (tdep->rx_fpsw_type, 4, "CZ"); append_flags_type_flag (tdep->rx_fpsw_type, 5, "CU"); append_flags_type_flag (tdep->rx_fpsw_type, 6, "CX"); append_flags_type_flag (tdep->rx_fpsw_type, 7, "CE"); append_flags_type_flag (tdep->rx_fpsw_type, 8, "DN"); append_flags_type_flag (tdep->rx_fpsw_type, 10, "EV"); append_flags_type_flag (tdep->rx_fpsw_type, 11, "EO"); append_flags_type_flag (tdep->rx_fpsw_type, 12, "EZ"); append_flags_type_flag (tdep->rx_fpsw_type, 13, "EU"); append_flags_type_flag (tdep->rx_fpsw_type, 14, "EX"); append_flags_type_flag (tdep->rx_fpsw_type, 26, "FV"); append_flags_type_flag (tdep->rx_fpsw_type, 27, "FO"); append_flags_type_flag (tdep->rx_fpsw_type, 28, "FZ"); append_flags_type_flag (tdep->rx_fpsw_type, 29, "FU"); append_flags_type_flag (tdep->rx_fpsw_type, 30, "FX"); append_flags_type_flag (tdep->rx_fpsw_type, 31, "FS"); } return tdep->rx_fpsw_type; } /* Implement the "register_type" gdbarch method. */ static struct type * rx_register_type (struct gdbarch *gdbarch, int reg_nr) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (reg_nr == RX_PC_REGNUM) return builtin_type (gdbarch)->builtin_func_ptr; else if (reg_nr == RX_PSW_REGNUM || reg_nr == RX_BPSW_REGNUM) return rx_psw_type (gdbarch); else if (reg_nr == RX_FPSW_REGNUM) return rx_fpsw_type (gdbarch); else if (reg_nr == RX_ACC_REGNUM) return builtin_type (gdbarch)->builtin_unsigned_long_long; else return builtin_type (gdbarch)->builtin_unsigned_long; } /* Function for finding saved registers in a 'struct pv_area'; this function is passed to pv_area_scan. If VALUE is a saved register, ADDR says it was saved at a constant offset from the frame base, and SIZE indicates that the whole register was saved, record its offset. */ static void check_for_saved (void *result_untyped, pv_t addr, CORE_ADDR size, pv_t value) { struct rx_prologue *result = (struct rx_prologue *) result_untyped; if (value.kind == pvk_register && value.k == 0 && pv_is_register (addr, RX_SP_REGNUM) && size == register_size (target_gdbarch (), value.reg)) result->reg_offset[value.reg] = addr.k; } /* Define a "handle" struct for fetching the next opcode. */ struct rx_get_opcode_byte_handle { CORE_ADDR pc; }; /* Fetch a byte on behalf of the opcode decoder. HANDLE contains the memory address of the next byte to fetch. If successful, the address in the handle is updated and the byte fetched is returned as the value of the function. If not successful, -1 is returned. */ static int rx_get_opcode_byte (void *handle) { struct rx_get_opcode_byte_handle *opcdata = (struct rx_get_opcode_byte_handle *) handle; int status; gdb_byte byte; status = target_read_code (opcdata->pc, &byte, 1); if (status == 0) { opcdata->pc += 1; return byte; } else return -1; } /* Analyze a prologue starting at START_PC, going no further than LIMIT_PC. Fill in RESULT as appropriate. */ static void rx_analyze_prologue (CORE_ADDR start_pc, CORE_ADDR limit_pc, enum rx_frame_type frame_type, struct rx_prologue *result) { CORE_ADDR pc, next_pc; int rn; pv_t reg[RX_NUM_REGS]; struct pv_area *stack; struct cleanup *back_to; CORE_ADDR after_last_frame_setup_insn = start_pc; memset (result, 0, sizeof (*result)); result->frame_type = frame_type; for (rn = 0; rn < RX_NUM_REGS; rn++) { reg[rn] = pv_register (rn, 0); result->reg_offset[rn] = 1; } stack = make_pv_area (RX_SP_REGNUM, gdbarch_addr_bit (target_gdbarch ())); back_to = make_cleanup_free_pv_area (stack); if (frame_type == RX_FRAME_TYPE_FAST_INTERRUPT) { /* This code won't do anything useful at present, but this is what happens for fast interrupts. */ reg[RX_BPSW_REGNUM] = reg[RX_PSW_REGNUM]; reg[RX_BPC_REGNUM] = reg[RX_PC_REGNUM]; } else { /* When an exception occurs, the PSW is saved to the interrupt stack first. */ if (frame_type == RX_FRAME_TYPE_EXCEPTION) { reg[RX_SP_REGNUM] = pv_add_constant (reg[RX_SP_REGNUM], -4); pv_area_store (stack, reg[RX_SP_REGNUM], 4, reg[RX_PSW_REGNUM]); } /* The call instruction (or an exception/interrupt) has saved the return address on the stack. */ reg[RX_SP_REGNUM] = pv_add_constant (reg[RX_SP_REGNUM], -4); pv_area_store (stack, reg[RX_SP_REGNUM], 4, reg[RX_PC_REGNUM]); } pc = start_pc; while (pc < limit_pc) { int bytes_read; struct rx_get_opcode_byte_handle opcode_handle; RX_Opcode_Decoded opc; opcode_handle.pc = pc; bytes_read = rx_decode_opcode (pc, &opc, rx_get_opcode_byte, &opcode_handle); next_pc = pc + bytes_read; if (opc.id == RXO_pushm /* pushm r1, r2 */ && opc.op[1].type == RX_Operand_Register && opc.op[2].type == RX_Operand_Register) { int r1, r2; int r; r1 = opc.op[1].reg; r2 = opc.op[2].reg; for (r = r2; r >= r1; r--) { reg[RX_SP_REGNUM] = pv_add_constant (reg[RX_SP_REGNUM], -4); pv_area_store (stack, reg[RX_SP_REGNUM], 4, reg[r]); } after_last_frame_setup_insn = next_pc; } else if (opc.id == RXO_mov /* mov.l rdst, rsrc */ && opc.op[0].type == RX_Operand_Register && opc.op[1].type == RX_Operand_Register && opc.size == RX_Long) { int rdst, rsrc; rdst = opc.op[0].reg; rsrc = opc.op[1].reg; reg[rdst] = reg[rsrc]; if (rdst == RX_FP_REGNUM && rsrc == RX_SP_REGNUM) after_last_frame_setup_insn = next_pc; } else if (opc.id == RXO_mov /* mov.l rsrc, [-SP] */ && opc.op[0].type == RX_Operand_Predec && opc.op[0].reg == RX_SP_REGNUM && opc.op[1].type == RX_Operand_Register && opc.size == RX_Long) { int rsrc; rsrc = opc.op[1].reg; reg[RX_SP_REGNUM] = pv_add_constant (reg[RX_SP_REGNUM], -4); pv_area_store (stack, reg[RX_SP_REGNUM], 4, reg[rsrc]); after_last_frame_setup_insn = next_pc; } else if (opc.id == RXO_add /* add #const, rsrc, rdst */ && opc.op[0].type == RX_Operand_Register && opc.op[1].type == RX_Operand_Immediate && opc.op[2].type == RX_Operand_Register) { int rdst = opc.op[0].reg; int addend = opc.op[1].addend; int rsrc = opc.op[2].reg; reg[rdst] = pv_add_constant (reg[rsrc], addend); /* Negative adjustments to the stack pointer or frame pointer are (most likely) part of the prologue. */ if ((rdst == RX_SP_REGNUM || rdst == RX_FP_REGNUM) && addend < 0) after_last_frame_setup_insn = next_pc; } else if (opc.id == RXO_mov && opc.op[0].type == RX_Operand_Indirect && opc.op[1].type == RX_Operand_Register && opc.size == RX_Long && (opc.op[0].reg == RX_SP_REGNUM || opc.op[0].reg == RX_FP_REGNUM) && (RX_R1_REGNUM <= opc.op[1].reg && opc.op[1].reg <= RX_R4_REGNUM)) { /* This moves an argument register to the stack. Don't record it, but allow it to be a part of the prologue. */ } else if (opc.id == RXO_branch && opc.op[0].type == RX_Operand_Immediate && next_pc < opc.op[0].addend) { /* When a loop appears as the first statement of a function body, gcc 4.x will use a BRA instruction to branch to the loop condition checking code. This BRA instruction is marked as part of the prologue. We therefore set next_pc to this branch target and also stop the prologue scan. The instructions at and beyond the branch target should no longer be associated with the prologue. Note that we only consider forward branches here. We presume that a forward branch is being used to skip over a loop body. A backwards branch is covered by the default case below. If we were to encounter a backwards branch, that would most likely mean that we've scanned through a loop body. We definitely want to stop the prologue scan when this happens and that is precisely what is done by the default case below. */ after_last_frame_setup_insn = opc.op[0].addend; break; /* Scan no further if we hit this case. */ } else { /* Terminate the prologue scan. */ break; } pc = next_pc; } /* Is the frame size (offset, really) a known constant? */ if (pv_is_register (reg[RX_SP_REGNUM], RX_SP_REGNUM)) result->frame_size = reg[RX_SP_REGNUM].k; /* Was the frame pointer initialized? */ if (pv_is_register (reg[RX_FP_REGNUM], RX_SP_REGNUM)) { result->has_frame_ptr = 1; result->frame_ptr_offset = reg[RX_FP_REGNUM].k; } /* Record where all the registers were saved. */ pv_area_scan (stack, check_for_saved, (void *) result); result->prologue_end = after_last_frame_setup_insn; do_cleanups (back_to); } /* Implement the "skip_prologue" gdbarch method. */ static CORE_ADDR rx_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc) { const char *name; CORE_ADDR func_addr, func_end; struct rx_prologue p; /* Try to find the extent of the function that contains PC. */ if (!find_pc_partial_function (pc, &name, &func_addr, &func_end)) return pc; /* The frame type doesn't matter here, since we only care about where the prologue ends. We'll use RX_FRAME_TYPE_NORMAL. */ rx_analyze_prologue (pc, func_end, RX_FRAME_TYPE_NORMAL, &p); return p.prologue_end; } /* Given a frame described by THIS_FRAME, decode the prologue of its associated function if there is not cache entry as specified by THIS_PROLOGUE_CACHE. Save the decoded prologue in the cache and return that struct as the value of this function. */ static struct rx_prologue * rx_analyze_frame_prologue (struct frame_info *this_frame, enum rx_frame_type frame_type, void **this_prologue_cache) { if (!*this_prologue_cache) { CORE_ADDR func_start, stop_addr; *this_prologue_cache = FRAME_OBSTACK_ZALLOC (struct rx_prologue); func_start = get_frame_func (this_frame); stop_addr = get_frame_pc (this_frame); /* If we couldn't find any function containing the PC, then just initialize the prologue cache, but don't do anything. */ if (!func_start) stop_addr = func_start; rx_analyze_prologue (func_start, stop_addr, frame_type, (struct rx_prologue *) *this_prologue_cache); } return (struct rx_prologue *) *this_prologue_cache; } /* Determine type of frame by scanning the function for a return instruction. */ static enum rx_frame_type rx_frame_type (struct frame_info *this_frame, void **this_cache) { const char *name; CORE_ADDR pc, start_pc, lim_pc; int bytes_read; struct rx_get_opcode_byte_handle opcode_handle; RX_Opcode_Decoded opc; gdb_assert (this_cache != NULL); /* If we have a cached value, return it. */ if (*this_cache != NULL) { struct rx_prologue *p = (struct rx_prologue *) *this_cache; return p->frame_type; } /* No cached value; scan the function. The frame type is cached in rx_analyze_prologue / rx_analyze_frame_prologue. */ pc = get_frame_pc (this_frame); /* Attempt to find the last address in the function. If it cannot be determined, set the limit to be a short ways past the frame's pc. */ if (!find_pc_partial_function (pc, &name, &start_pc, &lim_pc)) lim_pc = pc + 20; while (pc < lim_pc) { opcode_handle.pc = pc; bytes_read = rx_decode_opcode (pc, &opc, rx_get_opcode_byte, &opcode_handle); if (bytes_read <= 0 || opc.id == RXO_rts) return RX_FRAME_TYPE_NORMAL; else if (opc.id == RXO_rtfi) return RX_FRAME_TYPE_FAST_INTERRUPT; else if (opc.id == RXO_rte) return RX_FRAME_TYPE_EXCEPTION; pc += bytes_read; } return RX_FRAME_TYPE_NORMAL; } /* Given the next frame and a prologue cache, return this frame's base. */ static CORE_ADDR rx_frame_base (struct frame_info *this_frame, void **this_cache) { enum rx_frame_type frame_type = rx_frame_type (this_frame, this_cache); struct rx_prologue *p = rx_analyze_frame_prologue (this_frame, frame_type, this_cache); /* In functions that use alloca, the distance between the stack pointer and the frame base varies dynamically, so we can't use the SP plus static information like prologue analysis to find the frame base. However, such functions must have a frame pointer, to be able to restore the SP on exit. So whenever we do have a frame pointer, use that to find the base. */ if (p->has_frame_ptr) { CORE_ADDR fp = get_frame_register_unsigned (this_frame, RX_FP_REGNUM); return fp - p->frame_ptr_offset; } else { CORE_ADDR sp = get_frame_register_unsigned (this_frame, RX_SP_REGNUM); return sp - p->frame_size; } } /* Implement the "frame_this_id" method for unwinding frames. */ static void rx_frame_this_id (struct frame_info *this_frame, void **this_cache, struct frame_id *this_id) { *this_id = frame_id_build (rx_frame_base (this_frame, this_cache), get_frame_func (this_frame)); } /* Implement the "frame_prev_register" method for unwinding frames. */ static struct value * rx_frame_prev_register (struct frame_info *this_frame, void **this_cache, int regnum) { enum rx_frame_type frame_type = rx_frame_type (this_frame, this_cache); struct rx_prologue *p = rx_analyze_frame_prologue (this_frame, frame_type, this_cache); CORE_ADDR frame_base = rx_frame_base (this_frame, this_cache); if (regnum == RX_SP_REGNUM) { if (frame_type == RX_FRAME_TYPE_EXCEPTION) { struct value *psw_val; CORE_ADDR psw; psw_val = rx_frame_prev_register (this_frame, this_cache, RX_PSW_REGNUM); psw = extract_unsigned_integer (value_contents_all (psw_val), 4, gdbarch_byte_order ( get_frame_arch (this_frame))); if ((psw & 0x20000 /* U bit */) != 0) return rx_frame_prev_register (this_frame, this_cache, RX_USP_REGNUM); /* Fall through for the case where U bit is zero. */ } return frame_unwind_got_constant (this_frame, regnum, frame_base); } if (frame_type == RX_FRAME_TYPE_FAST_INTERRUPT) { if (regnum == RX_PC_REGNUM) return rx_frame_prev_register (this_frame, this_cache, RX_BPC_REGNUM); if (regnum == RX_PSW_REGNUM) return rx_frame_prev_register (this_frame, this_cache, RX_BPSW_REGNUM); } /* If prologue analysis says we saved this register somewhere, return a description of the stack slot holding it. */ if (p->reg_offset[regnum] != 1) return frame_unwind_got_memory (this_frame, regnum, frame_base + p->reg_offset[regnum]); /* Otherwise, presume we haven't changed the value of this register, and get it from the next frame. */ return frame_unwind_got_register (this_frame, regnum, regnum); } /* Return TRUE if the frame indicated by FRAME_TYPE is a normal frame. */ static int normal_frame_p (enum rx_frame_type frame_type) { return (frame_type == RX_FRAME_TYPE_NORMAL); } /* Return TRUE if the frame indicated by FRAME_TYPE is an exception frame. */ static int exception_frame_p (enum rx_frame_type frame_type) { return (frame_type == RX_FRAME_TYPE_EXCEPTION || frame_type == RX_FRAME_TYPE_FAST_INTERRUPT); } /* Common code used by both normal and exception frame sniffers. */ static int rx_frame_sniffer_common (const struct frame_unwind *self, struct frame_info *this_frame, void **this_cache, int (*sniff_p)(enum rx_frame_type) ) { gdb_assert (this_cache != NULL); if (*this_cache == NULL) { enum rx_frame_type frame_type = rx_frame_type (this_frame, this_cache); if (sniff_p (frame_type)) { /* The call below will fill in the cache, including the frame type. */ (void) rx_analyze_frame_prologue (this_frame, frame_type, this_cache); return 1; } else return 0; } else { struct rx_prologue *p = (struct rx_prologue *) *this_cache; return sniff_p (p->frame_type); } } /* Frame sniffer for normal (non-exception) frames. */ static int rx_frame_sniffer (const struct frame_unwind *self, struct frame_info *this_frame, void **this_cache) { return rx_frame_sniffer_common (self, this_frame, this_cache, normal_frame_p); } /* Frame sniffer for exception frames. */ static int rx_exception_sniffer (const struct frame_unwind *self, struct frame_info *this_frame, void **this_cache) { return rx_frame_sniffer_common (self, this_frame, this_cache, exception_frame_p); } /* Data structure for normal code using instruction-based prologue analyzer. */ static const struct frame_unwind rx_frame_unwind = { NORMAL_FRAME, default_frame_unwind_stop_reason, rx_frame_this_id, rx_frame_prev_register, NULL, rx_frame_sniffer }; /* Data structure for exception code using instruction-based prologue analyzer. */ static const struct frame_unwind rx_exception_unwind = { /* SIGTRAMP_FRAME could be used here, but backtraces are less informative. */ NORMAL_FRAME, default_frame_unwind_stop_reason, rx_frame_this_id, rx_frame_prev_register, NULL, rx_exception_sniffer }; /* Implement the "unwind_pc" gdbarch method. */ static CORE_ADDR rx_unwind_pc (struct gdbarch *gdbarch, struct frame_info *this_frame) { ULONGEST pc; pc = frame_unwind_register_unsigned (this_frame, RX_PC_REGNUM); return pc; } /* Implement the "unwind_sp" gdbarch method. */ static CORE_ADDR rx_unwind_sp (struct gdbarch *gdbarch, struct frame_info *this_frame) { ULONGEST sp; sp = frame_unwind_register_unsigned (this_frame, RX_SP_REGNUM); return sp; } /* Implement the "dummy_id" gdbarch method. */ static struct frame_id rx_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame) { return frame_id_build (get_frame_register_unsigned (this_frame, RX_SP_REGNUM), get_frame_pc (this_frame)); } /* Implement the "push_dummy_call" gdbarch method. */ static CORE_ADDR rx_push_dummy_call (struct gdbarch *gdbarch, struct value *function, struct regcache *regcache, CORE_ADDR bp_addr, int nargs, struct value **args, CORE_ADDR sp, int struct_return, CORE_ADDR struct_addr) { enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); int write_pass; int sp_off = 0; CORE_ADDR cfa; int num_register_candidate_args; struct type *func_type = value_type (function); /* Dereference function pointer types. */ while (TYPE_CODE (func_type) == TYPE_CODE_PTR) func_type = TYPE_TARGET_TYPE (func_type); /* The end result had better be a function or a method. */ gdb_assert (TYPE_CODE (func_type) == TYPE_CODE_FUNC || TYPE_CODE (func_type) == TYPE_CODE_METHOD); /* Functions with a variable number of arguments have all of their variable arguments and the last non-variable argument passed on the stack. Otherwise, we can pass up to four arguments on the stack. Once computed, we leave this value alone. I.e. we don't update it in case of a struct return going in a register or an argument requiring multiple registers, etc. We rely instead on the value of the ``arg_reg'' variable to get these other details correct. */ if (TYPE_VARARGS (func_type)) num_register_candidate_args = TYPE_NFIELDS (func_type) - 1; else num_register_candidate_args = 4; /* We make two passes; the first does the stack allocation, the second actually stores the arguments. */ for (write_pass = 0; write_pass <= 1; write_pass++) { int i; int arg_reg = RX_R1_REGNUM; if (write_pass) sp = align_down (sp - sp_off, 4); sp_off = 0; if (struct_return) { struct type *return_type = TYPE_TARGET_TYPE (func_type); gdb_assert (TYPE_CODE (return_type) == TYPE_CODE_STRUCT || TYPE_CODE (func_type) == TYPE_CODE_UNION); if (TYPE_LENGTH (return_type) > 16 || TYPE_LENGTH (return_type) % 4 != 0) { if (write_pass) regcache_cooked_write_unsigned (regcache, RX_R15_REGNUM, struct_addr); } } /* Push the arguments. */ for (i = 0; i < nargs; i++) { struct value *arg = args[i]; const gdb_byte *arg_bits = value_contents_all (arg); struct type *arg_type = check_typedef (value_type (arg)); ULONGEST arg_size = TYPE_LENGTH (arg_type); if (i == 0 && struct_addr != 0 && !struct_return && TYPE_CODE (arg_type) == TYPE_CODE_PTR && extract_unsigned_integer (arg_bits, 4, byte_order) == struct_addr) { /* This argument represents the address at which C++ (and possibly other languages) store their return value. Put this value in R15. */ if (write_pass) regcache_cooked_write_unsigned (regcache, RX_R15_REGNUM, struct_addr); } else if (TYPE_CODE (arg_type) != TYPE_CODE_STRUCT && TYPE_CODE (arg_type) != TYPE_CODE_UNION && arg_size <= 8) { /* Argument is a scalar. */ if (arg_size == 8) { if (i < num_register_candidate_args && arg_reg <= RX_R4_REGNUM - 1) { /* If argument registers are going to be used to pass an 8 byte scalar, the ABI specifies that two registers must be available. */ if (write_pass) { regcache_cooked_write_unsigned (regcache, arg_reg, extract_unsigned_integer (arg_bits, 4, byte_order)); regcache_cooked_write_unsigned (regcache, arg_reg + 1, extract_unsigned_integer (arg_bits + 4, 4, byte_order)); } arg_reg += 2; } else { sp_off = align_up (sp_off, 4); /* Otherwise, pass the 8 byte scalar on the stack. */ if (write_pass) write_memory (sp + sp_off, arg_bits, 8); sp_off += 8; } } else { ULONGEST u; gdb_assert (arg_size <= 4); u = extract_unsigned_integer (arg_bits, arg_size, byte_order); if (i < num_register_candidate_args && arg_reg <= RX_R4_REGNUM) { if (write_pass) regcache_cooked_write_unsigned (regcache, arg_reg, u); arg_reg += 1; } else { int p_arg_size = 4; if (TYPE_PROTOTYPED (func_type) && i < TYPE_NFIELDS (func_type)) { struct type *p_arg_type = TYPE_FIELD_TYPE (func_type, i); p_arg_size = TYPE_LENGTH (p_arg_type); } sp_off = align_up (sp_off, p_arg_size); if (write_pass) write_memory_unsigned_integer (sp + sp_off, p_arg_size, byte_order, u); sp_off += p_arg_size; } } } else { /* Argument is a struct or union. Pass as much of the struct in registers, if possible. Pass the rest on the stack. */ while (arg_size > 0) { if (i < num_register_candidate_args && arg_reg <= RX_R4_REGNUM && arg_size <= 4 * (RX_R4_REGNUM - arg_reg + 1) && arg_size % 4 == 0) { int len = min (arg_size, 4); if (write_pass) regcache_cooked_write_unsigned (regcache, arg_reg, extract_unsigned_integer (arg_bits, len, byte_order)); arg_bits += len; arg_size -= len; arg_reg++; } else { sp_off = align_up (sp_off, 4); if (write_pass) write_memory (sp + sp_off, arg_bits, arg_size); sp_off += align_up (arg_size, 4); arg_size = 0; } } } } } /* Keep track of the stack address prior to pushing the return address. This is the value that we'll return. */ cfa = sp; /* Push the return address. */ sp = sp - 4; write_memory_unsigned_integer (sp, 4, byte_order, bp_addr); /* Update the stack pointer. */ regcache_cooked_write_unsigned (regcache, RX_SP_REGNUM, sp); return cfa; } /* Implement the "return_value" gdbarch method. */ static enum return_value_convention rx_return_value (struct gdbarch *gdbarch, struct value *function, struct type *valtype, struct regcache *regcache, gdb_byte *readbuf, const gdb_byte *writebuf) { enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); ULONGEST valtype_len = TYPE_LENGTH (valtype); if (TYPE_LENGTH (valtype) > 16 || ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT || TYPE_CODE (valtype) == TYPE_CODE_UNION) && TYPE_LENGTH (valtype) % 4 != 0)) return RETURN_VALUE_STRUCT_CONVENTION; if (readbuf) { ULONGEST u; int argreg = RX_R1_REGNUM; int offset = 0; while (valtype_len > 0) { int len = min (valtype_len, 4); regcache_cooked_read_unsigned (regcache, argreg, &u); store_unsigned_integer (readbuf + offset, len, byte_order, u); valtype_len -= len; offset += len; argreg++; } } if (writebuf) { ULONGEST u; int argreg = RX_R1_REGNUM; int offset = 0; while (valtype_len > 0) { int len = min (valtype_len, 4); u = extract_unsigned_integer (writebuf + offset, len, byte_order); regcache_cooked_write_unsigned (regcache, argreg, u); valtype_len -= len; offset += len; argreg++; } } return RETURN_VALUE_REGISTER_CONVENTION; } /* Implement the "breakpoint_from_pc" gdbarch method. */ static const gdb_byte * rx_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr, int *lenptr) { static gdb_byte breakpoint[] = { 0x00 }; *lenptr = sizeof breakpoint; return breakpoint; } /* Implement the dwarf_reg_to_regnum" gdbarch method. */ static int rx_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg) { if (0 <= reg && reg <= 15) return reg; else if (reg == 16) return RX_PSW_REGNUM; else if (reg == 17) return RX_PC_REGNUM; else return -1; } /* Allocate and initialize a gdbarch object. */ static struct gdbarch * rx_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) { struct gdbarch *gdbarch; struct gdbarch_tdep *tdep; int elf_flags; /* Extract the elf_flags if available. */ if (info.abfd != NULL && bfd_get_flavour (info.abfd) == bfd_target_elf_flavour) elf_flags = elf_elfheader (info.abfd)->e_flags; else elf_flags = 0; /* Try to find the architecture in the list of already defined architectures. */ for (arches = gdbarch_list_lookup_by_info (arches, &info); arches != NULL; arches = gdbarch_list_lookup_by_info (arches->next, &info)) { if (gdbarch_tdep (arches->gdbarch)->elf_flags != elf_flags) continue; return arches->gdbarch; } /* None found, create a new architecture from the information provided. */ tdep = XNEW (struct gdbarch_tdep); gdbarch = gdbarch_alloc (&info, tdep); tdep->elf_flags = elf_flags; set_gdbarch_num_regs (gdbarch, RX_NUM_REGS); set_gdbarch_num_pseudo_regs (gdbarch, 0); set_gdbarch_register_name (gdbarch, rx_register_name); set_gdbarch_register_type (gdbarch, rx_register_type); set_gdbarch_pc_regnum (gdbarch, RX_PC_REGNUM); set_gdbarch_sp_regnum (gdbarch, RX_SP_REGNUM); set_gdbarch_inner_than (gdbarch, core_addr_lessthan); set_gdbarch_decr_pc_after_break (gdbarch, 1); set_gdbarch_breakpoint_from_pc (gdbarch, rx_breakpoint_from_pc); set_gdbarch_skip_prologue (gdbarch, rx_skip_prologue); set_gdbarch_print_insn (gdbarch, print_insn_rx); set_gdbarch_unwind_pc (gdbarch, rx_unwind_pc); set_gdbarch_unwind_sp (gdbarch, rx_unwind_sp); /* Target builtin data types. */ set_gdbarch_char_signed (gdbarch, 0); set_gdbarch_short_bit (gdbarch, 16); set_gdbarch_int_bit (gdbarch, 32); set_gdbarch_long_bit (gdbarch, 32); set_gdbarch_long_long_bit (gdbarch, 64); set_gdbarch_ptr_bit (gdbarch, 32); set_gdbarch_float_bit (gdbarch, 32); set_gdbarch_float_format (gdbarch, floatformats_ieee_single); if (elf_flags & E_FLAG_RX_64BIT_DOUBLES) { set_gdbarch_double_bit (gdbarch, 64); set_gdbarch_long_double_bit (gdbarch, 64); set_gdbarch_double_format (gdbarch, floatformats_ieee_double); set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double); } else { set_gdbarch_double_bit (gdbarch, 32); set_gdbarch_long_double_bit (gdbarch, 32); set_gdbarch_double_format (gdbarch, floatformats_ieee_single); set_gdbarch_long_double_format (gdbarch, floatformats_ieee_single); } /* DWARF register mapping. */ set_gdbarch_dwarf2_reg_to_regnum (gdbarch, rx_dwarf_reg_to_regnum); /* Frame unwinding. */ frame_unwind_append_unwinder (gdbarch, &rx_exception_unwind); dwarf2_append_unwinders (gdbarch); frame_unwind_append_unwinder (gdbarch, &rx_frame_unwind); /* Methods for saving / extracting a dummy frame's ID. The ID's stack address must match the SP value returned by PUSH_DUMMY_CALL, and saved by generic_save_dummy_frame_tos. */ set_gdbarch_dummy_id (gdbarch, rx_dummy_id); set_gdbarch_push_dummy_call (gdbarch, rx_push_dummy_call); set_gdbarch_return_value (gdbarch, rx_return_value); /* Virtual tables. */ set_gdbarch_vbit_in_delta (gdbarch, 1); return gdbarch; } /* -Wmissing-prototypes */ extern initialize_file_ftype _initialize_rx_tdep; /* Register the above initialization routine. */ void _initialize_rx_tdep (void) { register_gdbarch_init (bfd_arch_rx, rx_gdbarch_init); }