/* Target-dependent code for the MIPS architecture, for GDB, the GNU Debugger. Copyright 1988, 1989, 1990, 1991, 1992, 1993 Free Software Foundation, Inc. Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin. 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "defs.h" #include "frame.h" #include "inferior.h" #include "symtab.h" #include "value.h" #include "gdbcmd.h" #include "language.h" #include "gdbcore.h" #include "symfile.h" #include "objfiles.h" #include "opcode/mips.h" #define VM_MIN_ADDRESS (unsigned)0x400000 #if 0 static int mips_in_lenient_prologue PARAMS ((CORE_ADDR, CORE_ADDR)); #endif /* Some MIPS boards don't support floating point, so we permit the user to turn it off. */ int mips_fpu = 1; /* Heuristic_proc_start may hunt through the text section for a long time across a 2400 baud serial line. Allows the user to limit this search. */ static unsigned int heuristic_fence_post = 0; #define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) /* least address */ #define PROC_HIGH_ADDR(proc) ((proc)->pdr.iline) /* upper address bound */ #define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset) #define PROC_FRAME_REG(proc) ((proc)->pdr.framereg) #define PROC_REG_MASK(proc) ((proc)->pdr.regmask) #define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask) #define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset) #define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset) #define PROC_PC_REG(proc) ((proc)->pdr.pcreg) #define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym) #define _PROC_MAGIC_ 0x0F0F0F0F #define PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym == _PROC_MAGIC_) #define SET_PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym = _PROC_MAGIC_) struct linked_proc_info { struct mips_extra_func_info info; struct linked_proc_info *next; } *linked_proc_desc_table = NULL; #define READ_FRAME_REG(fi, regno) read_next_frame_reg((fi)->next, regno) static int read_next_frame_reg(fi, regno) FRAME fi; int regno; { /* If it is the frame for sigtramp we have a complete sigcontext immediately below the frame and we get the saved registers from there. If the stack layout for sigtramp changes we might have to change these constants and the companion fixup_sigtramp in mdebugread.c */ #ifndef SIGFRAME_BASE #define SIGFRAME_BASE 0x12c /* sizeof(sigcontext) */ #define SIGFRAME_PC_OFF (-SIGFRAME_BASE + 2 * 4) #define SIGFRAME_REGSAVE_OFF (-SIGFRAME_BASE + 3 * 4) #define SIGFRAME_REG_SIZE 4 #endif for (; fi; fi = fi->next) if (in_sigtramp(fi->pc, 0)) { int offset; if (regno == PC_REGNUM) offset = SIGFRAME_PC_OFF; else if (regno < 32) offset = (SIGFRAME_REGSAVE_OFF + regno * SIGFRAME_REG_SIZE); else return 0; return read_memory_integer(fi->frame + offset, 4); } else if (regno == SP_REGNUM) return fi->frame; else if (fi->saved_regs->regs[regno]) return read_memory_integer(fi->saved_regs->regs[regno], 4); return read_register(regno); } int mips_frame_saved_pc(frame) FRAME frame; { mips_extra_func_info_t proc_desc = frame->proc_desc; int pcreg = proc_desc ? PROC_PC_REG(proc_desc) : RA_REGNUM; if (proc_desc && PROC_DESC_IS_DUMMY(proc_desc)) return read_memory_integer(frame->frame - 4, 4); return read_next_frame_reg(frame, pcreg); } static struct mips_extra_func_info temp_proc_desc; static struct frame_saved_regs temp_saved_regs; /* This fencepost looks highly suspicious to me. Removing it also seems suspicious as it could affect remote debugging across serial lines. */ static CORE_ADDR heuristic_proc_start(pc) CORE_ADDR pc; { CORE_ADDR start_pc = pc; CORE_ADDR fence = start_pc - heuristic_fence_post; if (start_pc == 0) return 0; if (heuristic_fence_post == UINT_MAX || fence < VM_MIN_ADDRESS) fence = VM_MIN_ADDRESS; /* search back for previous return */ for (start_pc -= 4; ; start_pc -= 4) if (start_pc < fence) { /* It's not clear to me why we reach this point when stop_soon_quietly, but with this test, at least we don't print out warnings for every child forked (eg, on decstation). 22apr93 rich@cygnus.com. */ if (!stop_soon_quietly) { static int blurb_printed = 0; if (fence == VM_MIN_ADDRESS) warning("Hit beginning of text section without finding"); else warning("Hit heuristic-fence-post without finding"); warning("enclosing function for address 0x%x", pc); if (!blurb_printed) { printf_filtered ("\ This warning occurs if you are debugging a function without any symbols\n\ (for example, in a stripped executable). In that case, you may wish to\n\ increase the size of the search with the `set heuristic-fence-post' command.\n\ \n\ Otherwise, you told GDB there was a function where there isn't one, or\n\ (more likely) you have encountered a bug in GDB.\n"); blurb_printed = 1; } } return 0; } else if (ABOUT_TO_RETURN(start_pc)) break; start_pc += 8; /* skip return, and its delay slot */ #if 0 /* skip nops (usually 1) 0 - is this */ while (start_pc < pc && read_memory_integer (start_pc, 4) == 0) start_pc += 4; #endif return start_pc; } static mips_extra_func_info_t heuristic_proc_desc(start_pc, limit_pc, next_frame) CORE_ADDR start_pc, limit_pc; FRAME next_frame; { CORE_ADDR sp = next_frame ? next_frame->frame : read_register (SP_REGNUM); CORE_ADDR cur_pc; int frame_size; int has_frame_reg = 0; int reg30 = 0; /* Value of $r30. Used by gcc for frame-pointer */ unsigned long reg_mask = 0; if (start_pc == 0) return NULL; memset(&temp_proc_desc, '\0', sizeof(temp_proc_desc)); memset(&temp_saved_regs, '\0', sizeof(struct frame_saved_regs)); PROC_LOW_ADDR(&temp_proc_desc) = start_pc; if (start_pc + 200 < limit_pc) limit_pc = start_pc + 200; restart: frame_size = 0; for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += 4) { char buf[4]; unsigned long word; int status; status = read_memory_nobpt (cur_pc, buf, 4); if (status) memory_error (status, cur_pc); word = extract_unsigned_integer (buf, 4); if ((word & 0xFFFF0000) == 0x27bd0000) /* addiu $sp,$sp,-i */ frame_size += (-word) & 0xFFFF; else if ((word & 0xFFFF0000) == 0x23bd0000) /* addu $sp,$sp,-i */ frame_size += (-word) & 0xFFFF; else if ((word & 0xFFE00000) == 0xafa00000) { /* sw reg,offset($sp) */ int reg = (word & 0x001F0000) >> 16; reg_mask |= 1 << reg; temp_saved_regs.regs[reg] = sp + (word & 0xffff); } else if ((word & 0xFFFF0000) == 0x27be0000) { /* addiu $30,$sp,size */ if ((word & 0xffff) != frame_size) reg30 = sp + (word & 0xffff); else if (!has_frame_reg) { int alloca_adjust; has_frame_reg = 1; reg30 = read_next_frame_reg(next_frame, 30); alloca_adjust = reg30 - (sp + (word & 0xffff)); if (alloca_adjust > 0) { /* FP > SP + frame_size. This may be because * of an alloca or somethings similar. * Fix sp to "pre-alloca" value, and try again. */ sp += alloca_adjust; goto restart; } } } else if ((word & 0xFFE00000) == 0xafc00000) { /* sw reg,offset($30) */ int reg = (word & 0x001F0000) >> 16; reg_mask |= 1 << reg; temp_saved_regs.regs[reg] = reg30 + (word & 0xffff); } } if (has_frame_reg) { PROC_FRAME_REG(&temp_proc_desc) = 30; PROC_FRAME_OFFSET(&temp_proc_desc) = 0; } else { PROC_FRAME_REG(&temp_proc_desc) = SP_REGNUM; PROC_FRAME_OFFSET(&temp_proc_desc) = frame_size; } PROC_REG_MASK(&temp_proc_desc) = reg_mask; PROC_PC_REG(&temp_proc_desc) = RA_REGNUM; return &temp_proc_desc; } static mips_extra_func_info_t find_proc_desc(pc, next_frame) CORE_ADDR pc; FRAME next_frame; { mips_extra_func_info_t proc_desc; struct block *b = block_for_pc(pc); struct symbol *sym; CORE_ADDR startaddr; find_pc_partial_function (pc, NULL, &startaddr, NULL); if (b == NULL) sym = NULL; else { if (startaddr > BLOCK_START (b)) /* This is the "pathological" case referred to in a comment in print_frame_info. It might be better to move this check into symbol reading. */ sym = NULL; else sym = lookup_symbol (MIPS_EFI_SYMBOL_NAME, b, LABEL_NAMESPACE, 0, NULL); } if (sym) { /* IF this is the topmost frame AND * (this proc does not have debugging information OR * the PC is in the procedure prologue) * THEN create a "heuristic" proc_desc (by analyzing * the actual code) to replace the "official" proc_desc. */ proc_desc = (mips_extra_func_info_t)SYMBOL_VALUE(sym); if (next_frame == NULL) { struct symtab_and_line val; struct symbol *proc_symbol = PROC_DESC_IS_DUMMY(proc_desc) ? 0 : PROC_SYMBOL(proc_desc); if (proc_symbol) { val = find_pc_line (BLOCK_START (SYMBOL_BLOCK_VALUE(proc_symbol)), 0); val.pc = val.end ? val.end : pc; } if (!proc_symbol || pc < val.pc) { mips_extra_func_info_t found_heuristic = heuristic_proc_desc(PROC_LOW_ADDR(proc_desc), pc, next_frame); if (found_heuristic) proc_desc = found_heuristic; } } } else { /* Is linked_proc_desc_table really necessary? It only seems to be used by procedure call dummys. However, the procedures being called ought to have their own proc_descs, and even if they don't, heuristic_proc_desc knows how to create them! */ register struct linked_proc_info *link; for (link = linked_proc_desc_table; link; link = link->next) if (PROC_LOW_ADDR(&link->info) <= pc && PROC_HIGH_ADDR(&link->info) > pc) return &link->info; if (startaddr == 0) startaddr = heuristic_proc_start (pc); proc_desc = heuristic_proc_desc (startaddr, pc, next_frame); } return proc_desc; } mips_extra_func_info_t cached_proc_desc; FRAME_ADDR mips_frame_chain(frame) FRAME frame; { mips_extra_func_info_t proc_desc; CORE_ADDR saved_pc = FRAME_SAVED_PC(frame); if (saved_pc == 0 || inside_entry_file (saved_pc)) return 0; proc_desc = find_proc_desc(saved_pc, frame); if (!proc_desc) return 0; cached_proc_desc = proc_desc; /* If no frame pointer and frame size is zero, we must be at end of stack (or otherwise hosed). If we don't check frame size, we loop forever if we see a zero size frame. */ if (PROC_FRAME_REG (proc_desc) == SP_REGNUM && PROC_FRAME_OFFSET (proc_desc) == 0 /* The previous frame from a sigtramp frame might be frameless and have frame size zero. */ && !frame->signal_handler_caller) return 0; else return read_next_frame_reg(frame, PROC_FRAME_REG(proc_desc)) + PROC_FRAME_OFFSET(proc_desc); } void init_extra_frame_info(fci) struct frame_info *fci; { extern struct obstack frame_cache_obstack; /* Use proc_desc calculated in frame_chain */ mips_extra_func_info_t proc_desc = fci->next ? cached_proc_desc : find_proc_desc(fci->pc, fci->next); fci->saved_regs = (struct frame_saved_regs*) obstack_alloc (&frame_cache_obstack, sizeof(struct frame_saved_regs)); memset (fci->saved_regs, 0, sizeof (struct frame_saved_regs)); fci->proc_desc = proc_desc == &temp_proc_desc ? 0 : proc_desc; if (proc_desc) { int ireg; CORE_ADDR reg_position; /* r0 bit means kernel trap */ int kernel_trap = PROC_REG_MASK(proc_desc) & 1; /* Fixup frame-pointer - only needed for top frame */ /* This may not be quite right, if proc has a real frame register */ if (fci->pc == PROC_LOW_ADDR(proc_desc) && !PROC_DESC_IS_DUMMY(proc_desc)) fci->frame = read_register (SP_REGNUM); else fci->frame = READ_FRAME_REG(fci, PROC_FRAME_REG(proc_desc)) + PROC_FRAME_OFFSET(proc_desc); if (proc_desc == &temp_proc_desc) *fci->saved_regs = temp_saved_regs; else { /* What registers have been saved? Bitmasks. */ unsigned long gen_mask, float_mask; gen_mask = kernel_trap ? 0xFFFFFFFF : PROC_REG_MASK(proc_desc); float_mask = kernel_trap ? 0xFFFFFFFF : PROC_FREG_MASK(proc_desc); if (/* In any frame other than the innermost, we assume that all registers have been saved. This assumes that all register saves in a function happen before the first function call. */ fci->next == NULL /* In a dummy frame we know exactly where things are saved. */ && !PROC_DESC_IS_DUMMY (proc_desc) /* Not sure exactly what kernel_trap means, but if it means the kernel saves the registers without a prologue doing it, we better not examine the prologue to see whether registers have been saved yet. */ && !kernel_trap) { /* We need to figure out whether the registers that the proc_desc claims are saved have been saved yet. */ CORE_ADDR addr; int status; char buf[4]; unsigned long inst; /* Bitmasks; set if we have found a save for the register. */ unsigned long gen_save_found = 0; unsigned long float_save_found = 0; for (addr = PROC_LOW_ADDR (proc_desc); addr < fci->pc && (gen_mask != gen_save_found || float_mask != float_save_found); addr += 4) { status = read_memory_nobpt (addr, buf, 4); if (status) memory_error (status, addr); inst = extract_unsigned_integer (buf, 4); if (/* sw reg,n($sp) */ (inst & 0xffe00000) == 0xafa00000 /* sw reg,n($r30) */ || (inst & 0xffe00000) == 0xafc00000) { /* It might be possible to use the instruction to find the offset, rather than the code below which is based on things being in a certain order in the frame, but figuring out what the instruction's offset is relative to might be a little tricky. */ int reg = (inst & 0x001f0000) >> 16; gen_save_found |= (1 << reg); } else if (/* swc1 freg,n($sp) */ (inst & 0xffe00000) == 0xe7a00000 /* swc1 freg,n($r30) */ || (inst & 0xffe00000) == 0xe7c00000) { int reg = ((inst & 0x001f0000) >> 16); float_save_found |= (1 << reg); } } gen_mask = gen_save_found; float_mask = float_save_found; } /* Fill in the offsets for the registers which gen_mask says were saved. */ reg_position = fci->frame + PROC_REG_OFFSET (proc_desc); for (ireg= 31; gen_mask; --ireg, gen_mask <<= 1) if (gen_mask & 0x80000000) { fci->saved_regs->regs[ireg] = reg_position; reg_position -= 4; } /* Fill in the offsets for the registers which float_mask says were saved. */ reg_position = fci->frame + PROC_FREG_OFFSET (proc_desc); /* The freg_offset points to where the first *double* register is saved. So skip to the high-order word. */ reg_position += 4; for (ireg = 31; float_mask; --ireg, float_mask <<= 1) if (float_mask & 0x80000000) { fci->saved_regs->regs[FP0_REGNUM+ireg] = reg_position; reg_position -= 4; } } /* hack: if argument regs are saved, guess these contain args */ if ((PROC_REG_MASK(proc_desc) & 0xF0) == 0) fci->num_args = -1; else if ((PROC_REG_MASK(proc_desc) & 0x80) == 0) fci->num_args = 4; else if ((PROC_REG_MASK(proc_desc) & 0x40) == 0) fci->num_args = 3; else if ((PROC_REG_MASK(proc_desc) & 0x20) == 0) fci->num_args = 2; else if ((PROC_REG_MASK(proc_desc) & 0x10) == 0) fci->num_args = 1; fci->saved_regs->regs[PC_REGNUM] = fci->saved_regs->regs[RA_REGNUM]; } } /* MIPS stack frames are almost impenetrable. When execution stops, we basically have to look at symbol information for the function that we stopped in, which tells us *which* register (if any) is the base of the frame pointer, and what offset from that register the frame itself is at. This presents a problem when trying to examine a stack in memory (that isn't executing at the moment), using the "frame" command. We don't have a PC, nor do we have any registers except SP. This routine takes two arguments, SP and PC, and tries to make the cached frames look as if these two arguments defined a frame on the cache. This allows the rest of info frame to extract the important arguments without difficulty. */ FRAME setup_arbitrary_frame (argc, argv) int argc; FRAME_ADDR *argv; { if (argc != 2) error ("MIPS frame specifications require two arguments: sp and pc"); return create_new_frame (argv[0], argv[1]); } CORE_ADDR mips_push_arguments(nargs, args, sp, struct_return, struct_addr) int nargs; value *args; CORE_ADDR sp; int struct_return; CORE_ADDR struct_addr; { CORE_ADDR buf; register i; int accumulate_size = struct_return ? 4 : 0; struct mips_arg { char *contents; int len; int offset; }; struct mips_arg *mips_args = (struct mips_arg*)alloca(nargs * sizeof(struct mips_arg)); register struct mips_arg *m_arg; for (i = 0, m_arg = mips_args; i < nargs; i++, m_arg++) { extern value value_arg_coerce(); value arg = value_arg_coerce (args[i]); m_arg->len = TYPE_LENGTH (VALUE_TYPE (arg)); /* This entire mips-specific routine is because doubles must be aligned * on 8-byte boundaries. It still isn't quite right, because MIPS decided * to align 'struct {int a, b}' on 4-byte boundaries (even though this * breaks their varargs implementation...). A correct solution * requires an simulation of gcc's 'alignof' (and use of 'alignof' * in stdarg.h/varargs.h). */ if (m_arg->len > 4) accumulate_size = (accumulate_size + 7) & -8; m_arg->offset = accumulate_size; accumulate_size = (accumulate_size + m_arg->len + 3) & -4; m_arg->contents = VALUE_CONTENTS(arg); } accumulate_size = (accumulate_size + 7) & (-8); if (accumulate_size < 16) accumulate_size = 16; sp -= accumulate_size; for (i = nargs; m_arg--, --i >= 0; ) write_memory(sp + m_arg->offset, m_arg->contents, m_arg->len); if (struct_return) { buf = struct_addr; write_memory(sp, (char *)&buf, sizeof(CORE_ADDR)); } return sp; } /* MASK(i,j) == (1<info; CORE_ADDR sp = read_register (SP_REGNUM); CORE_ADDR save_address; REGISTER_TYPE buffer; link->next = linked_proc_desc_table; linked_proc_desc_table = link; #define PUSH_FP_REGNUM 16 /* must be a register preserved across calls */ #define GEN_REG_SAVE_MASK MASK(1,16)|MASK(24,28)|(1<<31) #define GEN_REG_SAVE_COUNT 22 #define FLOAT_REG_SAVE_MASK MASK(0,19) #define FLOAT_REG_SAVE_COUNT 20 #define SPECIAL_REG_SAVE_COUNT 4 /* * The registers we must save are all those not preserved across * procedure calls. Dest_Reg (see tm-mips.h) must also be saved. * In addition, we must save the PC, and PUSH_FP_REGNUM. * (Ideally, we should also save MDLO/-HI and FP Control/Status reg.) * * Dummy frame layout: * (high memory) * Saved PC * Saved MMHI, MMLO, FPC_CSR * Saved R31 * Saved R28 * ... * Saved R1 * Saved D18 (i.e. F19, F18) * ... * Saved D0 (i.e. F1, F0) * CALL_DUMMY (subroutine stub; see tm-mips.h) * Parameter build area (not yet implemented) * (low memory) */ PROC_REG_MASK(proc_desc) = GEN_REG_SAVE_MASK; PROC_FREG_MASK(proc_desc) = mips_fpu ? FLOAT_REG_SAVE_MASK : 0; PROC_REG_OFFSET(proc_desc) = /* offset of (Saved R31) from FP */ -sizeof(long) - 4 * SPECIAL_REG_SAVE_COUNT; PROC_FREG_OFFSET(proc_desc) = /* offset of (Saved D18) from FP */ -sizeof(double) - 4 * (SPECIAL_REG_SAVE_COUNT + GEN_REG_SAVE_COUNT); /* save general registers */ save_address = sp + PROC_REG_OFFSET(proc_desc); for (ireg = 32; --ireg >= 0; ) if (PROC_REG_MASK(proc_desc) & (1 << ireg)) { buffer = read_register (ireg); write_memory (save_address, (char *)&buffer, sizeof(REGISTER_TYPE)); save_address -= 4; } /* save floating-points registers starting with high order word */ save_address = sp + PROC_FREG_OFFSET(proc_desc) + 4; for (ireg = 32; --ireg >= 0; ) if (PROC_FREG_MASK(proc_desc) & (1 << ireg)) { buffer = read_register (ireg + FP0_REGNUM); write_memory (save_address, (char *)&buffer, 4); save_address -= 4; } write_register (PUSH_FP_REGNUM, sp); PROC_FRAME_REG(proc_desc) = PUSH_FP_REGNUM; PROC_FRAME_OFFSET(proc_desc) = 0; buffer = read_register (PC_REGNUM); write_memory (sp - 4, (char *)&buffer, sizeof(REGISTER_TYPE)); buffer = read_register (HI_REGNUM); write_memory (sp - 8, (char *)&buffer, sizeof(REGISTER_TYPE)); buffer = read_register (LO_REGNUM); write_memory (sp - 12, (char *)&buffer, sizeof(REGISTER_TYPE)); buffer = read_register (mips_fpu ? FCRCS_REGNUM : ZERO_REGNUM); write_memory (sp - 16, (char *)&buffer, sizeof(REGISTER_TYPE)); sp -= 4 * (GEN_REG_SAVE_COUNT + (mips_fpu ? FLOAT_REG_SAVE_COUNT : 0) + SPECIAL_REG_SAVE_COUNT); write_register (SP_REGNUM, sp); PROC_LOW_ADDR(proc_desc) = sp - CALL_DUMMY_SIZE + CALL_DUMMY_START_OFFSET; PROC_HIGH_ADDR(proc_desc) = sp; SET_PROC_DESC_IS_DUMMY(proc_desc); PROC_PC_REG(proc_desc) = RA_REGNUM; } void mips_pop_frame() { register int regnum; FRAME frame = get_current_frame (); CORE_ADDR new_sp = frame->frame; mips_extra_func_info_t proc_desc = frame->proc_desc; write_register (PC_REGNUM, FRAME_SAVED_PC(frame)); if (proc_desc) { for (regnum = 32; --regnum >= 0; ) if (PROC_REG_MASK(proc_desc) & (1 << regnum)) write_register (regnum, read_memory_integer (frame->saved_regs->regs[regnum], 4)); for (regnum = 32; --regnum >= 0; ) if (PROC_FREG_MASK(proc_desc) & (1 << regnum)) write_register (regnum + FP0_REGNUM, read_memory_integer (frame->saved_regs->regs[regnum + FP0_REGNUM], 4)); } write_register (SP_REGNUM, new_sp); flush_cached_frames (); /* We let mips_init_extra_frame_info figure out the frame pointer */ set_current_frame (create_new_frame (0, read_pc ())); if (proc_desc && PROC_DESC_IS_DUMMY(proc_desc)) { struct linked_proc_info *pi_ptr, *prev_ptr; for (pi_ptr = linked_proc_desc_table, prev_ptr = NULL; pi_ptr != NULL; prev_ptr = pi_ptr, pi_ptr = pi_ptr->next) { if (&pi_ptr->info == proc_desc) break; } if (pi_ptr == NULL) error ("Can't locate dummy extra frame info\n"); if (prev_ptr != NULL) prev_ptr->next = pi_ptr->next; else linked_proc_desc_table = pi_ptr->next; free (pi_ptr); write_register (HI_REGNUM, read_memory_integer(new_sp - 8, 4)); write_register (LO_REGNUM, read_memory_integer(new_sp - 12, 4)); if (mips_fpu) write_register (FCRCS_REGNUM, read_memory_integer(new_sp - 16, 4)); } } static void mips_print_register (regnum, all) int regnum, all; { unsigned char raw_buffer[MAX_REGISTER_RAW_SIZE]; /* Get the data in raw format. */ if (read_relative_register_raw_bytes (regnum, raw_buffer)) { printf_filtered ("%s: [Invalid]", reg_names[regnum]); return; } /* If an even floating pointer register, also print as double. */ if (regnum >= FP0_REGNUM && regnum < FP0_REGNUM+32 && !((regnum-FP0_REGNUM) & 1)) { char dbuffer[MAX_REGISTER_RAW_SIZE]; read_relative_register_raw_bytes (regnum, dbuffer); read_relative_register_raw_bytes (regnum+1, dbuffer+4); #ifdef REGISTER_CONVERT_TO_TYPE REGISTER_CONVERT_TO_TYPE(regnum, builtin_type_double, dbuffer); #endif printf_filtered ("(d%d: ", regnum-FP0_REGNUM); val_print (builtin_type_double, dbuffer, 0, gdb_stdout, 0, 1, 0, Val_pretty_default); printf_filtered ("); "); } fputs_filtered (reg_names[regnum], gdb_stdout); /* The problem with printing numeric register names (r26, etc.) is that the user can't use them on input. Probably the best solution is to fix it so that either the numeric or the funky (a2, etc.) names are accepted on input. */ if (regnum < 32) printf_filtered ("(r%d): ", regnum); else printf_filtered (": "); /* If virtual format is floating, print it that way. */ if (TYPE_CODE (REGISTER_VIRTUAL_TYPE (regnum)) == TYPE_CODE_FLT && ! INVALID_FLOAT (raw_buffer, REGISTER_VIRTUAL_SIZE(regnum))) { val_print (REGISTER_VIRTUAL_TYPE (regnum), raw_buffer, 0, gdb_stdout, 0, 1, 0, Val_pretty_default); } /* Else print as integer in hex. */ else { long val; val = extract_signed_integer (raw_buffer, REGISTER_RAW_SIZE (regnum)); if (val == 0) printf_filtered ("0"); else if (all) /* FIXME: We should be printing this in a fixed field width, so that registers line up. */ printf_filtered (local_hex_format(), val); else printf_filtered ("%s=%ld", local_hex_string(val), val); } } /* Replacement for generic do_registers_info. */ void mips_do_registers_info (regnum, fpregs) int regnum; int fpregs; { if (regnum != -1) { mips_print_register (regnum, 0); printf_filtered ("\n"); } else { for (regnum = 0; regnum < NUM_REGS; ) { if ((!fpregs) && regnum >= FP0_REGNUM && regnum <= FCRIR_REGNUM) { regnum++; continue; } mips_print_register (regnum, 1); regnum++; if ((regnum & 3) == 0 || regnum == NUM_REGS) printf_filtered (";\n"); else printf_filtered ("; "); } } } /* Return number of args passed to a frame. described by FIP. Can return -1, meaning no way to tell. */ int mips_frame_num_args(fip) FRAME fip; { #if 0 struct chain_info_t *p; p = mips_find_cached_frame(FRAME_FP(fip)); if (p->valid) return p->the_info.numargs; #endif return -1; } #if 0 /* Is this a branch with a delay slot? */ static int is_delayed (insn) unsigned long insn; { int i; for (i = 0; i < NUMOPCODES; ++i) if (mips_opcodes[i].pinfo != INSN_MACRO && (insn & mips_opcodes[i].mask) == mips_opcodes[i].match) break; return (i < NUMOPCODES && (mips_opcodes[i].pinfo & (INSN_UNCOND_BRANCH_DELAY | INSN_COND_BRANCH_DELAY | INSN_COND_BRANCH_LIKELY))); } #endif /* To skip prologues, I use this predicate. Returns either PC itself if the code at PC does not look like a function prologue; otherwise returns an address that (if we're lucky) follows the prologue. If LENIENT, then we must skip everything which is involved in setting up the frame (it's OK to skip more, just so long as we don't skip anything which might clobber the registers which are being saved. We must skip more in the case where part of the prologue is in the delay slot of a non-prologue instruction). */ CORE_ADDR mips_skip_prologue (pc, lenient) CORE_ADDR pc; int lenient; { unsigned long inst; int offset; int seen_sp_adjust = 0; /* Skip the typical prologue instructions. These are the stack adjustment instruction and the instructions that save registers on the stack or in the gcc frame. */ for (offset = 0; offset < 100; offset += 4) { char buf[4]; int status; status = read_memory_nobpt (pc + offset, buf, 4); if (status) memory_error (status, pc + offset); inst = extract_unsigned_integer (buf, 4); #if 0 if (lenient && is_delayed (inst)) continue; #endif if ((inst & 0xffff0000) == 0x27bd0000) /* addiu $sp,$sp,offset */ seen_sp_adjust = 1; else if ((inst & 0xFFE00000) == 0xAFA00000 && (inst & 0x001F0000)) continue; /* sw reg,n($sp) */ /* reg != $zero */ else if ((inst & 0xFFE00000) == 0xE7A00000) /* swc1 freg,n($sp) */ continue; else if ((inst & 0xF3E00000) == 0xA3C00000 && (inst & 0x001F0000)) /* sx reg,n($s8) */ continue; /* reg != $zero */ else if (inst == 0x03A0F021) /* move $s8,$sp */ continue; else if ((inst & 0xFF9F07FF) == 0x00800021) /* move reg,$a0-$a3 */ continue; else if ((inst & 0xffff0000) == 0x3c1c0000) /* lui $gp,n */ continue; else if ((inst & 0xffff0000) == 0x279c0000) /* addiu $gp,$gp,n */ continue; else if (inst == 0x0399e021 /* addu $gp,$gp,$t9 */ || inst == 0x033ce021) /* addu $gp,$t9,$gp */ continue; else break; } return pc + offset; /* FIXME schauer. The following code seems no longer necessary if we always skip the typical prologue instructions. */ #if 0 if (seen_sp_adjust) return pc + offset; /* Well, it looks like a frameless. Let's make sure. Note that we are not called on the current PC, but on the function`s start PC, and I have definitely seen optimized code that adjusts the SP quite later */ b = block_for_pc(pc); if (!b) return pc; f = lookup_symbol(MIPS_EFI_SYMBOL_NAME, b, LABEL_NAMESPACE, 0, NULL); if (!f) return pc; /* Ideally, I would like to use the adjusted info from mips_frame_info(), but for all practical purposes it will not matter (and it would require a different definition of SKIP_PROLOGUE()) Actually, it would not hurt to skip the storing of arguments on the stack as well. */ if (((mips_extra_func_info_t)SYMBOL_VALUE(f))->pdr.frameoffset) return pc + 4; return pc; #endif } #if 0 /* The lenient prologue stuff should be superceded by the code in init_extra_frame_info which looks to see whether the stores mentioned in the proc_desc have actually taken place. */ /* Is address PC in the prologue (loosely defined) for function at STARTADDR? */ static int mips_in_lenient_prologue (startaddr, pc) CORE_ADDR startaddr; CORE_ADDR pc; { CORE_ADDR end_prologue = mips_skip_prologue (startaddr, 1); return pc >= startaddr && pc < end_prologue; } #endif /* Given a return value in `regbuf' with a type `valtype', extract and copy its value into `valbuf'. */ void mips_extract_return_value (valtype, regbuf, valbuf) struct type *valtype; char regbuf[REGISTER_BYTES]; char *valbuf; { int regnum; regnum = TYPE_CODE (valtype) == TYPE_CODE_FLT && mips_fpu ? FP0_REGNUM : 2; memcpy (valbuf, regbuf + REGISTER_BYTE (regnum), TYPE_LENGTH (valtype)); #ifdef REGISTER_CONVERT_TO_TYPE REGISTER_CONVERT_TO_TYPE(regnum, valtype, valbuf); #endif } /* Given a return value in `regbuf' with a type `valtype', write it's value into the appropriate register. */ void mips_store_return_value (valtype, valbuf) struct type *valtype; char *valbuf; { int regnum; char raw_buffer[MAX_REGISTER_RAW_SIZE]; regnum = TYPE_CODE (valtype) == TYPE_CODE_FLT && mips_fpu ? FP0_REGNUM : 2; memcpy(raw_buffer, valbuf, TYPE_LENGTH (valtype)); #ifdef REGISTER_CONVERT_FROM_TYPE REGISTER_CONVERT_FROM_TYPE(regnum, valtype, raw_buffer); #endif write_register_bytes(REGISTER_BYTE (regnum), raw_buffer, TYPE_LENGTH (valtype)); } /* These exist in mdebugread.c. */ extern CORE_ADDR sigtramp_address, sigtramp_end; extern void fixup_sigtramp PARAMS ((void)); /* Exported procedure: Is PC in the signal trampoline code */ int in_sigtramp (pc, ignore) CORE_ADDR pc; char *ignore; /* function name */ { if (sigtramp_address == 0) fixup_sigtramp (); return (pc >= sigtramp_address && pc < sigtramp_end); } static void reinit_frame_cache_sfunc PARAMS ((char *, int, struct cmd_list_element *)); /* Just like reinit_frame_cache, but with the right arguments to be callable as an sfunc. */ static void reinit_frame_cache_sfunc (args, from_tty, c) char *args; int from_tty; struct cmd_list_element *c; { reinit_frame_cache (); } void _initialize_mips_tdep () { struct cmd_list_element *c; /* Let the user turn off floating point and set the fence post for heuristic_proc_start. */ add_show_from_set (add_set_cmd ("mipsfpu", class_support, var_boolean, (char *) &mips_fpu, "Set use of floating point coprocessor.\n\ Turn off to avoid using floating point instructions when calling functions\n\ or dealing with return values.", &setlist), &showlist); /* We really would like to have both "0" and "unlimited" work, but command.c doesn't deal with that. So make it a var_zinteger because the user can always use "999999" or some such for unlimited. */ c = add_set_cmd ("heuristic-fence-post", class_support, var_zinteger, (char *) &heuristic_fence_post, "\ Set the distance searched for the start of a function.\n\ If you are debugging a stripped executable, GDB needs to search through the\n\ program for the start of a function. This command sets the distance of the\n\ search. The only need to set it is when debugging a stripped executable.", &setlist); /* We need to throw away the frame cache when we set this, since it might change our ability to get backtraces. */ c->function.sfunc = reinit_frame_cache_sfunc; add_show_from_set (c, &showlist); }