diff options
Diffstat (limited to 'gdb/v850-tdep.c')
| -rw-r--r-- | gdb/v850-tdep.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/gdb/v850-tdep.c b/gdb/v850-tdep.c index b710920..7363fc2 100644 --- a/gdb/v850-tdep.c +++ b/gdb/v850-tdep.c @@ -30,6 +30,222 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "gdb_string.h" #include "gdbcore.h" + + +/* This function actually figures out the frame address for a given pc and + sp. This is tricky on the v850 because we only use an explicit frame + pointer when using alloca(). The only reliable way to get this info is to + examine the prologue. +*/ + +void +v850_init_extra_frame_info (fi) + struct frame_info *fi; +{ + struct symtab_and_line sal; + CORE_ADDR func_addr, prologue_end, current_pc; + int reg; + int frameoffset; + int framereg; + + if (fi->next) + fi->pc = v850_find_callers_reg (fi->next, RP_REGNUM); + + /* First, figure out the bounds of the prologue so that we can limit the + search to something reasonable. */ + + if (find_pc_partial_function (fi->pc, NULL, &func_addr, NULL)) + { + sal = find_pc_line (func_addr, 0); + + prologue_end = sal.end; + } + else + prologue_end = func_addr + 100; /* We're in the boondocks */ + + prologue_end = min (prologue_end, fi->pc); + + /* Now, search the prologue looking for instructions that setup fp, save + rp, adjust sp and such. */ + + framereg = SP_REGNUM; + frameoffset = 0; + memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); + + for (current_pc = func_addr; current_pc < prologue_end; current_pc += 2) + { + int insn; + + insn = read_memory_integer (current_pc, 2); + + if ((insn & 0xffe0) == ((SP_REGNUM << 11) | 0x0240)) /* add <imm>,sp */ + frameoffset = (insn & 0x1f) | ~0x1f; + else if (insn == ((SP_REGNUM << 11) | 0x0600 | SP_REGNUM)) /* addi <imm>,sp,sp */ + { + current_pc += 2; + + frameoffset = read_memory_integer (current_pc, 2); + } + else if (insn == ((FP_REGNUM << 11) | 0x0000 | 12)) /* mov r12,r2 */ + framereg = FP_REGNUM; /* Setting up fp */ + else if ((insn & 0x07ff) == (0x0760 | SP_REGNUM)) /* st.w <reg>,<offset>[sp] */ + { + reg = (insn >> 11) & 0x1f; /* Extract <reg> */ + current_pc += 2; + + insn = read_memory_integer (current_pc, 2) & ~1; + + fi->fsr.regs[reg] = insn + frameoffset; + } + else if ((insn & 0x07ff) == (0x0760 | FP_REGNUM)) /* st.w <reg>,<offset>[fp] */ + { + reg = (insn >> 11) & 0x1f; /* Extract <reg> */ + current_pc += 2; + + insn = read_memory_integer (current_pc, 2) & ~1; + + fi->fsr.regs[reg] = insn; + } + } + +#if 0 + if (!fi->next) + fi->frame = read_register (framereg); + else + if (framereg == SP_REGNUM) + fi->frame = fi->next->frame; + else + fi->frame = v850_find_callers_reg (fi, framereg); + + if (framereg == SP_REGNUM) + fi->frame -= frameoffset; +#else + if (!fi->next && framereg == SP_REGNUM) + fi->frame = read_register (framereg) - frameoffset; +#endif + + for (reg = 0; reg < NUM_REGS; reg++) + if (fi->fsr.regs[reg] != 0) + fi->fsr.regs[reg] += fi->frame; +} + +/* 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. */ + +CORE_ADDR +v850_find_callers_reg (fi, regnum) + struct frame_info *fi; + int regnum; +{ + for (; fi; fi = fi->next) + if (fi->fsr.regs[regnum] != 0) + return read_memory_integer (fi->fsr.regs[regnum], 4); + + return read_register (regnum); +} + +CORE_ADDR +v850_frame_chain (fi) + struct frame_info *fi; +{ + CORE_ADDR callers_pc, callers_sp; + struct frame_info temp_fi; + CORE_ADDR func_addr, prologue_end, current_pc; + int frameoffset; + + /* First, find out who called us */ + + callers_pc = v850_find_callers_reg (fi, RP_REGNUM); + + /* Next, figure out where his prologue is. */ + + if (find_pc_partial_function (callers_pc, NULL, &func_addr, NULL)) + { + struct symtab_and_line sal; + + sal = find_pc_line (func_addr, 0); + + prologue_end = sal.end; + } + else + prologue_end = func_addr + 100; /* We're in the boondocks */ + + prologue_end = min (prologue_end, callers_pc); + + /* Now, figure out the frame location of the caller by examining his prologue. + We're looking for either a load of the frame pointer register, or a stack + adjustment. */ + + frameoffset = 0; + + for (current_pc = func_addr; current_pc < prologue_end; current_pc += 2) + { + int insn; + + insn = read_memory_integer (current_pc, 2); + + if ((insn & 0xffe0) == ((SP_REGNUM << 11) | 0x0240)) /* add <imm>,sp */ + frameoffset = (insn & 0x1f) | ~0x1f; + else if (insn == ((SP_REGNUM << 11) | 0x0600 | SP_REGNUM)) /* addi <imm>,sp,sp */ + { + current_pc += 2; + + frameoffset = read_memory_integer (current_pc, 2); + } + else if (insn == ((FP_REGNUM << 11) | 0x0000 | 12)) /* mov r12,r2 */ + return v850_find_callers_reg (fi, FP_REGNUM); /* It's using a frame pointer reg */ + else if ((insn & 0x07ff) == (0x0760 | SP_REGNUM)) /* st.w <reg>,<offset>[sp] */ + current_pc += 2; + else if ((insn & 0x07ff) == (0x0760 | FP_REGNUM)) /* st.w <reg>,<offset>[fp] */ + current_pc += 2; + } + + return fi->frame - frameoffset; +} + +CORE_ADDR +v850_skip_prologue (pc) + 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.end < func_end) + return sal.end; + else + /* The line after the prologue is after the end of the function. In + this case, there probably isn't a prologue. */ + return pc; + } + +/* We can't find the start of this function, so there's nothing we can do. */ + return pc; +} + +struct frame_info * +v850_pop_frame (frame) + struct frame_info *frame; +{ + int regnum; + + 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_integer (frame->fsr.regs[regnum], 4)); + + write_register (SP_REGNUM, FRAME_FP (frame)); + flush_cached_frames (); + + return NULL; +} void _initialize_sparc_tdep () |