diff options
| -rw-r--r-- | gdb/ChangeLog | 6 | ||||
| -rw-r--r-- | gdb/v850-tdep.c | 319 |
2 files changed, 188 insertions, 137 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 2c8c52f..dc0af83 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +Mon Oct 21 14:40:50 1996 Stu Grossman (grossman@critters.cygnus.com) + + * v850-tdep.c: Cleanup lots of things. Add many comments. + * testsuite/gdb.base/nodebug.exp: Whack out -g options by hand so + that cflags can contains -gstabs, and work correctly for other tests. + Mon Oct 21 14:01:38 1996 Michael Snyder <msnyder@cleaver.cygnus.com> * top.c: Add new commands "set annotate" and "show annotate". diff --git a/gdb/v850-tdep.c b/gdb/v850-tdep.c index 25e607d..9169eeb 100644 --- a/gdb/v850-tdep.c +++ b/gdb/v850-tdep.c @@ -26,61 +26,85 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "bfd.h" #include "gdb_string.h" #include "gdbcore.h" +#include "symfile.h" + +/* Dummy frame. This saves the processor state just prior to setting up the + inferior function call. On most targets, the registers are saved on the + target stack, but that really slows down function calls. */ struct dummy_frame { struct dummy_frame *next; - CORE_ADDR fp; - CORE_ADDR sp; - CORE_ADDR rp; - CORE_ADDR pc; + char regs[REGISTER_BYTES]; }; static struct dummy_frame *dummy_frame_stack = NULL; - -/* 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; +static CORE_ADDR read_register_dummy PARAMS ((int regno)); + +/* Info gleaned from scanning a function's prologue. */ + +struct prologue_info { - struct symtab_and_line sal; - CORE_ADDR func_addr, prologue_end, current_pc; - int reg; - int frameoffset; int framereg; + int frameoffset; + int start_function; + struct frame_saved_regs *fsr; +}; - if (fi->next) - fi->pc = FRAME_SAVED_PC (fi->next); +static CORE_ADDR scan_prologue PARAMS ((CORE_ADDR pc, struct prologue_info *fs)); + +/* 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 CORE_ADDR +scan_prologue (pc, pi) + CORE_ADDR pc; + struct prologue_info *pi; +{ + CORE_ADDR func_addr, prologue_end, current_pc; + int fp_used; /* 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)) + if (find_pc_partial_function (pc, NULL, &func_addr, NULL)) { + struct symtab_and_line sal; + sal = find_pc_line (func_addr, 0); + if (func_addr == entry_point_address ()) + pi->start_function = 1; + else + pi->start_function = 0; + if (sal.line == 0) - prologue_end = fi->pc; + prologue_end = pc; else prologue_end = sal.end; } else - prologue_end = func_addr + 100; /* We're in the boondocks */ + { /* We're in the boondocks */ + func_addr = pc - 100; + prologue_end = pc; + } - prologue_end = min (prologue_end, fi->pc); + prologue_end = min (prologue_end, pc); /* Now, search the prologue looking for instructions that setup fp, save - rp, adjust sp and such. */ + rp, adjust sp and such. We also record the frame offset of any saved + registers. */ - framereg = SP_REGNUM; - frameoffset = 0; - memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); + pi->frameoffset = 0; + pi->framereg = SP_REGNUM; + fp_used = 0; for (current_pc = func_addr; current_pc < prologue_end; current_pc += 2) { @@ -89,136 +113,145 @@ v850_init_extra_frame_info (fi) insn = read_memory_unsigned_integer (current_pc, 2); if ((insn & 0xffe0) == ((SP_REGNUM << 11) | 0x0240)) /* add <imm>,sp */ - frameoffset = ((insn & 0x1f) ^ 0x10) - 0x10; + pi->frameoffset = ((insn & 0x1f) ^ 0x10) - 0x10; else if (insn == ((SP_REGNUM << 11) | 0x0600 | SP_REGNUM)) /* addi <imm>,sp,sp */ - frameoffset = read_memory_integer (current_pc + 2, 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] */ + pi->frameoffset = read_memory_integer (current_pc + 2, 2); + else if (insn == ((FP_REGNUM << 11) | 0x0000 | 12)) /* mov r12,fp */ { - reg = (insn >> 11) & 0x1f; /* Extract <reg> */ + fp_used = 1; + pi->framereg = FP_REGNUM; + } + else if ((insn & 0x07ff) == (0x0760 | SP_REGNUM) /* st.w <reg>,<offset>[sp] */ + || (fp_used + && (insn & 0x07ff) == (0x0760 | FP_REGNUM))) /* st.w <reg>,<offset>[fp] */ + if (pi->fsr) + { + int framereg; + int reg; + int offset; - insn = read_memory_integer (current_pc + 2, 2) & ~1; + framereg = insn & 0x1f; + reg = (insn >> 11) & 0x1f; /* Extract <reg> */ - fi->fsr.regs[reg] = insn + frameoffset; - } - else if ((insn & 0x07ff) == (0x0760 | FP_REGNUM)) /* st.w <reg>,<offset>[fp] */ - { - reg = (insn >> 11) & 0x1f; /* Extract <reg> */ + offset = read_memory_integer (current_pc + 2, 2) & ~1; - insn = read_memory_integer (current_pc + 2, 2) & ~1; + if (framereg == SP_REGNUM) /* Using SP? */ + offset += pi->frameoffset; /* Yes, correct for frame size */ - fi->fsr.regs[reg] = insn; - } + pi->fsr->regs[reg] = offset; + } if ((insn & 0x0780) >= 0x0600) /* Four byte instruction? */ current_pc += 2; } - if (PC_IN_CALL_DUMMY (fi->pc, NULL, NULL)) - fi->frame = dummy_frame_stack->sp; - else if (!fi->next && framereg == SP_REGNUM) - fi->frame = read_register (framereg) - frameoffset; - - for (reg = 0; reg < NUM_REGS; reg++) - if (fi->fsr.regs[reg] != 0) - fi->fsr.regs[reg] += fi->frame; + return current_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. */ +/* Setup the frame frame pointer, pc, and frame addresses for saved registers. + Most of the work is done in scan_prologue(). -CORE_ADDR -v850_find_callers_reg (fi, regnum) + 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 v850_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 +v850_init_extra_frame_info (fi) struct frame_info *fi; - int regnum; { - /* XXX - Won't work if multiple dummy frames are active */ + struct prologue_info pi; + int reg; + + if (fi->next) + fi->pc = FRAME_SAVED_PC (fi->next); + + memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); + + /* The call dummy doesn't save any registers on the stack, so we can return + now. */ if (PC_IN_CALL_DUMMY (fi->pc, NULL, NULL)) - switch (regnum) - { - case SP_REGNUM: - return dummy_frame_stack->sp; - break; - case FP_REGNUM: - return dummy_frame_stack->fp; - break; - case RP_REGNUM: - return dummy_frame_stack->pc; - break; - case PC_REGNUM: - return dummy_frame_stack->pc; - break; - } + { + /* We need to setup fi->frame here because run_stack_dummy gets it wrong + by assuming it's always FP. */ + fi->frame = read_register_dummy (SP_REGNUM); + return; + } - for (; fi; fi = fi->next) - if (fi->fsr.regs[regnum] != 0) - return read_memory_integer (fi->fsr.regs[regnum], 4); + pi.fsr = &fi->fsr; - return read_register (regnum); + scan_prologue (fi->pc, &pi); + + if (!fi->next && pi.framereg == SP_REGNUM) + fi->frame = read_register (pi.framereg) - pi.frameoffset; + + for (reg = 0; reg < NUM_REGS; reg++) + if (fi->fsr.regs[reg] != 0) + fi->fsr.regs[reg] += fi->frame; } +/* Figure out the frame prior to FI. Unfortunately, this involves scanning the + prologue of the caller, which will also be done shortly by + v850_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 v850_frame_chain (fi) struct frame_info *fi; { - CORE_ADDR callers_pc, callers_sp; - CORE_ADDR func_addr, prologue_end, current_pc; - int frameoffset; + CORE_ADDR callers_pc; + struct prologue_info pi; /* First, find out who called us */ callers_pc = FRAME_SAVED_PC (fi); if (PC_IN_CALL_DUMMY (callers_pc, NULL, NULL)) - return dummy_frame_stack->sp; /* XXX Won't work if multiple dummy frames on stack! */ + return read_register_dummy (SP_REGNUM); /* XXX Won't work if multiple dummy frames on stack! */ - /* Next, figure out where his prologue is. */ + pi.fsr = NULL; - if (find_pc_partial_function (callers_pc, NULL, &func_addr, NULL)) - { - struct symtab_and_line sal; + scan_prologue (callers_pc, &pi); - /* Stop when the caller is the entry point function */ - if (func_addr == entry_point_address ()) - return 0; + if (pi.start_function) + return 0; /* Don't chain beyond the start function */ - sal = find_pc_line (func_addr, 0); + if (pi.framereg == FP_REGNUM) + return v850_find_callers_reg (fi, pi.framereg); - if (sal.line == 0) - prologue_end = callers_pc; - else - 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; + return fi->frame - pi.frameoffset; +} - insn = read_memory_unsigned_integer (current_pc, 2); +/* 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. */ - if ((insn & 0xffe0) == ((SP_REGNUM << 11) | 0x0240)) /* add <imm>,sp */ - frameoffset = ((insn & 0x1f) ^ 0x10) - 0x10; - else if (insn == ((SP_REGNUM << 11) | 0x0600 | SP_REGNUM)) /* addi <imm>,sp,sp */ - frameoffset = read_memory_integer (current_pc + 2, 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 */ +CORE_ADDR +v850_find_callers_reg (fi, regnum) + struct frame_info *fi; + int regnum; +{ + /* XXX - Won't work if multiple dummy frames are active */ + /* When the caller requests RP from the dummy frame, we return PC because + that's where the previous routine appears to have done a call from. */ + if (PC_IN_CALL_DUMMY (fi->pc, NULL, NULL)) + if (regnum == RP_REGNUM) + regnum = PC_REGNUM; - if ((insn & 0x0780) >= 0x0600) /* Four byte instruction? */ - current_pc += 2; - } + for (; fi; fi = fi->next) + if (PC_IN_CALL_DUMMY (fi->pc, NULL, NULL)) + return read_register_dummy (regnum); + else if (fi->fsr.regs[regnum] != 0) + return read_memory_integer (fi->fsr.regs[regnum], 4); - return fi->frame - frameoffset; + return read_register (regnum); } CORE_ADDR @@ -248,7 +281,12 @@ v850_skip_prologue (pc) return pc; } -/* All we do here is record SP and FP on the call dummy stack */ +/* Save all the registers on the dummy frame stack. Most ports save the + registers on the target stack. This results in lots of unnecessary memory + references, which are slow when debugging via a serial line. Instead, we + save all the registers internally, and never write them to the stack. The + registers get restored when the called function returns to the entry point, + where a breakpoint is laying in wait. */ void v850_push_dummy_frame () @@ -257,14 +295,22 @@ v850_push_dummy_frame () dummy_frame = xmalloc (sizeof (struct dummy_frame)); - dummy_frame->fp = read_register (FP_REGNUM); - dummy_frame->sp = read_register (SP_REGNUM); - dummy_frame->rp = read_register (RP_REGNUM); - dummy_frame->pc = read_register (PC_REGNUM); + read_register_bytes (0, dummy_frame->regs, REGISTER_BYTES); + dummy_frame->next = dummy_frame_stack; dummy_frame_stack = dummy_frame; } +/* Read registers from the topmost dummy frame. */ + +CORE_ADDR +read_register_dummy (regno) + int regno; +{ + return extract_address (&dummy_frame_stack->regs[REGISTER_BYTE (regno)], + REGISTER_RAW_SIZE(regno)); +} + int v850_pc_in_call_dummy (pc) CORE_ADDR pc; @@ -274,6 +320,9 @@ v850_pc_in_call_dummy (pc) && pc <= CALL_DUMMY_ADDRESS () + DECR_PC_AFTER_BREAK; } +/* This routine gets called when either the user uses the `return' command, or + the call dummy breakpoint gets hit. */ + struct frame_info * v850_pop_frame (frame) struct frame_info *frame; @@ -290,32 +339,28 @@ v850_pop_frame (frame) dummy_frame_stack = dummy_frame->next; - write_register (FP_REGNUM, dummy_frame->fp); - write_register (SP_REGNUM, dummy_frame->sp); - write_register (RP_REGNUM, dummy_frame->rp); - write_register (PC_REGNUM, dummy_frame->pc); + write_register_bytes (0, dummy_frame->regs, REGISTER_BYTES); free (dummy_frame); - - flush_cached_frames (); - - return NULL; } + else + { + write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); - 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)); - 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)); + } - write_register (SP_REGNUM, FRAME_FP (frame)); flush_cached_frames (); return NULL; } -/* Put arguments in the right places, and setup return address register (RP) to - point at a convenient place to put a breakpoint. First four args go in +/* Setup arguments and RP for a call to the target. First four args go in R6->R9, subsequent args go into sp + 16 -> sp + ... Structs are passed by reference. 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 |