/* Nonzero if we just simulated a single step break. */
int one_stepped;
-#if 0
-
-/* This is Damon's implementation of single step simulation. It suffers the
- following program:
-
- 1 main () {
- 2 char buf[10];
- 3 puts ("test");
- 4 strcmp (buf, "test"); puts ("test");
- 5 exit (0);
- 6 }
-
- You cannot `next' on line 4 in the above program. gdb puts a breakpoint
- to the return address of `strcmp', and when execution arrives that point,
- it is still in the line range and gdb attemps to resume it with single
- steps. At that point the breakpoint at step_resume_break_address (return
- address of strcmp) and single step's breakpoint mixes up and we end up
- with a breakpoint which its shadow and itself are identical.
-
- Fix that problem and use this version. FIXMEmgo.
-*/
-
-
-static struct sstep_breaks {
- int address;
- int data;
-} tbreak[2];
-
-
-/*
- * branch_dest - calculate all places the current instruction may go
- */
-static
-branch_dest(tb)
- register struct sstep_breaks *tb;
-{
- register ulong opcode, iar;
- long instr;
- int immediate, absolute;;
-
- iar = read_pc(); /* current IAR */
- target_read_memory(iar, &instr, sizeof (instr)); /* current inst */
-
- opcode = instr >> 26;
- absolute = instr & 2;
-
- tb[1].address = -1;
-
- switch (opcode) {
- case 0x10: /* branch conditional */
- immediate = ((instr & ~3) << 16) >> 16;
-
- /*
- * two possible locations for next instruction
- */
- tb[0].address = iar + 4;
- tb[1].address = immediate + (absolute ? 0 : iar);
-
- break;
-
- case 0x12: /* branch unconditional */
- immediate = ((instr & ~3) << 6) >> 6;
-
- /*
- * only one possible location for next instr
- */
- tb[0].address = immediate + (absolute ? 0 : iar);
-
- break;
-
- case 0x13: /* branch conditional register */
- /*
- * WE NEED TO CHECK THE CR HERE, TO SEE IF THIS IS
- * REALLY UNCONDITIONAL.
- */
- tb++->address = iar + 4;
-
- switch ((instr >> 1) & 0x3ff) {
- case 0x10: /* branch conditional register */
- tb->address = read_register(LR_REGNUM) & ~3;
- sigtramp_chk(tb); /* return from sig handler? */
- break;
-
- case 0x210: /* branch cond to CTR */
- tb->address = read_register(CTR_REGNUM) & ~3;
- sigtramp_chk(tb); /* return from sig handler? */
- break;
-
- default:
- /*
- * not a branch.
- */
- tb->address = iar + 4;
- break;
- }
- break;
-
- default:
- /*
- * not a branch, flow proceeds normally
- */
- tb->address = iar + 4;
- break;
- }
-}
-
-/*
- * sigtramp_chk - heuristic check to see if we think we are returning
- * from a signal handler.
- *
- * Input:
- * tb - ^ to a single step branch location
- *
- * Note:
- * When we are at the "br" instruction returning to a signal handler,
- * we return in user mode to an address in the kernel. If the
- * segment of the branch target is 0, we may very well be in a
- * signal handler. From scrounging through this code, we note that
- * register 29 has the signal context pointer, from which we can
- * determine where we will end up next.
- */
-sigtramp_chk(tb)
-register struct sstep_breaks *tb; {
- struct sigcontext sc;
-
- if (tb->address & 0xf0000000)
- return; /* can't have been sigtramp */
-
- if (target_read_memory(read_register(GPR29), &sc, sizeof (sc)))
- return; /* read fails, heuristic fails */
-
- if ((sc.sc_jmpbuf.jmp_context.iar & 0xf0000000) == 0x10000000) {
- /*
- * looks like it might be ok.....
- */
- tb->address = sc.sc_jmpbuf.jmp_context.iar;
- }
-}
-
-
-/*
- * single_step - no trace mode harware support, or software support.
- * sigh.
- */
-single_step(signal) {
- register i;
-
- if (!one_stepped) {
- /*
- * need to set breakpoints for single step.
- * figure out all places the current instruction could go.
- */
- branch_dest(&tbreak[0]);
-
- /*
- * always at least one place to go to
- */
- target_insert_breakpoint(tbreak[0].address, &tbreak[0].data);
-
- /*
- * if there is another possible location, set a breakpoint there
- * as well.
- */
- if (tbreak[1].address != -1)
- target_insert_breakpoint(tbreak[1].address, &tbreak[1].data);
-
- one_stepped = 1;
- ptrace(PT_CONTINUE, inferior_pid, 1, signal, 0);
- } else {
- /*
- * need to clear the breakpoints.
- */
- for (i = 0; i < 2; ++i)
- if (tbreak[i].address != -1)
- target_remove_breakpoint(tbreak[i].address, &tbreak[i].data);
-
- one_stepped = 0;
- }
-
- return 1;
-}
-
-#else /* !DAMON'S VERSION */
-
/* Breakpoint shadows for the single step instructions will be kept here. */
static struct sstep_breaks {
default: return -1;
}
- return (dest < 0x10000000) ? safety : dest;
+ return (dest < TEXT_SEGMENT_BASE) ? safety : dest;
}
opcode = insn >> 26;
breaks[1] = branch_dest (opcode, insn, loc, breaks[0]);
+ /* Don't put two breakpoints on the same address. */
+ if (breaks[1] == breaks[0])
+ breaks[1] = -1;
+
stepBreaks[1].address = -1;
for (ii=0; ii < 2; ++ii) {
}
one_stepped = 1;
- ptrace (PT_CONTINUE, inferior_pid, 1, signal);
+ ptrace (PT_CONTINUE, inferior_pid, 1, signal, 0);
}
else {
one_stepped = 0;
}
+ errno = 0;
return 1;
}
-#endif /* !DAMON's version of single step. */
-
/* return pc value after skipping a function prologue. */
pc += 4;
op = read_memory_integer (pc, 4);
}
- else /* else, this is a frameless invocation */
- return pc;
if ((op & 0xfc00003e) == 0x7c000026) { /* mfcr Rx */
pc += 4;
op = read_memory_integer (pc, 4);
}
+#if 0
if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
pc += 4; /* store floating register double */
op = read_memory_integer (pc, 4);
}
+#endif
if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
pc += 4;
op = read_memory_integer (pc, 4);
}
- while ((op & 0xfc1f0000) == 0x90010000) { /* st r?, NUM(r1) */
- pc += 4;
- op = read_memory_integer (pc, 4);
- }
+ /* store parameters into stack */
+ while(
+ (op & 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
+ (op & 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */
+ (op & 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */
+ (op & 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */
+ {
+ pc += 4; /* store fpr double */
+ op = read_memory_integer (pc, 4);
+ }
if (op == 0x603f0000) { /* oril r31, r1, 0x0 */
pc += 4; /* this happens if r31 is used as */
op = read_memory_integer (pc, 4); /* frame ptr. (gcc does that) */
- if ((op >> 16) == 0x907f) { /* st r3, NUM(r31) */
- pc += 4;
+ tmp = 0;
+ while ((op >> 16) == (0x907f + tmp)) { /* st r3, NUM(r31) */
+ pc += 4; /* st r4, NUM(r31), ... */
op = read_memory_integer (pc, 4);
+ tmp += 0x20;
}
}
return pc;
}
+
/* text start and end addresses in virtual memory. */
CORE_ADDR text_start;
frames, etc.
*************************************************************************/
+/* The total size of dummy frame is 436, which is;
+
+ 32 gpr's - 128 bytes
+ 32 fpr's - 256 "
+ 7 the rest - 28 "
+ and 24 extra bytes for the callee's link area. The last 24 bytes
+ for the link area might not be necessary, since it will be taken
+ care of by push_arguments(). */
+
+#define DUMMY_FRAME_SIZE 436
+
#define DUMMY_FRAME_ADDR_SIZE 10
/* Make sure you initialize these in somewhere, in case gdb gives up what it
- was debugging and starts debugging something else. FIXMEmgo */
+ was debugging and starts debugging something else. FIXMEibm */
static int dummy_frame_count = 0;
static int dummy_frame_size = 0;
before writing register values into the new frame, decrement and update
%sp first in order to secure your frame. */
- write_register (SP_REGNUM, sp-408);
+ write_register (SP_REGNUM, sp-DUMMY_FRAME_SIZE);
-#if 1
/* gdb relies on the state of current_frame. We'd better update it,
otherwise things like do_registers_info() wouldn't work properly! */
flush_cached_frames ();
- set_current_frame (create_new_frame (sp-408, pc));
-#endif /* 0 */
+ set_current_frame (create_new_frame (sp-DUMMY_FRAME_SIZE, pc));
/* save program counter in link register's space. */
write_memory (sp+8, &pc, 4);
for (ii=1; ii <=32; ++ii)
write_memory (sp-256-(ii*4), ®isters[REGISTER_BYTE (32-ii)], 4);
- /* so far, 32*2 + 32 words = 384 bytes have been written. We need 6 words
- (24 bytes) for the rest of the registers. It brings the total to 408
- bytes.
- save sp or so call back chain right here. */
- write_memory (sp-408, &sp, 4);
- sp -= 408;
+ /* so far, 32*2 + 32 words = 384 bytes have been written.
+ 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */
+
+ for (ii=1; ii <= (LAST_SP_REGNUM-FIRST_SP_REGNUM+1); ++ii) {
+ write_memory (sp-384-(ii*4),
+ ®isters[REGISTER_BYTE (FPLAST_REGNUM + ii)], 4);
+ }
+
+ /* Save sp or so called back chain right here. */
+ write_memory (sp-DUMMY_FRAME_SIZE, &sp, 4);
+ sp -= DUMMY_FRAME_SIZE;
/* And finally, this is the back chain. */
write_memory (sp+8, &pc, 4);
In rs6000 when we push a dummy frame, we save all of the registers. This
is usually done before user calls a function explicitly.
- After a dummy frame is pushed, some instructions are copied into stack, and
- stack pointer is decremented even more. Since we don't have a frame pointer to
- get back to the parent frame of the dummy, we start having trouble poping it.
- Therefore, we keep a dummy frame stack, keeping addresses of dummy frames as
- such. When poping happens and when we detect that was a dummy frame, we pop
- it back to its parent by using dummy frame stack (`dummy_frame_addr' array).
+ After a dummy frame is pushed, some instructions are copied into stack,
+ and stack pointer is decremented even more. Since we don't have a frame
+ pointer to get back to the parent frame of the dummy, we start having
+ trouble poping it. Therefore, we keep a dummy frame stack, keeping
+ addresses of dummy frames as such. When poping happens and when we
+ detect that was a dummy frame, we pop it back to its parent by using
+ dummy frame stack (`dummy_frame_addr' array).
*/
pop_dummy_frame ()
read_memory (sp-256-(ii*4), ®isters[REGISTER_BYTE (32-ii)], 4);
}
- read_memory (sp-400, ®isters [REGISTER_BYTE(PC_REGNUM)], 4);
+ /* restore the rest of the registers. */
+ for (ii=1; ii <=(LAST_SP_REGNUM-FIRST_SP_REGNUM+1); ++ii)
+ read_memory (sp-384-(ii*4),
+ ®isters[REGISTER_BYTE (FPLAST_REGNUM + ii)], 4);
+
+ read_memory (sp-(DUMMY_FRAME_SIZE-8),
+ ®isters [REGISTER_BYTE(PC_REGNUM)], 4);
/* when a dummy frame was being pushed, we had to decrement %sp first, in
order to secure astack space. Thus, saved %sp (or %r1) value, is not the
projects / binutils.git / blobdiff