/* Target-dependent code for GDB, the GNU debugger.
- Copyright (C) 1986, 1987, 1989, 1991 Free Software Foundation, Inc.
+ Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997
+ Free Software Foundation, Inc.
This file is part of GDB.
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 <stdio.h>
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "frame.h"
#include "inferior.h"
#include "symtab.h"
#include "target.h"
+#include "gdbcore.h"
+#include "symfile.h"
+#include "objfiles.h"
+#include "xcoffsolib.h"
-#include <sys/param.h>
-#include <sys/dir.h>
-#include <sys/user.h>
-#include <signal.h>
-#include <sys/ioctl.h>
-#include <fcntl.h>
-
-#include <sys/ptrace.h>
-#include <sys/reg.h>
-
-#include <a.out.h>
-#include <sys/file.h>
-#include <sys/stat.h>
-#include <sys/core.h>
+extern struct obstack frame_cache_obstack;
extern int errno;
-extern int attach_flag;
/* 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.
-*/
-
+/* Breakpoint shadows for the single step instructions will be kept here. */
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;
+ /* Address, or 0 if this is not in use. */
+ CORE_ADDR address;
+ /* Shadow contents. */
+ char data[4];
+} stepBreaks[2];
- if (tb->address & 0xf0000000)
- return; /* can't have been sigtramp */
+/* Hook for determining the TOC address when calling functions in the
+ inferior under AIX. The initialization code in rs6000-nat.c sets
+ this hook to point to find_toc_address. */
- if (target_read_memory(read_register(GPR29), &sc, sizeof (sc)))
- return; /* read fails, heuristic fails */
+CORE_ADDR (*find_toc_address_hook) PARAMS ((CORE_ADDR)) = NULL;
- if ((sc.sc_jmpbuf.jmp_context.iar & 0xf0000000) == 0x10000000) {
- /*
- * looks like it might be ok.....
- */
- tb->address = sc.sc_jmpbuf.jmp_context.iar;
- }
-}
+/* Static function prototypes */
+static CORE_ADDR branch_dest PARAMS ((int opcode, int instr, CORE_ADDR pc,
+ CORE_ADDR safety));
-/*
- * 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;
- }
+static void frame_get_cache_fsr PARAMS ((struct frame_info *fi,
+ struct rs6000_framedata *fdatap));
- return 1;
-}
+static void pop_dummy_frame PARAMS ((void));
-#else /* !DAMON'S VERSION */
+/* Calculate the destination of a branch/jump. Return -1 if not a branch. */
-/* Breakpoint shadows for the single step instructions will be kept here. */
-
-static struct sstep_breaks {
- int address;
- int data;
-} stepBreaks[2];
-
-
-/*
- * Calculate the destination of a branch/jump. Return -1 if not a branch.
- */
-static int
+static CORE_ADDR
branch_dest (opcode, instr, pc, safety)
- int opcode, instr, pc, safety;
+ int opcode;
+ int instr;
+ CORE_ADDR pc;
+ CORE_ADDR safety;
{
- register long offset;
- unsigned dest;
+ CORE_ADDR dest;
int immediate;
int absolute;
int ext_op;
switch (opcode) {
case 18 :
- immediate = ((instr & ~3) << 6) >> 6; /* br unconditionl */
+ immediate = ((instr & ~3) << 6) >> 6; /* br unconditional */
+ if (absolute)
+ dest = immediate;
+ else
+ dest = pc + immediate;
+ break;
case 16 :
- if (opcode != 18) /* br conditional */
- immediate = ((instr & ~3) << 16) >> 16;
+ immediate = ((instr & ~3) << 16) >> 16; /* br conditional */
if (absolute)
dest = immediate;
else
ext_op = (instr>>1) & 0x3ff;
if (ext_op == 16) /* br conditional register */
- dest = read_register (LR_REGNUM) & ~3;
+ {
+ dest = read_register (LR_REGNUM) & ~3;
+
+ /* If we are about to return from a signal handler, dest is
+ something like 0x3c90. The current frame is a signal handler
+ caller frame, upon completion of the sigreturn system call
+ execution will return to the saved PC in the frame. */
+ if (dest < TEXT_SEGMENT_BASE)
+ {
+ struct frame_info *fi;
+
+ fi = get_current_frame ();
+ if (fi != NULL)
+ dest = read_memory_integer (fi->frame + SIG_FRAME_PC_OFFSET,
+ 4);
+ }
+ }
else if (ext_op == 528) /* br cond to count reg */
- dest = read_register (CTR_REGNUM) & ~3;
-
+ {
+ dest = read_register (CTR_REGNUM) & ~3;
+
+ /* If we are about to execute a system call, dest is something
+ like 0x22fc or 0x3b00. Upon completion the system call
+ will return to the address in the link register. */
+ if (dest < TEXT_SEGMENT_BASE)
+ dest = read_register (LR_REGNUM) & ~3;
+ }
else return -1;
break;
default: return -1;
}
- return (dest < 0x10000000) ? safety : dest;
+ return (dest < TEXT_SEGMENT_BASE) ? safety : dest;
}
/* AIX does not support PT_STEP. Simulate it. */
-int
+void
single_step (signal)
-int signal;
+ enum target_signal signal;
{
#define INSNLEN(OPCODE) 4
- static char breakp[] = BREAKPOINT;
- int ii, insn, ret, loc;
- int breaks[2], opcode;
+ static char le_breakp[] = LITTLE_BREAKPOINT;
+ static char be_breakp[] = BIG_BREAKPOINT;
+ char *breakp = TARGET_BYTE_ORDER == BIG_ENDIAN ? be_breakp : le_breakp;
+ int ii, insn;
+ CORE_ADDR loc;
+ CORE_ADDR breaks[2];
+ int opcode;
if (!one_stepped) {
- extern CORE_ADDR text_start;
loc = read_pc ();
- ret = read_memory (loc, &insn, sizeof (int));
- if (ret)
- printf ("Error in single_step()!!\n");
+ insn = read_memory_integer (loc, 4);
breaks[0] = loc + INSNLEN(insn);
opcode = insn >> 26;
breaks[1] = branch_dest (opcode, insn, loc, breaks[0]);
- stepBreaks[1].address = -1;
+ /* Don't put two breakpoints on the same address. */
+ if (breaks[1] == breaks[0])
+ breaks[1] = -1;
+
+ stepBreaks[1].address = 0;
for (ii=0; ii < 2; ++ii) {
if ( breaks[ii] == -1)
continue;
- read_memory (breaks[ii], &(stepBreaks[ii].data), sizeof(int));
+ read_memory (breaks[ii], stepBreaks[ii].data, 4);
- ret = write_memory (breaks[ii], breakp, sizeof(int));
+ write_memory (breaks[ii], breakp, 4);
stepBreaks[ii].address = breaks[ii];
}
one_stepped = 1;
- ptrace (PT_CONTINUE, inferior_pid, 1, signal);
- }
- else {
+ } else {
/* remove step breakpoints. */
for (ii=0; ii < 2; ++ii)
- if (stepBreaks[ii].address != -1)
+ if (stepBreaks[ii].address != 0)
write_memory
- (stepBreaks[ii].address, &(stepBreaks[ii].data), sizeof(int));
+ (stepBreaks[ii].address, stepBreaks[ii].data, 4);
one_stepped = 0;
}
- return 1;
+ errno = 0; /* FIXME, don't ignore errors! */
+ /* What errors? {read,write}_memory call error(). */
}
-#endif /* !DAMON's version of single step. */
+/* return pc value after skipping a function prologue and also return
+ information about a function frame.
-/* return pc value after skipping a function prologue. */
+ in struct rs6000_frameinfo fdata:
+ - frameless is TRUE, if function does not have a frame.
+ - nosavedpc is TRUE, if function does not save %pc value in its frame.
+ - offset is the number of bytes used in the frame to save registers.
+ - saved_gpr is the number of the first saved gpr.
+ - saved_fpr is the number of the first saved fpr.
+ - alloca_reg is the number of the register used for alloca() handling.
+ Otherwise -1.
+ - gpr_offset is the offset of the saved gprs
+ - fpr_offset is the offset of the saved fprs
+ - lr_offset is the offset of the saved lr
+ - cr_offset is the offset of the saved cr
+ */
-skip_prologue (pc)
-int pc;
-{
- unsigned int tmp;
- unsigned int op;
+#define SIGNED_SHORT(x) \
+ ((sizeof (short) == 2) \
+ ? ((int)(short)(x)) \
+ : ((int)((((x) & 0xffff) ^ 0x8000) - 0x8000)))
+
+#define GET_SRC_REG(x) (((x) >> 21) & 0x1f)
- if (target_read_memory (pc, (char *)&op, sizeof (op)))
+CORE_ADDR
+skip_prologue (pc, fdata)
+ CORE_ADDR pc;
+ struct rs6000_framedata *fdata;
+{
+ CORE_ADDR orig_pc = pc;
+ char buf[4];
+ unsigned long op;
+ long offset = 0;
+ int lr_reg = 0;
+ int cr_reg = 0;
+ int reg;
+ int framep = 0;
+ int minimal_toc_loaded = 0;
+ static struct rs6000_framedata zero_frame;
+
+ *fdata = zero_frame;
+ fdata->saved_gpr = -1;
+ fdata->saved_fpr = -1;
+ fdata->alloca_reg = -1;
+ fdata->frameless = 1;
+ fdata->nosavedpc = 1;
+
+ if (target_read_memory (pc, buf, 4))
return pc; /* Can't access it -- assume no prologue. */
- SWAP_TARGET_AND_HOST (&op, sizeof (op));
/* Assume that subsequent fetches can fail with low probability. */
+ pc -= 4;
+ for (;;)
+ {
+ pc += 4;
+ op = read_memory_integer (pc, 4);
- if (op == 0x7c0802a6) { /* mflr r0 */
- pc += 4;
- op = read_memory_integer (pc, 4);
- }
- else /* else, this is a frameless invocation */
- return pc;
+ if ((op & 0xfc1fffff) == 0x7c0802a6) { /* mflr Rx */
+ lr_reg = (op & 0x03e00000) | 0x90010000;
+ continue;
- if ((op & 0xfc00003e) == 0x7c000026) { /* mfcr Rx */
- pc += 4;
- op = read_memory_integer (pc, 4);
- }
+ } else if ((op & 0xfc1fffff) == 0x7c000026) { /* mfcr Rx */
+ cr_reg = (op & 0x03e00000) | 0x90010000;
+ continue;
- if ((op & 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
- pc += 4;
- op = read_memory_integer (pc, 4);
- }
+ } else if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
+ reg = GET_SRC_REG (op);
+ if (fdata->saved_fpr == -1 || fdata->saved_fpr > reg) {
+ fdata->saved_fpr = reg;
+ fdata->fpr_offset = SIGNED_SHORT (op) + offset;
+ }
+ continue;
- if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
- pc += 4; /* store floating register double */
- op = read_memory_integer (pc, 4);
- }
+ } else if (((op & 0xfc1f0000) == 0xbc010000) || /* stm Rx, NUM(r1) */
+ ((op & 0xfc1f0000) == 0x90010000 && /* st rx,NUM(r1), rx >= r13 */
+ (op & 0x03e00000) >= 0x01a00000)) {
- if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
- pc += 4;
- op = read_memory_integer (pc, 4);
- }
+ reg = GET_SRC_REG (op);
+ if (fdata->saved_gpr == -1 || fdata->saved_gpr > reg) {
+ fdata->saved_gpr = reg;
+ fdata->gpr_offset = SIGNED_SHORT (op) + offset;
+ }
+ continue;
- while (((tmp = op >> 16) == 0x9001) || /* st r0, NUM(r1) */
- (tmp == 0x9421) || /* stu r1, NUM(r1) */
- (op == 0x93e1fffc)) /* st r31,-4(r1) */
- {
- pc += 4;
- op = read_memory_integer (pc, 4);
- }
+ } else if ((op & 0xffff0000) == 0x3c000000) { /* addis 0,0,NUM, used for >= 32k frames */
+ fdata->offset = (op & 0x0000ffff) << 16;
+ fdata->frameless = 0;
+ continue;
- while ((tmp = (op >> 22)) == 0x20f) { /* l r31, ... or */
- pc += 4; /* l r30, ... */
- op = read_memory_integer (pc, 4);
- }
+ } else if ((op & 0xffff0000) == 0x60000000) { /* ori 0,0,NUM, 2nd half of >= 32k frames */
+ fdata->offset |= (op & 0x0000ffff);
+ fdata->frameless = 0;
+ continue;
- while ((op & 0xfc1f0000) == 0x90010000) { /* st r?, NUM(r1) */
- pc += 4;
- op = read_memory_integer (pc, 4);
- }
+ } else if ((op & 0xffff0000) == lr_reg) { /* st Rx,NUM(r1) where Rx == lr */
+ fdata->lr_offset = SIGNED_SHORT (op) + offset;
+ fdata->nosavedpc = 0;
+ lr_reg = 0;
+ continue;
- 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) */
+ } else if ((op & 0xffff0000) == cr_reg) { /* st Rx,NUM(r1) where Rx == cr */
+ fdata->cr_offset = SIGNED_SHORT (op) + offset;
+ cr_reg = 0;
+ continue;
- if ((op >> 16) == 0x907f) { /* st r3, NUM(r31) */
- pc += 4;
- op = read_memory_integer (pc, 4);
+ } else if (op == 0x48000005) { /* bl .+4 used in -mrelocatable */
+ continue;
+
+ } else if (op == 0x48000004) { /* b .+4 (xlc) */
+ break;
+
+ } else if (((op & 0xffff0000) == 0x801e0000 || /* lwz 0,NUM(r30), used in V.4 -mrelocatable */
+ op == 0x7fc0f214) && /* add r30,r0,r30, used in V.4 -mrelocatable */
+ lr_reg == 0x901e0000) {
+ continue;
+
+ } else if ((op & 0xffff0000) == 0x3fc00000 || /* addis 30,0,foo@ha, used in V.4 -mminimal-toc */
+ (op & 0xffff0000) == 0x3bde0000) { /* addi 30,30,foo@l */
+ continue;
+
+ } else if ((op & 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
+
+ fdata->frameless = 0;
+ /* Don't skip over the subroutine call if it is not within the first
+ three instructions of the prologue. */
+ if ((pc - orig_pc) > 8)
+ break;
+
+ op = read_memory_integer (pc+4, 4);
+
+ /* At this point, make sure this is not a trampoline function
+ (a function that simply calls another functions, and nothing else).
+ If the next is not a nop, this branch was part of the function
+ prologue. */
+
+ if (op == 0x4def7b82 || op == 0) /* crorc 15, 15, 15 */
+ break; /* don't skip over this branch */
+
+ continue;
+
+ /* update stack pointer */
+ } else if ((op & 0xffff0000) == 0x94210000) { /* stu r1,NUM(r1) */
+ fdata->frameless = 0;
+ fdata->offset = SIGNED_SHORT (op);
+ offset = fdata->offset;
+ continue;
+
+ } else if (op == 0x7c21016e) { /* stwux 1,1,0 */
+ fdata->frameless = 0;
+ offset = fdata->offset;
+ continue;
+
+ /* Load up minimal toc pointer */
+ } else if ((op >> 22) == 0x20f
+ && ! minimal_toc_loaded) { /* l r31,... or l r30,... */
+ minimal_toc_loaded = 1;
+ continue;
+
+ /* store parameters in stack */
+ } else if ((op & 0xfc1f0000) == 0x90010000 || /* st rx,NUM(r1) */
+ (op & 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
+ (op & 0xfc1f0000) == 0xfc010000) { /* frsp, fp?,NUM(r1) */
+ continue;
+
+ /* store parameters in stack via frame pointer */
+ } else if (framep &&
+ ((op & 0xfc1f0000) == 0x901f0000 || /* st rx,NUM(r1) */
+ (op & 0xfc1f0000) == 0xd81f0000 || /* stfd Rx,NUM(r1) */
+ (op & 0xfc1f0000) == 0xfc1f0000)) { /* frsp, fp?,NUM(r1) */
+ continue;
+
+ /* Set up frame pointer */
+ } else if (op == 0x603f0000 /* oril r31, r1, 0x0 */
+ || op == 0x7c3f0b78) { /* mr r31, r1 */
+ fdata->frameless = 0;
+ framep = 1;
+ fdata->alloca_reg = 31;
+ continue;
+
+ /* Another way to set up the frame pointer. */
+ } else if ((op & 0xfc1fffff) == 0x38010000) { /* addi rX, r1, 0x0 */
+ fdata->frameless = 0;
+ framep = 1;
+ fdata->alloca_reg = (op & ~0x38010000) >> 21;
+ continue;
+
+ } else {
+ break;
+ }
+ }
+
+#if 0
+/* I have problems with skipping over __main() that I need to address
+ * sometime. Previously, I used to use misc_function_vector which
+ * didn't work as well as I wanted to be. -MGO */
+
+ /* If the first thing after skipping a prolog is a branch to a function,
+ this might be a call to an initializer in main(), introduced by gcc2.
+ We'd like to skip over it as well. Fortunately, xlc does some extra
+ work before calling a function right after a prologue, thus we can
+ single out such gcc2 behaviour. */
+
+
+ if ((op & 0xfc000001) == 0x48000001) { /* bl foo, an initializer function? */
+ op = read_memory_integer (pc+4, 4);
+
+ if (op == 0x4def7b82) { /* cror 0xf, 0xf, 0xf (nop) */
+
+ /* check and see if we are in main. If so, skip over this initializer
+ function as well. */
+
+ tmp = find_pc_misc_function (pc);
+ if (tmp >= 0 && STREQ (misc_function_vector [tmp].name, "main"))
+ return pc + 8;
}
}
+#endif /* 0 */
+
+ fdata->offset = - fdata->offset;
return pc;
}
-/* text start and end addresses in virtual memory. */
-
-CORE_ADDR text_start;
-CORE_ADDR text_end;
-
/*************************************************************************
Support for creating pushind a dummy frame into the stack, and popping
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;
/* push a dummy frame into stack, save all register. Currently we are saving
only gpr's and fpr's, which is not good enough! FIXMEmgo */
+void
push_dummy_frame ()
{
- int sp, pc; /* stack pointer and link register */
+ /* stack pointer. */
+ CORE_ADDR sp;
+ /* Same thing, target byte order. */
+ char sp_targ[4];
+
+ /* link register. */
+ CORE_ADDR pc;
+ /* Same thing, target byte order. */
+ char pc_targ[4];
+
+ /* Needed to figure out where to save the dummy link area.
+ FIXME: There should be an easier way to do this, no? tiemann 9/9/95. */
+ struct rs6000_framedata fdata;
+
int ii;
+ target_fetch_registers (-1);
+
if (dummy_frame_count >= dummy_frame_size) {
dummy_frame_size += DUMMY_FRAME_ADDR_SIZE;
if (dummy_frame_addr)
}
sp = read_register(SP_REGNUM);
- pc = read_register(PC_REGNUM);
+ pc = read_register(PC_REGNUM);
+ store_address (pc_targ, 4, pc);
+
+ (void) skip_prologue (get_pc_function_start (pc) + FUNCTION_START_OFFSET, &fdata);
dummy_frame_addr [dummy_frame_count++] = sp;
/* Be careful! If the stack pointer is not decremented first, then kernel
- thinks he is free to use the sapce underneath it. And kernel actually
+ thinks he is free to use the space underneath it. And kernel actually
uses that area for IPC purposes when executing ptrace(2) calls. So
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);
+ /* FIXME: We don't check if the stack really has this much space.
+ This is a problem on the ppc simulator (which only grants one page
+ (4096 bytes) by default. */
+
+ 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 */
/* save program counter in link register's space. */
- write_memory (sp+8, &pc, 4);
+ write_memory (sp + (fdata.lr_offset ? fdata.lr_offset : DEFAULT_LR_SAVE),
+ pc_targ, 4);
- /* save full floating point registers here. They will be from F14..F31
- for know. I am not sure if we need to save everything here! */
+ /* save all floating point and general purpose registers here. */
/* fpr's, f0..f31 */
for (ii = 0; ii < 32; ++ii)
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. */
+ store_address (sp_targ, 4, sp);
+ write_memory (sp-DUMMY_FRAME_SIZE, sp_targ, 4);
+ sp -= DUMMY_FRAME_SIZE;
/* And finally, this is the back chain. */
- write_memory (sp+8, &pc, 4);
+ write_memory (sp+8, pc_targ, 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).
+
+FIXME: This whole concept is broken. You should be able to detect
+a dummy stack frame *on the user's stack itself*. When you do,
+then you know the format of that stack frame -- including its
+saved SP register! There should *not* be a separate stack in the
+GDB process that keeps track of these dummy frames! -- gnu@cygnus.com Aug92
*/
+static void
pop_dummy_frame ()
{
CORE_ADDR sp, pc;
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
/* Now we can restore all registers. */
- store_inferior_registers (-1);
+ target_store_registers (-1);
pc = read_pc ();
flush_cached_frames ();
- set_current_frame (create_new_frame (sp, pc));
}
/* pop the innermost frame, go back to the caller. */
+void
pop_frame ()
{
- int pc, lr, sp, prev_sp; /* %pc, %lr, %sp */
- FRAME fr = get_current_frame ();
- int offset = 0;
- int frameless = 0; /* TRUE if function is frameless */
+ CORE_ADDR pc, lr, sp, prev_sp; /* %pc, %lr, %sp */
+ struct rs6000_framedata fdata;
+ struct frame_info *frame = get_current_frame ();
int addr, ii;
- int saved_gpr, saved_fpr; /* # of saved gpr's and fpr's */
pc = read_pc ();
- sp = FRAME_FP (fr);
+ sp = FRAME_FP (frame);
if (stop_stack_dummy && dummy_frame_count) {
pop_dummy_frame ();
return;
}
+ /* Make sure that all registers are valid. */
+ read_register_bytes (0, NULL, REGISTER_BYTES);
+
/* figure out previous %pc value. If the function is frameless, it is
still in the link register, otherwise walk the frames and retrieve the
saved %pc value in the previous frame. */
- addr = get_pc_function_start (fr->pc) + FUNCTION_START_OFFSET;
- function_frame_info (addr, &frameless, &offset, &saved_gpr, &saved_fpr);
+ addr = get_pc_function_start (frame->pc) + FUNCTION_START_OFFSET;
+ (void) skip_prologue (addr, &fdata);
- read_memory (sp, &prev_sp, 4);
- if (frameless)
+ if (fdata.frameless)
+ prev_sp = sp;
+ else
+ prev_sp = read_memory_integer (sp, 4);
+ if (fdata.lr_offset == 0)
lr = read_register (LR_REGNUM);
else
- read_memory (prev_sp+8, &lr, 4);
+ lr = read_memory_integer (prev_sp + fdata.lr_offset, 4);
/* reset %pc value. */
write_register (PC_REGNUM, lr);
/* reset register values if any was saved earlier. */
- addr = prev_sp - offset;
+ addr = prev_sp - fdata.offset;
- if (saved_gpr != -1)
- for (ii=saved_gpr; ii <= 31; ++ii) {
+ if (fdata.saved_gpr != -1)
+ for (ii = fdata.saved_gpr; ii <= 31; ++ii) {
read_memory (addr, ®isters [REGISTER_BYTE (ii)], 4);
- addr += sizeof (int);
+ addr += 4;
}
- if (saved_fpr != -1)
- for (ii=saved_fpr; ii <= 31; ++ii) {
+ if (fdata.saved_fpr != -1)
+ for (ii = fdata.saved_fpr; ii <= 31; ++ii) {
read_memory (addr, ®isters [REGISTER_BYTE (ii+FP0_REGNUM)], 8);
addr += 8;
}
write_register (SP_REGNUM, prev_sp);
- store_inferior_registers (-1);
+ target_store_registers (-1);
flush_cached_frames ();
- set_current_frame (create_new_frame (prev_sp, lr));
}
-
/* fixup the call sequence of a dummy function, with the real function address.
its argumets will be passed by gdb. */
-fix_call_dummy(dummyname, pc, fun, nargs, type)
- char *dummyname;
- int pc;
- int fun;
- int nargs; /* not used */
- int type; /* not used */
-
+void
+rs6000_fix_call_dummy (dummyname, pc, fun, nargs, args, type, gcc_p)
+ char *dummyname;
+ CORE_ADDR pc;
+ CORE_ADDR fun;
+ int nargs;
+ value_ptr *args;
+ struct type *type;
+ int gcc_p;
{
#define TOC_ADDR_OFFSET 20
#define TARGET_ADDR_OFFSET 28
int ii;
- unsigned long target_addr;
- unsigned long tocvalue;
+ CORE_ADDR target_addr;
- target_addr = fun;
- tocvalue = find_toc_address (target_addr);
+ if (find_toc_address_hook != NULL)
+ {
+ CORE_ADDR tocvalue;
- ii = *(int*)((char*)dummyname + TOC_ADDR_OFFSET);
- ii = (ii & 0xffff0000) | (tocvalue >> 16);
- *(int*)((char*)dummyname + TOC_ADDR_OFFSET) = ii;
+ tocvalue = (*find_toc_address_hook) (fun);
+ ii = *(int*)((char*)dummyname + TOC_ADDR_OFFSET);
+ ii = (ii & 0xffff0000) | (tocvalue >> 16);
+ *(int*)((char*)dummyname + TOC_ADDR_OFFSET) = ii;
- ii = *(int*)((char*)dummyname + TOC_ADDR_OFFSET+4);
- ii = (ii & 0xffff0000) | (tocvalue & 0x0000ffff);
- *(int*)((char*)dummyname + TOC_ADDR_OFFSET+4) = ii;
+ ii = *(int*)((char*)dummyname + TOC_ADDR_OFFSET+4);
+ ii = (ii & 0xffff0000) | (tocvalue & 0x0000ffff);
+ *(int*)((char*)dummyname + TOC_ADDR_OFFSET+4) = ii;
+ }
+ target_addr = fun;
ii = *(int*)((char*)dummyname + TARGET_ADDR_OFFSET);
ii = (ii & 0xffff0000) | (target_addr >> 16);
*(int*)((char*)dummyname + TARGET_ADDR_OFFSET) = ii;
*(int*)((char*)dummyname + TARGET_ADDR_OFFSET+4) = ii;
}
-
-
-/* return information about a function frame.
- - frameless is TRUE, if function does not save %pc value in its frame.
- - offset is the number of bytes used in the frame to save registers.
- - saved_gpr is the number of the first saved gpr.
- - saved_fpr is the number of the first saved fpr.
- */
-function_frame_info (pc, frameless, offset, saved_gpr, saved_fpr)
- int pc;
- int *frameless, *offset, *saved_gpr, *saved_fpr;
-{
- unsigned int tmp;
- register unsigned int op;
-
- *offset = 0;
- *saved_gpr = *saved_fpr = -1;
-
- if (!inferior_pid)
- return;
-
- op = read_memory_integer (pc, 4);
- if (op == 0x7c0802a6) { /* mflr r0 */
- pc += 4;
- op = read_memory_integer (pc, 4);
- *frameless = 0;
- }
- else /* else, this is a frameless invocation */
- *frameless = 1;
-
-
- if ((op & 0xfc00003e) == 0x7c000026) { /* mfcr Rx */
- pc += 4;
- op = read_memory_integer (pc, 4);
- }
-
- if ((op & 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
- pc += 4;
- op = read_memory_integer (pc, 4);
- }
-
- if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
- pc += 4; /* store floating register double */
- op = read_memory_integer (pc, 4);
- }
-
- if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
- int tmp2;
- *saved_gpr = (op >> 21) & 0x1f;
- tmp2 = op & 0xffff;
- if (tmp2 > 0x7fff)
- tmp2 = 0xffff0000 | tmp2;
-
- if (tmp2 < 0) {
- tmp2 = tmp2 * -1;
- *saved_fpr = (tmp2 - ((32 - *saved_gpr) * 4)) / 8;
- if ( *saved_fpr > 0)
- *saved_fpr = 32 - *saved_fpr;
- else
- *saved_fpr = -1;
- }
- *offset = tmp2;
- }
-}
-
-
-/* Pass the arguments in either registers, or in the stack. In RS6000, the first
- eight words of the argument list (that might be less than eight parameters if
- some parameters occupy more than one word) are passed in r3..r11 registers.
- float and double parameters are passed in fpr's, in addition to that. Rest of
- the parameters if any are passed in user stack. There might be cases in which
- half of the parameter is copied into registers, the other half is pushed into
+/* Pass the arguments in either registers, or in the stack. In RS6000,
+ the first eight words of the argument list (that might be less than
+ eight parameters if some parameters occupy more than one word) are
+ passed in r3..r11 registers. float and double parameters are
+ passed in fpr's, in addition to that. Rest of the parameters if any
+ are passed in user stack. There might be cases in which half of the
+ parameter is copied into registers, the other half is pushed into
stack.
If the function is returning a structure, then the return address is passed
- in r3, then the first 7 words of the parametes can be passed in registers,
+ in r3, then the first 7 words of the parameters can be passed in registers,
starting from r4. */
CORE_ADDR
push_arguments (nargs, args, sp, struct_return, struct_addr)
- int nargs;
- value *args;
- CORE_ADDR sp;
- int struct_return;
- CORE_ADDR struct_addr;
+ int nargs;
+ value_ptr *args;
+ CORE_ADDR sp;
+ int struct_return;
+ CORE_ADDR struct_addr;
{
- int ii, len;
+ int ii;
+ int len = 0;
int argno; /* current argument number */
int argbytes; /* current argument byte */
char tmp_buffer [50];
- value arg;
int f_argno = 0; /* current floating point argno */
+ value_ptr arg = 0;
+ struct type *type;
- CORE_ADDR saved_sp, pc;
+ CORE_ADDR saved_sp;
if ( dummy_frame_count <= 0)
- printf ("FATAL ERROR -push_arguments()! frame not found!!\n");
+ printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n");
/* The first eight words of ther arguments are passed in registers. Copy
them appropriately.
for (argno=0, argbytes=0; argno < nargs && ii<8; ++ii) {
- arg = value_arg_coerce (args[argno]);
- len = TYPE_LENGTH (VALUE_TYPE (arg));
+ arg = args[argno];
+ type = check_typedef (VALUE_TYPE (arg));
+ len = TYPE_LENGTH (type);
- if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FLT) {
+ if (TYPE_CODE (type) == TYPE_CODE_FLT) {
/* floating point arguments are passed in fpr's, as well as gpr's.
There are 13 fpr's reserved for passing parameters. At this point
there is no way we would run out of them. */
if (len > 8)
- printf (
+ printf_unfiltered (
"Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno);
- bcopy (VALUE_CONTENTS (arg),
- ®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], len);
+ memcpy (®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], VALUE_CONTENTS (arg),
+ len);
++f_argno;
}
while (argbytes < len) {
*(int*)®isters[REGISTER_BYTE(ii+3)] = 0;
- bcopy ( ((char*)VALUE_CONTENTS (arg))+argbytes,
- ®isters[REGISTER_BYTE(ii+3)],
+ memcpy (®isters[REGISTER_BYTE(ii+3)],
+ ((char*)VALUE_CONTENTS (arg))+argbytes,
(len - argbytes) > 4 ? 4 : len - argbytes);
++ii, argbytes += 4;
}
else { /* Argument can fit in one register. No problem. */
*(int*)®isters[REGISTER_BYTE(ii+3)] = 0;
- bcopy (VALUE_CONTENTS (arg), ®isters[REGISTER_BYTE(ii+3)], len);
+ memcpy (®isters[REGISTER_BYTE(ii+3)], VALUE_CONTENTS (arg), len);
}
++argno;
}
if ((argno < nargs) || argbytes) {
int space = 0, jj;
- value val;
if (argbytes) {
space += ((len - argbytes + 3) & -4);
jj = argno;
for (; jj < nargs; ++jj) {
- val = value_arg_coerce (args[jj]);
+ value_ptr val = args[jj];
space += ((TYPE_LENGTH (VALUE_TYPE (val))) + 3) & -4;
}
write_register (SP_REGNUM, sp);
-#if 0
- pc = read_pc ();
- flush_cached_frames ();
- set_current_frame (create_new_frame (sp, pc));
-#endif
-
/* if the last argument copied into the registers didn't fit there
completely, push the rest of it into stack. */
/* push the rest of the arguments into stack. */
for (; argno < nargs; ++argno) {
- arg = value_arg_coerce (args[argno]);
- len = TYPE_LENGTH (VALUE_TYPE (arg));
+ arg = args[argno];
+ type = check_typedef (VALUE_TYPE (arg));
+ len = TYPE_LENGTH (type);
/* float types should be passed in fpr's, as well as in the stack. */
- if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FLT && f_argno < 13) {
+ if (TYPE_CODE (type) == TYPE_CODE_FLT && f_argno < 13) {
if (len > 8)
- printf (
+ printf_unfiltered (
"Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno);
- bcopy (VALUE_CONTENTS (arg),
- ®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], len);
+ memcpy (®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], VALUE_CONTENTS (arg),
+ len);
++f_argno;
}
- write_memory (sp+24+(ii*4), VALUE_CONTENTS (arg), len);
+ write_memory (sp+24+(ii*4), (char *) VALUE_CONTENTS (arg), len);
ii += ((len + 3) & -4) / 4;
}
}
- else {
-
+ else
/* Secure stack areas first, before doing anything else. */
write_register (SP_REGNUM, sp);
-#if 0
- pc = read_pc ();
- flush_cached_frames ();
- set_current_frame (create_new_frame (sp, pc));
-#endif
- }
-
saved_sp = dummy_frame_addr [dummy_frame_count - 1];
read_memory (saved_sp, tmp_buffer, 24);
write_memory (sp, tmp_buffer, 24);
- write_memory (sp, &saved_sp, 4); /* set back chain properly */
+ /* set back chain properly */
+ store_address (tmp_buffer, 4, saved_sp);
+ write_memory (sp, tmp_buffer, 4);
- store_inferior_registers (-1);
+ target_store_registers (-1);
return sp;
}
/* a given return value in `regbuf' with a type `valtype', extract and copy its
value into `valbuf' */
+void
extract_return_value (valtype, regbuf, valbuf)
- struct type *valtype;
- char regbuf[REGISTER_BYTES];
- char *valbuf;
+ struct type *valtype;
+ char regbuf[REGISTER_BYTES];
+ char *valbuf;
{
+ int offset = 0;
if (TYPE_CODE (valtype) == TYPE_CODE_FLT) {
necessary. */
if (TYPE_LENGTH (valtype) > 4) /* this is a double */
- bcopy (®buf[REGISTER_BYTE (FP0_REGNUM + 1)], valbuf,
+ memcpy (valbuf, ®buf[REGISTER_BYTE (FP0_REGNUM + 1)],
TYPE_LENGTH (valtype));
else { /* float */
- bcopy (®buf[REGISTER_BYTE (FP0_REGNUM + 1)], &dd, 8);
+ memcpy (&dd, ®buf[REGISTER_BYTE (FP0_REGNUM + 1)], 8);
ff = (float)dd;
- bcopy (&ff, valbuf, sizeof(float));
+ memcpy (valbuf, &ff, sizeof(float));
}
}
- else
+ else {
/* return value is copied starting from r3. */
- bcopy (®buf[REGISTER_BYTE (3)], valbuf, TYPE_LENGTH (valtype));
+ if (TARGET_BYTE_ORDER == BIG_ENDIAN
+ && TYPE_LENGTH (valtype) < REGISTER_RAW_SIZE (3))
+ offset = REGISTER_RAW_SIZE (3) - TYPE_LENGTH (valtype);
+
+ memcpy (valbuf, regbuf + REGISTER_BYTE (3) + offset,
+ TYPE_LENGTH (valtype));
+ }
}
-/* keep keep structure return address in this variable. */
+/* keep structure return address in this variable.
+ FIXME: This is a horrid kludge which should not be allowed to continue
+ living. This only allows a single nested call to a structure-returning
+ function. Come on, guys! -- gnu@cygnus.com, Aug 92 */
CORE_ADDR rs6000_struct_return_address;
-/* Throw away this debugging code. FIXMEmgo. */
-print_frame(fram)
-int fram;
-{
- int ii, val;
- for (ii=0; ii<40; ++ii) {
- if ((ii % 4) == 0)
- printf ("\n");
- val = read_memory_integer (fram + ii * 4, 4);
- printf ("0x%08x\t", val);
- }
- printf ("\n");
-}
-
-
-
-/* Indirect function calls use a piece of trampoline code do co context switching,
- i.e. to set the new TOC table. Skip such code if exists. */
+/* Indirect function calls use a piece of trampoline code to do context
+ switching, i.e. to set the new TOC table. Skip such code if we are on
+ its first instruction (as when we have single-stepped to here).
+ Also skip shared library trampoline code (which is different from
+ indirect function call trampolines).
+ Result is desired PC to step until, or NULL if we are not in
+ trampoline code. */
+CORE_ADDR
skip_trampoline_code (pc)
-int pc;
+ CORE_ADDR pc;
{
register unsigned int ii, op;
+ CORE_ADDR solib_target_pc;
static unsigned trampoline_code[] = {
0x800b0000, /* l r0,0x0(r11) */
0
};
+ /* If pc is in a shared library trampoline, return its target. */
+ solib_target_pc = find_solib_trampoline_target (pc);
+ if (solib_target_pc)
+ return solib_target_pc;
+
for (ii=0; trampoline_code[ii]; ++ii) {
op = read_memory_integer (pc + (ii*4), 4);
if (op != trampoline_code [ii])
- return NULL;
+ return 0;
}
ii = read_register (11); /* r11 holds destination addr */
pc = read_memory_integer (ii, 4); /* (r11) value */
return pc;
}
+/* Determines whether the function FI has a frame on the stack or not. */
+
+int
+frameless_function_invocation (fi)
+ struct frame_info *fi;
+{
+ CORE_ADDR func_start;
+ struct rs6000_framedata fdata;
+
+ /* Don't even think about framelessness except on the innermost frame
+ or if the function was interrupted by a signal. */
+ if (fi->next != NULL && !fi->next->signal_handler_caller)
+ return 0;
+
+ func_start = get_pc_function_start (fi->pc);
+
+ /* If we failed to find the start of the function, it is a mistake
+ to inspect the instructions. */
+
+ if (!func_start)
+ {
+ /* A frame with a zero PC is usually created by dereferencing a NULL
+ function pointer, normally causing an immediate core dump of the
+ inferior. Mark function as frameless, as the inferior has no chance
+ of setting up a stack frame. */
+ if (fi->pc == 0)
+ return 1;
+ else
+ return 0;
+ }
+
+ func_start += FUNCTION_START_OFFSET;
+ (void) skip_prologue (func_start, &fdata);
+ return fdata.frameless;
+}
+
+/* Return the PC saved in a frame */
+
+unsigned long
+frame_saved_pc (fi)
+ struct frame_info *fi;
+{
+ CORE_ADDR func_start;
+ struct rs6000_framedata fdata;
+
+ if (fi->signal_handler_caller)
+ return read_memory_integer (fi->frame + SIG_FRAME_PC_OFFSET, 4);
+
+ func_start = get_pc_function_start (fi->pc) + FUNCTION_START_OFFSET;
+
+ /* If we failed to find the start of the function, it is a mistake
+ to inspect the instructions. */
+ if (!func_start)
+ return 0;
+
+ (void) skip_prologue (func_start, &fdata);
+
+ if (fdata.lr_offset == 0 && fi->next != NULL)
+ {
+ if (fi->next->signal_handler_caller)
+ return read_memory_integer (fi->next->frame + SIG_FRAME_LR_OFFSET, 4);
+ else
+ return read_memory_integer (rs6000_frame_chain (fi) + DEFAULT_LR_SAVE,
+ 4);
+ }
+
+ if (fdata.lr_offset == 0)
+ return read_register (LR_REGNUM);
+
+ return read_memory_integer (rs6000_frame_chain (fi) + fdata.lr_offset, 4);
+}
+
+/* If saved registers of frame FI are not known yet, read and cache them.
+ &FDATAP contains rs6000_framedata; TDATAP can be NULL,
+ in which case the framedata are read. */
+
+static void
+frame_get_cache_fsr (fi, fdatap)
+ struct frame_info *fi;
+ struct rs6000_framedata *fdatap;
+{
+ int ii;
+ CORE_ADDR frame_addr;
+ struct rs6000_framedata work_fdata;
+
+ if (fi->cache_fsr)
+ return;
+
+ if (fdatap == NULL) {
+ fdatap = &work_fdata;
+ (void) skip_prologue (get_pc_function_start (fi->pc), fdatap);
+ }
+
+ fi->cache_fsr = (struct frame_saved_regs *)
+ obstack_alloc (&frame_cache_obstack, sizeof (struct frame_saved_regs));
+ memset (fi->cache_fsr, '\0', sizeof (struct frame_saved_regs));
+
+ if (fi->prev && fi->prev->frame)
+ frame_addr = fi->prev->frame;
+ else
+ frame_addr = read_memory_integer (fi->frame, 4);
+
+ /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr.
+ All fpr's from saved_fpr to fp31 are saved. */
+
+ if (fdatap->saved_fpr >= 0) {
+ int fpr_offset = frame_addr + fdatap->fpr_offset;
+ for (ii = fdatap->saved_fpr; ii < 32; ii++) {
+ fi->cache_fsr->regs [FP0_REGNUM + ii] = fpr_offset;
+ fpr_offset += 8;
+ }
+ }
+
+ /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr.
+ All gpr's from saved_gpr to gpr31 are saved. */
+
+ if (fdatap->saved_gpr >= 0) {
+ int gpr_offset = frame_addr + fdatap->gpr_offset;
+ for (ii = fdatap->saved_gpr; ii < 32; ii++) {
+ fi->cache_fsr->regs [ii] = gpr_offset;
+ gpr_offset += 4;
+ }
+ }
+
+ /* If != 0, fdatap->cr_offset is the offset from the frame that holds
+ the CR. */
+ if (fdatap->cr_offset != 0)
+ fi->cache_fsr->regs [CR_REGNUM] = frame_addr + fdatap->cr_offset;
+
+ /* If != 0, fdatap->lr_offset is the offset from the frame that holds
+ the LR. */
+ if (fdatap->lr_offset != 0)
+ fi->cache_fsr->regs [LR_REGNUM] = frame_addr + fdatap->lr_offset;
+}
+
+/* Return the address of a frame. This is the inital %sp value when the frame
+ was first allocated. For functions calling alloca(), it might be saved in
+ an alloca register. */
+
+CORE_ADDR
+frame_initial_stack_address (fi)
+ struct frame_info *fi;
+{
+ CORE_ADDR tmpaddr;
+ struct rs6000_framedata fdata;
+ struct frame_info *callee_fi;
+
+ /* if the initial stack pointer (frame address) of this frame is known,
+ just return it. */
+
+ if (fi->initial_sp)
+ return fi->initial_sp;
+
+ /* find out if this function is using an alloca register.. */
+
+ (void) skip_prologue (get_pc_function_start (fi->pc), &fdata);
+
+ /* if saved registers of this frame are not known yet, read and cache them. */
+
+ if (!fi->cache_fsr)
+ frame_get_cache_fsr (fi, &fdata);
+
+ /* If no alloca register used, then fi->frame is the value of the %sp for
+ this frame, and it is good enough. */
+
+ if (fdata.alloca_reg < 0) {
+ fi->initial_sp = fi->frame;
+ return fi->initial_sp;
+ }
+
+ /* This function has an alloca register. If this is the top-most frame
+ (with the lowest address), the value in alloca register is good. */
+
+ if (!fi->next)
+ return fi->initial_sp = read_register (fdata.alloca_reg);
+
+ /* Otherwise, this is a caller frame. Callee has usually already saved
+ registers, but there are exceptions (such as when the callee
+ has no parameters). Find the address in which caller's alloca
+ register is saved. */
+
+ for (callee_fi = fi->next; callee_fi; callee_fi = callee_fi->next) {
+
+ if (!callee_fi->cache_fsr)
+ frame_get_cache_fsr (callee_fi, NULL);
+
+ /* this is the address in which alloca register is saved. */
+
+ tmpaddr = callee_fi->cache_fsr->regs [fdata.alloca_reg];
+ if (tmpaddr) {
+ fi->initial_sp = read_memory_integer (tmpaddr, 4);
+ return fi->initial_sp;
+ }
+
+ /* Go look into deeper levels of the frame chain to see if any one of
+ the callees has saved alloca register. */
+ }
+
+ /* If alloca register was not saved, by the callee (or any of its callees)
+ then the value in the register is still good. */
+
+ return fi->initial_sp = read_register (fdata.alloca_reg);
+}
+
+CORE_ADDR
+rs6000_frame_chain (thisframe)
+ struct frame_info *thisframe;
+{
+ CORE_ADDR fp;
+ if (inside_entry_file ((thisframe)->pc))
+ return 0;
+ if (thisframe->signal_handler_caller)
+ fp = read_memory_integer (thisframe->frame + SIG_FRAME_FP_OFFSET, 4);
+ else if (thisframe->next != NULL
+ && thisframe->next->signal_handler_caller
+ && frameless_function_invocation (thisframe))
+ /* A frameless function interrupted by a signal did not change the
+ frame pointer. */
+ fp = FRAME_FP (thisframe);
+ else
+ fp = read_memory_integer ((thisframe)->frame, 4);
+
+ return fp;
+}
+\f
+/* Return nonzero if ADDR (a function pointer) is in the data space and
+ is therefore a special function pointer. */
+
+int
+is_magic_function_pointer (addr)
+ CORE_ADDR addr;
+{
+ struct obj_section *s;
+
+ s = find_pc_section (addr);
+ if (s && s->the_bfd_section->flags & SEC_CODE)
+ return 0;
+ else
+ return 1;
+}
+
+#ifdef GDB_TARGET_POWERPC
+int
+gdb_print_insn_powerpc (memaddr, info)
+ bfd_vma memaddr;
+ disassemble_info *info;
+{
+ if (TARGET_BYTE_ORDER == BIG_ENDIAN)
+ return print_insn_big_powerpc (memaddr, info);
+ else
+ return print_insn_little_powerpc (memaddr, info);
+}
+#endif
+
+void
+_initialize_rs6000_tdep ()
+{
+ /* FIXME, this should not be decided via ifdef. */
+#ifdef GDB_TARGET_POWERPC
+ tm_print_insn = gdb_print_insn_powerpc;
+#else
+ tm_print_insn = print_insn_rs6000;
+#endif
+}
projects / deliverable / binutils-gdb.git / blobdiff