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- /* Target-dependent code for GDB, the GNU debugger.
- Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995
- Free Software Foundation, Inc.
-
- 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 "target.h"
- #include "gdbcore.h"
-
- #include "xcoffsolib.h"
-
- #include <a.out.h>
-
- extern struct obstack frame_cache_obstack;
-
- extern int errno;
-
- /* Nonzero if we just simulated a single step break. */
- int one_stepped;
-
- /* Breakpoint shadows for the single step instructions will be kept here. */
-
- static struct sstep_breaks {
- /* Address, or 0 if this is not in use. */
- CORE_ADDR address;
- /* Shadow contents. */
- char data[4];
- } stepBreaks[2];
-
- /* Static function prototypes */
-
- static CORE_ADDR
- find_toc_address PARAMS ((CORE_ADDR pc));
-
- static CORE_ADDR
- branch_dest PARAMS ((int opcode, int instr, CORE_ADDR pc, CORE_ADDR safety));
-
- static void
- frame_get_cache_fsr PARAMS ((struct frame_info *fi,
- struct aix_framedata *fdatap));
-
- /*
- * Calculate the destination of a branch/jump. Return -1 if not a branch.
- */
- static CORE_ADDR
- branch_dest (opcode, instr, pc, safety)
- int opcode;
- int instr;
- CORE_ADDR pc;
- CORE_ADDR safety;
- {
- register long offset;
- CORE_ADDR dest;
- int immediate;
- int absolute;
- int ext_op;
-
- absolute = (int) ((instr >> 1) & 1);
-
- switch (opcode) {
- case 18 :
- immediate = ((instr & ~3) << 6) >> 6; /* br unconditional */
-
- case 16 :
- if (opcode != 18) /* br conditional */
- immediate = ((instr & ~3) << 16) >> 16;
- if (absolute)
- dest = immediate;
- else
- dest = pc + immediate;
- break;
-
- case 19 :
- ext_op = (instr>>1) & 0x3ff;
-
- if (ext_op == 16) /* br conditional register */
- dest = read_register (LR_REGNUM) & ~3;
-
- else if (ext_op == 528) /* br cond to count reg */
- {
- 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 < TEXT_SEGMENT_BASE) ? safety : dest;
- }
-
-
-
- /* AIX does not support PT_STEP. Simulate it. */
-
- void
- single_step (signal)
- int signal;
- {
- #define INSNLEN(OPCODE) 4
-
- static char breakp[] = BREAKPOINT;
- int ii, insn;
- CORE_ADDR loc;
- CORE_ADDR breaks[2];
- int opcode;
-
- if (!one_stepped) {
- loc = read_pc ();
-
- read_memory (loc, (char *) &insn, 4);
-
- breaks[0] = loc + INSNLEN(insn);
- 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 = 0;
-
- for (ii=0; ii < 2; ++ii) {
-
- /* ignore invalid breakpoint. */
- if ( breaks[ii] == -1)
- continue;
-
- read_memory (breaks[ii], stepBreaks[ii].data, 4);
-
- write_memory (breaks[ii], breakp, 4);
- stepBreaks[ii].address = breaks[ii];
- }
-
- one_stepped = 1;
- } else {
-
- /* remove step breakpoints. */
- for (ii=0; ii < 2; ++ii)
- if (stepBreaks[ii].address != 0)
- write_memory
- (stepBreaks[ii].address, stepBreaks[ii].data, 4);
-
- one_stepped = 0;
- }
- errno = 0; /* FIXME, don't ignore errors! */
- /* What errors? {read,write}_memory call error(). */
- }
-
-
- /* return pc value after skipping a function prologue. */
-
- skip_prologue (pc)
- CORE_ADDR pc;
- {
- char buf[4];
- unsigned int tmp;
- unsigned long op;
-
- if (target_read_memory (pc, buf, 4))
- return pc; /* Can't access it -- assume no prologue. */
- op = extract_unsigned_integer (buf, 4);
-
- /* Assume that subsequent fetches can fail with low probability. */
-
- if (op == 0x7c0802a6) { /* mflr r0 */
- pc += 4;
- op = read_memory_integer (pc, 4);
- }
-
- 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);
-
- /* 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 || /* crorc 15, 15, 15 */
- op == 0x0)
- return pc - 4; /* don't skip over this branch */
- }
-
- 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) */
- pc += 4;
- op = read_memory_integer (pc, 4);
- }
-
- while (((tmp = op >> 16) == 0x9001) || /* st r0, NUM(r1) */
- (tmp == 0x9421) || /* stu r1, NUM(r1) */
- (tmp == 0x93e1)) /* st r31,NUM(r1) */
- {
- pc += 4;
- op = read_memory_integer (pc, 4);
- }
-
- while ((tmp = (op >> 22)) == 0x20f) { /* l r31, ... or */
- pc += 4; /* l r30, ... */
- 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 */
- || op == 0x7c3f0b78) { /* mr r31, r1 */
- pc += 4; /* this happens if r31 is used as */
- op = read_memory_integer (pc, 4); /* frame ptr. (gcc does that) */
-
- 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;
- }
- }
- #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 */
-
- return pc;
- }
-
-
- /*************************************************************************
- 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. FIXMEibm */
-
- static int dummy_frame_count = 0;
- static int dummy_frame_size = 0;
- static CORE_ADDR *dummy_frame_addr = 0;
-
- extern int stop_stack_dummy;
-
- /* 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 ()
- {
- /* stack pointer. */
- CORE_ADDR sp;
-
- /* link register. */
- CORE_ADDR pc;
- /* Same thing, target byte order. */
- char pc_targ[4];
-
- int ii;
-
- target_fetch_registers (-1);
-
- if (dummy_frame_count >= dummy_frame_size) {
- dummy_frame_size += DUMMY_FRAME_ADDR_SIZE;
- if (dummy_frame_addr)
- dummy_frame_addr = (CORE_ADDR*) xrealloc
- (dummy_frame_addr, sizeof(CORE_ADDR) * (dummy_frame_size));
- else
- dummy_frame_addr = (CORE_ADDR*)
- xmalloc (sizeof(CORE_ADDR) * (dummy_frame_size));
- }
-
- sp = read_register(SP_REGNUM);
- pc = read_register(PC_REGNUM);
- memcpy (pc_targ, (char *) &pc, 4);
-
- 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 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-DUMMY_FRAME_SIZE);
-
- /* 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 ();
-
- /* save program counter in link register's space. */
- write_memory (sp+8, pc_targ, 4);
-
- /* save all floating point and general purpose registers here. */
-
- /* fpr's, f0..f31 */
- for (ii = 0; ii < 32; ++ii)
- write_memory (sp-8-(ii*8), ®isters[REGISTER_BYTE (31-ii+FP0_REGNUM)], 8);
-
- /* gpr's r0..r31 */
- 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.
- 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_targ, 4);
- }
-
-
- /* Pop a dummy frame.
-
- 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).
-
- 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
- */
-
- pop_dummy_frame ()
- {
- CORE_ADDR sp, pc;
- int ii;
- sp = dummy_frame_addr [--dummy_frame_count];
-
- /* restore all fpr's. */
- for (ii = 1; ii <= 32; ++ii)
- read_memory (sp-(ii*8), ®isters[REGISTER_BYTE (32-ii+FP0_REGNUM)], 8);
-
- /* restore all gpr's */
- for (ii=1; ii <= 32; ++ii) {
- read_memory (sp-256-(ii*4), ®isters[REGISTER_BYTE (32-ii)], 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
- one we should restore. Change it with the one we need. */
-
- *(int*)®isters [REGISTER_BYTE(FP_REGNUM)] = sp;
-
- /* Now we can restore all registers. */
-
- target_store_registers (-1);
- pc = read_pc ();
- flush_cached_frames ();
- }
-
-
- /* pop the innermost frame, go back to the caller. */
-
- void
- pop_frame ()
- {
- CORE_ADDR pc, lr, sp, prev_sp; /* %pc, %lr, %sp */
- struct aix_framedata fdata;
- struct frame_info *frame = get_current_frame ();
- int addr, ii;
-
- pc = read_pc ();
- 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 (frame->pc) + FUNCTION_START_OFFSET;
- function_frame_info (addr, &fdata);
-
- if (fdata.frameless)
- prev_sp = sp;
- else
- prev_sp = read_memory_integer (sp, 4);
- if (fdata.nosavedpc)
- lr = read_register (LR_REGNUM);
- else
- lr = read_memory_integer (prev_sp+8, 4);
-
- /* reset %pc value. */
- write_register (PC_REGNUM, lr);
-
- /* reset register values if any was saved earlier. */
- addr = prev_sp - fdata.offset;
-
- if (fdata.saved_gpr != -1)
- for (ii = fdata.saved_gpr; ii <= 31; ++ii) {
- read_memory (addr, ®isters [REGISTER_BYTE (ii)], 4);
- addr += 4;
- }
-
- 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);
- target_store_registers (-1);
- flush_cached_frames ();
- }
-
- /* fixup the call sequence of a dummy function, with the real function address.
- its argumets will be passed by gdb. */
-
- void
- fix_call_dummy(dummyname, pc, fun, nargs, type)
- char *dummyname;
- CORE_ADDR pc;
- CORE_ADDR fun;
- int nargs; /* not used */
- int type; /* not used */
- {
- #define TOC_ADDR_OFFSET 20
- #define TARGET_ADDR_OFFSET 28
-
- int ii;
- CORE_ADDR target_addr;
- CORE_ADDR tocvalue;
-
- target_addr = fun;
- tocvalue = find_toc_address (target_addr);
-
- 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 + TARGET_ADDR_OFFSET);
- ii = (ii & 0xffff0000) | (target_addr >> 16);
- *(int*)((char*)dummyname + TARGET_ADDR_OFFSET) = ii;
-
- ii = *(int*)((char*)dummyname + TARGET_ADDR_OFFSET+4);
- ii = (ii & 0xffff0000) | (target_addr & 0x0000ffff);
- *(int*)((char*)dummyname + TARGET_ADDR_OFFSET+4) = ii;
- }
-
-
- /* return information about a function frame.
- in struct aix_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.
- */
- void
- function_frame_info (pc, fdata)
- CORE_ADDR pc;
- struct aix_framedata *fdata;
- {
- unsigned int tmp;
- register unsigned int op;
- char buf[4];
-
- fdata->offset = 0;
- fdata->saved_gpr = fdata->saved_fpr = fdata->alloca_reg = -1;
- fdata->frameless = 1;
-
- /* Do not error out if we can't access the instructions. */
- if (target_read_memory (pc, buf, 4))
- return;
- op = extract_unsigned_integer (buf, 4);
- if (op == 0x7c0802a6) { /* mflr r0 */
- pc += 4;
- op = read_memory_integer (pc, 4);
- fdata->nosavedpc = 0;
- fdata->frameless = 0;
- }
- else /* else, pc is not saved */
- fdata->nosavedpc = 1;
-
- if ((op & 0xfc00003e) == 0x7c000026) { /* mfcr Rx */
- pc += 4;
- op = read_memory_integer (pc, 4);
- fdata->frameless = 0;
- }
-
- if ((op & 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
- pc += 4;
- op = read_memory_integer (pc, 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 || /* crorc 15, 15, 15 */
- op == 0x0)
- return; /* prologue is over */
- fdata->frameless = 0;
- }
-
- if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
- pc += 4; /* store floating register double */
- op = read_memory_integer (pc, 4);
- fdata->frameless = 0;
- }
-
- if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
- int tmp2;
- fdata->saved_gpr = (op >> 21) & 0x1f;
- tmp2 = op & 0xffff;
- if (tmp2 > 0x7fff)
- tmp2 = (~0 &~ 0xffff) | tmp2;
-
- if (tmp2 < 0) {
- tmp2 = tmp2 * -1;
- fdata->saved_fpr = (tmp2 - ((32 - fdata->saved_gpr) * 4)) / 8;
- if ( fdata->saved_fpr > 0)
- fdata->saved_fpr = 32 - fdata->saved_fpr;
- else
- fdata->saved_fpr = -1;
- }
- fdata->offset = tmp2;
- pc += 4;
- op = read_memory_integer (pc, 4);
- fdata->frameless = 0;
- }
-
- while (((tmp = op >> 16) == 0x9001) || /* st r0, NUM(r1) */
- (tmp == 0x9421) || /* stu r1, NUM(r1) */
- (tmp == 0x93e1)) /* st r31, NUM(r1) */
- {
- int tmp2;
-
- /* gcc takes a short cut and uses this instruction to save r31 only. */
-
- if (tmp == 0x93e1) {
- if (fdata->offset)
- /* fatal ("Unrecognized prolog."); */
- printf_unfiltered ("Unrecognized prolog!\n");
-
- fdata->saved_gpr = 31;
- tmp2 = op & 0xffff;
- if (tmp2 > 0x7fff) {
- tmp2 = - ((~0 &~ 0xffff) | tmp2);
- fdata->saved_fpr = (tmp2 - ((32 - 31) * 4)) / 8;
- if ( fdata->saved_fpr > 0)
- fdata->saved_fpr = 32 - fdata->saved_fpr;
- else
- fdata->saved_fpr = -1;
- }
- fdata->offset = tmp2;
- }
- pc += 4;
- op = read_memory_integer (pc, 4);
- fdata->frameless = 0;
- }
-
- while ((tmp = (op >> 22)) == 0x20f) { /* l r31, ... or */
- pc += 4; /* l r30, ... */
- op = read_memory_integer (pc, 4);
- fdata->frameless = 0;
- }
-
- /* 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);
- fdata->frameless = 0;
- }
-
- if (op == 0x603f0000 /* oril r31, r1, 0x0 */
- || op == 0x7c3f0b78) /* mr r31, r1 */
- {
- fdata->alloca_reg = 31;
- fdata->frameless = 0;
- }
- }
-
-
- /* 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,
- starting from r4. */
-
- CORE_ADDR
- push_arguments (nargs, args, sp, struct_return, struct_addr)
- int nargs;
- value_ptr *args;
- CORE_ADDR sp;
- int struct_return;
- CORE_ADDR struct_addr;
- {
- int ii, len;
- int argno; /* current argument number */
- int argbytes; /* current argument byte */
- char tmp_buffer [50];
- value_ptr arg;
- int f_argno = 0; /* current floating point argno */
-
- CORE_ADDR saved_sp, pc;
-
- if ( dummy_frame_count <= 0)
- printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n");
-
- /* The first eight words of ther arguments are passed in registers. Copy
- them appropriately.
-
- If the function is returning a `struct', then the first word (which
- will be passed in r3) is used for struct return address. In that
- case we should advance one word and start from r4 register to copy
- parameters. */
-
- ii = struct_return ? 1 : 0;
-
- for (argno=0, argbytes=0; argno < nargs && ii<8; ++ii) {
-
- arg = value_arg_coerce (args[argno]);
- len = TYPE_LENGTH (VALUE_TYPE (arg));
-
- if (TYPE_CODE (VALUE_TYPE (arg)) == 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_unfiltered (
- "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno);
-
- memcpy (®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], VALUE_CONTENTS (arg),
- len);
- ++f_argno;
- }
-
- if (len > 4) {
-
- /* Argument takes more than one register. */
- while (argbytes < len) {
-
- *(int*)®isters[REGISTER_BYTE(ii+3)] = 0;
- memcpy (®isters[REGISTER_BYTE(ii+3)],
- ((char*)VALUE_CONTENTS (arg))+argbytes,
- (len - argbytes) > 4 ? 4 : len - argbytes);
- ++ii, argbytes += 4;
-
- if (ii >= 8)
- goto ran_out_of_registers_for_arguments;
- }
- argbytes = 0;
- --ii;
- }
- else { /* Argument can fit in one register. No problem. */
- *(int*)®isters[REGISTER_BYTE(ii+3)] = 0;
- memcpy (®isters[REGISTER_BYTE(ii+3)], VALUE_CONTENTS (arg), len);
- }
- ++argno;
- }
-
- ran_out_of_registers_for_arguments:
-
- /* location for 8 parameters are always reserved. */
- sp -= 4 * 8;
-
- /* another six words for back chain, TOC register, link register, etc. */
- sp -= 24;
-
- /* if there are more arguments, allocate space for them in
- the stack, then push them starting from the ninth one. */
-
- if ((argno < nargs) || argbytes) {
- int space = 0, jj;
- value_ptr val;
-
- if (argbytes) {
- space += ((len - argbytes + 3) & -4);
- jj = argno + 1;
- }
- else
- jj = argno;
-
- for (; jj < nargs; ++jj) {
- val = value_arg_coerce (args[jj]);
- space += ((TYPE_LENGTH (VALUE_TYPE (val))) + 3) & -4;
- }
-
- /* add location required for the rest of the parameters */
- space = (space + 7) & -8;
- sp -= space;
-
- /* This is another instance we need to be concerned about securing our
- stack space. If we write anything underneath %sp (r1), we might conflict
- with the kernel who thinks he is free to use this area. So, update %sp
- first before doing anything else. */
-
- write_register (SP_REGNUM, sp);
-
- /* if the last argument copied into the registers didn't fit there
- completely, push the rest of it into stack. */
-
- if (argbytes) {
- write_memory (
- sp+24+(ii*4), ((char*)VALUE_CONTENTS (arg))+argbytes, len - argbytes);
- ++argno;
- ii += ((len - argbytes + 3) & -4) / 4;
- }
-
- /* push the rest of the arguments into stack. */
- for (; argno < nargs; ++argno) {
-
- arg = value_arg_coerce (args[argno]);
- len = TYPE_LENGTH (VALUE_TYPE (arg));
-
-
- /* 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 (len > 8)
- printf_unfiltered (
- "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno);
-
- memcpy (®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], VALUE_CONTENTS (arg),
- len);
- ++f_argno;
- }
-
- write_memory (sp+24+(ii*4), (char *) VALUE_CONTENTS (arg), len);
- ii += ((len + 3) & -4) / 4;
- }
- }
- else
- /* Secure stack areas first, before doing anything else. */
- write_register (SP_REGNUM, sp);
-
- 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 */
-
- 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;
- {
-
- if (TYPE_CODE (valtype) == TYPE_CODE_FLT) {
-
- double dd; float ff;
- /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes.
- We need to truncate the return value into float size (4 byte) if
- necessary. */
-
- if (TYPE_LENGTH (valtype) > 4) /* this is a double */
- memcpy (valbuf, ®buf[REGISTER_BYTE (FP0_REGNUM + 1)],
- TYPE_LENGTH (valtype));
- else { /* float */
- memcpy (&dd, ®buf[REGISTER_BYTE (FP0_REGNUM + 1)], 8);
- ff = (float)dd;
- memcpy (valbuf, &ff, sizeof(float));
- }
- }
- else
- /* return value is copied starting from r3. */
- memcpy (valbuf, ®buf[REGISTER_BYTE (3)], TYPE_LENGTH (valtype));
- }
-
-
- /* 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;
-
-
- /* 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)
- CORE_ADDR pc;
- {
- register unsigned int ii, op;
- CORE_ADDR solib_target_pc;
-
- static unsigned trampoline_code[] = {
- 0x800b0000, /* l r0,0x0(r11) */
- 0x90410014, /* st r2,0x14(r1) */
- 0x7c0903a6, /* mtctr r0 */
- 0x804b0004, /* l r2,0x4(r11) */
- 0x816b0008, /* l r11,0x8(r11) */
- 0x4e800420, /* bctr */
- 0x4e800020, /* br */
- 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 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.
- Called from the FRAMELESS_FUNCTION_INVOCATION macro in tm.h with a
- second argument of 0, and from the FRAME_SAVED_PC macro with a
- second argument of 1. */
-
- int
- frameless_function_invocation (fi, pcsaved)
- struct frame_info *fi;
- int pcsaved;
- {
- CORE_ADDR func_start;
- struct aix_framedata fdata;
-
- if (fi->next != NULL)
- /* Don't even think about framelessness except on the innermost frame. */
- /* FIXME: Can also be frameless if fi->next->signal_handler_caller (if
- a signal happens while executing in a frameless function). */
- return 0;
-
- 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;
-
- function_frame_info (func_start, &fdata);
- return pcsaved ? fdata.nosavedpc : fdata.frameless;
- }
-
-
- /* If saved registers of frame FI are not known yet, read and cache them.
- &FDATAP contains aix_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 aix_framedata *fdatap;
- {
- int ii;
- CORE_ADDR frame_addr;
- struct aix_framedata work_fdata;
-
- if (fi->cache_fsr)
- return;
-
- if (fdatap == NULL) {
- fdatap = &work_fdata;
- function_frame_info (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 right underneath caller
- stack pointer, starting from fp31 first. */
-
- if (fdatap->saved_fpr >= 0) {
- for (ii=31; ii >= fdatap->saved_fpr; --ii)
- fi->cache_fsr->regs [FP0_REGNUM + ii] = frame_addr - ((32 - ii) * 8);
- frame_addr -= (32 - fdatap->saved_fpr) * 8;
- }
-
- /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr.
- All gpr's from saved_gpr to gpr31 are saved right under saved fprs,
- starting from r31 first. */
-
- if (fdatap->saved_gpr >= 0)
- for (ii=31; ii >= fdatap->saved_gpr; --ii)
- fi->cache_fsr->regs [ii] = frame_addr - ((32 - ii) * 4);
- }
-
- /* 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 aix_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.. */
-
- function_frame_info (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
- fp = read_memory_integer ((thisframe)->frame, 4);
-
- return fp;
- }
-
- /* Keep an array of load segment information and their TOC table addresses.
- This info will be useful when calling a shared library function by hand. */
-
- struct loadinfo {
- CORE_ADDR textorg, dataorg;
- unsigned long toc_offset;
- };
-
- #define LOADINFOLEN 10
-
- static struct loadinfo *loadinfo = NULL;
- static int loadinfolen = 0;
- static int loadinfotocindex = 0;
- static int loadinfotextindex = 0;
-
-
- void
- xcoff_init_loadinfo ()
- {
- loadinfotocindex = 0;
- loadinfotextindex = 0;
-
- if (loadinfolen == 0) {
- loadinfo = (struct loadinfo *)
- xmalloc (sizeof (struct loadinfo) * LOADINFOLEN);
- loadinfolen = LOADINFOLEN;
- }
- }
-
-
- /* FIXME -- this is never called! */
- void
- free_loadinfo ()
- {
- if (loadinfo)
- free (loadinfo);
- loadinfo = NULL;
- loadinfolen = 0;
- loadinfotocindex = 0;
- loadinfotextindex = 0;
- }
-
- /* this is called from xcoffread.c */
-
- void
- xcoff_add_toc_to_loadinfo (unsigned long tocoff)
- {
- while (loadinfotocindex >= loadinfolen) {
- loadinfolen += LOADINFOLEN;
- loadinfo = (struct loadinfo *)
- xrealloc (loadinfo, sizeof(struct loadinfo) * loadinfolen);
- }
- loadinfo [loadinfotocindex++].toc_offset = tocoff;
- }
-
- void
- add_text_to_loadinfo (textaddr, dataaddr)
- CORE_ADDR textaddr;
- CORE_ADDR dataaddr;
- {
- while (loadinfotextindex >= loadinfolen) {
- loadinfolen += LOADINFOLEN;
- loadinfo = (struct loadinfo *)
- xrealloc (loadinfo, sizeof(struct loadinfo) * loadinfolen);
- }
- loadinfo [loadinfotextindex].textorg = textaddr;
- loadinfo [loadinfotextindex].dataorg = dataaddr;
- ++loadinfotextindex;
- }
-
-
- /* FIXME: This assumes that the "textorg" and "dataorg" elements
- of a member of this array are correlated with the "toc_offset"
- element of the same member. But they are sequentially assigned in wildly
- different places, and probably there is no correlation. FIXME! */
-
- static CORE_ADDR
- find_toc_address (pc)
- CORE_ADDR pc;
- {
- int ii, toc_entry, tocbase = 0;
-
- for (ii=0; ii < loadinfotextindex; ++ii)
- if (pc > loadinfo[ii].textorg && loadinfo[ii].textorg > tocbase) {
- toc_entry = ii;
- tocbase = loadinfo[ii].textorg;
- }
-
- return loadinfo[toc_entry].dataorg + loadinfo[toc_entry].toc_offset;
- }
-
- void
- _initialize_rs6000_tdep ()
- {
- /* FIXME, this should not be decided via ifdef. */
- #ifdef GDB_TARGET_POWERPC
- tm_print_insn = print_insn_big_powerpc;
- #else
- tm_print_insn = print_insn_rs6000;
- #endif
- }
-