#include "gdbcore.h"
#include "value.h"
#include "dis-asm.h"
+#include "inferior.h" /* for BEFORE_TEXT_END etc. */
extern int remote_write_size; /* in remote.c */
sh_frame_chain (frame)
struct frame_info *frame;
{
+ if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
+ return frame->frame; /* dummy frame same as caller's frame */
if (!inside_entry_file (frame->pc))
return read_memory_integer (FRAME_FP (frame) + frame->f_offset, 4);
else
return 0;
}
+/* 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. */
+
+CORE_ADDR
+sh_find_callers_reg (fi, regnum)
+ struct frame_info *fi;
+ int regnum;
+{
+ struct frame_saved_regs fsr;
+
+ for (; fi; fi = fi->next)
+ if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
+ /* When the caller requests PR from the dummy frame, we return PC because
+ that's where the previous routine appears to have done a call from. */
+ return generic_read_register_dummy (fi->pc, fi->frame, regnum);
+ else
+ {
+ FRAME_FIND_SAVED_REGS(fi, fsr);
+ if (fsr.regs[regnum] != 0)
+ return read_memory_integer (fsr.regs[regnum],
+ REGISTER_RAW_SIZE(regnum));
+ }
+ return read_register (regnum);
+}
+
/* Put here the code to store, into a struct frame_saved_regs, the
addresses of the saved registers of frame described by FRAME_INFO.
This includes special registers such as pc and fp saved in special
return for it IS the sp for the next frame. */
void
-frame_find_saved_regs (fi, fsr)
+sh_frame_find_saved_regs (fi, fsr)
struct frame_info *fi;
struct frame_saved_regs *fsr;
{
int opc;
int insn;
int r3_val = 0;
+ char * dummy_regs = generic_find_dummy_frame (fi->pc, fi->frame);
+
+ if (dummy_regs)
+ {
+ /* DANGER! This is ONLY going to work if the char buffer format of
+ the saved registers is byte-for-byte identical to the
+ CORE_ADDR regs[NUM_REGS] format used by struct frame_saved_regs! */
+ memcpy (&fsr->regs, dummy_regs, sizeof(fsr));
+ return;
+ }
opc = pc = get_pc_function_start (fi->pc);
fi->f_offset = depth - where[FP_REGNUM] - 4;
/* Work out the return pc - either from the saved pr or the pr
value */
-
- if (fsr->regs[PR_REGNUM])
- fi->return_pc = read_memory_integer (fsr->regs[PR_REGNUM], 4);
- else
- fi->return_pc = read_register (PR_REGNUM);
}
/* initialize the extra info saved in a FRAME */
void
-init_extra_frame_info (fromleaf, fi)
+sh_init_extra_frame_info (fromleaf, fi)
int fromleaf;
struct frame_info *fi;
{
- struct frame_saved_regs dummy;
+ struct frame_saved_regs fsr;
if (fi->next)
- fi->pc = fi->next->return_pc;
+ fi->pc = FRAME_SAVED_PC (fi->next);
- frame_find_saved_regs (fi, &dummy);
+ if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
+ {
+ /* We need to setup fi->frame here because run_stack_dummy gets it wrong
+ by assuming it's always FP. */
+ fi->frame = generic_read_register_dummy (fi->pc, fi->frame,
+ SP_REGNUM);
+ fi->return_pc = generic_read_register_dummy (fi->pc, fi->frame,
+ PC_REGNUM);
+ fi->f_offset = -(CALL_DUMMY_LENGTH + 4);
+ fi->leaf_function = 0;
+ return;
+ }
+ else
+ {
+ FRAME_FIND_SAVED_REGS (fi, fsr);
+ fi->return_pc = sh_find_callers_reg (fi, PR_REGNUM);
+ }
}
-
/* Discard from the stack the innermost frame,
restoring all saved registers. */
void
-pop_frame ()
+sh_pop_frame ()
{
register struct frame_info *frame = get_current_frame ();
register CORE_ADDR fp;
register int regnum;
struct frame_saved_regs fsr;
- fp = FRAME_FP (frame);
- get_frame_saved_regs (frame, &fsr);
+ if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
+ generic_pop_dummy_frame ();
+ else
+ {
+ fp = FRAME_FP (frame);
+ get_frame_saved_regs (frame, &fsr);
- /* Copy regs from where they were saved in the frame */
- for (regnum = 0; regnum < NUM_REGS; regnum++)
- {
+ /* Copy regs from where they were saved in the frame */
+ for (regnum = 0; regnum < NUM_REGS; regnum++)
if (fsr.regs[regnum])
+ write_register (regnum, read_memory_integer (fsr.regs[regnum], 4));
+
+ write_register (PC_REGNUM, frame->return_pc);
+ write_register (SP_REGNUM, fp + 4);
+ }
+ flush_cached_frames ();
+}
+
+/* Function: push_arguments
+ Setup the function arguments for calling a function in the inferior.
+
+ On the Hitachi SH architecture, there are four registers (R4 to R7)
+ which are dedicated for passing function arguments. Up to the first
+ four arguments (depending on size) may go into these registers.
+ The rest go on the stack.
+
+ Arguments that are smaller than 4 bytes will still take up a whole
+ register or a whole 32-bit word on the stack, and will be
+ right-justified in the register or the stack word. This includes
+ chars, shorts, and small aggregate types.
+
+ Arguments that are larger than 4 bytes may be split between two or
+ more registers. If there are not enough registers free, an argument
+ may be passed partly in a register (or registers), and partly on the
+ stack. This includes doubles, long longs, and larger aggregates.
+ As far as I know, there is no upper limit to the size of aggregates
+ that will be passed in this way; in other words, the convention of
+ passing a pointer to a large aggregate instead of a copy is not used.
+
+ An exceptional case exists for struct arguments (and possibly other
+ aggregates such as arrays) if the size is larger than 4 bytes but
+ not a multiple of 4 bytes. In this case the argument is never split
+ between the registers and the stack, but instead is copied in its
+ entirety onto the stack, AND also copied into as many registers as
+ there is room for. In other words, space in registers permitting,
+ two copies of the same argument are passed in. As far as I can tell,
+ only the one on the stack is used, although that may be a function
+ of the level of compiler optimization. I suspect this is a compiler
+ bug. Arguments of these odd sizes are left-justified within the
+ word (as opposed to arguments smaller than 4 bytes, which are
+ right-justified).
+
+
+ If the function is to return an aggregate type such as a struct, it
+ is either returned in the normal return value register R0 (if its
+ size is no greater than one byte), or else the caller must allocate
+ space into which the callee will copy the return value (if the size
+ is greater than one byte). In this case, a pointer to the return
+ value location is passed into the callee in register R2, which does
+ not displace any of the other arguments passed in via registers R4
+ to R7. */
+
+CORE_ADDR
+sh_push_arguments (nargs, args, sp, struct_return, struct_addr)
+ int nargs;
+ value_ptr *args;
+ CORE_ADDR sp;
+ unsigned char struct_return;
+ CORE_ADDR struct_addr;
+{
+ int stack_offset, stack_alloc;
+ int argreg;
+ int argnum;
+ struct type *type;
+ CORE_ADDR regval;
+ char *val;
+ char valbuf[4];
+ int len;
+ int odd_sized_struct;
+
+ /* first force sp to a 4-byte alignment */
+ sp = sp & ~3;
+
+ /* The "struct return pointer" pseudo-argument has its own dedicated
+ register */
+ if (struct_return)
+ write_register (STRUCT_RETURN_REGNUM, struct_addr);
+
+ /* Now make sure there's space on the stack */
+ for (argnum = 0, stack_alloc = 0;
+ argnum < nargs; argnum++)
+ stack_alloc += ((TYPE_LENGTH(VALUE_TYPE(args[argnum])) + 3) & ~3);
+ sp -= stack_alloc; /* make room on stack for args */
+
+
+ /* Now load as many as possible of the first arguments into
+ registers, and push the rest onto the stack. There are 16 bytes
+ in four registers available. Loop thru args from first to last. */
+
+ argreg = ARG0_REGNUM;
+ for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++)
+ {
+ type = VALUE_TYPE (args[argnum]);
+ len = TYPE_LENGTH (type);
+ memset(valbuf, 0, sizeof(valbuf));
+ if (len < 4)
+ { /* value gets right-justified in the register or stack word */
+ memcpy(valbuf + (4 - len),
+ (char *) VALUE_CONTENTS (args[argnum]), len);
+ val = valbuf;
+ }
+ else
+ val = (char *) VALUE_CONTENTS (args[argnum]);
+
+ if (len > 4 && (len & 3) != 0)
+ odd_sized_struct = 1; /* such structs go entirely on stack */
+ else
+ odd_sized_struct = 0;
+ while (len > 0)
{
- write_register (regnum, read_memory_integer (fsr.regs[regnum], 4));
+ if (argreg > ARGLAST_REGNUM || odd_sized_struct)
+ { /* must go on the stack */
+ write_memory (sp + stack_offset, val, 4);
+ stack_offset += 4;
+ }
+ /* NOTE WELL!!!!! This is not an "else if" clause!!!
+ That's because some *&^%$ things get passed on the stack
+ AND in the registers! */
+ if (argreg <= ARGLAST_REGNUM)
+ { /* there's room in a register */
+ regval = extract_address (val, REGISTER_RAW_SIZE(argreg));
+ write_register (argreg++, regval);
+ }
+ /* Store the value 4 bytes at a time. This means that things
+ larger than 4 bytes may go partly in registers and partly
+ on the stack. */
+ len -= REGISTER_RAW_SIZE(argreg);
+ val += REGISTER_RAW_SIZE(argreg);
}
}
+ return sp;
+}
- write_register (PC_REGNUM, frame->return_pc);
- write_register (SP_REGNUM, fp + 4);
- flush_cached_frames ();
+/* Function: push_return_address (pc)
+ Set up the return address for the inferior function call.
+ Needed for targets where we don't actually execute a JSR/BSR instruction */
+
+CORE_ADDR
+sh_push_return_address (pc, sp)
+ CORE_ADDR pc;
+ CORE_ADDR sp;
+{
+ write_register (PR_REGNUM, CALL_DUMMY_ADDRESS ());
+ return sp;
+}
+
+/* Function: fix_call_dummy
+ Poke the callee function's address into the destination part of
+ the CALL_DUMMY. The address is actually stored in a data word
+ following the actualy CALL_DUMMY instructions, which will load
+ it into a register using PC-relative addressing. This function
+ expects the CALL_DUMMY to look like this:
+
+ mov.w @(2,PC), R8
+ jsr @R8
+ nop
+ trap
+ <destination>
+ */
+
+int
+sh_fix_call_dummy (dummy, pc, fun, nargs, args, type, gcc_p)
+ char *dummy;
+ CORE_ADDR pc;
+ CORE_ADDR fun;
+ int nargs;
+ value_ptr *args;
+ struct type *type;
+ int gcc_p;
+{
+ *(unsigned long *) (dummy + 8) = fun;
+}
+
+/* Function: get_saved_register
+ Just call the generic_get_saved_register function. */
+
+void
+get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval)
+ char *raw_buffer;
+ int *optimized;
+ CORE_ADDR *addrp;
+ struct frame_info *frame;
+ int regnum;
+ enum lval_type *lval;
+{
+ generic_get_saved_register (raw_buffer, optimized, addrp,
+ frame, regnum, lval);
}
+
/* Command to set the processor type. */
void
/* Print the registers in a form similar to the E7000 */
static void
-show_regs (args, from_tty)
+sh_show_regs (args, from_tty)
char *args;
int from_tty;
{
read_register (14),
read_register (15));
}
-\f
+
+/* Function: extract_return_value
+ Find a function's return value in the appropriate registers (in regbuf),
+ and copy it into valbuf. */
+
+void
+sh_extract_return_value (type, regbuf, valbuf)
+ struct type *type;
+ void *regbuf;
+ void *valbuf;
+{
+ int len = TYPE_LENGTH(type);
+
+ if (len <= 4)
+ memcpy (valbuf, ((char *) regbuf) + 4 - len, len);
+ else if (len <= 8)
+ memcpy (valbuf, ((char *) regbuf) + 8 - len, len);
+ else
+ error ("bad size for return value");
+}
+
void
_initialize_sh_tdep ()
{
tmp_sh_processor_type = strsave (DEFAULT_SH_TYPE);
sh_set_processor_type_command (strsave (DEFAULT_SH_TYPE), 0);
- add_com ("regs", class_vars, show_regs, "Print all registers");
+ add_com ("regs", class_vars, sh_show_regs, "Print all registers");
/* Reduce the remote write size because some CMONs can't take
more than 400 bytes in a packet. 300 seems like a safe bet. */
remote_write_size = 300;
}
+