#include "gdbcore.h"
#include "symfile.h"
-/* Info gleaned from scanning a function's prologue. */
-
-struct pifsr /* Info about one saved reg */
+/* The main purpose of this file is dealing with prologues to extract
+ information about stack frames and saved registers.
+
+ For reference here's how prologues look on the mn10200:
+
+ With frame pointer:
+ mov fp,a0
+ mov sp,fp
+ add <size>,sp
+ Register saves for d2, d3, a1, a2 as needed. Saves start
+ at fp - <size> + <outgoing_args_size> and work towards higher
+ addresses. Note that the saves are actually done off the stack
+ pointer in the prologue! This makes for smaller code and easier
+ prologue scanning as the displacement fields will unlikely
+ be more than 8 bits!
+
+ Without frame pointer:
+ add <size>,sp
+ Register saves for d2, d3, a1, a2 as needed. Saves start
+ at sp + <outgoing_args_size> and work towards higher addresses.
+
+ Out of line prologue:
+ add <local size>,sp -- optional
+ jsr __prologue
+ add <outgoing_size>,sp -- optional
+
+ The stack pointer remains constant throughout the life of most
+ functions. As a result the compiler will usually omit the
+ frame pointer, so we must handle frame pointerless functions. */
+
+/* Analyze the prologue to determine where registers are saved,
+ the end of the prologue, etc etc. Return the end of the prologue
+ scanned.
+
+ We store into FI (if non-null) several tidbits of information:
+
+ * stack_size -- size of this stack frame. Note that if we stop in
+ certain parts of the prologue/epilogue we may claim the size of the
+ current frame is zero. This happens when the current frame has
+ not been allocated yet or has already been deallocated.
+
+ * fsr -- Addresses of registers saved in the stack by this frame.
+
+ * status -- A (relatively) generic status indicator. It's a bitmask
+ with the following bits:
+
+ MY_FRAME_IN_SP: The base of the current frame is actually in
+ the stack pointer. This can happen for frame pointerless
+ functions, or cases where we're stopped in the prologue/epilogue
+ itself. For these cases mn10200_analyze_prologue will need up
+ update fi->frame before returning or analyzing the register
+ save instructions.
+
+ MY_FRAME_IN_FP: The base of the current frame is in the
+ frame pointer register ($a2).
+
+ CALLER_A2_IN_A0: $a2 from the caller's frame is temporarily
+ in $a0. This can happen if we're stopped in the prologue.
+
+ NO_MORE_FRAMES: Set this if the current frame is "start" or
+ if the first instruction looks like mov <imm>,sp. This tells
+ frame chain to not bother trying to unwind past this frame. */
+
+#define MY_FRAME_IN_SP 0x1
+#define MY_FRAME_IN_FP 0x2
+#define CALLER_A2_IN_A0 0x4
+#define NO_MORE_FRAMES 0x8
+
+static CORE_ADDR
+mn10200_analyze_prologue (fi, pc)
+ struct frame_info *fi;
+ CORE_ADDR pc;
{
- int framereg; /* Frame reg (SP or FP) */
- int offset; /* Offset from framereg */
- int reg; /* Saved register number */
-};
+ CORE_ADDR func_addr, func_end, addr, stop;
+ CORE_ADDR stack_size;
+ unsigned char buf[4];
+ int status;
+ char *name;
+ int out_of_line_prologue = 0;
+
+ /* Use the PC in the frame if it's provided to look up the
+ start of this function. */
+ pc = (fi ? fi->pc : pc);
+
+ /* Find the start of this function. */
+ status = find_pc_partial_function (pc, &name, &func_addr, &func_end);
+
+ /* Do nothing if we couldn't find the start of this function or if we're
+ stopped at the first instruction in the prologue. */
+ if (status == 0)
+ return pc;
+
+ /* If we're in start, then give up. */
+ if (strcmp (name, "start") == 0)
+ {
+ fi->status = NO_MORE_FRAMES;
+ return pc;
+ }
-struct prologue_info
-{
- int framereg;
- int frameoffset;
- int start_function;
- struct pifsr *pifsrs;
-};
+ /* At the start of a function our frame is in the stack pointer. */
+ if (fi)
+ fi->status = MY_FRAME_IN_SP;
-/* Function: frame_chain
- Figure out and return the caller's frame pointer given current
- frame_info struct.
+ /* If we're physically on an RTS instruction, then our frame has already
+ been deallocated.
- We start out knowing the current pc, current sp, current fp.
- We want to determine the caller's fp and caller's pc. To do this
- correctly, we have to be able to handle the case where we are in the
- middle of the prologue which involves scanning the prologue.
+ fi->frame is bogus, we need to fix it. */
+ if (fi && fi->pc + 1 == func_end)
+ {
+ status = target_read_memory (fi->pc, buf, 1);
+ if (status != 0)
+ {
+ if (fi->next == NULL)
+ fi->frame = read_sp ();
+ return fi->pc;
+ }
- We don't handle dummy frames yet but we would probably just return the
- stack pointer that was in use at the time the function call was made?
-*/
+ if (buf[0] == 0xfe)
+ {
+ if (fi->next == NULL)
+ fi->frame = read_sp ();
+ return fi->pc;
+ }
+ }
-CORE_ADDR
-mn10200_frame_chain (fi)
- struct frame_info *fi;
-{
- struct prologue_info pi;
- CORE_ADDR callers_pc, callers_fp, curr_sp;
- CORE_ADDR past_prologue_addr;
- int past_prologue = 1; /* default to being past prologue */
- int n_movm_args = 4;
-
- struct pifsr *pifsr, *pifsr_tmp;
-
- /* current pc is fi->pc */
- /* current fp is fi->frame */
- /* current sp is: */
- curr_sp = read_register (SP_REGNUM);
-
-/*
- printf("curr pc = 0x%x ; curr fp = 0x%x ; curr sp = 0x%x\n",
- fi->pc, fi->frame, curr_sp);
-*/
-
- /* first inst after prologue is: */
- past_prologue_addr = mn10200_skip_prologue (fi->pc);
-
- /* Are we in the prologue? */
- /* Yes if mn10200_skip_prologue returns an address after the
- current pc in which case we have to scan prologue */
- if (fi->pc < mn10200_skip_prologue (fi->pc))
- past_prologue = 0;
-
- /* scan prologue if we're not past it */
- if (!past_prologue)
+ /* Similarly if we're stopped on the first insn of a prologue as our
+ frame hasn't been allocated yet. */
+ if (fi && fi->pc == func_addr)
+ {
+ if (fi->next == NULL)
+ fi->frame = read_sp ();
+ return fi->pc;
+ }
+
+ /* Figure out where to stop scanning. */
+ stop = fi ? fi->pc : func_end;
+
+ /* Don't walk off the end of the function. */
+ stop = stop > func_end ? func_end : stop;
+
+ /* Start scanning on the first instruction of this function. */
+ addr = func_addr;
+
+ status = target_read_memory (addr, buf, 2);
+ if (status != 0)
{
- /* printf("scanning prologue\n"); */
- /* FIXME -- fill out this case later */
- return 0x0; /* bogus value */
+ if (fi && fi->next == NULL && fi->status & MY_FRAME_IN_SP)
+ fi->frame = read_sp ();
+ return addr;
}
- if (past_prologue) /* if we don't need to scan the prologue */
+ /* First see if this insn sets the stack pointer; if so, it's something
+ we won't understand, so quit now. */
+ if (buf[0] == 0xdf
+ || (buf[0] == 0xf4 && buf[1] == 0x77))
{
- callers_pc = fi->frame - REGISTER_SIZE;
- callers_fp = fi->frame - (4 * REGISTER_SIZE);
-
-#if 0
- printf("callers_pc = 0x%x ; callers_fp = 0x%x\n",
- callers_pc, callers_fp);
- printf("*callers_pc = 0x%x ; *callers_fp = 0x%x\n",
- read_memory_integer(callers_pc, REGISTER_SIZE),
- read_memory_integer(callers_fp, REGISTER_SIZE));
-#endif
-
- return read_memory_integer(callers_fp, REGISTER_SIZE);
+ if (fi)
+ fi->status = NO_MORE_FRAMES;
+ return addr;
}
- /* we don't get here */
+ /* Now see if we have a frame pointer.
+
+ Search for mov a2,a0 (0xf278)
+ then mov a3,a2 (0xf27e). */
+
+ if (buf[0] == 0xf2 && buf[1] == 0x78)
+ {
+ /* Our caller's $a2 will be found in $a0 now. Note it for
+ our callers. */
+ if (fi)
+ fi->status |= CALLER_A2_IN_A0;
+ addr += 2;
+ if (addr >= stop)
+ {
+ /* We still haven't allocated our local stack. Handle this
+ as if we stopped on the first or last insn of a function. */
+ if (fi && fi->next == NULL)
+ fi->frame = read_sp ();
+ return addr;
+ }
+
+ status = target_read_memory (addr, buf, 2);
+ if (status != 0)
+ {
+ if (fi && fi->next == NULL)
+ fi->frame = read_sp ();
+ return addr;
+ }
+ if (buf[0] == 0xf2 && buf[1] == 0x7e)
+ {
+ addr += 2;
+
+ /* Our frame pointer is valid now. */
+ if (fi)
+ {
+ fi->status |= MY_FRAME_IN_FP;
+ fi->status &= ~MY_FRAME_IN_SP;
+ }
+ if (addr >= stop)
+ return addr;
+ }
+ else
+ {
+ if (fi && fi->next == NULL)
+ fi->frame = read_sp ();
+ return addr;
+ }
+ }
+
+ /* Next we should allocate the local frame.
+
+ Search for add imm8,a3 (0xd3XX)
+ or add imm16,a3 (0xf70bXXXX)
+ or add imm24,a3 (0xf467XXXXXX).
+
+ If none of the above was found, then this prologue has
+ no stack, and therefore can't have any register saves,
+ so quit now. */
+ status = target_read_memory (addr, buf, 2);
+ if (status != 0)
+ {
+ if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP))
+ fi->frame = read_sp ();
+ return addr;
+ }
+ if (buf[0] == 0xd3)
+ {
+ stack_size = extract_signed_integer (&buf[1], 1);
+ if (fi)
+ fi->stack_size = stack_size;
+ addr += 2;
+ if (addr >= stop)
+ {
+ if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP))
+ fi->frame = read_sp () - stack_size;
+ return addr;
+ }
+ }
+ else if (buf[0] == 0xf7 && buf[1] == 0x0b)
+ {
+ status = target_read_memory (addr + 2, buf, 2);
+ if (status != 0)
+ {
+ if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP))
+ fi->frame = read_sp ();
+ return addr;
+ }
+ stack_size = extract_signed_integer (buf, 2);
+ if (fi)
+ fi->stack_size = stack_size;
+ addr += 4;
+ if (addr >= stop)
+ {
+ if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP))
+ fi->frame = read_sp () - stack_size;
+ return addr;
+ }
+ }
+ else if (buf[0] == 0xf4 && buf[1] == 0x67)
+ {
+ status = target_read_memory (addr + 2, buf, 3);
+ if (status != 0)
+ {
+ if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP))
+ fi->frame = read_sp ();
+ return addr;
+ }
+ stack_size = extract_signed_integer (buf, 3);
+ if (fi)
+ fi->stack_size = stack_size;
+ addr += 5;
+ if (addr >= stop)
+ {
+ if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP))
+ fi->frame = read_sp () - stack_size;
+ return addr;
+ }
+ }
+
+ /* Now see if we have a call to __prologue for an out of line
+ prologue. */
+ status = target_read_memory (addr, buf, 2);
+ if (status != 0)
+ return addr;
+
+ /* First check for 16bit pc-relative call to __prologue. */
+ if (buf[0] == 0xfd)
+ {
+ CORE_ADDR temp;
+ status = target_read_memory (addr + 1, buf, 2);
+ if (status != 0)
+ {
+ if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP))
+ fi->frame = read_sp ();
+ return addr;
+ }
+
+ /* Get the PC this instruction will branch to. */
+ temp = (extract_signed_integer (buf, 2) + addr) & 0xffffff;
+
+ /* Get the name of the function at the target address. */
+ status = find_pc_partial_function (temp, &name, NULL, NULL);
+ if (status == 0)
+ {
+ if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP))
+ fi->frame = read_sp ();
+ return addr;
+ }
+
+ /* Note if it is an out of line prologue. */
+ out_of_line_prologue = (strcmp (name, "__prologue") == 0);
+
+ /* This sucks up 3 bytes of instruction space. */
+ if (out_of_line_prologue)
+ addr += 3;
+
+ if (addr >= stop)
+ {
+ if (fi && fi->next == NULL)
+ {
+ fi->stack_size -= 16;
+ fi->frame = read_sp () - fi->stack_size;
+ }
+ return addr;
+ }
+ }
+ /* Now check for the 24bit pc-relative call to __prologue. */
+ else if (buf[0] == 0xf4 && buf[1] == 0xe1)
+ {
+ CORE_ADDR temp;
+ status = target_read_memory (addr + 2, buf, 3);
+ if (status != 0)
+ {
+ if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP))
+ fi->frame = read_sp ();
+ return addr;
+ }
+
+ /* Get the PC this instruction will branch to. */
+ temp = (extract_signed_integer (buf, 3) + addr) & 0xffffff;
+
+ /* Get the name of the function at the target address. */
+ status = find_pc_partial_function (temp, &name, NULL, NULL);
+ if (status == 0)
+ {
+ if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP))
+ fi->frame = read_sp ();
+ return addr;
+ }
+
+ /* Note if it is an out of line prologue. */
+ out_of_line_prologue = (strcmp (name, "__prologue") == 0);
+
+ /* This sucks up 5 bytes of instruction space. */
+ if (out_of_line_prologue)
+ addr += 5;
+
+ if (addr >= stop)
+ {
+ if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP))
+ {
+ fi->stack_size -= 16;
+ fi->frame = read_sp () - fi->stack_size;
+ }
+ return addr;
+ }
+ }
+
+ /* Now actually handle the out of line prologue. */
+ if (out_of_line_prologue)
+ {
+ int outgoing_args_size = 0;
+
+ /* First adjust the stack size for this function. The out of
+ line prologue saves 4 registers (16bytes of data). */
+ if (fi)
+ fi->stack_size -= 16;
+
+ /* Update fi->frame if necessary. */
+ if (fi && fi->next == NULL)
+ fi->frame = read_sp () - fi->stack_size;
+
+ /* After the out of line prologue, there may be another
+ stack adjustment for the outgoing arguments.
+
+ Search for add imm8,a3 (0xd3XX)
+ or add imm16,a3 (0xf70bXXXX)
+ or add imm24,a3 (0xf467XXXXXX). */
+
+ status = target_read_memory (addr, buf, 2);
+ if (status != 0)
+ {
+ if (fi)
+ {
+ fi->fsr.regs[2] = fi->frame + fi->stack_size + 4;
+ fi->fsr.regs[3] = fi->frame + fi->stack_size + 8;
+ fi->fsr.regs[5] = fi->frame + fi->stack_size + 12;
+ fi->fsr.regs[6] = fi->frame + fi->stack_size + 16;
+ }
+ return addr;
+ }
+
+ if (buf[0] == 0xd3)
+ {
+ outgoing_args_size = extract_signed_integer (&buf[1], 1);
+ addr += 2;
+ }
+ else if (buf[0] == 0xf7 && buf[1] == 0x0b)
+ {
+ status = target_read_memory (addr + 2, buf, 2);
+ if (status != 0)
+ {
+ if (fi)
+ {
+ fi->fsr.regs[2] = fi->frame + fi->stack_size + 4;
+ fi->fsr.regs[3] = fi->frame + fi->stack_size + 8;
+ fi->fsr.regs[5] = fi->frame + fi->stack_size + 12;
+ fi->fsr.regs[6] = fi->frame + fi->stack_size + 16;
+ }
+ return addr;
+ }
+ outgoing_args_size = extract_signed_integer (buf, 2);
+ addr += 4;
+ }
+ else if (buf[0] == 0xf4 && buf[1] == 0x67)
+ {
+ status = target_read_memory (addr + 2, buf, 3);
+ if (status != 0)
+ {
+ if (fi && fi->next == NULL)
+ {
+ fi->fsr.regs[2] = fi->frame + fi->stack_size + 4;
+ fi->fsr.regs[3] = fi->frame + fi->stack_size + 8;
+ fi->fsr.regs[5] = fi->frame + fi->stack_size + 12;
+ fi->fsr.regs[6] = fi->frame + fi->stack_size + 16;
+ }
+ return addr;
+ }
+ outgoing_args_size = extract_signed_integer (buf, 3);
+ addr += 5;
+ }
+ else
+ outgoing_args_size = 0;
+
+ /* Now that we know the size of the outgoing arguments, fix
+ fi->frame again if this is the innermost frame. */
+ if (fi && fi->next == NULL)
+ fi->frame -= outgoing_args_size;
+
+ /* Note the register save information and update the stack
+ size for this frame too. */
+ if (fi)
+ {
+ fi->fsr.regs[2] = fi->frame + fi->stack_size + 4;
+ fi->fsr.regs[3] = fi->frame + fi->stack_size + 8;
+ fi->fsr.regs[5] = fi->frame + fi->stack_size + 12;
+ fi->fsr.regs[6] = fi->frame + fi->stack_size + 16;
+ fi->stack_size += outgoing_args_size;
+ }
+ /* There can be no more prologue insns, so return now. */
+ return addr;
+ }
+
+ /* At this point fi->frame needs to be correct.
+
+ If MY_FRAME_IN_SP is set and we're the innermost frame, then we
+ need to fix fi->frame so that backtracing, find_frame_saved_regs,
+ etc work correctly. */
+ if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP) != 0)
+ fi->frame = read_sp () - fi->stack_size;
+
+ /* And last we have the register saves. These are relatively
+ simple because they're physically done off the stack pointer,
+ and thus the number of different instructions we need to
+ check is greatly reduced because we know the displacements
+ will be small.
+
+ Search for movx d2,(X,a3) (0xf55eXX)
+ then movx d3,(X,a3) (0xf55fXX)
+ then mov a1,(X,a3) (0x5dXX) No frame pointer case
+ then mov a2,(X,a3) (0x5eXX) No frame pointer case
+ or mov a0,(X,a3) (0x5cXX) Frame pointer case. */
+
+ status = target_read_memory (addr, buf, 2);
+ if (status != 0)
+ return addr;
+ if (buf[0] == 0xf5 && buf[1] == 0x5e)
+ {
+ if (fi)
+ {
+ status = target_read_memory (addr + 2, buf, 1);
+ if (status != 0)
+ return addr;
+ fi->fsr.regs[2] = (fi->frame + stack_size
+ + extract_signed_integer (buf, 1));
+ }
+ addr += 3;
+ if (addr >= stop)
+ return addr;
+ status = target_read_memory (addr, buf, 2);
+ if (status != 0)
+ return addr;
+ }
+ if (buf[0] == 0xf5 && buf[1] == 0x5f)
+ {
+ if (fi)
+ {
+ status = target_read_memory (addr + 2, buf, 1);
+ if (status != 0)
+ return addr;
+ fi->fsr.regs[3] = (fi->frame + stack_size
+ + extract_signed_integer (buf, 1));
+ }
+ addr += 3;
+ if (addr >= stop)
+ return addr;
+ status = target_read_memory (addr, buf, 2);
+ if (status != 0)
+ return addr;
+ }
+ if (buf[0] == 0x5d)
+ {
+ if (fi)
+ {
+ status = target_read_memory (addr + 1, buf, 1);
+ if (status != 0)
+ return addr;
+ fi->fsr.regs[5] = (fi->frame + stack_size
+ + extract_signed_integer (buf, 1));
+ }
+ addr += 2;
+ if (addr >= stop)
+ return addr;
+ status = target_read_memory (addr, buf, 2);
+ if (status != 0)
+ return addr;
+ }
+ if (buf[0] == 0x5e || buf[0] == 0x5c)
+ {
+ if (fi)
+ {
+ status = target_read_memory (addr + 1, buf, 1);
+ if (status != 0)
+ return addr;
+ fi->fsr.regs[6] = (fi->frame + stack_size
+ + extract_signed_integer (buf, 1));
+ fi->status &= ~CALLER_A2_IN_A0;
+ }
+ addr += 2;
+ if (addr >= stop)
+ return addr;
+ return addr;
+ }
+ return addr;
}
+
+/* Function: frame_chain
+ Figure out and return the caller's frame pointer given current
+ frame_info struct.
-/* Function: find_callers_reg
- 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. */
+ We don't handle dummy frames yet but we would probably just return the
+ stack pointer that was in use at the time the function call was made? */
CORE_ADDR
-mn10200_find_callers_reg (fi, regnum)
+mn10200_frame_chain (fi)
struct frame_info *fi;
- int regnum;
{
-/* printf("mn10200_find_callers_reg\n"); */
+ struct frame_info dummy_frame;
- for (; fi; fi = fi->next)
- if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
- return generic_read_register_dummy (fi->pc, fi->frame, regnum);
- else if (fi->fsr.regs[regnum] != 0)
- return read_memory_unsigned_integer (fi->fsr.regs[regnum],
- REGISTER_RAW_SIZE(regnum));
+ /* Walk through the prologue to determine the stack size,
+ location of saved registers, end of the prologue, etc. */
+ if (fi->status == 0)
+ mn10200_analyze_prologue (fi, (CORE_ADDR)0);
- return read_register (regnum);
-}
+ /* Quit now if mn10200_analyze_prologue set NO_MORE_FRAMES. */
+ if (fi->status & NO_MORE_FRAMES)
+ return 0;
-/* Function: skip_prologue
- Return the address of the first inst past the prologue of the function.
-*/
+ /* Now that we've analyzed our prologue, determine the frame
+ pointer for our caller.
-CORE_ADDR
-mn10200_skip_prologue (pc)
- CORE_ADDR pc;
-{
- CORE_ADDR func_addr, func_end;
+ If our caller has a frame pointer, then we need to
+ find the entry value of $a2 to our function.
-/* printf("mn10200_skip_prologue\n"); */
+ If CALLER_A2_IN_A0, then the chain is in $a0.
- /* See what the symbol table says */
+ If fsr.regs[6] is nonzero, then it's at the memory
+ location pointed to by fsr.regs[6].
- if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
- {
- struct symtab_and_line sal;
+ Else it's still in $a2.
+
+ If our caller does not have a frame pointer, then his
+ frame base is fi->frame + -caller's stack size + 4. */
+
+ /* The easiest way to get that info is to analyze our caller's frame.
- sal = find_pc_line (func_addr, 0);
+ So we set up a dummy frame and call mn10200_analyze_prologue to
+ find stuff for us. */
+ dummy_frame.pc = FRAME_SAVED_PC (fi);
+ dummy_frame.frame = fi->frame;
+ memset (dummy_frame.fsr.regs, '\000', sizeof dummy_frame.fsr.regs);
+ dummy_frame.status = 0;
+ dummy_frame.stack_size = 0;
+ mn10200_analyze_prologue (&dummy_frame);
- if (sal.line != 0 && sal.end < func_end)
- return sal.end;
+ if (dummy_frame.status & MY_FRAME_IN_FP)
+ {
+ /* Our caller has a frame pointer. So find the frame in $a2, $a0,
+ or in the stack. */
+ if (fi->fsr.regs[6])
+ return (read_memory_integer (fi->fsr.regs[FP_REGNUM], REGISTER_SIZE)
+ & 0xffffff);
+ else if (fi->status & CALLER_A2_IN_A0)
+ return read_register (4);
else
- /* Either there's no line info, or the line after the prologue is after
- the end of the function. In this case, there probably isn't a
- prologue. */
- return pc;
+ return read_register (FP_REGNUM);
}
+ else
+ {
+ /* Our caller does not have a frame pointer. So his frame starts
+ at the base of our frame (fi->frame) + <his size> + 4 (saved pc). */
+ return fi->frame + -dummy_frame.stack_size + 4;
+ }
+}
-/* We can't find the start of this function, so there's nothing we can do. */
- return pc;
+/* Function: skip_prologue
+ Return the address of the first inst past the prologue of the function. */
+
+CORE_ADDR
+mn10200_skip_prologue (pc)
+ CORE_ADDR pc;
+{
+ /* We used to check the debug symbols, but that can lose if
+ we have a null prologue. */
+ return mn10200_analyze_prologue (NULL, pc);
}
/* Function: pop_frame
{
int regnum;
-/* printf("mn10200_pop_frame start\n"); */
-
if (PC_IN_CALL_DUMMY(frame->pc, frame->frame, frame->frame))
generic_pop_dummy_frame ();
else
{
write_register (PC_REGNUM, FRAME_SAVED_PC (frame));
+ /* Restore any saved registers. */
for (regnum = 0; regnum < NUM_REGS; regnum++)
if (frame->fsr.regs[regnum] != 0)
- write_register (regnum,
- read_memory_unsigned_integer (frame->fsr.regs[regnum],
- REGISTER_RAW_SIZE(regnum)));
+ {
+ ULONGEST value;
+
+ value = read_memory_unsigned_integer (frame->fsr.regs[regnum],
+ REGISTER_RAW_SIZE (regnum));
+ write_register (regnum, value);
+ }
+ /* Actually cut back the stack. */
write_register (SP_REGNUM, FRAME_FP (frame));
+
+ /* Don't we need to set the PC?!? XXX FIXME. */
}
+ /* Throw away any cached frame information. */
flush_cached_frames ();
-
-/* printf("mn10200_pop_frame end\n"); */
}
/* Function: push_arguments
Setup arguments for a call to the target. Arguments go in
- order on the stack.
-*/
+ order on the stack. */
CORE_ADDR
mn10200_push_arguments (nargs, args, sp, struct_return, struct_addr)
{
int argnum = 0;
int len = 0;
- int stack_offset = 0; /* copy args to this offset onto stack */
+ int stack_offset = 0;
+ int regsused = struct_return ? 1 : 0;
-/* printf("mn10200_push_arguments start\n"); */
+ /* This should be a nop, but align the stack just in case something
+ went wrong. Stacks are two byte aligned on the mn10200. */
+ sp &= ~1;
- /* First, just for safety, make sure stack is aligned */
- sp &= ~3;
+ /* Now make space on the stack for the args.
- /* Now make space on the stack for the args. */
+ XXX This doesn't appear to handle pass-by-invisible reference
+ arguments. */
for (argnum = 0; argnum < nargs; argnum++)
- len += ((TYPE_LENGTH(VALUE_TYPE(args[argnum])) + 3) & ~3);
+ {
+ int arg_length = (TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 1) & ~1;
+ /* If we've used all argument registers, then this argument is
+ pushed. */
+ if (regsused >= 2 || arg_length > 4)
+ {
+ regsused = 2;
+ len += arg_length;
+ }
+ /* We know we've got some arg register space left. If this argument
+ will fit entirely in regs, then put it there. */
+ else if (arg_length <= 2
+ || TYPE_CODE (VALUE_TYPE (args[argnum])) == TYPE_CODE_PTR)
+ {
+ regsused++;
+ }
+ else if (regsused == 0)
+ {
+ regsused = 2;
+ }
+ else
+ {
+ regsused = 2;
+ len += arg_length;
+ }
+ }
+
+ /* Allocate stack space. */
sp -= len;
+ regsused = struct_return ? 1 : 0;
/* Push all arguments onto the stack. */
for (argnum = 0; argnum < nargs; argnum++)
{
int len;
char *val;
+ /* XXX Check this. What about UNIONS? */
if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT
&& TYPE_LENGTH (VALUE_TYPE (*args)) > 8)
{
- /* for now, pretend structs aren't special */
+ /* XXX Wrong, we want a pointer to this argument. */
len = TYPE_LENGTH (VALUE_TYPE (*args));
val = (char *)VALUE_CONTENTS (*args);
}
val = (char *)VALUE_CONTENTS (*args);
}
- while (len > 0)
+ if (regsused < 2
+ && (len <= 2
+ || TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_PTR))
{
- write_memory (sp + stack_offset, val, 4);
-
- len -= 4;
- val += 4;
- stack_offset += 4;
+ write_register (regsused, extract_unsigned_integer (val, 4));
+ regsused++;
+ }
+ else if (regsused == 0 && len == 4)
+ {
+ write_register (regsused, extract_unsigned_integer (val, 2));
+ write_register (regsused + 1, extract_unsigned_integer (val + 2, 2));
+ regsused = 2;
+ }
+ else
+ {
+ regsused = 2;
+ while (len > 0)
+ {
+ write_memory (sp + stack_offset, val, 2);
+
+ len -= 2;
+ val += 2;
+ stack_offset += 2;
+ }
}
args++;
}
-/* printf"mn10200_push_arguments end\n"); */
-
return sp;
}
CORE_ADDR pc;
CORE_ADDR sp;
{
-/* printf("mn10200_push_return_address\n"); */
+ unsigned char buf[4];
- /* write_register (RP_REGNUM, CALL_DUMMY_ADDRESS ()); */
+ store_unsigned_integer (buf, 4, CALL_DUMMY_ADDRESS ());
+ write_memory (sp - 4, buf, 4);
+ return sp - 4;
+}
+
+/* Function: store_struct_return (addr,sp)
+ Store the structure value return address for an inferior function
+ call. */
+
+CORE_ADDR
+mn10200_store_struct_return (addr, sp)
+ CORE_ADDR addr;
+ CORE_ADDR sp;
+{
+ /* The structure return address is passed as the first argument. */
+ write_register (0, addr);
return sp;
}
mn10200_frame_saved_pc (fi)
struct frame_info *fi;
{
-/* printf("mn10200_frame_saved_pc\n"); */
-
- return (read_memory_integer(fi->frame - REGISTER_SIZE, REGISTER_SIZE));
+ /* The saved PC will always be at the base of the current frame. */
+ return (read_memory_integer (fi->frame, REGISTER_SIZE) & 0xffffff);
}
void
int regnum;
enum lval_type *lval;
{
-/* printf("get_saved_register\n"); */
-
generic_get_saved_register (raw_buffer, optimized, addrp,
frame, regnum, lval);
}
/* Function: init_extra_frame_info
Setup the frame's frame pointer, pc, and frame addresses for saved
- registers. Most of the work is done in frame_chain().
+ registers. Most of the work is done in mn10200_analyze_prologue().
Note that when we are called for the last frame (currently active frame),
that fi->pc and fi->frame will already be setup. However, fi->frame will
be valid only if this routine uses FP. For previous frames, fi-frame will
- always be correct (since that is derived from v850_frame_chain ()).
+ always be correct. mn10200_analyze_prologue will fix fi->frame if
+ it's not valid.
We can be called with the PC in the call dummy under two circumstances.
First, during normal backtracing, second, while figuring out the frame
- pointer just prior to calling the target function (see run_stack_dummy).
-*/
+ pointer just prior to calling the target function (see run_stack_dummy). */
void
mn10200_init_extra_frame_info (fi)
struct frame_info *fi;
{
- struct prologue_info pi;
- struct pifsr pifsrs[NUM_REGS + 1], *pifsr;
- int reg;
-
if (fi->next)
fi->pc = FRAME_SAVED_PC (fi->next);
memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs);
+ fi->status = 0;
+ fi->stack_size = 0;
- /* The call dummy doesn't save any registers on the stack, so we can return
- now. */
-/*
- if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
- return;
-
- pi.pifsrs = pifsrs;
-*/
-
- /* v850_scan_prologue (fi->pc, &pi); */
-/*
- if (!fi->next && pi.framereg == SP_REGNUM)
- fi->frame = read_register (pi.framereg) - pi.frameoffset;
-
- for (pifsr = pifsrs; pifsr->framereg; pifsr++)
- {
- fi->fsr.regs[pifsr->reg] = pifsr->offset + fi->frame;
-
- if (pifsr->framereg == SP_REGNUM)
- fi->fsr.regs[pifsr->reg] += pi.frameoffset;
- }
-*/
-/* printf("init_extra_frame_info\n"); */
+ mn10200_analyze_prologue (fi, 0);
}
void
_initialize_mn10200_tdep ()
{
-/* printf("_initialize_mn10200_tdep\n"); */
-
tm_print_insn = print_insn_mn10200;
}