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* mn10200-tdep.c (mn10200_analyze_prologue): Update prologue comments

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to reflect current reality.  Gross attempt at handling out of
        line prologues.
This commit is contained in:
Jeff Law 1997-05-14 22:04:28 +00:00
parent 46686c7839
commit 4dbe5f8d3c
2 changed files with 199 additions and 12 deletions
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4
gdb/ChangeLog
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@ -1,5 +1,9 @@
Wed May 14 08:58:55 1997 Jeffrey A Law (law@cygnus.com)
* mn10200-tdep.c (mn10200_analyze_prologue): Update prologue comments
to reflect current reality. Gross attempt at handling out of
line prologues.
* mn10200-tdep.c (mn10200_skip_prologue): Don't look at the debug
symbols to find the end of the prologue.
* mn10300-tdep.c (mn10300_skip_prologue): Likewise.

205
gdb/mn10200-tdep.c
View File

@ -38,21 +38,25 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
mov sp,fp
add <size>,sp
Register saves for d2, d3, a1, a2 as needed. Saves start
at fp - <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 never
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 and work towards higher addresses.
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
One day we might keep the stack pointer constant, that won't
change the code for prologues, but it will make the frame
pointerless case much more common. */
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
@ -102,6 +106,7 @@ mn10200_analyze_prologue (fi, pc)
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. */
@ -302,10 +307,188 @@ mn10200_analyze_prologue (fi, pc)
return addr;
}
}
else
/* 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)
{
if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP))
fi->frame = read_sp ();
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;
}