* dwarf2-frame.c: Fix some comments and whitespace problems.
This commit is contained in:
Mark Kettenis
parent
c84fca4d18
commit
e4e9607c60
|
|
@ -1,5 +1,7 @@
|
|||
2003-11-27 Mark Kettenis <kettenis@gnu.org>
|
||||
|
||||
* dwarf2-frame.c: Fix some comments and whitespace problems.
|
||||
|
||||
* i386nbsd-tdep.c: Don't include "gdbtypes.h". Include
|
||||
"gdb_assert.h" and "gdb_string.h".
|
||||
(i386nbsd_r_reg_offset): Rename from regmap.
|
||||
|
|
|
|||
|
|
@ -99,19 +99,18 @@ static struct dwarf2_fde *dwarf2_frame_find_fde (CORE_ADDR *pc);
|
|||
|
||||
enum dwarf2_reg_rule
|
||||
{
|
||||
/* Make certain that 0 maps onto the correct enum value - the
|
||||
/* Make certain that 0 maps onto the correct enum value; the
|
||||
corresponding structure is being initialized using memset zero.
|
||||
This indicates that CFI didn't provide any information at all
|
||||
about a register - leaving how to obtain it's value totally
|
||||
about a register, leaving how to obtain it's value totally
|
||||
unspecified. */
|
||||
REG_UNSPECIFIED = 0,
|
||||
/* The term "undefined" comes from the DWARF2 CFI spec which this
|
||||
code is moddeling - it indicates that the register's value is
|
||||
"undefined". */
|
||||
/* NOTE: cagney/2003-09-08: GCC uses the less formal term "unsaved"
|
||||
- it's definition is a combination of REG_UNDEFINED and
|
||||
REG_UNSPECIFIED - the failure to differentiate the two helps
|
||||
explain a few problems with the CFI GCC outputs. */
|
||||
code is moddeling; it indicates that the register's value is
|
||||
"undefined". GCC uses the less formal term "unsaved". Its
|
||||
definition is a combination of REG_UNDEFINED and REG_UNSPECIFIED.
|
||||
The failure to differentiate the two helps explain a few problems
|
||||
with the CFI generated by GCC. */
|
||||
REG_UNDEFINED,
|
||||
REG_SAVED_OFFSET,
|
||||
REG_SAVED_REG,
|
||||
|
|
@ -500,18 +499,15 @@ dwarf2_frame_cache (struct frame_info *next_frame, void **this_cache)
|
|||
to abort), the compiler might optimize away the instruction at
|
||||
NEXT_FRAME's return address. As a result the return address will
|
||||
point at some random instruction, and the CFI for that
|
||||
instruction is probably wortless to us. GCC's unwinder solves
|
||||
instruction is probably worthless to us. GCC's unwinder solves
|
||||
this problem by substracting 1 from the return address to get an
|
||||
address in the middle of a presumed call instruction (or the
|
||||
instruction in the associated delay slot). This should only be
|
||||
done for "normal" frames and not for resume-type frames (signal
|
||||
handlers, sentinel frames, dummy frames).
|
||||
|
||||
frame_unwind_address_in_block does just this.
|
||||
|
||||
It's not clear how reliable the method is though - there is the
|
||||
potential for the register state pre-call being different to that
|
||||
on return. */
|
||||
handlers, sentinel frames, dummy frames). The function
|
||||
frame_unwind_address_in_block does just this. It's not clear how
|
||||
reliable the method is though; there is the potential for the
|
||||
register state pre-call being different to that on return. */
|
||||
fs->pc = frame_unwind_address_in_block (next_frame);
|
||||
|
||||
/* Find the correct FDE. */
|
||||
|
|
@ -555,6 +551,7 @@ dwarf2_frame_cache (struct frame_info *next_frame, void **this_cache)
|
|||
unspecified. */
|
||||
{
|
||||
int regnum;
|
||||
|
||||
for (regnum = 0; regnum < num_regs; regnum++)
|
||||
cache->reg[regnum].how = REG_UNSPECIFIED;
|
||||
}
|
||||
|
|
@ -563,6 +560,7 @@ dwarf2_frame_cache (struct frame_info *next_frame, void **this_cache)
|
|||
location information in the cache. */
|
||||
{
|
||||
int column; /* CFI speak for "register number". */
|
||||
|
||||
for (column = 0; column < fs->regs.num_regs; column++)
|
||||
{
|
||||
int regnum;
|
||||
|
|
@ -573,9 +571,10 @@ dwarf2_frame_cache (struct frame_info *next_frame, void **this_cache)
|
|||
RETADDR_COLUMN corresponds to a real register (and,
|
||||
worse, that isn't the PC_REGNUM)? I'm guessing that the
|
||||
PC_REGNUM further down is trying to handle this. That
|
||||
can't be right though - PC_REGNUM may not be valid (it
|
||||
can be -ve). I think, instead when RETADDR_COLUM isn't a
|
||||
real register, it should map itself onto frame_pc_unwind. */
|
||||
can't be right though; PC_REGNUM may not be valid (it can
|
||||
be negative). I think, instead when RETADDR_COLUM isn't
|
||||
a real register, it should map itself onto
|
||||
frame_pc_unwind. */
|
||||
continue;
|
||||
|
||||
/* Use the GDB register number as the destination index. */
|
||||
|
|
@ -586,15 +585,15 @@ dwarf2_frame_cache (struct frame_info *next_frame, void **this_cache)
|
|||
continue;
|
||||
|
||||
/* NOTE: cagney/2003-09-05: CFI should specify the disposition
|
||||
of all debug info registers. If it doesn't complain (but
|
||||
not too loudly). It turns out that GCC, assumes that an
|
||||
of all debug info registers. If it doesn't, complain (but
|
||||
not too loudly). It turns out that GCC assumes that an
|
||||
unspecified register implies "same value" when CFI (draft
|
||||
7) specifies nothing at all. Such a register could equally
|
||||
be interpreted as "undefined". Also note that this check
|
||||
isn't sufficient - it only checks that all registers in the
|
||||
range [0 .. max column] are specified - and won't detect
|
||||
isn't sufficient; it only checks that all registers in the
|
||||
range [0 .. max column] are specified, and won't detect
|
||||
problems when a debug info register falls outside of the
|
||||
table. Need a way of iterating through all the valid
|
||||
table. We need a way of iterating through all the valid
|
||||
DWARF2 register numbers. */
|
||||
if (fs->regs.reg[column].how == REG_UNSPECIFIED)
|
||||
complaint (&symfile_complaints,
|
||||
|
|
@ -606,14 +605,14 @@ dwarf2_frame_cache (struct frame_info *next_frame, void **this_cache)
|
|||
}
|
||||
|
||||
/* Store the location of the return addess. If the return address
|
||||
column (adjusted) is not the same as gdb's PC_REGNUM, then this
|
||||
implies a copy from the ra column register. */
|
||||
column (adjusted) is not the same as GDB's PC_REGNUM, then this
|
||||
implies a copy from the return address column register. */
|
||||
if (fs->retaddr_column < fs->regs.num_regs
|
||||
&& fs->regs.reg[fs->retaddr_column].how != REG_UNDEFINED)
|
||||
{
|
||||
/* See comment above about a possibly -ve PC_REGNUM. If this
|
||||
assertion fails, it's a problem with this code and not the
|
||||
architecture. */
|
||||
/* See comment above about a possibly negative PC_REGNUM. If
|
||||
this assertion fails, it's a problem with this code and not
|
||||
the architecture. */
|
||||
gdb_assert (PC_REGNUM >= 0);
|
||||
cache->reg[PC_REGNUM] = fs->regs.reg[fs->retaddr_column];
|
||||
}
|
||||
|
|
@ -622,9 +621,9 @@ dwarf2_frame_cache (struct frame_info *next_frame, void **this_cache)
|
|||
int reg = DWARF2_REG_TO_REGNUM (fs->retaddr_column);
|
||||
if (reg != PC_REGNUM)
|
||||
{
|
||||
/* See comment above about PC_REGNUM being -ve. If this
|
||||
assertion fails, it's a problem with this code and not
|
||||
the architecture. */
|
||||
/* See comment above about PC_REGNUM being negative. If
|
||||
this assertion fails, it's a problem with this code and
|
||||
not the architecture. */
|
||||
gdb_assert (PC_REGNUM >= 0);
|
||||
cache->reg[PC_REGNUM].loc.reg = reg;
|
||||
cache->reg[PC_REGNUM].how = REG_SAVED_REG;
|
||||
|
|
@ -660,7 +659,7 @@ dwarf2_frame_prev_register (struct frame_info *next_frame, void **this_cache,
|
|||
{
|
||||
case REG_UNDEFINED:
|
||||
/* If CFI explicitly specified that the value isn't defined,
|
||||
mark it as optimized away - the value isn't available. */
|
||||
mark it as optimized away; the value isn't available. */
|
||||
*optimizedp = 1;
|
||||
*lvalp = not_lval;
|
||||
*addrp = 0;
|
||||
|
|
@ -681,8 +680,8 @@ dwarf2_frame_prev_register (struct frame_info *next_frame, void **this_cache,
|
|||
/* FIXME: cagney/2003-07-07: I don't understand this. The
|
||||
CFI info should have provided unwind information for the
|
||||
SP register and then pointed ->cfa_reg at it, not the
|
||||
reverse. Assuming that SP_REGNUM is !-ve, there is a
|
||||
very real posibility that CFA is an offset from some
|
||||
reverse. Assuming that SP_REGNUM isn't negative, there
|
||||
is a very real posibility that CFA is an offset from some
|
||||
other register, having nothing to do with the unwound SP
|
||||
value. */
|
||||
/* FIXME: cagney/2003-09-05: I think I understand. GDB was
|
||||
|
|
@ -770,7 +769,7 @@ dwarf2_frame_prev_register (struct frame_info *next_frame, void **this_cache,
|
|||
defines the rule which computes the CFA value; it may be
|
||||
either a register and a signed offset that are added
|
||||
together or a DWARF expression that is evaluated. */
|
||||
/* NOTE: cagney/2003-09-05: Should issue a complain.
|
||||
/* NOTE: cagney/2003-09-05: Should issue a complaint.
|
||||
Unfortunately it turns out that DWARF2 CFI has a problem.
|
||||
Since CFI specifies the location at which a register was
|
||||
saved (not its value) it isn't possible to specify
|
||||
|
|
|
|||
Loading…
Reference in New Issue