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(output_bound_representation): Treat default case as variable bounds,

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then look inside for SAVE_EXPR.

From-SVN: r12543
This commit is contained in:
Richard Kenner 1996-07-20 09:28:26 -04:00
parent 653b32a670
commit 56b3408df2
1 changed files with 51 additions and 57 deletions
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108
gcc/dwarfout.c
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@ -1722,79 +1722,73 @@ output_bound_representation (bound, dim_num, u_or_l)
switch (TREE_CODE (bound))
{
case ERROR_MARK:
return;
case ERROR_MARK:
return;
/* All fixed-bounds are represented by INTEGER_CST nodes. */
case INTEGER_CST:
ASM_OUTPUT_DWARF_DATA4 (asm_out_file,
(unsigned) TREE_INT_CST_LOW (bound));
break;
case INTEGER_CST:
ASM_OUTPUT_DWARF_DATA4 (asm_out_file,
(unsigned) TREE_INT_CST_LOW (bound));
break;
default:
/* Dynamic bounds may be represented by NOP_EXPR nodes containing
SAVE_EXPR nodes. */
SAVE_EXPR nodes, in which case we can do something, or as
an expression, which we cannot represent. */
{
char begin_label[MAX_ARTIFICIAL_LABEL_BYTES];
char end_label[MAX_ARTIFICIAL_LABEL_BYTES];
case NOP_EXPR:
bound = TREE_OPERAND (bound, 0);
/* ... fall thru... */
sprintf (begin_label, BOUND_BEGIN_LABEL_FMT,
current_dienum, dim_num, u_or_l);
case SAVE_EXPR:
{
char begin_label[MAX_ARTIFICIAL_LABEL_BYTES];
char end_label[MAX_ARTIFICIAL_LABEL_BYTES];
sprintf (end_label, BOUND_END_LABEL_FMT,
current_dienum, dim_num, u_or_l);
sprintf (begin_label, BOUND_BEGIN_LABEL_FMT,
current_dienum, dim_num, u_or_l);
ASM_OUTPUT_DWARF_DELTA2 (asm_out_file, end_label, begin_label);
ASM_OUTPUT_LABEL (asm_out_file, begin_label);
sprintf (end_label, BOUND_END_LABEL_FMT,
current_dienum, dim_num, u_or_l);
/* If optimization is turned on, the SAVE_EXPRs that describe
how to access the upper bound values are essentially bogus.
They only describe (at best) how to get at these values at
the points in the generated code right after they have just
been computed. Worse yet, in the typical case, the upper
bound values will not even *be* computed in the optimized
code, so these SAVE_EXPRs are entirely bogus.
ASM_OUTPUT_DWARF_DELTA2 (asm_out_file, end_label, begin_label);
ASM_OUTPUT_LABEL (asm_out_file, begin_label);
In order to compensate for this fact, we check here to see
if optimization is enabled, and if so, we effectively create
an empty location description for the (unknown and unknowable)
upper bound.
/* If we are working on a bound for a dynamic dimension in C,
the dynamic dimension in question had better have a static
(zero) lower bound and a dynamic *upper* bound. */
This should not cause too much trouble for existing (stupid?)
debuggers because they have to deal with empty upper bounds
location descriptions anyway in order to be able to deal with
incomplete array types.
if (u_or_l != 'u')
abort ();
Of course an intelligent debugger (GDB?) should be able to
comprehend that a missing upper bound specification in a
array type used for a storage class `auto' local array variable
indicates that the upper bound is both unknown (at compile-
time) and unknowable (at run-time) due to optimization. */
/* If optimization is turned on, the SAVE_EXPRs that describe
how to access the upper bound values are essentially bogus.
They only describe (at best) how to get at these values at
the points in the generated code right after they have just
been computed. Worse yet, in the typical case, the upper
bound values will not even *be* computed in the optimized
code, so these SAVE_EXPRs are entirely bogus.
if (! optimize)
{
while (TREE_CODE (bound) == NOP_EXPR
|| TREE_CODE (bound) == CONVERT_EXPR)
bound = TREE_OPERAND (bound, 0);
In order to compensate for this fact, we check here to see
if optimization is enabled, and if so, we effectively create
an empty location description for the (unknown and unknowable)
upper bound.
if (TREE_CODE (bound) == SAVE_EXPR_RTL)
output_loc_descriptor
(eliminate_regs (SAVE_EXPR_RTL (bound), 0, NULL_RTX));
}
This should not cause too much trouble for existing (stupid?)
debuggers because they have to deal with empty upper bounds
location descriptions anyway in order to be able to deal with
incomplete array types.
ASM_OUTPUT_LABEL (asm_out_file, end_label);
}
break;
Of course an intelligent debugger (GDB?) should be able to
comprehend that a missing upper bound specification in a
array type used for a storage class `auto' local array variable
indicates that the upper bound is both unknown (at compile-
time) and unknowable (at run-time) due to optimization.
*/
if (! optimize)
output_loc_descriptor
(eliminate_regs (SAVE_EXPR_RTL (bound), 0, NULL_RTX));
ASM_OUTPUT_LABEL (asm_out_file, end_label);
}
break;
default:
abort ();
}
}