static int isreg; /* Object lives in register.
decode_locdesc's return value is
the register number. */
-static int offreg; /* Object's address is the sum of the
- register specified by basereg, plus
- the offset returned. */
-static int basereg; /* See `offreg'. */
-static int isderef; /* Value described by flags above is
- the address of a pointer to the object. */
-
-/* DW_AT_frame_base values for the current function.
- frame_base_reg is -1 if DW_AT_frame_base is missing, otherwise it
- contains the register number for the frame register.
- frame_base_offset is the offset from the frame register to the
- virtual stack frame. */
-static int frame_base_reg;
-static CORE_ADDR frame_base_offset;
/* This value is added to each symbol value. FIXME: Generalize to
the section_offsets structure used by dbxread (once this is done,
objfile->ei.entry_func_highpc = highpc;
}
- /* Decode DW_AT_frame_base location descriptor if present, keep result
- for DW_OP_fbreg operands in decode_locdesc. */
- frame_base_reg = -1;
- frame_base_offset = 0;
- attr = dwarf_attr (die, DW_AT_frame_base);
- if (attr)
- {
- CORE_ADDR addr;
-
- /* Support the .debug_loc offsets */
- if (attr_form_is_block (attr))
- {
- addr = decode_locdesc (DW_BLOCK (attr), cu);
- }
- else if (attr->form == DW_FORM_data4 || attr->form == DW_FORM_data8)
- {
- dwarf2_complex_location_expr_complaint ();
- addr = 0;
- }
- else
- {
- dwarf2_invalid_attrib_class_complaint ("DW_AT_frame_base", name);
- addr = 0;
- }
-
- if (isderef)
- dwarf2_unsupported_at_frame_base_complaint (name);
- else if (isreg)
- frame_base_reg = addr;
- else if (offreg)
- {
- frame_base_reg = basereg;
- frame_base_offset = addr;
- }
- else
- dwarf2_unsupported_at_frame_base_complaint (name);
- }
-
new = push_context (0, lowpc);
new->name = new_symbol (die, die->type, cu);
- /* If there was a location expression for DW_AT_frame_base above,
- record it. We still need to decode it above because not all
- symbols use location expressions exclusively. */
+ /* If there is a location expression for DW_AT_frame_base, record
+ it. */
+ attr = dwarf_attr (die, DW_AT_frame_base);
if (attr)
dwarf2_symbol_mark_computed (attr, new->name, cu);
Given a pointer to a dwarf block that defines a location, compute
the location and return the value.
- FIXME: This is a kludge until we figure out a better
- way to handle the location descriptions.
- Gdb's design does not mesh well with the DWARF2 notion of a location
- computing interpreter, which is a shame because the flexibility goes unused.
- FIXME: Implement more operations as necessary.
+ NOTE drow/2003-11-18: This function is called in two situations
+ now: for the address of static or global variables (partial symbols
+ only) and for offsets into structures which are expected to be
+ (more or less) constant. The partial symbol case should go away,
+ and only the constant case should remain. That will let this
+ function complain more accurately. A few special modes are allowed
+ without complaint for global variables (for instance, global
+ register values and thread-local values).
A location description containing no operations indicates that the
- object is optimized out. The return value is meaningless for that case.
+ object is optimized out. The return value is 0 for that case.
FIXME drow/2003-11-16: No callers check for this case any more; soon all
callers will only want a very basic result and this can become a
complaint.
When the result is a register number, the global isreg flag is set,
otherwise it is cleared.
- When the result is a base register offset, the global offreg flag is set
- and the register number is returned in basereg, otherwise it is cleared.
-
- When the DW_OP_fbreg operation is encountered without a corresponding
- DW_AT_frame_base attribute, we complain.
-
Note that stack[0] is unused except as a default error return.
Note that stack overflow is not yet handled. */
stacki = 0;
stack[stacki] = 0;
isreg = 0;
- offreg = 0;
- isderef = 0;
while (i < size)
{
case DW_OP_reg31:
isreg = 1;
stack[++stacki] = op - DW_OP_reg0;
+ if (i < size)
+ dwarf2_complex_location_expr_complaint ();
break;
case DW_OP_regx:
unsnd = read_unsigned_leb128 (NULL, (data + i), &bytes_read);
i += bytes_read;
stack[++stacki] = unsnd;
- break;
-
- case DW_OP_breg0:
- case DW_OP_breg1:
- case DW_OP_breg2:
- case DW_OP_breg3:
- case DW_OP_breg4:
- case DW_OP_breg5:
- case DW_OP_breg6:
- case DW_OP_breg7:
- case DW_OP_breg8:
- case DW_OP_breg9:
- case DW_OP_breg10:
- case DW_OP_breg11:
- case DW_OP_breg12:
- case DW_OP_breg13:
- case DW_OP_breg14:
- case DW_OP_breg15:
- case DW_OP_breg16:
- case DW_OP_breg17:
- case DW_OP_breg18:
- case DW_OP_breg19:
- case DW_OP_breg20:
- case DW_OP_breg21:
- case DW_OP_breg22:
- case DW_OP_breg23:
- case DW_OP_breg24:
- case DW_OP_breg25:
- case DW_OP_breg26:
- case DW_OP_breg27:
- case DW_OP_breg28:
- case DW_OP_breg29:
- case DW_OP_breg30:
- case DW_OP_breg31:
- offreg = 1;
- basereg = op - DW_OP_breg0;
- stack[++stacki] = read_signed_leb128 (NULL, (data + i), &bytes_read);
- i += bytes_read;
- break;
-
- case DW_OP_bregx:
- offreg = 1;
- basereg = read_unsigned_leb128 (NULL, (data + i), &bytes_read);
- i += bytes_read;
- stack[++stacki] = read_signed_leb128 (NULL, (data + i), &bytes_read);
- i += bytes_read;
- break;
-
- case DW_OP_fbreg:
- stack[++stacki] = read_signed_leb128 (NULL, (data + i), &bytes_read);
- i += bytes_read;
- if (frame_base_reg >= 0)
- {
- offreg = 1;
- basereg = frame_base_reg;
- stack[stacki] += frame_base_offset;
- }
- else
- {
- complaint (&symfile_complaints,
- "DW_AT_frame_base missing for DW_OP_fbreg");
- }
+ if (i < size)
+ dwarf2_complex_location_expr_complaint ();
break;
case DW_OP_addr:
break;
case DW_OP_deref:
- isderef = 1;
/* If we're not the last op, then we definitely can't encode
- this using GDB's address_class enum. */
+ this using GDB's address_class enum. This is valid for partial
+ global symbols, although the variable's address will be bogus
+ in the psymtab. */
if (i < size)
dwarf2_complex_location_expr_complaint ();
break;
of the thread control block at which the variable is located. */
/* Nothing should follow this operator, so the top of stack would
be returned. */
+ /* This is valid for partial global symbols, but the variable's
+ address will be bogus in the psymtab. */
if (i < size)
dwarf2_complex_location_expr_complaint ();
break;
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