dwarf_get_fde_info_for_cfa_regs3 —
retrieve a CFA register rule
DWARF Access Library (libdwarf, -ldwarf)
#include
<libdwarf.h>
int
dwarf_get_fde_info_for_cfa_regs3(
Dwarf_Fde
fde,
Dwarf_Addr pc,
Dwarf_Small *type,
Dwarf_Signed *offset_relevant,
Dwarf_Signed *register_num,
Dwarf_Signed *offset_or_block_len,
Dwarf_Ptr *block_ptr,
Dwarf_Addr *row_pc,
Dwarf_Error *err);
Function
dwarf_get_fde_info_for_cfa_reg3()
retrieves the CFA register rule for a given program counter address from the
register rule table associated with an FDE descriptor.
Argument
fde should reference a valid DWARF FDE
descriptor.
Argument
pc should hold the program counter
address to be used to locate the desired register rule row.
On successful execution,
dwarf_get_fde_info_for_cfa_reg3() stores
information about the CFA register rule found into the locations pointed to by
the arguments
type,
offset_relevant,
register_num,
offset_or_block_len,
block_ptr and
row_pc.
Argument
type should point to a location which
will hold the type code of the register rule found. The returned value is one
of the
DW_EXPR_*
contants defined in the
header file
<libdwarf.h>.
If there is an offset value associated with the CFA register rule, the location
pointed to by argument
offset_relevant will
be set to 1.
Argument
register_num should point to a
location which will hold the register number associated with the CFA register
rule.
If the CFA register rule is of type
DW_EXPR_OFFSET
or
DW_EXPR_VAL_OFFSET
, the location pointed to
by argument
offset_or_block_len will be set
to the offset value associated with the register rule, or to 0 if the register
rule does not have an offset value. If the type code is
DW_EXPR_EXPRESSION
or
DW_EXPR_VAL_EXPRESSION
, the location
pointed to by argument
offset_or_block_len
will be set to the length in bytes of the DWARF expression block associated
with the register rule.
Argument
block_ptr should point to a location
which will be set to a pointer to the content of the DWARF expression block
associated with the CFA register rule.
Argument
row_pc should point to a location
which will be set to the lowest program counter address associated with the
register rule found.
If argument
err is not NULL, it will be used to
return an error descriptor in case of an error.
Function
dwarf_get_fde_info_for_cfa_reg3() returns
DW_DLV_OK
when it succeeds. In case of an
error, it returns
DW_DLV_ERROR
and sets the
argument
err.
Function
dwarf_get_fde_info_for_cfa_reg3() can fail
with:
-
-
- [
DW_DLE_ARGUMENT
]
- One of the arguments
block_ptr,
fde,
offset_or_block_len,
offset_relevant,
register_num,
row_pc, or
type was NULL.
-
-
- [
DW_DLE_PC_NOT_IN_FDE_RANGE
]
- The program counter value provided in argument
pc did not fall in the range covered by
argument fde.
dwarf(3),
dwarf_get_fde_at_pc(3),
dwarf_get_fde_info_for_all_regs(3),
dwarf_get_fde_info_for_all_regs3(3),
dwarf_get_fde_info_for_reg(3),
dwarf_get_fde_info_for_reg3(3),
dwarf_get_fde_n(3),
dwarf_set_frame_cfa_value(3),
dwarf_set_frame_rule_initial_value(3),
dwarf_set_frame_rule_table_size(3),
dwarf_set_frame_same_value(3),
dwarf_set_frame_undefined_value(3)