DWARF_GET_FDE_INFO_FOR_REG3(3) | Library Functions Manual | DWARF_GET_FDE_INFO_FOR_REG3(3) |
dwarf_get_fde_info_for_reg3
—
#include <libdwarf.h>
int
dwarf_get_fde_info_for_reg3
(Dwarf_Fde
fde, Dwarf_Half table_column,
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 *error);
dwarf_get_fde_info_for_reg3
() retrieves a
register rule from the register rule table associated with a given FDE
descriptor, given a program counter address and rule column number.
Argument fde should reference a valid DWARF FDE descriptor.
Arugment table_column should hold the column number of the register rule desired.
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_reg3
() stores information
about the 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 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 register rule.
If the 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 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.
dwarf_get_fde_info_for_reg3
() returns
DW_DLV_OK
when it succeeds. In case of an error, it
returns DW_DLV_ERROR
and sets the argument
err.
dwarf_get_fde_info_for_reg3
() can fail with:
DW_DLE_ARGUMENT
]DW_DLE_FRAME_TABLE_COL_BAD
]DW_DLE_PC_NOT_IN_FDE_RANGE
]Dwarf_Fde fde; Dwarf_Off fde_offset, cie_offset; Dwarf_Unsigned func_len, fde_length; Dwarf_Signed cie_index, offset_relevant, register_num; Dwarf_Signed offset_or_block_len; Dwarf_Addr low_pc, row_pc; Dwarf_Ptr fde_addr, block_ptr; Dwarf_Small type; Dwarf_Error de; /* ... assuming `fde` references a valid FDE descriptor... */ if (dwarf_get_fde_range(fde, &low_pc, &func_len, &fde_addr, &fde_length, &cie_offset, &cie_index, &fde_offset, &de) != DW_DLV_OK) errx(EXIT_FAILURE, "dwarf_get_fde_range failed: %s", dwarf_errmsg(de)); /* Iterate all the table rows. */ for (pc = low_pc; pc < low_pc + func_len; pc++) { if (dwarf_get_fde_info_for_reg3(fde, 3, pc, &type, &offset_relevant, ®ister_num, &offset_or_block_len, &block_ptr, &row_pc, &de) != DW_DLV_OK) { warnx("dwarf_get_fde_info_for_reg3 failed: %s", dwarf_errmsg(de)); continue; } /* ... use the retrieved register rule ... */ }
November 9, 2011 | NetBSD 9.2 |