freebsd-src/contrib/elftoolchain/libdwarf/dwarf_get_fde_info_for_cfa_reg3.3
Ed Maste ae500c1ff8 Update to ELF Tool Chain r3668
Highlights:
- Make sure that only TLS sections are sorted into TLS segment.
- Fixed multiple errors in "Section to Segment mapping".
- Man page updates
- ar improvements
- elfcopy: avoid filter_reloc uninitialized variable for rela
- elfcopy: avoid stripping relocations from static binaries
- readelf: avoid printing directory in front of absolute path
- readelf: add NT_FREEBSD_FEATURE_CTL FreeBSD note type
- test improvements

NOTES:

Some of these changes originated in FreeBSD and simply reduce diffs
between contrib and vendor.

ELF Tool Chain ar is not (currently) used in FreeBSD, and there are
improvements in both FreeBSD and ELF Tool Chain ar that are not in
the other.

Sponsored by:	The FreeBSD Foundation
2019-01-10 14:35:23 +00:00

172 lines
4.9 KiB
Groff

.\" Copyright (c) 2011 Kai Wang
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.\" $Id: dwarf_get_fde_info_for_cfa_reg3.3 3644 2018-10-15 19:55:01Z jkoshy $
.\"
.Dd June 12, 2011
.Dt DWARF_GET_FDE_INFO_FOR_CFA_REGS3 3
.Os
.Sh NAME
.Nm dwarf_get_fde_info_for_cfa_regs3
.Nd retrieve a CFA register rule
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft int
.Fo dwarf_get_fde_info_for_cfa_regs3
.Fa "Dwarf_Fde fde"
.Fa "Dwarf_Addr pc"
.Fa "Dwarf_Small *type"
.Fa "Dwarf_Signed *offset_relevant"
.Fa "Dwarf_Signed *register_num"
.Fa "Dwarf_Signed *offset_or_block_len"
.Fa "Dwarf_Ptr *block_ptr"
.Fa "Dwarf_Addr *row_pc"
.Fa "Dwarf_Error *err"
.Fc
.Sh DESCRIPTION
Function
.Fn 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.
.Pp
Argument
.Ar fde
should reference a valid DWARF FDE descriptor.
.Pp
Argument
.Ar pc
should hold the program counter address to be used to locate the
desired register rule row.
.Pp
On successful execution,
.Fn dwarf_get_fde_info_for_cfa_reg3
stores information about the CFA register rule found into the locations
pointed to by the arguments
.Ar type ,
.Ar offset_relevant ,
.Ar register_num ,
.Ar offset_or_block_len ,
.Ar block_ptr
and
.Ar row_pc .
.Pp
Argument
.Ar type
should point to a location which will hold the type code of the
register rule found.
The returned value is one of the
.Dv DW_EXPR_*
contants defined in the header file
.In libdwarf.h .
.Pp
If there is an offset value associated with the CFA register rule,
the location pointed to by argument
.Ar offset_relevant
will be set to 1.
.Pp
Argument
.Ar register_num
should point to a location which will hold the register number associated
with the CFA register rule.
.Pp
If the CFA register rule is of type
.Dv DW_EXPR_OFFSET
or
.Dv DW_EXPR_VAL_OFFSET ,
the location pointed to by argument
.Ar 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
.Dv DW_EXPR_EXPRESSION
or
.Dv DW_EXPR_VAL_EXPRESSION ,
the location pointed to by argument
.Ar offset_or_block_len
will be set to the length in bytes of the DWARF expression block
associated with the register rule.
.Pp
Argument
.Ar 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.
.Pp
Argument
.Ar row_pc
should point to a location which will be set to the lowest program
counter address associated with the register rule found.
.Pp
If argument
.Ar err
is not NULL, it will be used to return an error descriptor in case
of an error.
.Sh RETURN VALUES
Function
.Fn dwarf_get_fde_info_for_cfa_reg3
returns
.Dv DW_DLV_OK
when it succeeds.
In case of an error, it returns
.Dv DW_DLV_ERROR
and sets the argument
.Ar err .
.Sh ERRORS
Function
.Fn dwarf_get_fde_info_for_cfa_reg3
can fail with:
.Bl -tag -width ".Bq Er DW_DLE_PC_NOT_IN_FDE_RANGE"
.It Bq Er DW_DLE_ARGUMENT
One of the arguments
.Ar block_ptr ,
.Ar fde ,
.Ar offset_or_block_len ,
.Ar offset_relevant ,
.Ar register_num ,
.Ar row_pc ,
or
.Ar type
was NULL.
.It Bq Er DW_DLE_PC_NOT_IN_FDE_RANGE
The program counter value provided in argument
.Ar pc
did not fall in the range covered by argument
.Ar fde .
.El
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_get_fde_at_pc 3 ,
.Xr dwarf_get_fde_info_for_all_regs 3 ,
.Xr dwarf_get_fde_info_for_all_regs3 3 ,
.Xr dwarf_get_fde_info_for_reg 3 ,
.Xr dwarf_get_fde_info_for_reg3 3 ,
.Xr dwarf_get_fde_n 3 ,
.Xr dwarf_set_frame_cfa_value 3 ,
.Xr dwarf_set_frame_rule_initial_value 3 ,
.Xr dwarf_set_frame_rule_table_size 3 ,
.Xr dwarf_set_frame_same_value 3 ,
.Xr dwarf_set_frame_undefined_value 3