/* libunwind - a platform-independent unwind library
Copyright (c) 2003 Hewlett-Packard Development Company, L.P.
Contributed by David Mosberger-Tang <firstname.lastname@example.org>
This file is part of libunwind.
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/* This header file defines the format of a DWARF exception-header
section (.eh_frame_hdr, pointed to by program-header
PT_GNU_EH_FRAME). The exception-header is self-describing in the
sense that the format of the addresses contained in it is expressed
as a one-byte type-descriptor called a "pointer-encoding" (PE).
The exception header encodes the address of the .eh_frame section
and optionally contains a binary search table for the
Frame Descriptor Entries (FDEs) in the .eh_frame. The contents of
.eh_frame has the format described by the DWARF v3 standard
(http://www.eagercon.com/dwarf/dwarf3std.htm), except that code
addresses may be encoded in different ways. Also, .eh_frame has
augmentations that allow encoding a language-specific data-area
(LSDA) pointer and a pointer to a personality-routine.
The Common Information Entry (CIE) associated with an FDE may
contain an augmentation string. Each character in this string has
a specific meaning and either one or two associated operands. The
operands are stored in an augmentation body which appears right
after the "return_address_register" member and before the
"initial_instructions" member. The operands appear in the order
in which the characters appear in the string. For example, if the
augmentation string is "zL", the operand for 'z' would be first in
the augmentation body and the operand for 'L' would be second.
The following characters are supported for the CIE augmentation
'z': The operand for this character is a uleb128 value that gives the
length of the CIE augmentation body, not counting the length
of the uleb128 operand itself. If present, this code must
appear as the first character in the augmentation body.
'L': Indicates that the FDE's augmentation body contains an LSDA
pointer. The operand for this character is a single byte
that specifies the pointer-encoding (PE) that is used for
the LSDA pointer.
'R': Indicates that the code-pointers (FDE members
"initial_location" and "address_range" and the operand for
DW_CFA_set_loc) in the FDE have a non-default encoding. The
operand for this character is a single byte that specifies
the pointer-encoding (PE) that is used for the
code-pointers. Note: the "address_range" member is always
encoded as an absolute value. Apart from that, the specified
FDE pointer-encoding applies.
'P': Indicates the presence of a personality routine (handler).
The first operand for this character specifies the
pointer-encoding (PE) that is used for the second operand,
which specifies the address of the personality routine.
If the augmentation string contains any other characters, the
remainder of the augmentation string should be ignored.
Furthermore, if the size of the augmentation body is unknown
(i.e., 'z' is not the first character of the augmentation string),
then the entire CIE as well all associated FDEs must be ignored.
A Frame Descriptor Entries (FDE) may contain an augmentation body
which, if present, appears right after the "address_range" member
and before the "instructions" member. The contents of this body
is implicitly defined by the augmentation string of the associated
CIE. The meaning of the characters in the CIE's augmentation
string as far as FDEs are concerned is as follows:
'z': The first operand in the FDE's augmentation body specifies
the total length of the augmentation body as a uleb128 (not
counting the length of the uleb128 operand itself).
'L': The operand for this character is an LSDA pointer, encoded
in the format specified by the corresponding operand in the
CIE's augmentation body.
#define DW_EH_VERSION 1 /* The version we're implementing */
unsigned char version;
unsigned char eh_frame_ptr_enc;
unsigned char fde_count_enc;
unsigned char table_enc;
/* The rest of the header is variable-length and consists of the
encoded_t start_ip; // first address covered by this FDE
encoded_t fde_addr; // address of the FDE
#endif /* dwarf_eh_h */