diff --git a/include/dwarf-eh.h b/include/dwarf-eh.h index e69de29b..405e394a 100644 --- a/include/dwarf-eh.h +++ b/include/dwarf-eh.h @@ -0,0 +1,128 @@ +/* libunwind - a platform-independent unwind library + Copyright (c) 2003 Hewlett-Packard Development Company, L.P. + Contributed by David Mosberger-Tang <davidm@hpl.hp.com> + +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. */ + +#ifndef dwarf_eh_h +#define dwarf_eh_h + +#include "dwarf.h" + +/* 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. + + Details: + + 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 + string: + + '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 */ + +struct dwarf_eh_frame_hdr + { + 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 + following members: + + encoded_t eh_frame_ptr; + encoded_t fde_count; + struct + { + encoded_t start_ip; // first address covered by this FDE + encoded_t fde_addr; // address of the FDE + } + binary_search_table[fde_count]; */ + }; + +#endif /* dwarf_eh_h */