December 13, 2011 dwarf_lineoff() is now deprecated, dwarf_lineoff_b() is strongly recommended instead. dwarf_add_line_entry() does not have all the line fields needed for generating DWARF3/4, use dwarf_add_line_entry_b() instead. Generation of DWARF3/4 is not yet functional, this new function is a first step. October 29, 2011 Added support for reading .debug_types (type unit) data. October 26,2011 Revised the Makefile.in and README to make building libdwarf easier to accomplish with unusual locations of libelf headers or other headers or libraries. June 04,2011 Non-Elf objects could be used with libdwarf, but no one has contributed non-elf-reading code for libdwarf and a crucial detail was not documented so those writing such object-reading code have not done it entirely correctly. Fundamentally such code must treat a section index of 0 as a real but empty section with no name (an empty name). dwarf_elf_access.c and dwarf_elf_init_finish.c have some comments on this point now. March 29,2011 All the code changed a lot because indentations were all over the map, now they are consistent. Additions were made to DWARF4 support. Now we use dicheck (a new open source application) to check indentation. Library users will not see any change, all interfaces remain as before. January 12,2010 A libdwarf user has noticed that the April 4, 2009 consumer function changes introduced a problem: the default CFA column was DW_FRAME_CFA_COL even when a newer DWARF3 consumer frame interface like dwarf_get_fde_info_for_all_regs3() is used. The libdwarf2.1.pdf documentation stated the default should be DW_FRAME_CFA_COL3 in that case. The introduction of a caller-specified frame-column function (dwarf_set_frame_cfa_value()) in that April 4, 2009 release was flawed in that it failed to match the documentation. Now the default frame column is DW_FRAME_CFA_COL3 unless the configure option --enable-oldframecol is used at libdwarf build time. If you are using libdwarf old frame consumer interfaces dwarf_get_fde_info_for_reg(), dwarf_get_fde_info_for_cfa_reg(), and dwarf_get_fde_info_for_all_regs() and want unchanged operation then please configure libdwarf with --enable-oldframecol . or add the call dwarf_set_frame_cfa_value(dbg,DW_FRAME_CFA_COL) after calling a libdwarf initialization function. It is impossible to configure a single libdwarf.a so that it transparently defaults to both DW_FRAME_CFA_COL and DW_FRAME_CFA_COL3. A call such as dwarf_set_frame_cfa_value(dbg,DW_FRAME_CFA_COL3) or dwarf_set_frame_cfa_value(dbg,DW_FRAME_CFA_COL) (or some other name/value of your choosing) following the dwarf_init() call gives your application full control of the frame cfa column independent of the libdwarf configure option. See the libdwarf2.1.pdf documentation for details. We strongly recommend that you use dwarf_set_frame_cfa_value() to avoid a configure-time dependency. July 7, 2009 Implemented support for elf 'rela' relocations so libdwarf and dwarfdump can read *nix .o files with such relocations reasonably, at least for some machines (see dwarf_elf_access.c for EM_ in 'case' statements.) This changes the binary access for non-Elf object users (folks who have coded there own non-Elf access routines do reference internals of dwarf_opaque.h), but the new data can be left zero and the rest of the code should work fine. dwarf_opaque.h gathers section data in Dwarf_Section_s structs which simplifies the code in dwarf_init_finish.c and clarifies what fields are section related. July 4, 2009 When something erroneous is detected in a die information about the CU context may be of interest. So we added dwarf_CU_dieoffset_given_die(), a function which allows clients to find the relevant CU die for any die. The consumer can use normal attribute access functions to print information about that CU die (and the erroneous die, of course). See the libdwarf consumer document for more information. April 27, 2009 Interface additions: dwarf_loclist_from_expr_a() and dwarf_get_ranges_a() are new interfaces like dwarf_loclist_from_expr() and dwarf_get_ranges() respectively, but with arguments allowing full support for different CIEs in an executable having different address-sizes (and their compilation unit DIEs if .debug_info is present). dwarf_get_loclist_entry() does not support differing address sizes per CIE/CU. April 4, 2009 Added new functions dwarf_set_frame_cfa_value() dwarf_set_frame_same_value(), and dwarf_set_frame_undefined_value(). These are essential for ABIs where the real register numbers exceed 1033 (such as ppc). Failing to use these leads to frame instructions DW_CFA_undefined and DW_CFA_same_value emitting values that cannot be interpreted correctly by a libdwarf consumer. See dwarfdump for examples of use. Feb 14, 2009 Added configure option --enable-nonstandardprintf which makes it easy to get printf of Dwarf_Unsigned (etc) types correct even for non-standard compilers. Dec 30, 2008 Added interfaces for getting and printing the .debug_ranges data. Dec 8, 2008 Record the abbreviation 'code' (index) in each DIE. Making it possible for a pretty-printer to print the abbreviation code. Sep 30, 2008 Phil Mucci provided an a.out test chase which demonstrates a bug in 64bit DWARF2 output by gcc. Now libdwarf works around this and with -v -v -v -v prints a warning. Sep 29, 2008 Thanks to Phil Mucci for providing a little-endian 64bit test object file that exposed a problem when there are 'extra' bytes (possibly unused) after a line table prologue header and before the line table itself. This releases fixes the bug. Thanks to Matthew Legendre for pointing out that we were sharing de_fde_count for eh and non-eh and that could cause erroneous error returns in a couple of functions. These counts are now separate. April 9, 2008 libdwarf would behave badly if one compilation unit had more than 64K abbreviations: It was both very slow dealing with abbreviations and would get mixed up and error-off. Increased the size of some internal variables and rewrote abbreviation lookup. February 18, 2008 It is now possible to write one's own access to objects, making it possible to use a different library than libelf or even read a completely different object format than ELF. See dwarf_object_init() and see the new source files dwarf_original_elf_init.c and dwarf_elf_access.c for example code using the new function-pointer approach as it's implementation. Thanks to Josh Fuhs for doing the design and 99% of the work to make this happen. February 2, 2008 Now pro_init() defaults to standard DWARF3 generated offset sizes. But if a new flag DW_DLC_OFFSET_SIZE_64 or'd into flags passed to dwarf_produser_init() or dwarf_producer_init_b, the DWARF3 extended offset size is generated (if the address size is 64 bit). The new configure option --enable-dwarf-format-strict-32bit forces pro_init() to always cause 32bit offset dwarf generation. The new configure option --enable-dwarf-format-sgi-irix forces the old SGI IRIX 64bit offset generation for 64bit pointer size objects. This is intended to simplify standard DWARF3 generation with the now-normal use of 32bit DWARF offsets for both 32 and 64 bit pointer objects. It does require that anyone wanting SGI IRIX dwarf generation with its non-standard offsets for 64bit objects use the new --enable-dwarf-format-sgi-irix configure time option. This has no effect on dwarf reader code. It affects code calling the libdwarf producer interfaces. December 8, 2007 Had to add an ugly configure conditional as libelf has unconditional use of off64_t in recent libelf.h July 3, 2007 A new interface function, dwarf_loclist_from_expr(), allows easy extraction of dwarf expression bytes from expressions in frame data. May 8, 2007 Now documents released as .mm and .pdf (no longer as .ps). May 7, 2007 Incorporates Sun Microsystems extensions to dwarf.h and to the consumer and producer libraries. The changes include corrections so the producer library cleans up it's memory use on a call to dwarf_producer_finish(dbg). Thanks to Chris Quenelle of Sun for these contributions. March 20, 2007 nroff/troff and the AT&T -mm package are not widely available, so now the Makefile refers to groff, which works quite nicely. February 20, 2007 Documented libdwarf thread safety in README. Fixed memory leak in dwarf macro reading code. Removed use of static data in dwarf macro reading code: now uses stack/heap (for thread safety). February 9, 2007 Maintenance of libdwarf is now outside SGI as David Anderson has left SGI. March 29, 2006 The March 27, 2006 version accomodates DWARF3. Some people have been using the library without altering dwarf.h, libdwarf.h to accomodate large numbers of registers. This exposed a bug (an off-by-one error) but also makes it clear additional documentation is needed. So in libdwarf large new comments near 'TARGET DEPENDENCY' attempt to explain better. Oct 03, 2005 The July version had an incompatible interface: old dealloc code did not always work right. The incompatibility is now fixed and the new features remain. July 15, 2005 New optional alloc-check code optionally checks all allocated memory is freed (malloc_check.h malloc_check.c) Various new dealloc routines written as the previous approach of letting client code do detailed dealloc turned out not to dealloc all memory. To get the new checking you must manually change a line in malloc_check.h and rebuild libdwarf. Mar 31, 2005 Documented the libexc.so/.debug_funcnames dependency and the 64bit-offset DWARF extension in mips_extentions.{mm,ps}. Mar 21, 2005 gcc 3.3 and 3.4 .eh_frame 'z' augmentations are not handled correctly, so libdwarf gives an error when attempting to print such. gcc 2 'eh' augmentation is simpler and prints correctly. (.eh_frame is a GNU section, not DWARF2/3, and what is recorded in .eh_frame is not specified by DWARF2/3, though .eh_frame does resemble DWARF2/3 .debug_frame). Oct 28, 2004 Updated contact address in copyright: SGI moved 1/4 mile in 2003 to a new address: 1500 Crittenden Lane. Documented additional vendor extensions. Oct 27, 2004 Added known vendor extensions to dwarf2/3 to dwarf.h HP, GNU, PGI and UPC extensions are now recorded. Recorded vendor extensions from Concurrent. Feb 3, 2004 If 'Dwarf_Word' is 64 bits, two macros reading leb numbers fail to initialize upper bits of the values read. First noticed with bogus line numbers printing from dwarfdump. Now we use already-existing functions, avoiding the problem. Oct 02, 2003 Support .debug_loc section fully. Sept 29, 2003 Support DW_FORM_indirect properly. Supports loclists in part (but not multiple loclist entries yet). Support 'padding bytes' at end of .debug_arange and .debug_pubnames and .debug_pubtypes per CU (recent dwarf committee email made it clear this is appropriate). May 23, 2002 Libdwarf now asks for sections only when they are used, so that unneeded sections aren't loaded. Support for using SGI's ELF library as an alternative to using AT&T libelf-style has been added (the SGI ELF library is presently only available internally to SGI). Jan 10, 2002 Fixed memory leak in dwarf_finish(). Aug 21, 2001 If one called dwarf_add_file_decl() or dwarf_add_directory_decl() but never added a line, .debug_line was not produced. This was a mistake, as if any file or directory was provided .debug_line should be produced. Now it is produced. June 14, 2001 Given a cu header offset, it was not easy to derive the CU header DIE offset. Created the new function dwarf_get_cu_die_offset_given_cu_header_offset() do get the CU header DIE offset. Added the function dwarf_get_arange_cu_header_offset() so the cu header offset could be retrieved from .debug_aranges information. June 07, 2001 Major bug in dwarf_leb.c decoding large integers (Dwarf_Signed 64 bit where library is compiled in ILP32) found and fixed. May 21, 2001 Some small fixes have been found by various folks, so it seems time to prepare a new source release. See ChangeLog for details. April 15, 2000 The libdwarf copyright has changed to version 2.1 of the GNU Lesser General Public License. Anyone holding a version of libdwarf that was published before this new copyright is allowed to use the copyright published in that earlier libdwarf source on the earlier source or to use this new copyright on the earlier source, at their option. December 08, 1999 The dwarf committee has adopted the offset-extension proposal. This allows compatibly emitting dwarf with 64bit offsets. The dwarf reader now automatically figures out which is in use. The dwarf writer configures itself at the time the writer initialization routine is called, though the writer is restricted, at libdwarf compile time, to one of mips/sgi pure 32/pure 64 offsets/pointers. 32bit offsets only (per dwarf 2.0.0 and cygnus) 32bit offsets with extension to 64bit offsets allowed (the offset-extension newly passed). In addition, a great deal of duplicate code for the sgi .debug_weaknames, .debug_funcnames, .debug_varnames and .debug_typenames sections has been removed: a single set of functions does the real work now. Sept 29, 1999 Just found out that cygnus is, on 64bit targets, generating 32bit offsets (as elf32 has, for example) with 64 bit pointers (in references to text and data). Whereas sgi has always generated 64bit dwarf with 64 bit offsets (as in elf64) and 64bit pointers for 64bit pointer objects. I'll call the sgi approach 64-bit and the cygnus approach 32bit-offsets. Cygnus is following the DWARF2 spec as written, so they are right in doing only 32bit-offsets. Folks at sgi (including me) think that, as for elf64, the offsets in dwarf for 64bit pointer-apps should be 64 bits. We think it is only a matter of time before we really *need* 64bit offsets and when that happens it will be on an important app. Disk space is cheap, so lets just go 64 bit on 64bit apps (such as ia64 apps) to avoid a future problem. I(davea@sgi.com) think the 'pointer-size' references in the dwarf spec were really written for 64-bit pointer apps. I don't recall serious consideration of 64bit pointer apps in the committee deliberations (I did miss a couple of meetings) and think 64bit offsets are consistent with dwarf2, even though the speci was not written for such. We think true full 64 bit dwarf2 is the right way to go (the spec changes are obvious: file and section offsets become 64bit with 64bit pointer objects. MIPS/SGI is definitely 64-bit offsets for 64 bit objects, cygnus is definitely 32bit-offsets for earlier 64bit pointer environments. At any rate, now the dwarf reader allows and accomodates both and the dwarf producer also accomodates both. Some tweaking of the pro_init.c or dwarf_init_finish.c files may be necessary in future: no other changes should be needed to accomodate the two 64bit approaches, as the library (and dwarfdump) now deal with both forms. August 20, 1999 Added some #ifndef/#define to pro_util.h to let libdwarf build on more hosts. (since those hosts don't need the producer code, AFAIK, zero values suffice for missing #defines.) July 21, 1999 Now reader transparently reads either-endianness data from an either-endianness object. Updated dwarf.h and libdwarf.h to recognize GNU egcs dwarf extensions and to print the egcs eh_frame section. June 10, 1999 gnu configure version of libdwarf made available for the first time. Still allows only same-endian-as-host in objects. August, 1994 libdwarf source made available for ftp on sgigate.sgi.com /ftp/pub June, 1994 Consumer interface changed completely, following "Candy Machine Interfaces" chapter from "Writing Solid Code" by Steve Maguire (Microsoft Press). April, 1993 Initial version of libdwarf for dwarf version 2 written at sgi.