On Tue, Jul 30, 2013 at 06:05:00PM +0400, Andrey Ponomarenko wrote: > Hi, > > I created a dump of a library debug-info by the "eu-readelf > --debug-dump=info" command. The formal_parameter of a subprogram has > type "(GNU_ref_alt) [ N]", but N is not described anywhere in the > dump. > > I have take a look at the source code of elfutils and found, that > DW_FORM_GNU_ref_alt is an offset in the "alternate debuginfo": > > DW_FORM_GNU_ref_alt = 0x1f20, /* offset in alternate .debuginfo. */ > DW_FORM_GNU_strp_alt = 0x1f21 /* offset in alternate .debug_str. */ > > How can I read/dump this "alternate debuginfo"?
DWARF extensions elfutils recognizes/supports are described at: https://fedorahosted.org/elfutils/wiki/DwarfExtensions When configured with --enable-dwz libdw will resolve these FORMs. The new forms are described in this DWARF5 proposal: http://www.dwarfstd.org/ShowIssue.php?issue=120604.1 You can find the alt dwz file by reading the .gnu_debugaltlink section. Which contains a file name followed by the build-id of the dwz file. Resolving the build-id is done in the regular way as described at https://fedoraproject.org/wiki/Releases/FeatureBuildId#Find_files_by_build_ID The build-id symlink will point at the /usr/lib/debug/.dwz/ file. Cheers, Mark _______________________________________________ elfutils-devel mailing list [email protected] https://lists.fedorahosted.org/mailman/listinfo/elfutils-devel
