* Plan to contribute for supporting split dwarf (-gsplit-dwarf) in dwz @ 2021-02-15 17:26 Sharma, Alok Kumar 2021-02-15 18:54 ` Mark Wielaard 0 siblings, 1 reply; 5+ messages in thread From: Sharma, Alok Kumar @ 2021-02-15 17:26 UTC (permalink / raw) To: dwz; +Cc: George, Jini Susan, E, Nagajyothi, Achra, Nitika Hi all, I am planning to contribute for supporting split DWARF. Please let me know if it is already being worked on? Regards, Alok ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Plan to contribute for supporting split dwarf (-gsplit-dwarf) in dwz 2021-02-15 17:26 Plan to contribute for supporting split dwarf (-gsplit-dwarf) in dwz Sharma, Alok Kumar @ 2021-02-15 18:54 ` Mark Wielaard 2021-02-17 5:53 ` E, Nagajyothi 0 siblings, 1 reply; 5+ messages in thread From: Mark Wielaard @ 2021-02-15 18:54 UTC (permalink / raw) To: Sharma, Alok Kumar; +Cc: dwz, George, Jini Susan, E, Nagajyothi, Achra, Nitika Hi Alok, On Mon, Feb 15, 2021 at 05:26:29PM +0000, Sharma, Alok Kumar via Dwz wrote: > I am planning to contribute for supporting split DWARF. > > Please let me know if it is already being worked on? That is great. Nobody is currently working on that as far as I know. One issue to resolve is knowing how to "unsplit" the DWARF first. Since it isn't clear (to me) whether it makes sense to do split DWARF .dwo (sections/files) together with Supplementary DWARF Object references. One idea might be to handle DWP processed files? There are a couple of bugs that might be prerequirements for handling split DWARF, you probably need "split" variants of these bugs: https://sourceware.org/bugzilla/show_bug.cgi?id=27376 https://sourceware.org/bugzilla/show_bug.cgi?id=27375 https://sourceware.org/bugzilla/show_bug.cgi?id=27373 See also this comment: https://sourceware.org/bugzilla/show_bug.cgi?id=24726#c5 Which describes some other issues, like DW_FORM_strx, .debug_str_offset, DW_FORM_rnglistx and various _base attributes that need supporting. (This should probabably have their own bugs filed.) There is already one explicit -gsplit-dwarf variant bug: https://sourceware.org/bugzilla/show_bug.cgi?id=24756 But that is only for part of the problem (and might be simply resolved by bug #27375). Cheers, Mark ^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: Plan to contribute for supporting split dwarf (-gsplit-dwarf) in dwz 2021-02-15 18:54 ` Mark Wielaard @ 2021-02-17 5:53 ` E, Nagajyothi 2021-02-18 14:45 ` Mark Wielaard 0 siblings, 1 reply; 5+ messages in thread From: E, Nagajyothi @ 2021-02-17 5:53 UTC (permalink / raw) To: Mark Wielaard, dwz Cc: George, Jini Susan, Achra, Nitika, Sharma, Alok Kumar, E, Nagajyothi [AMD Official Use Only - Internal Distribution Only] Hi, I am working on adding support for the dwarf5 .debug_str_offsets, .debug_addr sections and the related forms DW_FORM_strx[1234], DW_FORM_addrx[1234]. Please let me know if anyone has already started work on these. Thanks, Nagajyothi -----Original Message----- From: Mark Wielaard <mark@klomp.org> Sent: Tuesday, February 16, 2021 12:24 AM To: Sharma, Alok Kumar <AlokKumar.Sharma@amd.com> Cc: dwz@sourceware.org; George, Jini Susan <JiniSusan.George@amd.com>; E, Nagajyothi <Nagajyothi.E@amd.com>; Achra, Nitika <Nitika.Achra@amd.com> Subject: Re: Plan to contribute for supporting split dwarf (-gsplit-dwarf) in dwz [CAUTION: External Email] Hi Alok, On Mon, Feb 15, 2021 at 05:26:29PM +0000, Sharma, Alok Kumar via Dwz wrote: > I am planning to contribute for supporting split DWARF. > > Please let me know if it is already being worked on? That is great. Nobody is currently working on that as far as I know. One issue to resolve is knowing how to "unsplit" the DWARF first. Since it isn't clear (to me) whether it makes sense to do split DWARF .dwo (sections/files) together with Supplementary DWARF Object references. One idea might be to handle DWP processed files? There are a couple of bugs that might be prerequirements for handling split DWARF, you probably need "split" variants of these bugs: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsourceware.org%2Fbugzilla%2Fshow_bug.cgi%3Fid%3D27376&data=04%7C01%7CNagajyothi.E%40amd.com%7Cedeb271285e94b3a6d6b08d8d1e3447a%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637490121349829241%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=HiyzxPs6SJnUE%2BMEKAsUE8HL2dvneJD1V7Yfcb9ZDcQ%3D&reserved=0 https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsourceware.org%2Fbugzilla%2Fshow_bug.cgi%3Fid%3D27375&data=04%7C01%7CNagajyothi.E%40amd.com%7Cedeb271285e94b3a6d6b08d8d1e3447a%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637490121349829241%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=QpjPErW8i8JG75ke528vxPry5pvkwfIq6QO3yxdxURo%3D&reserved=0 https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsourceware.org%2Fbugzilla%2Fshow_bug.cgi%3Fid%3D27373&data=04%7C01%7CNagajyothi.E%40amd.com%7Cedeb271285e94b3a6d6b08d8d1e3447a%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637490121349829241%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=h4WU7ejc7KeSBEluEAgnM5%2FRMRTOVMjRXuzZVbdBlec%3D&reserved=0 See also this comment: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsourceware.org%2Fbugzilla%2Fshow_bug.cgi%3Fid%3D24726%23c5&data=04%7C01%7CNagajyothi.E%40amd.com%7Cedeb271285e94b3a6d6b08d8d1e3447a%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637490121349829241%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=uLu90OuqGGBKIFwqItGHPNomPHb2HJNG8TkXKJ%2FUggM%3D&reserved=0 Which describes some other issues, like DW_FORM_strx, .debug_str_offset, DW_FORM_rnglistx and various _base attributes that need supporting. (This should probabably have their own bugs filed.) There is already one explicit -gsplit-dwarf variant bug: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsourceware.org%2Fbugzilla%2Fshow_bug.cgi%3Fid%3D24756&data=04%7C01%7CNagajyothi.E%40amd.com%7Cedeb271285e94b3a6d6b08d8d1e3447a%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637490121349829241%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=%2BoaV%2Fqfl7feS7siRNIsze0aZui7S9qN17vBj%2FYOkjdA%3D&reserved=0 But that is only for part of the problem (and might be simply resolved by bug #27375). Cheers, Mark ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Plan to contribute for supporting split dwarf (-gsplit-dwarf) in dwz 2021-02-17 5:53 ` E, Nagajyothi @ 2021-02-18 14:45 ` Mark Wielaard 2021-02-22 3:39 ` E, Nagajyothi 0 siblings, 1 reply; 5+ messages in thread From: Mark Wielaard @ 2021-02-18 14:45 UTC (permalink / raw) To: E, Nagajyothi, dwz; +Cc: George, Jini Susan, Achra, Nitika, Sharma, Alok Kumar Hi Nagajyothi, On Wed, 2021-02-17 at 05:53 +0000, E, Nagajyothi via Dwz wrote: > I am working on adding support for the dwarf5 .debug_str_offsets, > .debug_addr sections and the related forms DW_FORM_strx[1234], DW_FORM_addrx[1234]. > Please let me know if anyone has already started work on these. Thanks, I don't believe anybody is working on this right now. There is already a bug for .debug_addr/DW_FORM_addrx[1234] support: https://sourceware.org/bugzilla/show_bug.cgi?id=27375 I think this shouldn't be too hard. Any DIE that references an address cannot be moved to an alt file, so simply mark it with die_no_multifile. We do try to optimize DW_AT_low/high_pc attribute pairs, so double check that doesn't interfere with DW_FORM_addrx[1234] processing. Also note that there are two new location operations DW_OP_addrx and DW_OP_constx that can reference the .debug_addr section index. As a followup you could try optimizing things, but then you need to keep track of all the addresses used and see if there are duplicates that could be turned into a (smaller) DW_FORM_addrx[1234] index. But I would keep that separate from the initial implementation. For .debug_str_offset/DW_FORM_strx[1234] I opened a new bug. https://sourceware.org/bugzilla/show_bug.cgi?id=27434 This is a little trickier than DW_FORM_addrx[1234] since such DIEs using DW_FORM_strx may be moved to a multifile. You also probably want to make them equal to DW_FORM_strp entries pointing (indirectly) to the same string. You might want to add a note to the the bugs that you are working on them. Thanks, Mark ^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: Plan to contribute for supporting split dwarf (-gsplit-dwarf) in dwz 2021-02-18 14:45 ` Mark Wielaard @ 2021-02-22 3:39 ` E, Nagajyothi 0 siblings, 0 replies; 5+ messages in thread From: E, Nagajyothi @ 2021-02-22 3:39 UTC (permalink / raw) To: Mark Wielaard, dwz; +Cc: George, Jini Susan, Achra, Nitika, Sharma, Alok Kumar [AMD Official Use Only - Internal Distribution Only] Thanks Mark, for your valuable pointers. -----Original Message----- From: Mark Wielaard <mark@klomp.org> Sent: Thursday, February 18, 2021 8:15 PM To: E, Nagajyothi <Nagajyothi.E@amd.com>; dwz@sourceware.org Cc: George, Jini Susan <JiniSusan.George@amd.com>; Achra, Nitika <Nitika.Achra@amd.com>; Sharma, Alok Kumar <AlokKumar.Sharma@amd.com> Subject: Re: Plan to contribute for supporting split dwarf (-gsplit-dwarf) in dwz [CAUTION: External Email] Hi Nagajyothi, On Wed, 2021-02-17 at 05:53 +0000, E, Nagajyothi via Dwz wrote: > I am working on adding support for the dwarf5 .debug_str_offsets, > .debug_addr sections and the related forms DW_FORM_strx[1234], DW_FORM_addrx[1234]. > Please let me know if anyone has already started work on these. Thanks, I don't believe anybody is working on this right now. There is already a bug for .debug_addr/DW_FORM_addrx[1234] support: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsourceware.org%2Fbugzilla%2Fshow_bug.cgi%3Fid%3D27375&data=04%7C01%7CNagajyothi.E%40amd.com%7C37c0fb4399464264b01808d8d41bcb9c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637492563147320988%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=7AjB%2BXKo9J5gTlW1CeEhHXZykYKB2vFZ%2BTnBQvW4%2BIA%3D&reserved=0 I think this shouldn't be too hard. Any DIE that references an address cannot be moved to an alt file, so simply mark it with die_no_multifile. We do try to optimize DW_AT_low/high_pc attribute pairs, so double check that doesn't interfere with DW_FORM_addrx[1234] processing. Also note that there are two new location operations DW_OP_addrx and DW_OP_constx that can reference the .debug_addr section index. As a followup you could try optimizing things, but then you need to keep track of all the addresses used and see if there are duplicates that could be turned into a (smaller) DW_FORM_addrx[1234] index. But I would keep that separate from the initial implementation. For .debug_str_offset/DW_FORM_strx[1234] I opened a new bug. https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsourceware.org%2Fbugzilla%2Fshow_bug.cgi%3Fid%3D27434&data=04%7C01%7CNagajyothi.E%40amd.com%7C37c0fb4399464264b01808d8d41bcb9c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637492563147330979%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=AqQRLjgKh9h7YHPIr4wDiqP1rRTXz2kG6IZlAT0SaSQ%3D&reserved=0 This is a little trickier than DW_FORM_addrx[1234] since such DIEs using DW_FORM_strx may be moved to a multifile. You also probably want to make them equal to DW_FORM_strp entries pointing (indirectly) to the same string. You might want to add a note to the the bugs that you are working on them. Thanks, Mark ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-02-22 3:39 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-02-15 17:26 Plan to contribute for supporting split dwarf (-gsplit-dwarf) in dwz Sharma, Alok Kumar 2021-02-15 18:54 ` Mark Wielaard 2021-02-17 5:53 ` E, Nagajyothi 2021-02-18 14:45 ` Mark Wielaard 2021-02-22 3:39 ` E, Nagajyothi
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