Commit Graph

925 Commits

Author SHA1 Message Date
Rui Ueyama ac2b0a168d Remove dead code.
llvm-svn: 258539
2016-01-22 19:55:01 +00:00
George Rimar 237b218770 [ELF] - fix possible UB when dereferencing null
In InputSection.cpp it was possible to dereference null.
Had to change signature of relocateTlsOptimize to accept pointer instead of reference.

Differential revision: http://reviews.llvm.org/D16466

llvm-svn: 258508
2016-01-22 18:02:28 +00:00
George Rimar d0cb85b62d Use of llvm_unreachable instead of warning in EhFrameHeader<ELFT>::assignEhFrame().
llvm-svn: 258499
2016-01-22 10:57:39 +00:00
Rui Ueyama bef81f3a70 ELF: Move code to emit copyrel to one place. NFC.
In this code, we avoid calling needsCopyRel in writeTo because
we called that function already in scanRelocs. Making the same
decision twice is a waste and has a risk of a bug that we get
inconsistent resuts.

llvm-svn: 258430
2016-01-21 20:59:22 +00:00
Rui Ueyama 88d79a06b7 Style change. NFC.
llvm-svn: 258427
2016-01-21 20:18:36 +00:00
George Rimar bfd29a1567 [ELF] - Refactoring of Writer<ELFT>::scanRelocs()
Code for handling TLS relocations was moved out scanRelocs() to new function handleTlsRelocations().
That is because scanRelocs already too large to put more TLS code into it.

Differential revision: http://reviews.llvm.org/D16354

llvm-svn: 258392
2016-01-21 09:14:22 +00:00
Simon Atanasyan 56ab5f0289 [ELF][MIPS] Initial support of MIPS local GOT entries
Some MIPS relocation (for now R_MIPS_GOT16) requires creation of GOT
entries for symbol not included in the dynamic symbol table. They are
local symbols and non-local symbols with 'local' visibility. Local GOT
entries occupy continuous block between GOT header and regular GOT
entries.

The patch adds initial support for handling local GOT entries. The main
problem is allocating local GOT entries for local symbols. Such entries
should be initialized by high 16-bit of the symbol value. In ideal world
there should be no duplicated entries with the same values. But at the
moment of the `Writer::scanRelocs` call we do not know a value of the
symbol. In this patch we create new local GOT entry for each relocation
against local symbol, though we can exhaust GOT quickly. That needs to
be optimized later. When we calculate relocation we know a final symbol
value and request local GOT entry index. To do that we maintain map
between addresses and local GOT entry indexes. If we start to calculate
relocations in parallel we will have to serialize access to this map.

Differential Revision: http://reviews.llvm.org/D16324

llvm-svn: 258388
2016-01-21 05:33:23 +00:00
Rui Ueyama 90f76fbb54 Return early before iterating over local symbols. NFC.
llvm-svn: 258385
2016-01-21 03:07:38 +00:00
Rui Ueyama c5e372db40 Simplify function signature. NFC.
StringTable is a member variable, so we don't need to pass it around.

llvm-svn: 258382
2016-01-21 02:10:12 +00:00
Rui Ueyama 1e056ebe3c Fix indentation.
llvm-svn: 258374
2016-01-21 00:45:39 +00:00
Simon Atanasyan 0d5e1b753e [ELF] Do not keep STT_FILE symbols in the symbol table
STT_FILE symbols usually contain source file names. It is redundant
to keep this information in the output file.

llvm-svn: 258331
2016-01-20 18:59:45 +00:00
Rafael Espindola 65e80b963a Rename IgnoredWeak to Ignored.
Thanks to Rui for the suggestion.

llvm-svn: 258189
2016-01-19 21:19:52 +00:00
George Rimar ffb673515e [ELF] - R_386_GOT32 relocation calculation fix.
R_386_GOT32 has multiple descriptions:

"System V Application Binary Interface Intel386 Architecture Processor Supplement Version 1.1" (https://github.com/hjl-tools/x86-psABI/wiki/intel386-psABI-1.1.pdf), p36 contains next calculation for R_386_GOT32: G + A - GOT.
SYSTEM V APPLICATION BINARY INTERFACE 4 (https://refspecs.linuxfoundation.org/elf/abi386-4.pdf, p78) tolds us its G + A - P.
Oracle docs (https://docs.oracle.com/cd/E19455-01/816-0559/chapter6-26/index.html) says its should be G + A.

gold/bfd calculates it as "G + A - GOT", but GOT means the end of the GOT section.
Patch fixes current calculation to gold/ld behavior.

Differential revision: http://reviews.llvm.org/D15750

llvm-svn: 258115
2016-01-19 11:00:48 +00:00
Rafael Espindola 3a6a0a0109 Delete addIgnoredStrong.
It is not needed now that we resolve symbols is shared libraries
correctly.

llvm-svn: 258104
2016-01-19 00:05:54 +00:00
Rafael Espindola 0bc0c02387 Prefer symbols from .o over .so.
This matches the behavior of gold and bfd ld.

llvm-svn: 258102
2016-01-18 23:54:05 +00:00
Rafael Espindola 591c6cefae Delete dead code.
llvm-svn: 258078
2016-01-18 20:50:28 +00:00
Rafael Espindola f312d89f50 Clarify the comment and code a bit. NFC.
llvm-svn: 258069
2016-01-18 20:06:59 +00:00
George Rimar f6bc65a3b2 Reapply r257753 with fix:
Added check for terminator CIE/FDE which has zero data size.
void EHOutputSection<ELFT>::addSectionAux(
...
 // If CIE/FDE data length is zero then Length is 4, this
 // shall be considered a terminator and processing shall end.
    if (Length == 4)
      break;
...

After this "Bug 25923 - lld/ELF2 linked application crashes if exceptions were used." is fixed for me. Self link of clang also works.

Initial commit message:
[ELF] - implemented --eh-frame-hdr command line option.

--eh-frame-hdr
Request creation of ".eh_frame_hdr" section and ELF "PT_GNU_EH_FRAME" segment header.

Both gold and the GNU linker support an option --eh-frame-hdr which tell them to construct a header for all the .eh_frame sections. This header is placed in a section named .eh_frame_hdr and also in a PT_GNU_EH_FRAME segment. At runtime the unwinder can find all the PT_GNU_EH_FRAME segments by calling dl_iterate_phdr.
This section contains a lookup table for quick binary search of FDEs.
Detailed info can be found here:
http://www.airs.com/blog/archives/462

Differential revision: http://reviews.llvm.org/D15712

llvm-svn: 257889
2016-01-15 13:34:52 +00:00
Davide Italiano 2dfc5fd1ea [ELF/AArch64] Add support for R_AARCH64_LDST16_ABS_LO12_NC relocation.
Found while trying to self-host the toolchain that libLTO needs it.

llvm-svn: 257854
2016-01-15 01:49:51 +00:00
Simon Atanasyan ca558ea627 [ELF][MIPS] Create dynamic relocations for R_MIPS_32/64 relocations
llvm-svn: 257806
2016-01-14 21:34:50 +00:00
Rui Ueyama 489a806965 Update for LLVM function name change.
llvm-svn: 257801
2016-01-14 20:53:50 +00:00
Simon Atanasyan 682aeea9de [ELF][MIPS] Ignore 'hint' relocations like R_MIPS_JALR in the `scanRelocs` method
MIPS ABI has relocations like R_MIPS_JALR which is just a hint for
linker to make some code optimization. Such relocations should not be
handled as a regular ones and lead to say dynamic relocation creation.

The patch introduces new virtual `Target::isHintReloc` method, overrides
it in the `MipsTargetInfo` class and calls it in the `Writer<ELFT>::scanRelocs`
method.

Differential Revision: http://reviews.llvm.org/D16193

llvm-svn: 257798
2016-01-14 20:42:09 +00:00
Rui Ueyama 5f91ace828 Revert r257753: "[ELF] - implemented --eh-frame-hdr command line option."
This reverts commit r257753 because we cannot link Clang with this patch.

llvm-svn: 257797
2016-01-14 20:32:19 +00:00
George Rimar 28f4fbe480 [ELF] - implemented --eh-frame-hdr command line option.
--eh-frame-hdr
Request creation of ".eh_frame_hdr" section and ELF "PT_GNU_EH_FRAME" segment header.

Both gold and the GNU linker support an option --eh-frame-hdr which tell them to construct a header for all the .eh_frame sections. This header is placed in a section named .eh_frame_hdr and also in a PT_GNU_EH_FRAME segment. At runtime the unwinder can find all the PT_GNU_EH_FRAME segments by calling dl_iterate_phdr.
This section contains a lookup table for quick binary search of FDEs.
Detailed info can be found here:
http://www.airs.com/blog/archives/462

Differential revision: http://reviews.llvm.org/D15712

llvm-svn: 257753
2016-01-14 10:30:32 +00:00
Davide Italiano 0d4fbae0e7 [ELF/AArch64] Support R_AARCH64_LDST128_ABS_LO12_NC relocation.
llvm-svn: 257731
2016-01-14 01:30:21 +00:00
Rui Ueyama df1545163f Update comment for __cxa_demangle again to make it precise.
Thanks for Ed Maste for the suggestion.

llvm-svn: 257685
2016-01-13 22:09:09 +00:00
Rui Ueyama e16d1b0a9c Update comment for __cxa_demangle.
llvm-svn: 257678
2016-01-13 21:39:40 +00:00
Rui Ueyama 5fa978b4c0 Attempt to make FreeBSD buildbot green.
It seems that __cxa_demangle function on the buildbot tried to demangle
a variable "tlsvar" as a C++ symbol. Do not call that function unless
it does not start with "_Z" which is the prefix of mangled names.

llvm-svn: 257661
2016-01-13 19:40:13 +00:00
Rui Ueyama a4a628fb51 Demangle symbols when including them in error messages.
llvm-svn: 257647
2016-01-13 18:55:39 +00:00
George Rimar 3d737e45c0 Reapply r257588
Fix: Added missed input file.

Initial commit message:
[ELF/AArch64] - Implemented R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21 and R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC relocations

* R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21 is calculated as Page(G(GTPREL(S+A))) – Page(P), set an ADRP immediate field to bits [32:12] of X; check –2^32 ≤ X < 2^32;
* R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC is calculated as G(GTPREL(S+A)), set an LD offset field to bits [11:3] of X. No overflow check; check that X&7 = 0.

Differential revision: http://reviews.llvm.org/D16117

llvm-svn: 257596
2016-01-13 13:04:46 +00:00
George Rimar cc6c093f6f Revert r257588 as it broke buildbot
http://lab.llvm.org:8011/builders/lld-x86_64-darwin13/builds/18715/steps/test_lld/logs/stdio

llvm-svn: 257595
2016-01-13 12:58:51 +00:00
George Rimar 253dbf5405 [ELF/AArch64] - Implemented R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21 and R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC relocations
* R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21 is calculated as Page(G(GTPREL(S+A))) – Page(P), set an ADRP immediate field to bits [32:12] of X; check –2^32 ≤ X < 2^32;
* R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC is calculated as G(GTPREL(S+A)), set an LD offset field to bits [11:3] of X. No overflow check; check that X&7 = 0.

Differential revision: http://reviews.llvm.org/D16117

llvm-svn: 257588
2016-01-13 11:29:45 +00:00
Rui Ueyama ab12361c4e Merge two consecutive if's. NFC.
llvm-svn: 257527
2016-01-12 21:57:44 +00:00
Rui Ueyama 09eb0b3b3f Rename IgnoredUndef -> Ignored since it is not an undefined symbol.
Also rename Ignored -> IgnoredWeak and IgnoredStrong -> Ignored,
since strong symbol is a norm.

llvm-svn: 257507
2016-01-12 19:24:55 +00:00
Simon Atanasyan 3a5b6e2750 [ELF][MIPS] Do not create dynamic relocations against _gp_disp symbol
MIPS _gp_disp designates offset between start of function and gp pointer
into GOT therefore any relocations against it do not require dynamic
relocation.

llvm-svn: 257492
2016-01-12 17:31:45 +00:00
Simon Atanasyan db147eb5ac [ELF][MIPS] Fix a typo in the comment
llvm-svn: 257450
2016-01-12 06:24:02 +00:00
Simon Atanasyan 188558e5eb [ELF][MIPS] Prevent substitution of _gp_disp symbol
On MIPS O32 ABI, _gp_disp is a magic symbol designates offset between
start of function and gp pointer into GOT. To make seal with such symbol
we add new method addIgnoredStrong(). It adds ignored symbol with global
binding to prevent the symbol substitution. The addIgnored call is not
enough here because this call adds a weak symbol which might be
substituted by symbol from shared library.

Differential Revision: http://reviews.llvm.org/D16084

llvm-svn: 257449
2016-01-12 06:23:57 +00:00
Davide Italiano 15414cd0a7 [ELF] FreeBSD has slightly different emulation strings for PPC.
Teach lld about them.

llvm-svn: 257437
2016-01-12 02:58:59 +00:00
Rui Ueyama 94b08e3bf0 Simplify. NFC.
llvm-svn: 257432
2016-01-12 01:33:23 +00:00
Rui Ueyama 902c75cd7b Remove dead code.
llvm-svn: 257421
2016-01-12 00:32:49 +00:00
Rui Ueyama f949f7f15e Merge two small functions. NFC.
llvm-svn: 257418
2016-01-11 23:50:55 +00:00
Davide Italiano 8c344436c4 Initial support for PPC target in the new ELF linker.
Differential Revision:	http://reviews.llvm.org/D15968

llvm-svn: 257374
2016-01-11 19:45:33 +00:00
George Rimar 7af0562808 Fixed typo in comment. NFC.
llvm-svn: 257356
2016-01-11 17:19:40 +00:00
George Rimar 1395dbdbc6 [ELF/AARCH64] - Implemented R_AARCH64_TSTBR14 relocation.
R_AARCH64_TSTBR14 is calculated as S+A-P,
Set the immediate field of a TBZ/TBNZ instruction to bits [15:2] of X; check -2^15 ≤ X < 2^15

Differential revision: http://reviews.llvm.org/D15824

llvm-svn: 257334
2016-01-11 14:27:05 +00:00
George Rimar 4102bfbe71 [ELF/AARCH64] - Implemented R_AARCH64_CONDBR19 relocation.
R_AARCH64_CONDBR19 is calculated as S+A-P,
Set the immediate field of a conditional branch instruction to bits [20:2] of X; check -2^20 ≤ X< 2^20.

Afaik there is no document for AARCH64 instruction encoding from official for unknown reason, so 
I used gold source code and next link as a reference for implementation: http://kitoslab-eng.blogspot.ru/2012/10/armv8-aarch64-instruction-encoding.html. From which is clear that immediate field of a conditional branch instruction is 5 bits off. That is proved by output which is is equal to gold/bfd now.

Differential revision: http://reviews.llvm.org/D15809

llvm-svn: 257333
2016-01-11 14:22:00 +00:00
George Rimar a48043521f [ELF/AARCH64] - Implemented R_AARCH64_IRELATIVE relocation.
Implemented in the same way as was already done for x86/x64 targets (http://reviews.llvm.org/D15235).

Differential revision: http://reviews.llvm.org/D15806

llvm-svn: 257332
2016-01-11 14:15:17 +00:00
Rui Ueyama 52c7c5fa3e Group members to match a comment. NFC.
llvm-svn: 257218
2016-01-08 22:20:00 +00:00
Rui Ueyama 131e0ffa10 Use shorter name. NFC.
llvm-svn: 257217
2016-01-08 22:17:42 +00:00
Rui Ueyama 683564ea63 Update comments.
llvm-svn: 257216
2016-01-08 22:14:15 +00:00
Rui Ueyama 8b4879aec0 Remove an empty constructor.
We used to have code in SymbolTable constructor to add entry symbols, etc.
That code has been moved to Driver. We can remove the constructor.

llvm-svn: 257214
2016-01-08 22:06:25 +00:00