Commit Graph

346 Commits

Author SHA1 Message Date
Rafael Espindola
f1e245315b Use relocations to fill statically known got entries.
Right now we just remember a SymbolBody for each got entry and
duplicate a bit of logic to decide what value, if any, should be
written for that SymbolBody.

With ARM there will be more complicated values, and it seems better to
just use the relocation code to fill the got entries. This makes it
clear that each entry is filled by the dynamic linker or by the static
linker.

llvm-svn: 288107
2016-11-29 03:45:36 +00:00
Rui Ueyama
da06bfb794 Move getLocation from Relocations.cpp to InputSection.cpp.
The function was used only within Relocations.cpp, but now we are
using it in many places, so this patch moves it to a file that fits
to the functionality.

llvm-svn: 287943
2016-11-25 18:51:53 +00:00
Eugene Leviant
ab024a353f [ELF] Refactor getDynRel to print error location
Differential revision: https://reviews.llvm.org/D27055

llvm-svn: 287915
2016-11-25 08:56:36 +00:00
Rui Ueyama
a3ac17372b Define toString(const SymbolBody &) and remove maybeDemangle instead.
Differential Revision: https://reviews.llvm.org/D27065

llvm-svn: 287899
2016-11-24 20:24:18 +00:00
Rui Ueyama
f373dd76ce Remove HasError and use ErrorCount instead.
HasError was always true if ErrorCount > 0, so we can use ErrorCount instead.

llvm-svn: 287849
2016-11-24 01:43:21 +00:00
Rui Ueyama
d3a06ffb1c Use llvm::utohexstr instead of Twine::utohexstr.
They are essentially the same in this context, so I prefer the one
that doesn't need `Twine::`.

llvm-svn: 287814
2016-11-23 21:24:26 +00:00
Rui Ueyama
3fc0f7e54f Define toString() as a generic function to get a string for error message.
We have different functions to stringize objects to construct
error messages. For InputFile, we have getFilename, and for
InputSection, we have getName. You had to memorize them.

I think this is the case where the function overloading comes in handy.

This patch defines toString() functions that are overloaded for all these
types, so that you just call it in error().

Differential Revision: https://reviews.llvm.org/D27030

llvm-svn: 287787
2016-11-23 18:07:33 +00:00
Rui Ueyama
c72ba3a4d7 Allow calling getName() on local symbols.
Previously, we stored offsets in string tables to symbols, so
you needed to pass a string table to get a symbol name. This patch
stores const char pointers instead to eliminate the need to pass
a string table.

llvm-svn: 287737
2016-11-23 04:57:25 +00:00
Rui Ueyama
e8785ba4d7 Change the way how we print out line numbers.
LLD's error messages contain line numbers, function names or section names.
Currently they are formatter as follows.

  foo.c (32): symbol 'foo' not found
  foo.c (function bar): symbol 'foo' not found
  foo.c (.text+0x1234): symbol 'foo' not found

This patch changes them so that they are consistent with Clang's output.

  foo.c:32: symbol 'foo' not found
  foo.c:(function bar): symbol 'foo' not found
  foo.c:(.text+0x1234): symbol 'foo' not found

Differential Revision: https://reviews.llvm.org/D26901

llvm-svn: 287537
2016-11-21 13:49:57 +00:00
Eugene Leviant
ff23d3e741 [ELF] Convert PltSection to input section
Differential revision: https://reviews.llvm.org/D26842

llvm-svn: 287346
2016-11-18 14:35:03 +00:00
Simon Atanasyan
725dc14bb2 [ELF][MIPS] Add MipsGotSection to handle MIPS GOT
MIPS GOT handling is very different from other targets so it is better
to keep the code in the separatre section class MipsGotSection. This
patch introduces the new section and moves all MIPS specific code from
GotSection to the new class. I did not rename fields and methods in the
MipsGotSection class to reduce the diff and plan to do that by the
separate commit.

Differential revision: https://reviews.llvm.org/D26733

llvm-svn: 287150
2016-11-16 21:01:02 +00:00
George Rimar
7759e5b61b [ELF] - Change error message according to review comment. NFC.
Forgot about that, I am sorry.

llvm-svn: 287123
2016-11-16 17:45:45 +00:00
George Rimar
76f429b4db [ELF] - Improve diagnostic messages.
Particulaty "cannot preempt symbol" message
is extended with locations now.

Differential revision: https://reviews.llvm.org/D26738

llvm-svn: 287120
2016-11-16 17:24:06 +00:00
Eugene Leviant
a96d9027a3 [ELF] Convert RelocationSection to input section
Differential revision: https://reviews.llvm.org/D26669

llvm-svn: 287092
2016-11-16 10:02:27 +00:00
George Rimar
f3c143188d [ELF] - Better diagnostic for "can't create dynamic relocation" error.
Patch improves message to show locations for
"can't create dynamic relocation" error.

Differential revision: https://reviews.llvm.org/D26548

llvm-svn: 287086
2016-11-16 08:34:19 +00:00
George Rimar
463984d4bf [ELF] - Better diagnostic for relative relocation to an absolute value error.
Patch adds a filename to that error message.

I faced next error when debugged one of FreeBSD port:
error: relocation R_X86_64_PLT32 cannot refer to absolute symbol __tls_get_addr

error message was poor and this patch improves it to show the locations 
of symbol declaration and using.

Differential revision: https://reviews.llvm.org/D26508

llvm-svn: 286940
2016-11-15 08:07:14 +00:00
Vitaly Buka
029d730bad Avoid creating reference from nullptr.
Summary:
getFile() can return nullptr. This usually happens when Rels is empty so
the reference is never used. Still UBSAN complains.

Reviewers: rafael

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D26662

llvm-svn: 286937
2016-11-15 07:32:51 +00:00
Eugene Leviant
ad4439e802 [ELF] Convert .got section to input section
Differential revision: https://reviews.llvm.org/D26498

llvm-svn: 286580
2016-11-11 11:33:32 +00:00
Rafael Espindola
9f0c4bb795 Parse relocations only once.
Relocations are the last thing that we wore storing a raw section
pointer to and parsing on demand.

With this patch we parse it only once and store a pointer to the
actual data.

The patch also changes where we store it. It is now in
InputSectionBase. Not all sections have relocations, but most do and
this simplifies the logic. It also means that we now only support one
relocation section per section. Given that that constraint is
maintained even with -r with gold bfd and lld, I think it is OK.

llvm-svn: 286459
2016-11-10 14:53:24 +00:00
Eugene Leviant
41ca327b5e [ELF] Convert .got.plt section to input section
Differential revision: https://reviews.llvm.org/D26349

llvm-svn: 286443
2016-11-10 09:48:29 +00:00
George Rimar
1a33c0f242 [ELF] - Implemented --symbol-ordering-file option.
Patch allows to pass a symbols file to linker.
LLD will map symbols to sections and sort sections
in output according to symbol ordering file.

That can help to reduce the startup time and/or
amount of pagefaults during startup.

Also, interesting benchmark result was produced by Rafael Espíndola. 
After applying the symbols file for clang he timed compiling 
X86MCTargetDesc.ii to an object file.  

The page faults went from just
56,988 to 56,946 since most faults are not in the binary.
Running time went from 4.403053515 to 4.178112244. 
The speedup seems to be because of better cache
locality.

Differential revision: https://reviews.llvm.org/D26130

llvm-svn: 286440
2016-11-10 09:05:20 +00:00
Simon Atanasyan
ce02cf0099 [ELF][MIPS] Convert .reginfo and .MIPS.options sections to synthetic input sections
Previously, we have both input and output sections for .reginfo and
.MIPS.options. Now for each such sections we have one synthetic input
sections: MipsReginfoSection and MipsOptionsSection respectively.

Both sections are handled as regular sections until the control reaches
Writer. Writer then aggregates all sections whose type is SHT_MIPS_REGINFO
or SHT_MIPS_OPTIONS to create a single synthesized input section. In that
moment Writer also save GP0 value to the MipsGp0 field of the corresponding
ObjectFile. This value required for R_MIPS_GPREL16 and R_MIPS_GPREL32
relocations calculation.

Differential revision: https://reviews.llvm.org/D26444

llvm-svn: 286397
2016-11-09 21:36:56 +00:00
Rafael Espindola
04a2e348bb Split Header into individual fields.
This is similar to what was done for InputSection.

With this the various fields are stored in host order and only
converted to target order when writing.

llvm-svn: 286327
2016-11-09 01:42:41 +00:00
Rui Ueyama
edc183e437 Simplify getLocation() function.
All tests pass without the first parameter, so I guess we don't need it.

Differential Revision: https://reviews.llvm.org/D26411

llvm-svn: 286287
2016-11-08 20:30:19 +00:00
Eugene Leviant
825e538559 [ELF] Better error reporting for duplicate symbol
Differential revision: https://reviews.llvm.org/D26397

llvm-svn: 286244
2016-11-08 16:26:32 +00:00
Simon Atanasyan
9e0297b8bc [ELF][MIPS] N32 ABI support
In short the patch introduces support for linking object file conform
MIPS N32 ABI [1]. This ABI is similar to N64 ABI but uses 32-bit
pointer size.

The most non-trivial requirement of this ABI is one more relocation
packing format. N64 ABI puts multiple relocation type into the single
relocation record. The N32 ABI uses series of successive relocations
with the same offset for this purpose. In this patch, new function
`mergeMipsN32RelTypes` handle this case and "convert" N32 relocation to
the N64 relocation so the rest of the code keep unchanged.

For now, linker does not support series of relocations applied to sections
without SHF_ALLOC bit. Probably later I will add the support or insert
some sort of assert into the `relocateNonAlloc` routine to catch this
case.

[1] ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/MIPS-N32-ABI-Handbook.pdf

Differential revision: https://reviews.llvm.org/D26298

llvm-svn: 286052
2016-11-05 22:58:01 +00:00
Rafael Espindola
8e232573a8 Simplify now that this is only used for global symbols.
llvm-svn: 285966
2016-11-03 20:48:57 +00:00
Rafael Espindola
e19abab9a7 Now that the ELFFile constructor does nothing, create it when needed.
This avoids duplicating the buffer in InputFile.

llvm-svn: 285965
2016-11-03 20:44:50 +00:00
Rafael Espindola
454fe154a7 Update for llvm change.
llvm-svn: 285956
2016-11-03 19:07:44 +00:00
Rui Ueyama
7556f6b276 Reduce number of classes by merging DIHelper with ObjectFile.
DIHelper is a class having only one member, and ObjectFile has
a unique pointer to a DIHelper. So we can directly have ObjectFile
have the member.

Differential Revision: https://reviews.llvm.org/D26223

llvm-svn: 285850
2016-11-02 18:42:13 +00:00
Eugene Leviant
c4681203e1 Allow fetching source line, when multiple "AX" sections present
Differential revision: https://reviews.llvm.org/D26070

llvm-svn: 285680
2016-11-01 09:17:50 +00:00
Rafael Espindola
d598c8103a Be less aggressive at relaxing got access in this case.
This fixes pr30803 by not relaxing that particular access. We could
also let adjustRelaxExpr know that the target is absolute so that it
uses R_RELAX_GOT_PC_NOPIC, but it is not clear if it is worth it.

llvm-svn: 285317
2016-10-27 17:28:56 +00:00
Rui Ueyama
e784ee7348 Fix build breakage.
llvm-svn: 285236
2016-10-26 20:27:38 +00:00
Rui Ueyama
5f7e6e6cfb Add comments.
llvm-svn: 285235
2016-10-26 20:26:29 +00:00
Rui Ueyama
5ce977ccd0 Define a helper function to demangle symbols.
llvm-svn: 285219
2016-10-26 18:28:06 +00:00
Rafael Espindola
1854a8ebb8 Delete trivial getters. NFC.
llvm-svn: 285190
2016-10-26 12:36:56 +00:00
Eugene Leviant
b380b24e6e [ELF] Better error reporting for undefined symbols
This patch make lld show following details for undefined symbol errors:
- file (line)
- file (function name)
- file (section name + offset)

Differential revision: https://reviews.llvm.org/D25826

llvm-svn: 285186
2016-10-26 11:07:09 +00:00
Rafael Espindola
58139d1758 Delete getSectionHdr.
We were fairly inconsistent as to what information should be accessed
with getSectionHdr and what information (like alignment) was stored
elsewhere.

Now all section info has a dedicated getter. The code is also a bit
more compact.

llvm-svn: 285079
2016-10-25 16:14:25 +00:00
Simon Atanasyan
bed04bf1df [ELF][MIPS] Put local GOT entries accessed via a 16-bit index first
Some MIPS relocations used to access GOT entries are able to manipulate
16-bit index. The other ones like R_MIPS_CALL_HI16/LO16 can handle
32-bit indexes. 16-bit relocations are generated by default. The 32-bit
relocations are generated by -mxgot flag passed to compiler. Usually
these relocation are not mixed in the same code but files like crt*.o
contain 16-bit relocations so even if all "user's" code compiled with
-mxgot flag a few 16-bit relocations might come to the linking phase.

Now LLD does not differentiate local GOT entries accessed via a 16-bit
and 32-bit indexes. That might lead to relocation's overflow if 16-bit
entries are allocated to far from the beginning of the GOT.

The patch introduces new "part" of MIPS GOT dedicated to the local GOT
entries accessed by 32-bit relocations. That allows to put local GOT
entries accessed via a 16-bit index first and escape relocation's overflow.

Differential revision: https://reviews.llvm.org/D25833

llvm-svn: 284809
2016-10-21 07:22:30 +00:00
Rafael Espindola
113860b9ae Compact SectionPiece.
We allocate a lot of these when linking debug info. This speeds up the
link of debug programs by 1% to 2%.

llvm-svn: 284716
2016-10-20 10:55:58 +00:00
Peter Smith
d648603415 [ELF] Allow relative exceptions relocations in shared libraries
The R_ARM_PREL31 and R_ARM_NONE relocations should not be faulted in
shared libraries. In the case of R_ARM_NONE, we have moved the TLS
relaxation hint instruction to R_TLSDESC_CALL so that R_HINT can be used
without side-effects. In the case of R_ARM_PREL31 we permit it to be used
against PLT entries as the personality routines are imported when used in
shared libraries.

Differential Revision: https://reviews.llvm.org/D25721

llvm-svn: 284710
2016-10-20 09:59:26 +00:00
George Rimar
a4c7e74d4b [ELF] - Applied clang format. NFC.
llvm-svn: 284705
2016-10-20 08:36:42 +00:00
Eugene Leviant
898375994b [ELF] Don't fail if undefined symbol is not used
Differential revision: https://reviews.llvm.org/D25240

llvm-svn: 283431
2016-10-06 09:45:04 +00:00
Rui Ueyama
d31e13f287 Rename warning -> warn.
It's better because it's a verb.

llvm-svn: 282763
2016-09-29 21:00:23 +00:00
Peter Smith
fde6213fe8 [ARM] ARM TLS shouldn't use relaxations
The ARM TLS relocations are placed on literal data and not the 
code-sequence, it is therefore not possible to implement the relaxTls* 
functions. This change updates handleMipsTlsRelocation() to
handleNoRelaxTlsRelocation() and incorporates ARM as well as Mips.

The ARM support in handleNoRelaxTlsRelocation() currently needs to ouput
the module index dynamic relocation in all cases as it is relying on the 
dynamic linker to set the module index in the got.

Should address PR30218

Differential Revision: https://reviews.llvm.org/D24827

llvm-svn: 282250
2016-09-23 13:54:48 +00:00
Rafael Espindola
c7e1e03498 Store an ArrayRef for Data in InputSectionData.
llvm-svn: 281210
2016-09-12 13:13:53 +00:00
Simon Atanasyan
919a58c456 [ELF][MIPS] Fix initialization of TLS-related GOT entries
This patch allows static linking of TLS code. To do that it fixes
GOT entries initialization.

If TLS-related GOT entry created for a preemptible symbol i.e. has
a corresponding dynamic relocation, leave the entry initialized by zero.
Write down adjusted TLS symbol's values otherwise. For the adjustments
calculation use offsets for thread-local storage.

https://www.linux-mips.org/wiki/NPTL

llvm-svn: 280914
2016-09-08 09:07:19 +00:00
Simon Atanasyan
af52f6af22 [ELF][MIPS] Update the comment
llvm-svn: 280913
2016-09-08 09:07:12 +00:00
Rafael Espindola
664c6522fa Delete dead field. NFC.
llvm-svn: 280856
2016-09-07 20:37:34 +00:00
Rafael Espindola
719f55d379 Mark R_GOTREL_FROM_END as a relative expression.
Fixes pr30282.

llvm-svn: 280709
2016-09-06 13:57:15 +00:00