Commit Graph

557 Commits

Author SHA1 Message Date
Manoj Gupta 30232770fb Revert r369233.
This breaks building of some projects like libfuse and alsa-lib
that now fail when linking.
Error details in PR43092.

llvm-svn: 369790
2019-08-23 18:01:13 +00:00
Fangrui Song d9a071c54b [MC] Simplify ELFObjectWriter::recordRelocation. NFC
llvm-svn: 369248
2019-08-19 10:05:59 +00:00
Fangrui Song b127771f7d [MC] Delete unnecessary diagnostic: "No relocation available to represent this relative expression"
Replace

- error: No relocation available to represent this relative expression

with

+ error: symbol 'undef' can not be undefined in a subtraction expression

or

+ error: Cannot represent a difference across sections

Keep !IsPcRel as an assertion after the two diagnostic checks are done.

llvm-svn: 369239
2019-08-19 07:59:35 +00:00
Fangrui Song 38426c114f [MC] Don't emit .symver redirected symbols to the symbol table
GNU as keeps the original symbol in the symbol table for defined @ and
@@, but suppresses it in other cases (@@@ or undefined). The original
symbol is usually undesired:
In a shared object, the original symbol can be localized with a version
script, but it is hard to remove/localize in an archive:

1) a post-processing step removes the undesired original symbol
2) consumers (executable) of the archive are built with the
   version script

Moreover, it can cause linker issues like binutils PR/18703 if the
original symbol name and the base name of the versioned symbol is the
same (both ld.bfd and gold have some code to work around defined @ and
@@). In lld, if it sees f and f@v1:

  --version-script =(printf 'v1 {};') => f and f@v1
  --version-script =(printf 'v1 { f; };') => f@v1 and f@@v1

It can be argued that @@@ added on 2000-11-13 corrected the @ and @@ mistake.

This patch catches some more multiple version errors (defined @ and @@),
and consistently suppress the original symbol. This addresses all the
problems listed above.

If the user wants other aliases to the versioned symbol, they can copy
the original symbol to other symbol names with .set directive, e.g.

    .symver f, f@v1  # emit f@v1 but not f into .symtab
    .set f_impl, f   # emit f_impl into .symtab

llvm-svn: 369233
2019-08-19 06:17:30 +00:00
Jonas Devlieghere 0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
2019-08-15 15:54:37 +00:00
Vlad Tsyrklevich 5874a28ac5 Revert "Reland [ELF] Loose a condition for relocation with a symbol"
This reverts commit r366686 as it appears to be causing buildbot
failures on sanitizer-x86_64-linux-android and sanitizer-x86_64-linux.

llvm-svn: 366708
2019-07-22 17:48:53 +00:00
Nikola Prica 0166cff09b Reland [ELF] Loose a condition for relocation with a symbol
This patch was not the reason of the buildbot failure.

Deleted code was introduced as a work around for a bug in the gold linker
(http://sourceware.org/PR16794). Test case that was given as a reason for
this part of code, the one on previous link, now works for the gold.
This condition is too strict and when a code is compiled with debug info
it forces generation of numerous relocations with symbol for architectures
that do not have relocation addend.

Reviewers: arsenm, espindola

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D64327

llvm-svn: 366686
2019-07-22 13:07:01 +00:00
Nikola Prica bbfa4cf70b Revert "[ELF] Loose a condition for relocation with a symbol"
This reverts commit 8507eca1647118e73435b0ce1de8a1952a021d01.

Reveting due to some suspicious failurse in santizer-x86_64-linux.

llvm-svn: 365685
2019-07-10 18:58:05 +00:00
Nikola Prica fb163b4b20 [ELF] Loose a condition for relocation with a symbol
Deleted code was introduced as a work around for a bug in the gold linker
(http://sourceware.org/PR16794). Test case that was given as a reason for
this part of code, the one on previous link, now works for the gold.
This condition is too strict and when a code is compiled with debug info
it forces generation of numerous relocations with symbol for architectures
that do not have relocation addend.

Reviewers: arsenm, espindola

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D64327

llvm-svn: 365618
2019-07-10 11:17:48 +00:00
Nicolai Haehnle 08e8cb5760 AMDGPU/MC: Add .amdgpu_lds directive
Summary:
The directive defines a symbol as an group/local memory (LDS) symbol.
LDS symbols behave similar to common symbols for the purposes of ELF,
using the processor-specific SHN_AMDGPU_LDS as section index.

It is the linker and/or runtime loader's job to "instantiate" LDS symbols
and resolve relocations that reference them.

It is not possible to initialize LDS memory (not even zero-initialize
as for .bss).

We want to be able to link together objects -- starting with relocatable
objects, but possible expanding to shared objects in the future -- that
access LDS memory in a flexible way.

LDS memory is in an address space that is entirely separate from the
address space that contains the program image (code and normal data),
so having program segments for it doesn't really make sense.

Furthermore, we want to be able to compile multiple kernels in a
compilation unit which have disjoint use of LDS memory. In that case,
we may want to place LDS symbols differently for different kernels
to save memory (LDS memory is very limited and physically private to
each kernel invocation), so we can't simply place LDS symbols in a
.lds section.

Hence this solution where LDS symbols always stay undefined.

Change-Id: I08cbc37a7c0c32f53f7b6123aa0afc91dbc1748f

Reviewers: arsenm, rampitec, t-tye, b-sumner, jsjodin

Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, rupprecht, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61493

llvm-svn: 364296
2019-06-25 11:51:35 +00:00
Fangrui Song c841b9abf0 [MC][ELF] Don't create relocations with section symbols for STB_LOCAL ifunc
We should keep the symbol type (STT_GNU_IFUNC) for a local ifunc because
it may result in an IRELATIVE reloc that the dynamic loader will use to
resolve the address at startup time.

There is another problem that is not fixed by this patch: a PC relative
relocation should also create a relocation with the ifunc symbol.

llvm-svn: 362767
2019-06-07 03:47:22 +00:00
Fangrui Song 9529c563eb [MC][ELF] Copy top 3 bits of st_other to .symver aliases
On PowerPC64 ELFv2 ABI, the top 3 bits of st_other encode the local
entry offset. A versioned symbol alias created by .symver should copy
the bits from the source symbol.

This partly fixes PR41048. A full fix needs tracking of .set assignments
and updating st_other fields when finish() is called, see D56586.

Patch by Alfredo Dal'Ava Júnior

Differential Revision: https://reviews.llvm.org/D59436

llvm-svn: 360442
2019-05-10 17:09:25 +00:00
George Rimar b9ed9cb5d7 [llvm-mc] - Properly set the the address align field of the compressed sections.
About the compressed sections spec says:
(https://docs.oracle.com/cd/E37838_01/html/E36783/section_compression.html)
sh_addralign fields of the section header for a compressed section
reflect the requirements of the compressed section.

Currently, llvm-mc always puts uncompressed section alignment to sh_addralign.
It is not correct. zlib styled section contains an Elfxx_Chdr header,
so we should either use 4 or 8 values depending on the target
(Uncompressed section alignment is stored in ch_addralign field of the compression header).

GNU assembler version 2.31.1 also has this issue,
but in 2.32.51 it was already fixed. This is how it was found
during debugging of the https://bugs.llvm.org/show_bug.cgi?id=40482
actually.

Differential revision: https://reviews.llvm.org/D60965

llvm-svn: 358960
2019-04-23 09:16:53 +00:00
Fangrui Song 88838d5be7 [MC] Fix typo: .symtab_shndxr -> .symtab_shndx
This special section is named .symtab_shndx, according to gABI Chapter 4
Sections, and the name is used by some other tools. Though the section
type SHT_SYMTAB_SHNDX is what really matters, let's fix the typo
introduced in rL204769 :)

llvm-svn: 358247
2019-04-12 02:16:15 +00:00
Nirav Dave 05e2335076 [MC] Teach ELFObjectWriter that parse-time variables do not appear in
symbol table.

llvm-svn: 355325
2019-03-04 19:12:56 +00:00
Konstantin Zhuravlyov e0484eb2f2 MC/ELF: Allow targets to set ABI version
Tests are in the follow up change

Differential Revision: https://reviews.llvm.org/D57810

llvm-svn: 354072
2019-02-14 22:42:09 +00:00
Reid Kleckner afe1e3e669 [MC] Make symbol version errors non-fatal
We stil don't have a source location, which is pretty lame, but at least
we won't tell the user to file a clang bug report anymore.

Fixes PR40712

llvm-svn: 353907
2019-02-13 01:39:32 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
George Rimar 79ace92fcd Recommit r348243 - "[llvm-mc] - Do not crash when referencing undefined debug sections."
The patch triggered an unrelated msan issue: LayoutOrder variable was not initialized.
(http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/26794/steps/check-llvm%20msan/logs/stdio)
It was fixed.

Original commit message:
MC has code that pre-creates few debug sections:
https://github.com/llvm-mirror/llvm/blob/master/lib/MC/MCObjectFileInfo.cpp#L396

If users code has a reference to such section but does not redefine it,
MC code currently asserts, because still thinks they are normally defined.

The patch fixes the issue.

Differential revision: https://reviews.llvm.org/D55173
----
Modified : /llvm/trunk/lib/MC/ELFObjectWriter.cpp
Added : /llvm/trunk/test/MC/ELF/undefined-debug.s

llvm-svn: 348349
2018-12-05 10:43:58 +00:00
George Rimar c968d83399 Revert r348243 "[llvm-mc] - Do not crash when referencing undefined debug sections."
It broke msan and asan bots it seems:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/26794/steps/check-llvm%20msan/logs/stdio
http://lab.llvm.org:8011/builders/clang-s390x-linux/builds/20993/steps/ninja%20check%201/logs/stdio

llvm-svn: 348248
2018-12-04 10:55:03 +00:00
George Rimar 026cc2ff95 [llvm-mc] - Do not crash when referencing undefined debug sections.
MC has code that pre-creates few debug sections:
https://github.com/llvm-mirror/llvm/blob/master/lib/MC/MCObjectFileInfo.cpp#L396

If users code has a reference to such section but does not redefine it,
MC code currently asserts, because still thinks they are normally defined.

The patch fixes the issue.

Differential revision: https://reviews.llvm.org/D55173

llvm-svn: 348243
2018-12-04 10:10:50 +00:00
Eric Christopher fe83270ee9 The initial .text section generated in object files was missing the
SHF_ARM_PURECODE flag when being built with the -mexecute-only flag.
All code sections of an ELF must have the flag set for the final .text
section to be execute-only, otherwise the flag gets removed.

A HasData flag is added to MCSection to aid in the determination that
the section is empty. A virtual setTargetSectionFlags is added to
MCELFObjectTargetWriter to allow subclasses to set target specific
section flags to be added to sections which we then use in the ARM
backend to set SHF_ARM_PURECODE.

Patch by Ivan Lozano!

Reviewed By: echristo

Differential Revision: https://reviews.llvm.org/D48792

llvm-svn: 341593
2018-09-06 22:09:31 +00:00
Peter Collingbourne 69dd7cd45e MC: Redirect .addrsig directives referring to private (.L) symbols to the section symbol.
This matches our behaviour for regular (i.e. relocated) references to
private symbols and therefore avoids needing to unnecessarily write
address-significant .L symbols to the object file's symbol table,
which can interfere with stack traces.

Fixes check-cfi after r339050.

llvm-svn: 339066
2018-08-06 21:59:58 +00:00
Peter Collingbourne 3e22733698 MC: Implement support for new .addrsig and .addrsig_sym directives.
Part of the address-significance tables proposal:
http://lists.llvm.org/pipermail/llvm-dev/2018-May/123514.html

Differential Revision: https://reviews.llvm.org/D47744

llvm-svn: 337328
2018-07-17 22:17:18 +00:00
Michael J. Spencer ae6eeaea92 [MC] Add assembler support for .cg_profile.
Object FIle Representation
At codegen time this is emitted into the ELF file a pair of symbol indices and a weight. In assembly it looks like:

.cg_profile a, b, 32
.cg_profile freq, a, 11
.cg_profile freq, b, 20

When writing an ELF file these are put into a SHT_LLVM_CALL_GRAPH_PROFILE (0x6fff4c02) section as (uint32_t, uint32_t, uint64_t) tuples as (from symbol index, to symbol index, weight).

Differential Revision: https://reviews.llvm.org/D44965

llvm-svn: 333823
2018-06-02 16:33:01 +00:00
Peter Collingbourne 63062d9d0f MC: Introduce an ELF dwo object writer and teach llvm-mc about it.
Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47051

llvm-svn: 332875
2018-05-21 19:44:54 +00:00
Peter Collingbourne f0226e62a8 MC: Extract a derived class from ELFObjectWriter. NFCI.
This class will be used to create regular, non-split ELF files.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47049

llvm-svn: 332870
2018-05-21 19:30:59 +00:00
Peter Collingbourne a29fe579f4 MC: Extract ELFObjectWriter's ELF writing functionality into an ELFWriter class. NFCI.
The idea is that we will be able to use this class to create multiple
files.

Differential Revision: https://reviews.llvm.org/D47048

llvm-svn: 332867
2018-05-21 19:18:28 +00:00
Peter Collingbourne 59a6fc469f MC: Remove stream and output functions from MCObjectWriter. NFCI.
Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47043

llvm-svn: 332864
2018-05-21 18:28:57 +00:00
Peter Collingbourne 438390fae1 MC: Have the object writers return the number of bytes written. NFCI.
This removes the last external use of the stream.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47042

llvm-svn: 332863
2018-05-21 18:23:50 +00:00
Peter Collingbourne f17b149d8c MC: Change object writers to use endian::Writer. NFCI.
Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47040

llvm-svn: 332861
2018-05-21 18:17:42 +00:00
Peter Collingbourne 147db3e628 MC: Change MCAssembler::writeSectionData and writeFragmentPadding to take a raw_ostream. NFCI.
Also clean up a couple of hacks where we were writing the section
contents to another stream by setting the object writer's stream,
writing and setting it back.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47038

llvm-svn: 332858
2018-05-21 18:11:35 +00:00
Peter Collingbourne e3f652973e Support: Simplify endian stream interface. NFCI.
Provide some free functions to reduce verbosity of endian-writing
a single value, and replace the endianness template parameter with
a field.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47032

llvm-svn: 332757
2018-05-18 19:46:24 +00:00
Peter Collingbourne 8e173e1189 MC: Remove dead code. NFCI.
We should never emit an SHT_DYNSYM into an object file.

llvm-svn: 331821
2018-05-08 22:59:05 +00:00
Sam Clegg 22c568ba73 [MC] ELFObjectWriter: Removing unneeded variable and cast
Differential Revision: https://reviews.llvm.org/D46289

llvm-svn: 331704
2018-05-07 23:52:17 +00:00
Vlad Tsyrklevich 201a1086cf ELFObjectWriter: Allow one unique symver per symbol
Summary:
Only allow a single unique .symver alias per symbol. This matches the
behavior of gas. I noticed that we ignored multiple mismatched symver
directives looking at https://reviews.llvm.org/D45798

Reviewers: pcc, tejohnson, espindola

Reviewed By: pcc

Subscribers: emaste, arichardson, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D45845

llvm-svn: 331078
2018-04-27 20:32:34 +00:00
Rafael Espindola 47b4d6ba19 Delay creating an alias for @@@.
With this we only create an alias for @@@ once we know if it should
use @ or @@. This avoids last minutes renames and hacks to handle MS
names.

This only handles the ELF writer. LTO still has issues with @@@
aliases.

llvm-svn: 327160
2018-03-09 18:42:25 +00:00
Lang Hames 60fbc7cc38 [MC] Thread unique_ptr<MCObjectWriter> through the create.*ObjectWriter
functions.

This makes the ownership of the resulting MCObjectWriter clear, and allows us
to remove one instance of MCObjectStreamer's bizarre "holding ownership via
someone else's reference" trick.

llvm-svn: 315327
2017-10-10 16:28:07 +00:00
Lang Hames dcb312bdb9 [MC] Plumb unique_ptr<MCELFObjectTargetWriter> through createELFObjectWriter to
ELFObjectWriter's constructor.

Fixes the same ownership issue for ELF that r315245 did for MachO:
ELFObjectWriter takes ownership of its MCELFObjectTargetWriter, so we want to
pass this through to the constructor via a unique_ptr, rather than a raw ptr.

llvm-svn: 315254
2017-10-09 23:53:15 +00:00
Simon Atanasyan ede43b71f8 [mips] Implement generation of relocations "chains" used by N32 ABI
In case of using a "nested" relocation expressions like this
`%hi(%neg(%gp_rel()))`, N32 ABI requires generation of three consecutive
relocations. That differs from the N64 ABI case where all relocations
are packed into the single relocation record.

llvm-svn: 313879
2017-09-21 14:04:53 +00:00
Simon Atanasyan 9f676a7798 [mips] Do not pass redundant IsN64 flag to MCELFObjectTargetWriter. NFC
Now we pass the 'Is64_' flag to the MCELFObjectTargetWriter ctor iif
when we make deal with N64 ABI. So it is redundant to pass additional
'IsN64' flag.

llvm-svn: 313878
2017-09-21 14:04:47 +00:00
Rafael Espindola ceecfe5be2 Simplify interface now that we don't need to pass IsPCRel. NFC.
llvm-svn: 307734
2017-07-11 23:56:10 +00:00
Rafael Espindola 8a261c2565 Add a common error checking for some invalid expressions.
This refactors a bit of duplicated code and fixes an assertion failure
on ELF.

llvm-svn: 306035
2017-06-22 17:25:35 +00:00
Saleem Abdulrasool 1f62f57b37 sink DebugCompressionType into MC for exposing to clang
This is a preparatory change to expose the debug compression style to
clang.  It requires exposing the enumeration and passing the actual
value through to the backend from the frontend in actual value form
rather than a boolean that selects the GNU style of debug info
compression.

Minor tweak to the ELF Object Writer to use a variable for re-used
values.  Add an assertion that debug information format is one of the
two currently known types if debug information is being compressed.

llvm-svn: 305038
2017-06-09 00:40:19 +00:00
Zachary Turner 264b5d9e88 Move Object format code to lib/BinaryFormat.
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.

Differential Revision: https://reviews.llvm.org/D33843

llvm-svn: 304864
2017-06-07 03:48:56 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Eugene Zelenko 7975b99fe6 [MC] Fix some Clang-tidy modernize-use-using warnings; other minor fixes (NFC).
llvm-svn: 301485
2017-04-26 22:31:39 +00:00
Peter Collingbourne 36003057ac MC: Remove unused virtual function MCObjectWriter::isWeak. NFC.
llvm-svn: 299817
2017-04-08 23:35:49 +00:00
Evgeniy Stepanov 43dcf4d330 Fix asm printing of associated sections.
Make MCSectionELF::AssociatedSection be a link to a symbol, because
that's how it works in the assembly, and use it in the asm printer.

llvm-svn: 297769
2017-03-14 19:28:51 +00:00
Vassil Vassilev 89e36cc04c Silence a warning "hiding virtual function".
llvm-svn: 297018
2017-03-06 15:50:59 +00:00