__DATA, __objc_catlist contains a list of pointers to categories.
We want to atomize it so that the ObjC pass can later optimize and remove
categories. That will be a later patch.
llvm-svn: 259386
This avoids the need to have reserve and addString in sync.
We avoid hashing the global symbols again. This means that we don't
merge a global symbol that has the same name as some other string, but
that doesn't seem very common. The string table size is the same in
clang an scylladb with or without hashing global symbols again.
llvm-svn: 259136
This function is a predicate that a given relocation can be relaxed.
The previous name implied that it returns true if a given relocation
has already been optimized away.
llvm-svn: 259128
In many situations, we don't want to exit at the first error even in the
process model. For example, it is better to report all undefined symbols
rather than reporting the first one that the linker picked up randomly.
In order to handle such errors, we don't need to wrap everything with
ErrorOr (thanks for David Blaikie for pointing this out!) Instead, we
can set a flag to record the fact that we found an error and keep it
going until it reaches a reasonable checkpoint.
This idea should be applicable to other places. For example, we can
ignore broken relocations and check for errors after visiting all relocs.
In this patch, I rename error to fatal, and introduce another version of
error which doesn't call exit. That function instead sets HasError to true.
Once HasError becomes true, it stays true, so that we know that there
was an error if it is true.
I think introducing a non-noreturn error reporting function is by itself
a good idea, and it looks to me that this also provides a gradual path
towards lld-as-a-library (or at least embed-lld-to-your-program) without
sacrificing code readability with lots of ErrorOr's.
http://reviews.llvm.org/D16641
llvm-svn: 259069
This does not solve the problem that we call isGnuIFunc function
both from RelocationSection and from the Writer::scanRelocs, but
this at least should improve readability. I'm taking an incremental
approach to reduce complexity.
llvm-svn: 258753
The TrieNode/TrieEdge data structures here are allocated in a bumpptrallocator.
Unfortunately, TrieNode contained a std::list<TrieEdge> and as the allocator doesn't
call the TrieNode destructor, we ended up leaking the memory allocated by the std::list
itself.
Instead we can use an intrusive list as then we save the extra allocations anyway.
llvm-svn: 258725
There are a few cases where we have almost duplicated code.
This patches fixes the simplest: the finalize and write of dynamic
section. Right now they have to have exactly the same structure to
decide if a DT_* entry is needed and then to actually write it.
We cannot just write it to a std::vector in the first pass since
addresses have not been computed yet.
llvm-svn: 258723
Main executable did not export symbols that exist both in the main executable and in DSOs before this patch.
Symbols from object files that override symbols in DSO should be added to .dynsym table.
Differential revision: http://reviews.llvm.org/D16405
llvm-svn: 258672
Summary: It looks like this snuck through in r256143/D15383.
Reviewers: ruiu, grimar
Differential Revision: http://reviews.llvm.org/D16500
llvm-svn: 258599
There was an off by one error because the StringRef.substr functions
second argument is a length, not the end index.
Also updated a few ELF files which failed when run on Jenkins with paths
including the @ character. This is often used in Jenkins for shared
workspace plugin.
Reviewed by Rui Ueyama
llvm-svn: 258583
This option matches the behaviour of ld64, that is it prevents globals
from being dead stripped in executables and dylibs.
Reviewed by Lang Hames
Differential Revision: http://reviews.llvm.org/D16026
llvm-svn: 258554
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
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
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
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
This pass currently emits an objc image info section if one is required.
This section contains the aggregated version and flags for all of the input
files.
llvm-svn: 258197
Like arch, os, etc, when we know we are going to use a file, we check
that the file has compatible objc constraints to the context, throw
appropriate errors where that is not the case, and hopefully set the
objc constraints on the context for use later.
Added 2 tests to ensure that we don't have incompatibilities between
host and simulator code as both will get x86 based architectures.
llvm-svn: 258173
Image info flags describe the objc constraint which is GC/retain/release/etc.
These need to be parsed and stored in the file so that we can do error checking.
That will come in a later commit.
llvm-svn: 258160
When generating a relocatable file, its only valid to set this flag if
all of the inputs also had the flag. Otherwise we may atomize incorrectly
when we link the relocatable file again.
Reviewed by Lang Hames.
Differential Revision: http://reviews.llvm.org/D16018
llvm-svn: 257976
The image info struct contains flags for what kind of GC/retain/release is required.
Give an error if we parse GC flags as these are unsupported.
llvm-svn: 257974
This file was failing to build with asan enabled. The reason being that
applyFixupFinal was writing 4-bytes worth of fixup in to an atom only
a single byte in length.
The test case didn't actually need this particular reloc so i've removed
it, although i'll follow up with future commits to actually verify that
relocs are to an address with enough space for the fixup to be applied.
llvm-svn: 257906
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
This patch makes use of the handleLoadedFile hook added in r257814.
That method is used to check the arch and the OS of the files we are linking
against the arch and OS on the context.
The first test to use this ensures that we do not try to combine i386 Mac OS code
with i386 simulator code.
llvm-svn: 257837
This is to enable isa<> support for any files which need it.
It will be used in an upcoming patch to differentiate MachOFile from other implicitly generated files.
Reviewed by Lang Hames.
Differential Revision: http://reviews.llvm.org/D16103
llvm-svn: 257830
This is called from the resolver on each file we decide we actually want to use.
Future commits will make use of this to extract useful information from the files and do
error checking against the context. For example, ensure that files are the same arch as
each other.
Reviewed by Lang Hames.
Differential Revision: http://reviews.llvm.org/D16093
llvm-svn: 257814
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
--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
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
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
* 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
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
On Windows different versions of 'sed' work in different text/binary
mode by default. If default mode is text, sed produces corrupted binary
files. Unfortunately there is no standard command line option to select
the mode. Some 'sed' support '-b' to switch to binary mode, while other
ones support '--text' option and does not have '-b' option at all.
llvm-svn: 257471
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
Summary: This is no longer needed now that the new ELF implementation supports AMDGPU.
Reviewers: ruiu, rafael
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15954
llvm-svn: 257390
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
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
* Added instructions to generate R_X86_64_32 relocations. Without that next part of code was uncovered by test, code worked without it:
bool X86_64TargetInfo::relocNeedsPlt(uint32_t Type, const SymbolBody &S) const {
if (needsCopyRel(Type, S))
return false;
* Removed -e main, added _start
Differential revision: http://reviews.llvm.org/D15714
llvm-svn: 257331
DLL export tables usually contain dllexport'ed symbol RVAs so that
applications which use the DLLs can find symbols from the DLLs.
However, there's a minor feature to "forward" DLL symbols to other
DLLs.
If you set an RVA to a string whose form is "<dllname>.<symbolname>"
(e.g. "KERNEL32.ExitProcess") instead of symbol RVA to the export
table, the loader interprets that as a forwarder symbol, and resolve
that symbol from the specified DLL.
This patch implements that feature.
llvm-svn: 257243
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
For historical reasons, some add* functions for SymbolTable returns a
pointer to a SymbolBody, while some are not. This patch is to make them
consistently return a pointer to a newly added symbol.
llvm-svn: 257211
R_X86_64_PLT32 is handled in the same way as R_X86_64_PC32 by
relocateOne(), so this function does not seems to be needed.
Without this code, all tests still pass.
http://reviews.llvm.org/D15971
llvm-svn: 257203
All non-trivial relocation decisions need explanations like this
to help readers understand not only how relocations are handled but
why they are handled these ways. This is a start.
llvm-svn: 257119
It wasn't actually pointing to the function at the start of the text section, and so the offset in the binary differed when we passed the file through a second time.
The __eh_frame section uses implicit relocations and when reducing this test case from explicit to implicit, I got
the offset wrong. This makes sure it is correct.
llvm-svn: 257101
The __eh_frame section contains relocations which can always be implicitly generated.
This patch tracks whether sections have only implicitly relocations and skips emitting them to the object file if that is the case.
The test case here ensures that this is the case for __eh_frame sections.
Reviewed by Lang Hames.
http://reviews.llvm.org/D15594
llvm-svn: 257099
In this patch, all symbols are resolved normally and then wrap options
are applied. Renaming is implemented by mutating `Body` pointers of
Symbols. (As a result, Symtab.find(SymbolName)->getName() may return
a string that's different from SymbolName, but that is by design.
I designed the symbol and the symbol table to allow this kind of
operations.)
http://reviews.llvm.org/D15896
llvm-svn: 257075
Summary: This will allow us to remove the AMDGPU support from old ELF.
Reviewers: rafael, ruiu
Differential Revision: http://reviews.llvm.org/D15895
llvm-svn: 257023
String tables in unstripped executable files are fairly large in size.
For example, lld's executable file is about 34.4 MB in my environment,
and of which 3.5 MB is the string table. Efficiency of string table
construction matters.
Previously, the string table was built in an inefficient way. We used
StringTableBuilder to build that and enabled string tail merging,
although tail merging is not effective for the symbol table (you can
only make the string table 0.3% smaller for lld.) Tail merging is
computation intensive task and slow.
This patch eliminates string tail merging.
I changed the way of adding strings to the string table in this patch
too. Previously, strings were added using add() and the same strings
were then passed to getOffset() to get their offsets in the string table.
In this way, getOffset() needs to look up a hash table to get offsets
for given strings. This is a violation of "we look up the symbol table
(or a hash table) only once for each symbol" dogma of the new LLD's
design. Hash table lookup for long C++ mangled names is slow.
I eliminated that lookup in this patch.
In total, this patch improves link time of lld itself about 12%
(3.50 seconds -> 3.08 seconds.)
llvm-svn: 257017
In a UI such as XCode, it can group the headers for a library with that library.
This is done in the CMakeLists.txt for the library itself by setting the path(s)
as ADDITIONAL_HEADER_DIRS.
LLVM already does this for all of its libraries, so just adding this to lld to
make things easier. Should be NFC.
llvm-svn: 257002
In a UI such as XCode, LLVM source files are in 'libraries' while clang
files are in 'clang libraries'.
This change moves the lld source to 'lld libraries' to make code browsing easier.
It should be NFC as the build itself is still the same, just the structure in a
UI differs.
llvm-svn: 257001
Pete Cooper