DefinedElf was a superclass of DefinedRegular and SharedSymbol classes
and represented the notion of defined symbols created for ELF symbols.
It turned out that we didn't use that class often. We had only two
occurrences of dyn_cast'ing to DefinedElf, and both were easily
rewritten without it.
The class was also a bit confusing. The concept of "created for ELF
symbol" is orthogonal to defined/undefined types. However, we had
two distinct classes, DefinedElf and UndefinedElf.
This patch simply removes the class. Now the class hierarchy is one
level shallower.
llvm-svn: 265234
If a symbol is defined in an archive, when we replace its body
the isUsedInRegularObj wasn't set correctly. Internalize makes
its decision based on that bit so we ended up internalizing
symbols that we shouldn't (because they're referenced).
This should fix. Thanks to Peter and Rafael for discussion
and help diagnosing the issue!
Found during LTO of unittests.
llvm-svn: 265208
c:\b\slave\sanitizer-windows\llvm\tools\lld\elf\Config.h(94) : error C2797: 'lld:🧝:Configuration::MLlvm': list initialization inside member initializer list or non-static data member initializer is not implemented
llvm-svn: 265207
Extracts code for initializing dummies sections
to avoid possible duplication in following patches.
Differential review: http://reviews.llvm.org/D18691
llvm-svn: 265159
Some functions in Writer reports error using HasError, and some reports
their return values. This patch makes them to consistently use HasError.
llvm-svn: 265156
fixAbsoluteSymbols fixes linker-created symbol addresses. Since we don't
create such symbols for relocatable output, we don't need to call this
function.
llvm-svn: 265154
assignAddressesRelocatable function did not set addresses to sections
despite its name. What it actually did is to set file offsets to sections.
assignAddresses function assigned addresses and file offsets to sections.
So there was a confusion what they were doing, and they had duplicate code.
This patch separates file offset assignments from address assignments.
A new function, assignFileOffsets assign file offsets. assignAddresses
do not care about file offsets anymore.
llvm-svn: 265151
The extra fix is to note that it still requires copy relocations.
Original message:
Change how we handle R_MIPS_LO16.
Mips aligns PT_LOAD to 16 bits (0x10000). That means that the lower 16
bits are always the same, so we can, effectively, say that the
relocation is relative.
P.S.: Suggestions for a better name for the predicate are welcome :-)
llvm-svn: 265150
That is consistent with other symbols: _edata, _etext
and can help to avoid duplicate code.
Differential revision: http://reviews.llvm.org/D18655
llvm-svn: 265129
This fixes bootstrap of llvm-tblgen (with LTO) and PR27150.
Slightly longer explanation follows.
Emission of .init_array instead of .ctors is supported only on a
subset of the Target LLVM supports. Codegen needs to be conservative
and always emit .ctors unless instructed otherwise (based on target).
If the dynamic linker sees .init_array it completely ignores
what's inside .ctors and therefore some constructors are not called
(and this causes llvm-tblgen to crash on startup).
Teach LLD/LTO about the Codegen options so we end up always emitting
.init_array and avoid this issue.
In future, we might end up supporting mix of .ctors and .init_array
in different input files if this shows up as a real-world use case.
The way gold handles this case is mapping .ctors from input into
.init_array in output. There's also another caveat because
as far as I understand .ctors run in reverse order so when we do
the copy/mapping we need to reverse copy in the output if there's
more than one ctor. That's why I'd rather avoid this complicate logic
unless there's a real need.
An analogous reasoning holds for .dtors/.fini_array.
llvm-svn: 265085
Some targets might require creation of thunks. For example, MIPS targets
require stubs to call PIC code from non-PIC one. The patch implements
infrastructure for thunk code creation and provides support for MIPS
LA25 stubs. Any MIPS PIC code function is invoked with its address
in register $t9. So if we have a branch instruction from non-PIC code
to the PIC one we cannot make the jump directly and need to create a small
stub to save the target function address.
See page 3-38 ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
- In relocation scanning phase we ask target about thunk creation necessity
by calling `TagetInfo::needsThunk` method. The `InputSection` class
maintains list of Symbols requires thunk creation.
- Reassigning offsets performed for each input sections after relocation
scanning complete because position of each section might change due
thunk creation.
- The patch introduces new dedicated value for DefinedSynthetic symbols
DefinedSynthetic::SectionEnd. Synthetic symbol with that value always
points to the end of the corresponding output section. That allows to
escape updating synthetic symbols if output sections sizes changes after
relocation scanning due thunk creation.
- In the `InputSection::writeTo` method we write thunks after corresponding
input section. Each thunk is written by calling `TargetInfo::writeThunk` method.
- The patch supports the only type of thunk code for each target. For now,
it is enough.
Differential Revision: http://reviews.llvm.org/D17934
llvm-svn: 265059
We have to check the final value that is written.
I don't think this has any real word implications (unless something
supports unaligned instructions), but unblocks simplifying the handling
of PC relative relocations.
llvm-svn: 265009
This reverts commit r264945.
The commit only removed an unreachable in a method with a covered switch, but
GCC is likely to warn on this, and the coding standards recommend just leaving
in the unreachable.
llvm-svn: 264983
make_dynamic_error_code was used to create a std::error_code with
a std::string message. Now that we are migrating to llvm::Error,
there are no calls to these make_dynamic_error_code methods.
There is one single call to make_dynamic_error_code remaining, the one
inside GenericError::convertToErrorCode(). That method is only called
from File::doParse() which should be a temporary situation. We need
to work out how to deal with File::parse() caching the error result from
doParse(). Caching errors isn't supported in the new scheme, and probably
isn't needed here, but we need to work that out.
Once thats done, dynamic error and all utilities around it can be deleted.
llvm-svn: 264982
These methods weren't really throwing errors. The only error used
was that a file could not be found, which isn't really an error at all
as we are searching paths and libraries for a file. All of the callers
also ignored errors and just used the returned path if one was available.
Changing to return Optional<StringRef> as that actually reflects what
we are trying to do here: optionally find a given path.
llvm-svn: 264979
These methods were responsible for some of the few remaining calls
to llvm::errorCodeToError. Converting them makes us have more Error's
in the api and fewer error_code's.
llvm-svn: 264974
If we make R_MIPS_LO16 a relative relocation, linker:
- never creates R_MIPS_COPY relocation for it
- attempts to create R_MIPS_REL32 dynamic relocation if R_MIPS_LO16's
target is a preemptible symbol
Differential Revision: http://reviews.llvm.org/D18607
llvm-svn: 264956
Pretty mechanical change here. Just replacing all the std::error_code() with
llvm::Error() and make_dynamic_error_code with make_error<GenericError>
llvm-svn: 264917
Windows seems to complain that the file cannot be removed because
it is still in use. We don't have to remove the file but instead
just overwrite it, so do that.
llvm-svn: 264915
Adds a GenericError class to lld/Core which can carry a string. This is
analygous to the dynamic_error we currently use in lld/Core.
Use this GenericError instead of make_dynamic_error_code. Also, provide
an implemention of GenericError::convertToErrorCode which for now converts
it in to the dynamic_error_code we used to have. This will go away once
all the APIs are converted.
llvm-svn: 264910
This patch add a TLS relax optimization test when transforming
Initial-Exec to Local-Exec for local symbols (which can not be preempted).
llvm-svn: 264903
gold and bfd do not include the undefined locals in symtab.
We have no reasons to support that either.
That fixes PR27016
Differential revision: http://reviews.llvm.org/D18554
llvm-svn: 264843
The original comments were separated by new code that is irrelevant to
the comment. This patch moves the comment to the right place and update it.
llvm-svn: 264816
This simplifies a few things
* Read the value as early as possible, instead of passing a pointer to
the location.
* Print the warning for missing pair close to where we find out it is
missing.
* Don't pass the value to relocateOne.
llvm-svn: 264802
Mips aligns PT_LOAD to 16 bits (0x10000). That means that the lower 16
bits are always the same, so we can, effectively, say that the
relocation is relative.
llvm-svn: 264761
Local symbol which requires GOT entry initialized by "page" address.
This address is high 16 bits of sum of the symbol value and the relocation
addend. In the relocation scanning phase final values of symbols are unknown
so to reduce number of allocated GOT entries do the following trick. Save
all output sections referenced by GOT relocations during the relocation
scanning phase. Then later in the `GotSection::finalize` method calculate
number of "pages" required to cover all saved output sections and allocate
appropriate number of GOT entries. We assume the worst case - each 64kb
page of the output section has at least one GOT relocation against it.
Differential Revision: http://reviews.llvm.org/D18349
llvm-svn: 264730
When R_X86_64_PC32/R_X86_64_32 relocations are
used against preemptible symbol and output is position independent,
error should be generated.
Differential revision: http://reviews.llvm.org/D18190
llvm-svn: 264707
Some optimizations, e.g. SimplifyLibCalls, can replace functions with
others as part of the lowering, e.g. printf => puts.
The new symbols don't have the isUsedInRegularObj flag set so they
don't get included in the final symbol table (and dynamic symbol
table), and the dynamic linker gets confused. Include them as a fix.
Differential Revision: http://reviews.llvm.org/D18357
llvm-svn: 264688
searchArchivesToOverrideTentativeDefinitions and
searchSharedLibrariesToOverrideTentativeDefinitions are always false.
For the dead flags, we have a fairly large amount of code which is
never be executed.
http://reviews.llvm.org/D17791
llvm-svn: 264653
IPO doesn't work very well across symbols referenced
by others TUs. The linker here tries to evaluate
which symbols are safe to internalize and switches
their linkage.
Differential Revision: http://reviews.llvm.org/D18415
llvm-svn: 264585
This flag disables link.exe's crash handler so that normal windows error
reporting and crash dumping occurs. For now it is reasonable for LLD to
ignore the flag.
Chromium is currently using this flag to collect minidumps of link.exe
crashing, and it breaks the LLD build.
llvm-svn: 264439
This patch simplifies the isRelRelative for AArch64 and add the missing
ones for bootstrap and test-suite. It also adds more testing for
shared object creation.
llvm-svn: 264322
The stack-size.yaml test had an empty atom content array. This is
legal, but asking a BumpPtrAllocator for 0 sized data may not be
legal. Instead just avoid requesting any data when we can just return
an empty ArrayRef instead.
llvm-svn: 264234
Its possible for file to have no entry atom which means that there
is no atom to check for being a thumb function. Instead just skip
the thumb check and set the entry address to 0, which matches the
current behaviour of getting a default initialised int from a map.
llvm-svn: 264233
On a 32-bit output, we may write LC_MAIN (which contains a uint64_t) to
an unaligned address. This changes it to use a memcpy instead which is UB safe.
llvm-svn: 264232
We were casting a potentially unaligned pointer to uint32_t and
dereferencing. As the pointer ultimately comes from the object file,
there's no way to guarantee alignment, so use the little32_t read instead.
Also, little32_t knows about endianness, so in theory this may have broken on
big endian machines.
llvm-svn: 264231
The .o path always makes sure to store a power of 2 value in the
Section alignment. However, the YAML code didn't verify this.
Added verification and updated all the tests which had a 3 but meant
to have 2^3.
llvm-svn: 264228
The size of a section can be zero, even when it contains atoms, so
long as all of the atoms are also size 0. In this case we were
allocating space for a 0 sized buffer.
Changed this to only allocate when we need the space, but also cleaned
up all the code to use MutableArrayRef instead of uint8_t* so its much much
safer as we get bounds checking on all of our section creation logic.
llvm-svn: 264204
On a 32-bit output, we may write LC_SOURCE_VERSION (which contains a uint64_t) to
an unaligned address. This changes it to use a memcpy instead which is UB safe.
llvm-svn: 264202
We were already copying this data to a temporary for endian swaps. Now
we just always copy it, but still only do the endian swaps when needed.
llvm-svn: 264172
Turns out that checking only x86 for empty atoms to fix UBSan then
requires the same code in the other targets too. Better to just
check this in the main run loop instead of in each target.
Should be NFC, other than fixing UBSan failures.
llvm-svn: 264116
This was caught by the UBSan bot. When the atom has no size, we would
issue a memcpy with size0 and a nullptr for the source.
Also, this code should never have references inside an empty atom so
add an assert for that while we're here.
llvm-svn: 264115
Ensure we keep the symbol we need to before it reaches
the Writer (and hit an assertion), changing its linkage
from linkonce_odr to weak. For a more detailed description
of the problem, see PR19901 where a similar problem was
fixed for the gold plugin. Thanks to Rafael for providing
a testcase.
llvm-svn: 264111
If the LHS of 'a = b' already had an atom in it then we wouldn't
call the destructor. This happens when we use something like
std::remove_if which is done in the CompactUnwindPass. Should fix
the leaks on the mach-o/unwind-info-simple-x86_64.yaml test case.
Lang and I are going to take a look at removing OwningAtomPtr in
favour of a std::unique_ptr but just trying to get the bots green
so we have a good baseline first.
llvm-svn: 264097
The code for LTO has been growing, so now is probably a good time to
move it to its own file. SymbolTable.cpp is for symbol table, and
because compiling bitcode files are semantically not a part of
symbol table, this is I think a good thing to do.
http://reviews.llvm.org/D18370
llvm-svn: 264091
OwningAtomPtr does not have OwningAtomPtr(OwningAtomPtr&) or the equivalent
operator= as we only want to use rvalue references in it.
SortKey didn't like this on MSVC as it was synthesizing SortKey(SortKey&) and
trying to use the OwningAtomPtr(OwningAtomPtr&) method which was private an
unimplemented.
Now we explicitly have the methods on SortKey so hopefully the bot will be
happier.
llvm-svn: 264077
The AtomVector class is an internal detail of File so I moved it
to be protected in r264067. However, the MSVC bots don't like the
global declarations of type File::AtomVector in File.cpp so it needs
to go back to being public for now.
llvm-svn: 264070
This is a re-commit of r264022 with a fix for MSVC. The issue there was
that the code was running DefinedAtom::~Atom() for some value and instead
needed to cast to Atom before running ~Atom. Original commit message follows.
Currently each File contains an BumpPtrAllocator in which Atom's are
allocated. Some Atom's contain data structures like std::vector which
leak as we don't run ~Atom when they are BumpPtrAllocate'd.
Now each File actually owns its Atom's using an OwningAtomPtr. This
is analygous to std::unique_ptr and may be replaced by it if possible.
An Atom can therefore only be owned by a single File, so the Resolver now
moves them from one File to another. The MachOLinkingContext owns the File's
and so clears all the Atom's in ~MachOLinkingContext, then delete's all the
File's. This makes sure all Atom's have been destructed before any of the
BumpPtrAllocator's in which they run have gone away.
Should hopefully fix the remaining leaks. Will keep an eye on the bots to
make sure.
llvm-svn: 264067
When a tls access is optimized, a group of relocations is converted at a
time.
We were already skipping relocations that were optimized out in
relocate, but not in scanRelocs.
This is a small optimization. I got here while working on a patch that
will always keep scanRelocs and relocate in sync.
llvm-svn: 264048
R_X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX relocations were added in latest ABI:
https://github.com/hjl-tools/x86-psABI/wiki/x86-64-psABI-r249.pdf
They should be generated instead of R_X86_64_GOTPCREL for cases
when relaxation is possible. Currently this patch just process them in the
same way like R_X86_64_GOTPCREL. That should work for now
and we can implement relaxations later.
There is no testcases provided as I think there is no way to generate
such relocations using llvm-mc atm.
Differential revision: http://reviews.llvm.org/D18301
llvm-svn: 264043
Now local symbols have SymbolBody so we can handle all kind of symbols
in the GotSection::addEntry method. The patch moves the code from
addMipsLocalEntry to addEntry. NFC.
Differential Revision: http://reviews.llvm.org/D18302
llvm-svn: 264032
This reverts commit r264022.
This breaks the Window's bots which don't like that i'm calling ~Atom when
the this pointer is a sublcass of Atom.
Reverting for now until I try find a better fix. I tried using std::unique_ptr with
a custom deleter as a quick fix, but it didn't work well in the YAML parser.
llvm-svn: 264023
Currently each File contains an BumpPtrAllocator in which Atom's are
allocated. Some Atom's contain data structures like std::vector which
leak as we don't run ~Atom when they are BumpPtrAllocate'd.
Now each File actually owns its Atom's using an OwningAtomPtr. This
is analygous to std::unique_ptr and may be replaced by it if possible.
An Atom can therefore only be owned by a single File, so the Resolver now
moves them from one File to another. The MachOLinkingContext owns the File's
and so clears all the Atom's in ~MachOLinkingContext, then delete's all the
File's. This makes sure all Atom's have been destructed before any of the
BumpPtrAllocator's in which they run have gone away.
Should hopefully fix the remaining leaks. Will keep an eye on the bots to
make sure.
llvm-svn: 264022
In trying to fix the leaks in the MachO lld codebase, we need to have
a better model for file and atom ownership. Having the context own
everything seems like the simplest model, so change all the passes to
allocate File's on the context instead of owning files as a member.
llvm-svn: 264004
Some declarations of memcpy (like glibc's for example) are attributed
with notnull which makes it UB for NULL to get passed in, even if the
memcpy count is zero.
To account for this, guard the memcpy with an appropriate precondition.
This should fix the last UBSan bug, exposed by the test suite, in the
COFF linker.
llvm-svn: 263919
LLD type-punned an integral type and a pointer type using a pointer
field. This is problematic because the pointer type has alignment
greater than some of the integral values.
This would be less problematic if a union was used but it turns out the
integral values are only present for a short, transient, amount of time.
Let's remove this undefined behavior by skipping the punning altogether
by storing the state in a separate memory location: a vector which
informs us which symbols to process for weak externs.
llvm-svn: 263918
Just ignore the -rpath-link command line
option in the same way like gold do.
Behavior of lld/gold differs from gnu ld here.
GNU ld tries to resolve undefined symbols in all
shared object files at link time.
Differential revision: http://reviews.llvm.org/D18269
llvm-svn: 263876
This is required to get 'clang -flto' to work transparently
with lld. Please refer to the short comment in the code
for a more detailed explanation.
llvm-svn: 263862
Rui Ueyama