These references are used to implement MachO/x64-64 subtractor relocations
where the minuend is being fixed up, rather than the subtrahend. The 64-bit
version was not previously supported, the 32-bit version was partially
implemented but contained bugs not caught by existing test cases. This
patch fixes both functionality and test coverage.
llvm-svn: 273759
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
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
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
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
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
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
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
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
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
The current code for processCIE and processFDE returns out if it sees
any references. The problem with this is that some references could be
explicit in the binary, while others are implicit as they can be
inferred from the content of the EHFrame itself.
This change walks the references we have against the references we
need, and verifies that all explicit references are in the correct place,
and generates any missing implicit ones.
Reviewed by Lang Hames and Nick Kledzik.
Differential Revision: http://reviews.llvm.org/D15439
llvm-svn: 263590
We have a vector of all of the compact unwind entries anyway, and
its live as long as we need it to be. So instead of copying from that
vector to another, just take references to the range of the original vector
we need for each compact unwind page.
llvm-svn: 260437
The non lazy atoms generated in the stubs pass use an image cache to
hold all of the pointers. On arm archs, this is the __got section,
but on x86 archs it should be __nl_symbol_ptr.
rdar://problem/24572729
llvm-svn: 260271
ld64 aligns most of the stub's to 2 byte alignment, expect for
the stub helper common atoms which are 4 byte aligned.
This adds a new field to StubInfo which tracks this alignment
and ensures that this is the alignment we get in the final image.
rdar://problem/24570220
llvm-svn: 260248
Also added the defaults for whether to generate this load command, which
the cmdline options are able to override.
There was also a difference to ld64 which is fixed here in that ld64 will
generate an empty data in code command if requested.
rdar://problem/24472630
llvm-svn: 260191
This load command generates data in the LINKEDIT section which
is a list of ULEB128 delta's to all of the functions in the __text section.
It is then 0 terminated and pointer aligned to pad.
ld64 exposes the -function-starts and no-function-starts cmdline options
to override behaviour from the defaults based on file types.
rdar://problem/24472630
llvm-svn: 260188
This was a bug in our handling of these symbols compared to ld64.
Turns out that ld64 always marks these symbols as being not dead stripped.
llvm-svn: 260185
The atom content type enum is used as a tie breaker to sort atoms.
In that case, we want MachHeader to be before typeCode as it really will
be before the code in the final executable.
Test case to follow in the next commit or two.
llvm-svn: 260184
Lang Hames