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
The initial segment protection was also being used to set the maximum
segment protection level. Instead, the maximum should be set according
to the architecture we are linking. For example on Mac OS it should be
RWX on most pages, but on iOS is often on R_X.
rdar://problem/24515136
llvm-svn: 259966
We currently tag on a "__LINKEDIT" when we are emitting the segments.
However, an upcoming patch aims to set the initprot and maxprot segment members
to their correct values, and in order to share code, its better to create this
segment for real and handle it in buildFileOffsets the same way ld64 does.
The commit for segment protections will add a test for this all being correct so
no test here until that code is committed.
llvm-svn: 259960
On Mac OS 10.5 and later, with X86_64 and outputting a dynamic executable,
ld64 set the CPU_SUBTYPE_LIB64 mask on the cpusubtype in the mach_header.
This adds the same functionality to lld.
rdar://problem/24507177
llvm-svn: 259826
This is of the form A.B.C.D.E and to match ld64's behaviour, is
always output to files, even when the version is 0.
rdar://problem/24472630
llvm-svn: 259746
ld64 sets both S_ATTR_PURE_INSTRUCTIONS and S_ATTR_SOME_INSTRUCTIONS
on __TEXT, __text. We only had the S_ATTR_PURE_INSTRUCTIONS attribute.
rdar://problem/24495801
llvm-svn: 259744
In the case where we are emitting to an object file, the platform is
possibly unknown, and the source object files contained load commands
for version min, we can take the maximum of those min versions and
emit in in the output object file.
This test also tests r259739.
llvm-svn: 259742
Defaulting to unknown matches ld64, but it also makes sure that all
of our code can handle not knowing the platform. For example, a later
commit will add support for version min load commands with an unknown
platform, which is a feature supported by ld64.
No test case here. The next commit will have one with the version min
code that needed this patch.
llvm-svn: 259739
This option is emitted in the min_version load commands.
Note, there's currently a difference in behaviour compared to ld64 in
that we emit a warning if we generate a min_version load command and
didn't give an sdk_version. We need to decide what the correct behaviour
is here as its possible we want to emit an error and force clients to
provide the option.
llvm-svn: 259729
If the command line contains something like -macosx_version_min and we
don't explicitly disable generation with -no_version_load_command then
we generate the LC_VERSION_MIN command in the output file.
There's a couple of FIXME's in here. These will be handled soon with
more tests but I didn't want to grow this patch any more than it already was.
rdar://problem/24472630
llvm-svn: 259718
In r259574 I fixed some of the issues with the mach header symbols
and DSO handles.
This is the next issue whereby the __mh_execute_header has to not
be dead stripped, and (to match ld64) should be dynamically referenced.
The test here should also have been added in r259574 to make sure that
we emit this symbol. But checking that it is not only emitted but also
has the correct reference type is fine.
llvm-svn: 259589
The magic file which contained these symbols inherited from archive
which meant that the resolver didn't add the required atoms as archive
members only get added when referenced. Instead we now inherit from
SimpleFile which always links in the atoms needed.
The second issue was in the handling of these symbols when we emit
the MachO. The mach header symbol needs to be in the atom list as
it gets an offset (0), and being in the atom list makes sure it is
emitted to the symbol table. DSO handles are not emitted to the
symbol table.
rdar://problem/24450654
llvm-svn: 259574
When we do debug printing of atoms, they expect their parent file
to have an ordinal. Right now we trigger a bunch of asserts.
This doesn't actually manifest in differences in any real tests, but
even if the only thing it does is improve debuggability then its still
useful.
llvm-svn: 259450
The ObjCPass is going to need to create pointer sized relocations in
the ObjC sections. This method will be used to give us a target independent
way of getting the correct kind for the refererence.
llvm-svn: 259441
An upcoming patch will use this to create lists of ObjC methods.
Adding it now to reduce the amount of code in that patch.
Test cases will follow in the other patch too.
llvm-svn: 259440
This adds the no_objc_category_merging cmdline option which will
be used in an upcoming commit to disable the category optimizer.
It is on by default in ld64 so we match that here.
Test case will come soon with the patch to make use of this option.
llvm-svn: 259439
Most of the other methods to access Reference's were on DefinedAtom so
this just keeps them all together.
This will be used in a future patch in ObjCPass which needs to add
new references. The method is virtual because we may add references to
different data structures depending on whether we parsed a macho file or
yaml.
llvm-svn: 259436
When we parse a MachoFile, we set a number of members from the parsed
file, for example, subsectionsViaSymbols.
However, a number of passes, such as ObjCPass, create local copies of
MachoFile and don't get the benefit of setting flags and other fields in
the parser. Instead we can just give a more sensible default as the parser
will definitely get the correct value from the file anyway.
llvm-svn: 259426
Now that MachoFile has classof(), we can use dyn_cast instead which
is actually the only safe way to handle this.
Turns out this actually manifests as a bug as we were incorrectly
casting instances which weren't MachoFile in to a MachoFile.
Unfortunately, there's no reliable way of checking for this as it
requires that the file we are looking for has a 0 at exactly the byte
we need for the load of subsectionsViaSymbols.
llvm-svn: 259413
__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
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
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
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
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 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
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
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 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
The fixup content we encode here should be the offset from the
fixup location back to the last nonlocal label. We were only encoding
the address of the fixup, and not taking in to account the base address
of the atom we are in.
Updated the test case here to have a text section which will come before
the data section where the relocation lives. .data being at offset 0 had
previously been hiding this bug.
llvm-svn: 256974
The final section order in relocatable files was just a side effect
of the atom sorter. This meant that sections like __data were before
__text because __data has RW permissions and __text RX and RW was less
than RX in our enum.
Final linked images had an actual section/segment sorter. There was no
reason for the difference, so simplify a bunch of code and just use the
same sorted for everything.
Reviewed by Lang Hames.
http://reviews.llvm.org/D15868
llvm-svn: 256786
The encoded value should be an offset from the fixup location, which
means that it should take in to account the fixup offset in its section.
We weren't subtracting the base address of the atom, which meant that when
we parsed the file again for a round trip, we had 2x the atom address in our
target address.
I've also improved comments for these to try and describe what is going on.
There's no test case right now, as the bug is only exhibited when __data is at
a non-zero address in a -r link. A commit will soon sort the sections differently
and move __data to after __text. Then these relocations in
test/mach-o/parse-data-relocs-x86_64.yaml will test for this bug.
llvm-svn: 256779
negDelta32 is only ever implicitly generated as the FDE->CIE reference.
We therefore don't emit a relocation for it in the object file in -r mode.
The value we write in to the FDE location therefore needs to point to the
final target address of the CIE, and not the inAtomAddress as it was currently
doing.
llvm-svn: 255835
We used to parse the LLVM options in Driver::link. However, that is
after parse() where we load files. By moving the LLVM option handling
earlier, we can add DEBUG() to code such as MachONormalizedFileToAtoms.cpp
and have it enabled correctly by '-mllvm --debug'.
llvm-svn: 255819
We had some DEBUG prints these passes, but add more so that its clear where we are dumping
things, and what state we are in when we do so.
I'll be adding more and more DEBUG printing to try make it easier to observe whats going on
without having to attach a debugger.
llvm-svn: 255805
The delta64 relocation is represented as the pair ARM64_RELOC_SUBTRACTOR and ARM64_RELOC_UNSIGNED.
Those should always have the same offset, so this adds a check and tests to ensure this is the case.
Also updated the error printing in this case to shows both relocs when erroring on pair.
llvm-svn: 255274
table.
The first entry in the MachO symbol table is always the empty string: make sure
we reserve space for it, or we will overflow the symbol table by one byte.
No test case - this manifests as an occasional memory error. In the near future
I hope to set up a bot building and runnnig LLD with sanitizers - that should
catch future instances of this issue.
llvm-svn: 255178
The gcc_except_tab was generating these references to point to the typeinfo in the data section.
gcc_except_tab also had the DW_EH_PE_indirect flag set which means that at runtime we are going
to dereference this entry as if it is in the GOT.
Reviewed by Nick Kledzik in http://reviews.llvm.org/D15360.
llvm-svn: 255085
MachODefinedCustomSectionAtom.
The section names for these atoms are initialized from temporaries (e.g.
segName + "/" + sectName), so we can't use StringRef here.
llvm-svn: 251610
GNU linkers accept both variants and at least for MIPS target gcc passes
joined variant of the '-m' option.
Differential Revision: http://reviews.llvm.org/D14133
llvm-svn: 251497
This is a basic initial implementation of the -flat_namespace and
-undefined options for LLD-darwin. It ignores several subtlties,
but the result is close enough that we can now link LLVM (but not
clang) on Darwin and pass all regression tests.
llvm-svn: 248732
Now it is possible to have mips-linux-gnu-ld executable and link MIPS 64-bit
little-endian binaries providing -melf64ltsmip command line argument.
llvm-svn: 246335
This is a basic implementation that allows lld to emit binaries
consumable by the HSA runtime.
Differential Revision: http://reviews.llvm.org/D11267
llvm-svn: 246155
Add PT_PHDR segment depending on its availability in linker script's
PHDRS command, fallback if no linker script is given.
Handle FILEHDR, PHDRS and FLAGS attributes of program header.
Differential Revision: http://reviews.llvm.org/D11589
llvm-svn: 244743
This has a few advantages
* Less C++ code (about 300 lines less).
* Less machine code (about 14 KB of text on a linux x86_64 build).
* It is more debugger friendly. Just set a breakpoint on the exit function and
you get the complete lld stack trace of when the error was found.
* It is a more robust API. The errors are handled early and we don't get a
std::error_code hot potato being passed around.
* In most cases the error function in a better position to print diagnostics
(it has more context).
llvm-svn: 244215
Put sections to segments according to linker scripts if available.
Rework the code of TargetLayout::assignSectionsToSegments so it operates
on the given list of segments, which can be either read from linker scripts
or constructed as before.
Handle NONE segments defined in linker scripts by putting corresponding sections
to PT_NULL segment.
Consider flags set for segments through linker scripts.
Differential Revision: http://reviews.llvm.org/D10918
llvm-svn: 243002
This patch fixes the TLS dynamic variable exportation from .got.plt segments,
created by General-dynamic relocations (TLSDESC). Current code only export
symbols in dynamic table from .got sections.
llvm-svn: 242142
When using a linker script expression to change the address of a section, even
if the new address is more than a page of distance from the old address, lld
may put everything in the same segment, forcing it to be unnecessarily large.
This patch changes the logic in Segment::assignVirtualAddress() and
Segment::assignFileOffsets() to allow the segment to be sliced into two or more
if it detects a linker script expression that changes a section address.
Differential Revision: http://reviews.llvm.org/D10952
llvm-svn: 242096
When calculating the start address and size of a segment, lld mistakenly
attributed the start address of the last segment slice to the whole segment
when it should consider the start address of the first slice. In this case, in a
multi-slice segment, Segment::assignVirtualAddress() will return a wrong
segment start address to TargetLayout::assignVirtualAddress(). The effect of
this miscalculation is to allocate some program headers in unnecessarily far
away addresses. This commit fixes this.
Differential Revision: http://reviews.llvm.org/D10951
llvm-svn: 242089
This is a direct port of the new PE/COFF linker to ELF.
It can take a single object file and generate a valid executable that executes at the first byte in the text section.
llvm-svn: 242088
The function uses parallel_for() and then writes error messages from the
parallel loop's body. This produces nondetermistic error messages. Instead,
copy error messages to a vector and sort it by the atom's file offsets before
printing all error messages after the parallel_for(). This results in a few
string copies, but only in the error case. (And passing tests seem more
important than performance.)
This makes tests elf/AArch64/rel-prel16-overflow.test and
elf/AArch64/rel-prel32-overflow.test pass on Windows: Both tests check that
atom error messages are emitted in a certain order, and on Windows they
happened to be emitted in a different order before this patch.
llvm-svn: 241988
This patch reimplements ELFLinkingContext::getDefaultInterpreter for aarch64
with correct loader name. It is required to exclude the loader from DT_NEEDED
in shared library creation.
llvm-svn: 241371
This patch reimplements ELFLinkingContext::getDefaultInterpreter for aarch64
with correct loader name. It is required to exclude the loader from DT_NEEDED
in shared library creation.
llvm-svn: 241370
This is GNU ELF linker extension used particularly by LibC code.
If input object files contain section named XXX, and the XXX is a valid C
identifier, and there are undefined or weak symbols __start_XXX/__stop_XXX,
linker should define __start_XXX/__stop_XXX symbols point to the begin/end
of the XXX section correspondingly.
For example, without support of this extension statically linked executables
for X86_64 and Mips (maybe other) targets do not flush IO buffers at the end
of executing.
llvm-svn: 241341
This patch adds initial general-dynamic TLS support for AArch64. Currently
no optimization is done to realx for more performance-wise models (initial-exec
or local-exec). This patch also only currently handles correctly executable
generation, although priliminary DSO support through PLT specific creation
is also added.
With this change clang/llvm bootstrap with lld is possible in static configuration
(some DSO creation fails due missing Linker script support, not AArch64 specific),
although make check also shows some issues.
llvm-svn: 241192
Some compilers may not add the section symbol in '.symtab' for the
.init_array and 'ldd' just ignore it. It results in global constructor
not being called in final executable.
This patch add both '.init_array' and '.fini_array' to be added in
Atom graph generation even when the section contains no symbol. An
already existing testcase is modified to check for such scenario.
The issue fixes the llvm test-suite regressions for both Single
and MultiSource files.
llvm-svn: 240570
The ObjectFileYAML.roundTrip serializes a default-constructed
NormalizedFile to YAML, triggering uninitialized memory reads.
While there use in-class member initializers.
llvm-svn: 240446
None of the implementations replace the SimpleFile with some other file,
they just modify the SimpleFile in-place, so a direct reference to the
file is sufficient.
llvm-svn: 240167
Common symbols will be handled in a separate patch because it seems
Hexagon redefines the notion of common symbol, which I'm not (yet)
very familiar with.
llvm-svn: 239951
Current approach for initial-exec in ELF/x86_64 is to create a GOT entry
and change the relocation to R_X86_64_PC32 to be handled as a GOT offfset.
However there are two issues with this approach: 1. the R_X86_64_PC32 is
not really required since the GOT relocation will be handle dynamically and
2. the TLS symbols are not being exported externally and then correct
realocation are not being applied.
This patch fixes the R_X86_64_GOTTPOFF handling by just emitting a
R_X86_64_TPOFF64 dynamically one; it also sets R_X86_64_TPOFF64 to be
handled by runtime one. For second part, the patches uses a similar
strategy used for aarch64, by reimplementing buildDynamicSymbolTable
from X86_64ExecutableWriter and adding the TLS symbols in the dynamic
symbol table.
Some tests had to be adjusted due the now missing R_X86_64_PC32 relocation.
With this test the simple testcase:
* t1.c:
__thread int t0;
__thread int t1;
__thread int t2;
__thread int t3;
* t0.c:
extern __thread int t0;
extern __thread int t1;
extern __thread int t2;
extern __thread int t3;
__thread int t4;
__thread int t5;
__thread int t6;
__thread int t7;
int main ()
{
t0 = 1;
t1 = 2;
t2 = 3;
t3 = 4;
t4 = 5;
t5 = 6;
t6 = 7;
t7 = 8;
printf ("%i %i %i %i\n", t0, t1, t2, t3);
printf ("%i %i %i %i\n", t4, t5, t6, t7);
return 0;
}
Shows correct output for x86_64.
llvm-svn: 239908
This patch fixes the wrong .tbss segment size generated for cases where
multiple modules have non initialized threads variables. For instance:
* t0.c
__thread int x0;
__thread int x1;
__thread int x2;
extern __thread int e0;
extern __thread int e1;
extern __thread int e2;
extern __thread int e3;
int foo0 ()
{
return x0;
}
int main ()
{
return x0;
}
* t1.c
__thread int e0;
__thread int e1;
__thread int e2;
__thread int e3;
lld is generating (for aarch64):
[14] .tbss NOBITS 0000000000401000 00001000
0000000000000010 0000000000000000 WAT 0 0 4
Where is just taking in consideration the largest tbss segment, not all
from all objects. ld generates a correct output:
[17] .tbss NOBITS 0000000000410dec 00000dec
000000000000001c 0000000000000000 WAT 0 0 4
This issue is at 'lib/ReaderWriter/ELF/SegmentChunks.cpp' where
Segment<ELFT>::assignVirtualAddress is setting wrong slice values, not taking care
of although tbss segments file size does noy play role in other segment virtual
address placement, its size should still be considered.
llvm-svn: 239906
Add method to query segments for specified output section name.
Return error if the section is assigned to unknown segment.
Check matching of sections to segments during layout on the subject of correctness.
NOTE: no actual functionality of using custom segments is implemented.
Differential Revision: http://reviews.llvm.org/D10359
llvm-svn: 239719
As noted on Errc.h:
// * std::errc is just marked with is_error_condition_enum. This means that
// common patters like AnErrorCode == errc::no_such_file_or_directory take
// 4 virtual calls instead of two comparisons.
And on some libstdc++ those virtual functions conclude that
------------------------
int main() {
std::error_code foo = std::make_error_code(std::errc::no_such_file_or_directory);
return foo == std::errc::no_such_file_or_directory;
}
-------------------------
should exit with 0.
llvm-svn: 239685
Reid Kleckner