We normally avoid "switch (Config->EKind)", but in this case I think
it is worth it.
It is only executed when there is an error and it allows detemplating
a lot of code.
llvm-svn: 321404
This is part of PR35720.
Currently LLD allows dynamic relocations against text when -z notext is given.
Though for non-PIC relocations like R_X86_64_PC32 that does not work,
we produce "relocation R_X86_64_PC32 cannot be used against shared object;"
error because they may overflow in runtime.
Solution implemented is to use PLT for them.
Differential revision: https://reviews.llvm.org/D41541
llvm-svn: 321400
When two linker script symbols are subtracted, the result should be absolute.
This is the behavior of binutils' ld.
Patch by Erick Reyes!
llvm-svn: 321390
Summary:
Currently the test only checks behaviour for weak function symbols.
Should be good to merge straight away?
Reviewers: sbc100
Reviewed By: sbc100
Subscribers: jfb, dschuff, jgravelle-google, aheejin, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D41449
llvm-svn: 321308
In this case we are calling a function pointer which
a type that doesn't otherwise exist in the code.
Clearly this code can't would trap if it was ever
called (because there is not such function that
the pointer can resolve to).
But it should valid and compile and link and validation
time.
llvm-svn: 321134
Store data relocations with their respective segment.
This allows relocations to be applied as each segment
is written (and therefore in parallel).
Differential Revision: https://reviews.llvm.org/D41410
llvm-svn: 321105
This change add support for init functions in the linking
section, but only in -r/--relocatable mode.
Differential Revision: https://reviews.llvm.org/D41375
llvm-svn: 321088
A more efficient PLT sequence can be used when the distance between the
.plt and the end of the .plt.got is less than 128 Megabytes, which is
frequently true. We fall back to the old sequence when the offset is larger
than 128 Megabytes. This gives us an alternative to forcing the longer
entries with --long-plt as we gracefully fall back to it as needed.
See ELF for the ARM Architecture Appendix A for details of the PLT sequence.
Differential Revision: https://reviews.llvm.org/D41246
llvm-svn: 320987
This is a preparetory change for function gc which also
requires relocations to be copied in ranges like this.
Differential Revision: https://reviews.llvm.org/D41313
llvm-svn: 320948
Summary:
1. Use stream 0 only for combined module. Previously if combined module was not
processes ThinLTO used the stream for own output. However small changes in input,
could trigger combined module and shuffle outputs making life of llvm::LTO harder.
2. Always process combined module and write output to stream 0. Processing empty
combined module is cheap and allows llvm::LTO users to avoid implementing processing
which is already done in llvm::LTO.
Subscribers: mehdi_amini, inglorion, eraman, hiraditya
Differential Revision: https://reviews.llvm.org/D41267
llvm-svn: 320905
/debug and /debug:dwarf are orthogonal. An object file can contain both
CodeView and DWARF debug info, so the combination of /debug:dwarf and
/debug should generate both DWARF and a PDB, rather than /debug:dwarf
always suppressing PDB creation.
/nopdb is now redundant and can be removed. /debug /nopdb was previously
used to support DWARF, but specifying /debug:dwarf is entirely
equivalent to that combination now.
Differential Revision: https://reviews.llvm.org/D41310
llvm-svn: 320896
We can just pass multiple options to hasArgs (which will check for any
of those options being present) instead of calling it multiple times.
llvm-svn: 320892
The COFF linker automatically sets the IMAGE_DLL_CHARACTERISTICS_NO_SEH
when suitable, similarly to link.exe.
Differential Revision: https://reviews.llvm.org/D41275
llvm-svn: 320861
We add dynamic section entries both in the ctor of the class and
DynamicSection::finalizeContents(). Some entries need to be added early
in the ctor because they add strings to .dynstr. Other entries were
intended to be added in finalizeContents(). However, some entries are
added in the ctor even though they don't add strings. This patch
fix the issue.
llvm-svn: 320851
Since imports are undefined symbols we know we can
find all of them my looking at the symbol table alone.
(i.e. imports cannot be have local binding).
This will be strictly faster and also allows us
to to remove a method from Symbol class
Differential Revision: https://reviews.llvm.org/D41304
llvm-svn: 320847
We only need to exceed 128 Megabytes to provoke the generation of a range
extension thunk. This brings the file size down to just over 128 Megabytes.
llvm-svn: 320821
I noticed that the continue this patch deletes was not tested. Trying
to add a test I realized that we never put a VER_NDX_LOCAL symbol in
the dynamic symbol table. There doesn't seem to be any reason for a
linker to use VER_NDX_LOCAL for a defined shared symbol.
llvm-svn: 320817
The ARM.exidx section contains a table of 8-byte entries with the first
word of each entry an offset to the function it describes and the second
word instructions for unwinding if an exception is thrown from that
function. The SHF_LINK_ORDER processing will order the table in ascending
order of the functions described by the exception table entries. As the
address range of an exception table entry is terminated by the next table
entry, it is possible to merge consecutive table entries that have
identical unwind instructions.
For this implementation we define a table entry to be identical if:
- Both entries are the special EXIDX_CANTUNWIND.
- Both entries have the same inline unwind instructions.
We do not attempt to establish if table entries that are references to
.ARM.extab sections are identical.
This implementation works at a granularity of a single .ARM.exidx
InputSection. If all entries in the InputSection are identical to the
previous table entry we can remove the InputSection. A more sophisticated
but more complex implementation would rewrite InputSection contents so that
duplicates within a .ARM.exidx InputSection can be merged.
Differential Revision: https://reviews.llvm.org/D40967
llvm-svn: 320803
This patch provides the mechanism to fix instances of the instruction
sequence that may trigger the cortex-a53 843419 erratum. The fix is
provided by an alternative instruction sequence to remove one of the
erratum conditions. To reach this alternative instruction sequence we
replace the original instruction with a branch to the alternative
sequence. The alternative sequence is responsible for branching back to
the original.
As there is only erratum to fix the implementation is specific to
AArch64 and the specific erratum conditions. It should be generalizable
to other targets and erratum if needed.
Differential Revision: https://reviews.llvm.org/D36749
llvm-svn: 320800
Windows paths have colons in them, so the regex will fail there. Just
match for any character; the rest of the message will restrict the match
to the path anyway.
llvm-svn: 320793
Locally imported symbols are a very surprising linker feature. link.exe
warns for them, and we should warn too.
Differential Revision: https://reviews.llvm.org/D41269
llvm-svn: 320792
Specifically, libwidevinecdm.so in Chrome has such bad symbol.
It seems the BFD linker handles them as local symbols, so instead
of inserting them to the symbol table, we should skip them too.
Differential Revision: https://reviews.llvm.org/D41257
llvm-svn: 320770
This adds the /DEBUG:GHASH option to LLD which will look for
the existence of .debug$H sections in linker inputs and use them
to accelerate type merging. The clang-cl side has already been
added, so this completes the work necessary to begin experimenting
with this feature.
Differential Revision: https://reviews.llvm.org/D40980
llvm-svn: 320719
This is similar to what was added in SVN r277838 for 24 bit
branch instructions.
Differential Revision: https://reviews.llvm.org/D41163
llvm-svn: 320677
This works for linking the output from the MSVC compiler.
The pdata entries for arm64 seem to be 8 bytes in the same
(or at least similar) form to arm.
Differential Revision: https://reviews.llvm.org/D41160
llvm-svn: 320676
We might crash in 'ARMExidxSentinelSection::writeTo()' because it expected
the sentinel entry to be put in the same 'InputSectionDescription' as
the last real entry. This assumption fails if the last output section command
for .ARM.exidx is anything but an input section description, because in this
case 'OutputSection::addSection()' creates a new 'InputSectionDescription'.
Differential Revision: https://reviews.llvm.org/D41105
llvm-svn: 320668
It is currently in InputSectionBase. Only InputSections are used in
ICF, so Repl should be move to InputSection to clear the class
hierarchy or, like this patch does, to SectionBase for convenience.
The convenience of having it on the base class is that we can just
access the replacement without having to first check if it is an
InputSection. It is a bit less code and a bit faster as some of this
code is very hot.
I got up to 1.77% improvement in clang-gdb-index and no regressions
according to lnt.
llvm-svn: 320654
Without this the LLVM_BUILD_LLVM_DYLIB+DLLVM_LINK_LLVM_DYLIB build
break.
Also remove unneeded lldCore from wasm/CMakeLists.txt
Differential Revision: https://reviews.llvm.org/D41194
llvm-svn: 320610
Having a SectionBase method check Repl is inconsistent with how we
handle other section information.
For example, if a section is replaced, Sec->Live is false and it is
natural for Sec->getOutputSection() to be null.
It is the symbol that is moved to the replacement section.
llvm-svn: 320599
The linker refuses using -dynamicbase:no on these architectures.
Stop passing -dynamicbase (which just reinforces the lld-link
default) for simplicity.
Differential Revision: https://reviews.llvm.org/D41052
llvm-svn: 320518
Moving the SHF_LINK_ORDER processing out of OutputSection::finalize()
means that we no longer need to copy all InputSections as we now only need
the first one.
Differential Revision: https://reviews.llvm.org/D40966
llvm-svn: 320478
By moving this step before thunk creation and other processing that depends
on the size of sections, we permit removal of duplicates in the .ARM.exidx
section.
Differential Revision: https://reviews.llvm.org/D40964
llvm-svn: 320477
The size of an OutputSection is calculated early, to aid handling of compressed
debug sections. However, subsequent to this point, unused synthetic sections are
removed. In the event that an OutputSection, from which such an InputSection is
removed, is still required (e.g. because it has a symbol assignment), and no longer
has any InputSections, dot assignments, or BYTE()-family directives, the size
member is never updated when processing the commands. If the removed InputSection
had a non-zero size (such as a .got.plt section), the section ends up with the
wrong size in the output.
The fix is to reset the OutputSection size prior to processing the linker script
commands relating to that OutputSection. This ensures that the size is correct even
in the above situation.
Additionally, to reduce the risk of developers misusing OutputSection Size and
InputSection OutSecOff, they are set to simply the number of InputSections in an
OutputSection, and the corresponding index respectively. We cannot completely
stop using them, due to SHF_LINK_ORDER sections requiring them.
Compressed debug sections also require the full size. This is now calculated in
maybeCompress for these kinds of sections.
Reviewers: ruiu, rafael
Differential Revision: https://reviews.llvm.org/D38361
llvm-svn: 320472
By using an index instead of a pointer for verdef we can put the index
next to the alignment field. This uses the otherwise wasted area and
reduces the shared symbol size.
By itself the performance change of this is in the noise, but I have a
followup patch to remove another 8 bytes that improves performance
when combined with this.
llvm-svn: 320449
An internal linker has support for merging identical data and in some
cases it can be a significant win.
This is behind an off by default flag so it has to be requested
explicitly.
llvm-svn: 320448
Rafael Espindola