Commit Graph

14505 Commits

Author SHA1 Message Date
Keith Smiley dfeaa1941b [lld][test] Remove /usr/local/lib test requirement
This field only exists if the directory exists on the machine running
the test. It likely exists for most Intel macOS users because of
homebrew, but doesn't exist on some of the CI machines. This
unfortunately makes this test a bit less strict.

Differential Revision: https://reviews.llvm.org/D111361
2021-10-07 15:17:52 -07:00
Keith Smiley 0885afb8b0 [lld][test] Fix darwin REQUIRES (NFC)
Some subprojects like compiler-rt define the `darwin` feature in their
lit config, but lld does not do that, so we need to use the global
system-darwin here instead. This test seems to have drifted from the
actual behavior so I also had to add `/usr/local/lib` here to make it
pass.

Differential Revision: https://reviews.llvm.org/D111268
2021-10-07 12:37:37 -07:00
Heejin Ahn 3ec1760d91 [WebAssembly] Remove WasmTagType
This removes `WasmTagType`. `WasmTagType` contained an attribute and a
signature index:
```
struct WasmTagType {
  uint8_t Attribute;
  uint32_t SigIndex;
};
```

Currently the attribute field is not used and reserved for future use,
and always 0. And that this class contains `SigIndex` as its property is
a little weird in the place, because the tag type's signature index is
not an inherent property of a tag but rather a reference to another
section that changes after linking. This makes tag handling in the
linker also weird that tag-related methods are taking both `WasmTagType`
and `WasmSignature` even though `WasmTagType` contains a signature
index. This is because the signature index changes in linking so it
doesn't have any info at this point. This instead moves `SigIndex` to
`struct WasmTag` itself, as we did for `struct WasmFunction` in D111104.

In this CL, in lib/MC and lib/Object, this now treats tag types in the
same way as function types. Also in YAML, this removes `struct Tag`,
because now it only contains the tag index. Also tags set `SigIndex` in
`WasmImport` union, as functions do.

I think this makes things simpler and makes tag handling more in line
with function handling. These two shares similar properties in that both
of them have signatures, but they are kind of nominal so having the same
signature doesn't mean they are the same element.

Also a drive-by fix: the reserved 'attirubute' part's encoding changed
from uleb32 to uint8 a while ago. This was fixed in lib/MC and
lib/Object but not in YAML. This doesn't change object files because the
field's value is always 0 and its encoding is the same for the both
encoding.

This is effectively NFC; I didn't mark it as such just because it
changed YAML test results.

Reviewed By: sbc100, tlively

Differential Revision: https://reviews.llvm.org/D111086
2021-10-05 17:11:22 -07:00
Heejin Ahn 9a9ec8e04b [lld][WebAssembly] Remove redundant check for undefined global (NFC)
Also does some refactoring.

Reviewed By: sbc100

Differential Revision: https://reviews.llvm.org/D111101
2021-10-05 15:11:27 -07:00
Sam Clegg 8fe128476e [lld][WebAssembly] Create optional internal symbols only after LTO object as been added
This is important for the cases where new symbols can be introduced
during LTO.   Specifically this happens for during TLS-lowering where
references to `__tls_base` can be introduced.

Fixes: https://github.com/emscripten-core/emscripten/issues/12489

Differential Revision: https://reviews.llvm.org/D111171
2021-10-05 13:31:09 -07:00
Andrew Ng 3334b9d70b [ELF][test] Enhance relative dynamic relocation tests
Add checking of the value of the relocation with an addend. Also check
all relocation offsets.

Differential Revision: https://reviews.llvm.org/D111071
2021-10-05 11:32:22 +01:00
Igor Kudrin 65c284a7be [ELF][test][NFC] Make a test standard compliant
PT_LOAD segments in the program header must be sorted by their virtual
addresses, so they should be defined in a similar order as the
associated sections.

Differential Revision: https://reviews.llvm.org/D111068
2021-10-05 11:40:02 +07:00
Sam Clegg c0039de295 [Object][WebAssemlby] Report function types (signatures). NFC
This simplifies the code in a number of ways and avoids
having to track functions and their types separately.

Differential Revision: https://reviews.llvm.org/D111104
2021-10-04 17:33:56 -07:00
Nico Weber f3091831f4 [lld] Use checkError more
No behavior change.
2021-10-04 11:46:16 -04:00
Andrew Ng 39f3f7c08f [ELF][test] Fix several LLD ICF tests
A number of the ICF tests were not updated to use --print-icf-sections
instead of --verbose and various '-NOT' checks were not updated to the
latest output format of --print-icf-sections. Because these are all
'negative' tests, these issues have gone unnoticed.

Differential Revision: https://reviews.llvm.org/D110353
2021-10-04 11:10:10 +01:00
Daniel Rodríguez Troitiño 657f02d458 Revert "Extract LC_CODE_SIGNATURE related implementation out of LLD"
This reverts commit cc8229603b.

As discussed in the review of https://reviews.llvm.org/D109972, this was not
right approach, so we are reverting to start with a different approach.

Differential Revision: https://reviews.llvm.org/D110974
2021-10-01 17:19:50 -07:00
Teresa Johnson b55a964197 Second attempt to fix Windows failures from test changes
Try to address Windows flakes from d87bdc272b
by adding "|| true" as suggested in D110276 so the whole test doesn't
fail when Windows thinks it can't remove the binary.
2021-09-29 19:24:35 -07:00
Teresa Johnson 2f1b99ca67 Use rm -f to fix Windows failures from test changes
Try to address Windows flakes from d87bdc272b
by using 'rm -f' instead of just 'rm' as discussed in D110276. For example:
http://45.33.8.238/win/46115/step_7.txt
2021-09-29 08:01:22 -07:00
Nico Weber c19315ef60 [lld/mac] Don't warn on both --icf=all and -no_deduplicate
Instead, just make the later flag win, like usual.
Implement this by making -no_deduplicate an actual alias for --icf=none
at the Options.td level.

Differential Revision: https://reviews.llvm.org/D110672
2021-09-29 08:25:21 -04:00
Teresa Johnson d87bdc272b Clean up large copies of binaries copied into temp directories in tests
In looking at the disk space used by a ninja check-all, I found that a
few of the largest files were copies of clang and lld made into temp
directories by a couple of tests. These tests were added in D53021 and
D74811. Clean up these copies after usage.

Differential Revision: https://reviews.llvm.org/D110276
2021-09-28 17:04:09 -07:00
Shoaib Meenai f9b3c18e74 [CodeGen] Fix wrapping personality symbol on ARM
The ARM backend was explicitly setting global binding on the personality
symbol. This was added without any comment in a7ec2dcefd, which
introduced EHABI support (back in 2011). None of the other backends do
anything equivalent, as far as I can tell.

This causes problems when attempting to wrap the personality symbol.
Wrapped symbols are marked as weak inside LTO to inhibit IPO (see
https://reviews.llvm.org/D33621). When we wrap the personality symbol,
it initially gets weak binding, and then the ARM backend attempts to
change the binding to global, which causes an error in MC because of
attempting to change the binding of a symbol from non-global to global
(the error was added in https://reviews.llvm.org/D90108).

Simply drop the ARM backend's explicit global binding setting to fix
this. This matches all the other backends, and a large internal
application successfully linked and ran with this change, so it
shouldn't cause any problems. Test via LLD, since wrapping is required
to exhibit the issue.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D110609
2021-09-28 15:01:05 -07:00
Fangrui Song 74a47e54be [llvm-objdump] Fix -R display and support ET_EXEC
* Add a newline before `DYNAMIC RELOCATION RECORDS` (see D101796)
* Add the missing `OFFSET TYPE VALUE` line
* Align columns

Note: llvm-readobj/ELFDumper.cpp `loadDynamicTable` has sophisticated PT_DYNAMIC
code which is unavailable in llvm-objdump.

Reviewed By: jhenderson, Higuoxing

Differential Revision: https://reviews.llvm.org/D110595
2021-09-28 09:58:27 -07:00
Fangrui Song 2bf06d9345 [ELF] Support symbol names with space in linker script expressions
Fix PR51961

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D110490
2021-09-27 09:50:42 -07:00
Fangrui Song db6a00daa0 [ELF] Remove unneeded binding parameter from addOptionalRegular. NFC
__rela_iplt_start uses spurious STB_WEAK, but it doesn't matter because STV_HIDDEN overrides the binding.
2021-09-25 15:47:27 -07:00
Fangrui Song d23fd8ae89 [ELF] Replace noneRel = R_*_NONE with static constexpr. NFC
All architectures define R_*_NONE to 0.
2021-09-25 15:16:44 -07:00
Fangrui Song 40cd4db442 [ELF] Default gotBaseSymInGotPlt to false (NFC for most architectures)
Most architectures use .got instead of .got.plt, so switching the default can
minimize customization.

This fixes an issue for SPARC V9 which uses .got .
AVR, AMDGPU, and MSP430 don't seem to use _GLOBAL_OFFSET_TABLE_.
2021-09-25 15:06:09 -07:00
Fangrui Song a892c0e49e [ELF][test] Improve test coverage 2021-09-25 11:57:54 -07:00
Mike Hommey 08ef24f6ab Wrap xar/xar.h include in extern "C" block
Without such wrapping, linking lld fails with missing symbols because of
C++ symbol mangling with older versions of the MacOSX SDK, in which
xar.h doesn't have an extern "C" block itself.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D110224
2021-09-23 09:37:30 +02:00
Fangrui Song 19d53d45f2 [ELF][AArch64] Refine and fix the condition when BTI/PAC PLT needs bti c
(As I mentioned in https://reviews.llvm.org/D62609#1534158 ,
the condition for using bti c for executable can be loosened.)

In two cases the address of a PLT may escape:

* canonical PLT entry for a STT_FUNC
* non-preemptible STT_GNU_IFUNC which is converted to STT_FUNC

The first case can be detected with `needsPltAddr`.

The second case is not straightforward to detect because for the Relocations.cpp
created `directSym`, it's difficult to know whether the associated `sym` has
exercised the `!needsPlt(expr)` code path. Just use the conservative `isInIplt`
condition. A non-preemptible ifunc not referenced by non-GOT-generating
non-PLT-generating relocations will have an unneeded `bti c`, but the cost is acceptable.

The second case fixes a bug as well: a -shared link may have non-preemptible ifunc.
Before the patch we did not emit `bti c` and could be wrong if the PLT address escaped.
GNU ld doesn't handle the case: `relocation R_AARCH64_ADR_PREL_PG_HI21 against STT_GNU_IFUNC symbol 'ifunc2' isn't handled by elf64_aarch64_final_link_relocate` (https://sourceware.org/bugzilla/show_bug.cgi?id=28370)

For -shared, if BTI is enabled but PAC is disabled, the PLT entry size increases
from 16 to 24 because we have to select the PLT scheme early, but the cost is
acceptable.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D110217
2021-09-22 11:51:09 -07:00
Hongtao Yu d9b511d8e8 [CSSPGO] Set PseudoProbeInserter as a default pass.
Currenlty PseudoProbeInserter is a pass conditioned on a target switch. It works well with a single clang invocation. It doesn't work so well when the backend is called separately (i.e, through the linker or llc), where user has always to pass -pseudo-probe-for-profiling explictly. I'm making the pass a default pass that requires no command line arg to trigger, but will be actually run depending on whether the CU comes with `llvm.pseudo_probe_desc` metadata.

Reviewed By: wenlei

Differential Revision: https://reviews.llvm.org/D110209
2021-09-22 09:09:48 -07:00
Andrew Ng 05b1303421 [ELF][test] Restore important part of ICF alignment test
Restore the checking of addresses in ICF test which was testing the
behaviour of ICF with regards to different alignments of otherwise
identical sections. Also make the test more robust to layout changes.

Differential Revision: https://reviews.llvm.org/D110090
2021-09-22 14:15:33 +01:00
Amy Huang 6e994a833e [lld] Remove timers.ll because inconsistent timers behavior causes the test to fail sometimes
See https://reviews.llvm.org/D109904
2021-09-20 09:57:18 -07:00
Fangrui Song a954bb18b1 [ELF] Add --why-extract= to query why archive members/lazy object files are extracted
Similar to D69607 but for archive member extraction unrelated to GC. This patch adds --why-extract=.

Prior art:

GNU ld -M prints
```
Archive member included to satisfy reference by file (symbol)

a.a(a.o)                      main.o (a)
b.a(b.o)                      (b())
```

-M is mainly for input section/symbol assignment <-> output section mapping
(often huge output) and the information may appear ad-hoc.

Apple ld64
```
__Z1bv forced load of b.a(b.o)
_a forced load of a.a(a.o)
```

It doesn't say the reference file.

Arm's proprietary linker
```
Selecting member vsnprintf.o(c_wfu.l) to define vsnprintf.
...
Loading member vsnprintf.o from c_wfu.l.
              definition:  vsnprintf
              reference :  _printf_a
```

---

--why-extract= gives the user the full data (which is much shorter than GNU ld
-Map). It is easy to track a chain of references to one archive member with a
one-liner, e.g.

```
% ld.lld main.o a_b.a b_c.a c.a -o /dev/null --why-extract=- | tee stdout
reference       extracted       symbol
main.o  a_b.a(a_b.o)    a
a_b.a(a_b.o)    b_c.a(b_c.o)    b()
b_c.a(b_c.o)    c.a(c.o)        c()

% ruby -ane 'BEGIN{p={}}; p[$F[1]]=[$F[0],$F[2]] if $.>1; END{x="c.a(c.o)"; while y=p[x]; puts "#{y[0]} extracts #{x} to resolve #{y[1]}"; x=y[0] end}' stdout
b_c.a(b_c.o) extracts c.a(c.o) to resolve c()
a_b.a(a_b.o) extracts b_c.a(b_c.o) to resolve b()
main.o extracts a_b.a(a_b.o) to resolve a
```

Archive member extraction happens before --gc-sections, so this may not be a live path
under --gc-sections, but I think it is a good approximation in practice.

* Specifying a file avoids output interleaving with --verbose.
* Required `=` prevents accidental overwrite of an input if the user forgets `=`. (Most of compiler drivers' long options accept `=` but not ` `)

Differential Revision: https://reviews.llvm.org/D109572
2021-09-20 09:52:30 -07:00
Fangrui Song d001ab82e4 [ELF] Don't fall back to .text for e_entry
We have the rule to simulate
(https://sourceware.org/binutils/docs/ld/Entry-Point.html),
but the behavior is questionable
(https://sourceware.org/pipermail/binutils/2021-September/117929.html).

gold doesn't fall back to .text.
The behavior is unlikely relied by projects (there is even a warning for
executable links), so let's just delete this fallback path.

Reviewed By: jhenderson, peter.smith

Differential Revision: https://reviews.llvm.org/D110014
2021-09-20 09:35:12 -07:00
Nico Weber 1b2c36aa5f [lld/mac] Fix comment typo to cycle bots 2021-09-18 11:15:21 -04:00
Amy Huang 724a1dff8a [lld] Fix small error in previous commit
6f7483b1ec.
2021-09-17 17:47:21 -07:00
Amy Huang 6f7483b1ec Reland "[LLD] Remove global state in lld/COFF" after fixing asan and msan test failures
Original commit description:

  [LLD] Remove global state in lld/COFF

  This patch removes globals from the lldCOFF library, by moving globals
  into a context class (COFFLinkingContext) and passing it around wherever
  it's needed.

  See https://lists.llvm.org/pipermail/llvm-dev/2021-June/151184.html for
  context about removing globals from LLD.

  I also haven't moved the `driver` or `config` variables yet.

  Differential Revision: https://reviews.llvm.org/D109634

This reverts commit a2fd05ada9.

Original commits were b4fa71eed3
and e03c7e367a.
2021-09-17 17:18:42 -07:00
Jez Ng 91ace9f062 [lld-macho] Construct CFString literals by copying the ConcatInputSection
... instead of constructing a new one each time. This allows us
to take advantage of {D105305}.

I didn't see a substantial difference when linking chromium_framework,
but this paves the way for reusing similar logic for splitting compact
unwind entries into sections. There are a lot more of those, so the
performance impact is significant.

Differential Revision: https://reviews.llvm.org/D109895
2021-09-17 19:46:20 -04:00
Vy Nguyen b428c3e8c1 [lld-macho] Ignore local personality symbols if non-local with the same name exisst, to avoid "too many personalities" error.
Sometimes people intentionally re-define a dylib personlity symbol as a local defined symbol as a workaround to a ld -r bug.
    As a result, we could see "too many personalities" to encode. This patch tries to handle this case by ignoring the local symbols entirely.

    Differential Revision: https://reviews.llvm.org/D107533
2021-09-17 12:59:42 -04:00
Nuri Amari aaf00f3f19 Add MachO signature verification test
Add a test to ensure that MachO files including
a LC_CODE_SIGNATURE load command produced by lld
are signed correctly.

Reviewed By: #lld-macho, int3

Differential Revision: https://reviews.llvm.org/D109840
2021-09-16 17:55:32 -07:00
Nuri Amari cc8229603b Extract LC_CODE_SIGNATURE related implementation out of LLD
Move the functionality in lld that handles writing of the LC_CODE_SIGNATURE load command and associated data section to a central reusable location.

This change is in preparation for another change that modifies llvm-objcopy to reproduce the LC_CODE_SIGNATURE load command and corresponding
data section to maintain the validity of signed macho object files passed through llvm-objcopy.

Reviewed By: #lld-macho, int3, oontvoo

Differential Revision: https://reviews.llvm.org/D109803
2021-09-16 17:43:39 -07:00
Fangrui Song 1d08a19a38 [ELF] Clarify --export-dynamic-symbol/--dynamic-list. NFC 2021-09-16 17:13:08 -07:00
Amy Huang a2fd05ada9 Temporarily revert "[LLD] Remove global state in lld/COFF" and "[lld] Add test to
check for timer output"

Seems to be causing a number of asan test failures.

This reverts commit b4fa71eed3
and e03c7e367a.
2021-09-16 11:58:11 -07:00
Amy Huang e03c7e367a [lld] Add test to check for timer output
This test checks that timers are working and printing as expected.

I also seem to have changed the order of the timers in my globals refactoring
patch, so I fixed it here.

Differential Revision: https://reviews.llvm.org/D109904
2021-09-16 11:36:46 -07:00
Amy Huang b4fa71eed3 [LLD] Remove global state in lld/COFF
This patch removes globals from the lldCOFF library, by moving globals
into a context class (COFFLinkingContext) and passing it around wherever
it's needed.

See https://lists.llvm.org/pipermail/llvm-dev/2021-June/151184.html for
context about removing globals from LLD.

I also haven't moved the `driver` or `config` variables yet.

Differential Revision: https://reviews.llvm.org/D109634
2021-09-16 11:00:23 -07:00
Alfonso Gregory a2c319fdc6 [LLVM][CMake][NFC] Resolve FIXME: Rename LLVM_CMAKE_PATH to LLVM_CMAKE_DIR throughout the project
This way, we do not need to set LLVM_CMAKE_PATH to LLVM_CMAKE_DIR when (NOT LLVM_CONFIG_FOUND)

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D107717
2021-09-16 18:29:57 +02:00
Thomas Lively 962acf0a27 [lld][WebAssembly] Use llvm-objdump to test __wasm_init_memory
Rather than depending on the hex dump from obj2yaml. Now the test shows the
expected function body in a human readable format.

Differential Revision: https://reviews.llvm.org/D109730
2021-09-14 18:07:59 -07:00
Nico Weber ed2f0ad307 [lld/mac] Search .tbd before binary for framework files too
This matters for example for the iPhoneSimulator14.0.sdk, which has
a System/Library/Frameworks/UIKit.framework/UIKit that has
LC_BUILD_VERSION with minos of 14.0, so linking against that file
will produce warnings like:

   .../iPhoneSimulator14.0.sdk/System/Library/Frameworks/UIKit.framework/UIKit
   has version 14.0.0, which is newer than target minimum of 12.0.0

when targeting x86_64-apple-ios12.0-simulator. That doens't happen when
linking against UIKit.tbd instead, obviously.

Linking with RC_TRACE_DYLIB_SEARCHING=1 shows that ld64 also searches
the tbd file first, and we already get that right for non-framework
dylibs.

Fixes crbug.com/1249456.

Differential Revision: https://reviews.llvm.org/D109768
2021-09-14 15:26:45 -04:00
Sam Clegg 6ee55f9ab5 Fix test failure created by ef8c9135ef
Followup to https://reviews.llvm.org/D108877 to fix test
failure.
2021-09-14 07:35:05 -07:00
Sam Clegg ef8c9135ef [WebAssembly] Allow import and export of TLS symbols between DSOs
We previously had a limitation that TLS variables could not
be exported (and therefore could also not be imported).  This
change removed that limitation.

Differential Revision: https://reviews.llvm.org/D108877
2021-09-14 06:47:37 -07:00
Thomas Lively b2032f18c9 [lld][WebAssembly] Relax limitations on multithreaded instantiation
For multithreaded modules (i.e. modules with a shared memory), lld injects a
synthetic Wasm start function that is automatically called during instantiation
to initialize memory from passive data segments. Even though the module will be
instantiated separately on each thread, memory initialization should happen only
once. Furthermore, memory initialization should be finished by the time each
thread finishes instantiation. Since multiple threads may be instantiating their
modules at the same time, the synthetic function must synchronize them.

The current synchronization tries to atomically increment a flag from 0 to 1 in
memory then enters one of two cases. First, if the increment was successful, the
current thread is responsible for initializing memory. It does so, increments
the flag to 2 to signify that memory has been initialized, then notifies all
threads waiting on the flag. Otherwise, the thread atomically waits on the flag
with an expected value of 1 until memory has been initialized. Either the
initializer thread finishes initializing memory (i.e. sets the flag to 2) first
and the waiter threads do not end up blocking, or the waiter threads succesfully
start waiting before memory is initialized so they will be woken by the
initializer thread once it has finished.

One complication with this scheme is that there are various contexts on the Web,
most notably on the main browser thread, that cannot successfully execute a
wait. Executing a wait in these contexts causes a trap, and in this case would
cause instantiation to fail. The embedder must therefore ensure that these
contexts win the race and become responsible for initializing memory, since that
is the only code path that does not execute a wait.

Unfortunately, since only one thread can win the race and initialize memory,
this scheme makes it impossible to have multiple threads in contexts that cannot
wait. For example, it is not currently possible to instantiate the module on
both the main browser thread as well as in an AudioWorklet. To loosen this
restriction, this commit inserts an extra check so that the wait will not be
executed at all when memory has already been initialized, i.e. when the flag
value is 2. After this change, the module can be instantiated on threads in
non-waiting contexts as long as the embedder can guarantee either that the
thread will win the race and initialize memory (as before) or that memory has
already been initialized when instantiation begins. Threads in contexts that can
wait can continue racing to initialize memory.

Fixes (or at least improves) PR51702.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D109722
2021-09-13 15:03:51 -07:00
Sam Clegg b78c85a44a [WebAssembly] Convert to new "dylink.0" section format
This format is based on sub-sections (like the "linking" and "name"
sections) and is therefore easier to extend going forward.

spec change: https://github.com/WebAssembly/tool-conventions/pull/170
binaryen change: https://github.com/WebAssembly/binaryen/pull/4141
wabt change:  https://github.com/WebAssembly/wabt/pull/1707
emscripten change: https://github.com/emscripten-core/emscripten/pull/15019

Differential Revision: https://reviews.llvm.org/D109595
2021-09-12 05:30:38 -07:00
Sam Clegg 3a7bcba34b [lld][WebAssembly] Cleanup output of --verbose
Remove some unnecessary logging from wasm-ld when running under
`--verbose`.  Unlike `-debug` this logging is available in release
builds.  This change makes it little more minimal/readable.

Also, avoid compiling the `debugWrite` function in releaase builds
where it does nothing.  This should remove a lot debug strings from
the binary, and avoid having to construct unused debug strings at
runtime.

Differential Revision: https://reviews.llvm.org/D109583
2021-09-10 11:35:50 -04:00
Fangrui Song bcc34ab6c8 [lld] Enable ANSI escape code for Windows
Buffered diagnostics need ENABLE_VIRTUAL_TERMINAL_PROCESSING after D87272.
Do it unconditionally like FileCheck.
2021-09-09 16:51:11 -07:00
Sam Clegg 6355234660 [lld][WebAssembly] Fix crash on un-used __tls_base symbol
In the case that TLS is used in the single-threaded program, and
therefore effectively lowered away, we still optionally create a
`__tls_base` symbols, but the code for setting it was assuming it was
always created.

Differential Revision: https://reviews.llvm.org/D109518
2021-09-09 12:45:58 -04:00