Summary:
We want the tool conventions to state that `__tls_align` will be a power of 2.
It makes sense to not have an exception for when there is no TLS.
Reviewers: tlively, sunfish
Reviewed By: tlively
Subscribers: dschuff, sbc100, jgravelle-google, aheejin, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65177
llvm-svn: 366948
Summary:
Add immutable WASM global `__tls_align` which stores the alignment
requirements of the TLS segment.
Add `__builtin_wasm_tls_align()` intrinsic to get this alignment in Clang.
The expected usage has now changed to:
__wasm_init_tls(memalign(__builtin_wasm_tls_align(),
__builtin_wasm_tls_size()));
Reviewers: tlively, aheejin, sbc100, sunfish, alexcrichton
Reviewed By: tlively
Subscribers: dschuff, jgravelle-google, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D65028
llvm-svn: 366624
Summary:
This change makes it so that passing --shared-memory is all a user
needs to do to get proper multithreaded code. This default can still
be explicitly overridden for any reason using --passive-segments and
--active-segments.
Reviewers: sbc100, quantum
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64950
llvm-svn: 366504
When hidden symbols are discarded by comdat rules we still want to
create a local defined symbol, otherwise `Symbol::isDiscarded()` relies
on begin able to check `getChunk->discarded`.
This is a followup on rL362769. The comdat.ll test was previously GC'ing
the `__wasm_call_ctors` functions so `do_init` was not actually being
included in the link. Once that function was included in triggered the
crash bug that this change addresses.
Fixes: https://github.com/emscripten-core/emscripten/issues/8981
Differential Revision: https://reviews.llvm.org/D64872
llvm-svn: 366358
Summary:
Thread local variables are placed inside a `.tdata` segment. Their symbols are
offsets from the start of the segment. The address of a thread local variable
is computed as `__tls_base` + the offset from the start of the segment.
`.tdata` segment is a passive segment and `memory.init` is used once per thread
to initialize the thread local storage.
`__tls_base` is a wasm global. Since each thread has its own wasm instance,
it is effectively thread local. Currently, `__tls_base` must be initialized
at thread startup, and so cannot be used with dynamic libraries.
`__tls_base` is to be initialized with a new linker-synthesized function,
`__wasm_init_tls`, which takes as an argument a block of memory to use as the
storage for thread locals. It then initializes the block of memory and sets
`__tls_base`. As `__wasm_init_tls` will handle the memory initialization,
the memory does not have to be zeroed.
To help allocating memory for thread-local storage, a new compiler intrinsic
is introduced: `__builtin_wasm_tls_size()`. This instrinsic function returns
the size of the thread-local storage for the current function.
The expected usage is to run something like the following upon thread startup:
__wasm_init_tls(malloc(__builtin_wasm_tls_size()));
Reviewers: tlively, aheejin, kripken, sbc100
Subscribers: dschuff, jgravelle-google, hiraditya, sunfish, jfb, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D64537
llvm-svn: 366272
Summary:
We agreed to rename `except_ref` to `exnref` for consistency with other
reference types in
https://github.com/WebAssembly/exception-handling/issues/79. This also
renames WebAssemblyInstrExceptRef.td to WebAssemblyInstrRef.td in order
to use the file for other reference types in future.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64703
llvm-svn: 366145
Summary:
This was causing large addresses to be emitted as negative numbers,
which rightfully caused crashes in binaryen.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64612
llvm-svn: 365930
This patch does the same thing as r365595 to other subdirectories,
which completes the naming style change for the entire lld directory.
With this, the naming style conversion is complete for lld.
Differential Revision: https://reviews.llvm.org/D64473
llvm-svn: 365730
This puts handling of undefined symbols in a single location. Its
also more in line with the ELF backend which only reports undefined
symbols based on relocations.
One side effect is that we no longer report undefined symbols that are
only referenced in GC'd sections.
This also fixes a crash reported in the emscripten toolchain:
https://github.com/emscripten-core/emscripten/issues/8930.
Differential Revision: https://reviews.llvm.org/D64280
llvm-svn: 365553
This should always have been ".data". Without this we treat the
section as a user-defined section in other places (such as the
generation of __start/__stop symbols).
Differential Revision: https://reviews.llvm.org/D64439
llvm-svn: 365547
We should be generating one __start/__stop pair per output segment
not per input segment. The test wasn't catching this because it was
only linking a single object file.
Fixes PR41565
Differential Revision: https://reviews.llvm.org/D64148
llvm-svn: 365308
On Windows, the bitfield layout rule places `ussigned Referenced : 1` at
byte offset 40, instead of byte offset 37 on *NIX. The consequence is that
sizeof(SymbolUnion) == 104 on Windows while 96 on *NIX.
To eliminate this difference, change these unsigned bitfields to bool.
Reviewed By: ruiu
Differential Revision: https://reviews.llvm.org/D64238
llvm-svn: 365296
Since OPT_UNKNOWN args never have any values and consist only of
spelling (and are never aliased), this doesn't make any difference in
practice, but it's more consistent with Arg's guidance to use
getAsString() for diagnostics, and it matches what clang does.
Also tweak two tests to use an unknown option that contains '=' for
additional coverage while here. (The new tests pass fine with the old
code too though.)
llvm-svn: 365200
This fixes an 8-year-old regression. r105763 made it so that aliases
always refer to the unaliased option – but it missed the "joined" branch
of JoinedOrSeparate flags. (r162231 then made the Args classes
non-virtual, and r169344 moved them from clang to llvm.)
Back then, there was no JoinedOrSeparate flag that was an alias, so it
wasn't observable. Now /U in CLCompatOptions is a JoinedOrSeparate alias
in clang, and warn_slash_u_filename incorrectly used the aliased arg id
(using the unaliased one isn't really a regression since that warning
checks if the undefined macro contains slash or backslash and only then
emits the warning – and no valid use will pass "-Ufoo/bar" or similar).
Also, lld has many JoinedOrSeparate aliases, and due to this bug it had
to explicitly call `getUnaliasedOption()` in a bunch of places, even
though that shouldn't be necessary by design. After this fix in Option,
these calls really don't have an effect any more, so remove them.
No intended behavior change.
(I accidentally fixed this bug while working on PR29106 but then
wondered why the warn_slash_u_filename broke. When I figured it out, I
thought it would make sense to land this in a separate commit.)
Differential Revision: https://reviews.llvm.org/D64156
llvm-svn: 365186
On 64-bit systems, this decreases sizeof(SymbolUnion) from 112 to 96.
Add a static_assert to avoid accidental increases in future.
Reviewed By: sbc100
Differential Revision: https://reviews.llvm.org/D64208
llvm-svn: 365169
Summary:
Adds `--passive-segments` and `--active-segments` flags to control
what kind of segments are emitted. For now the default is always
to emit active segments so this is not a breaking change, but in
the future the default will be changed to passive segments when
shared memory is requested and active segments otherwise. When
passive segments are emitted, corresponding memory.init and
data.drop instructions are emitted in a `__wasm_init_memory`
function that is automatically called at the beginning of
`__wasm_call_ctors`.
Reviewers: sbc100, aheejin, dschuff
Subscribers: azakai, dschuff, jgravelle-google, sunfish, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59343
llvm-svn: 365088
Summary:
This is needed for address sanitizer on Emscripten. As everything in
memory starts at the value passed to --global-base, everything before
that can be used as shadow memory.
This symbol is added so that the library for the ASan runtime can know
where the shadow memory ends and real memory begins.
This is split from D63742.
Reviewers: tlively, aheejin, sbc100
Subscribers: sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63833
llvm-svn: 364467
There was another place where handling for this relocation was missing
that was accidentally omitted from rLLD364367, causing the newly added
test to fail on the buildbots.
llvm-svn: 364371
Summary:
Before:
```
wasm-ld: error: Relocations not in offset order
```
After
```
wasm-ld: error: While processing `libjulia.so`: Relocations not in offset order
```
At least this way you get to find out which input file is malformed.
Reviewers: sbc100
Differential Revision: https://reviews.llvm.org/D63694
llvm-svn: 364368
Summary:
The list of relocations with addend in lld was missing `R_WASM_MEMORY_ADDR_REL_SLEB`,
causing `wasm-ld` to generate corrupted output. This fixes that problem and while
we're at it pulls the list of such relocations into the Wasm.h header, to avoid
duplicating it in multiple places.
Reviewers: sbc100
Differential Revision: https://reviews.llvm.org/D63696
llvm-svn: 364367
This is fairly common with wasm since GNU ar (most likely the system ar)
doesn't support the wasm object format so user who don't override AR
will end up with archives without an index. We don't want to silently
ignore this issue.
In the future we could choose to instead behave like the ELF backend and
read the symbols from each object file in the archive if they are all of
the same type. However, error'ing out seem like a conservative approach
for now.
Fixes: PR42376
Differential Revision: https://reviews.llvm.org/D63739
llvm-svn: 364338
When a function is excluded via comdat we shouldn't add it to the
final list of init functions.
Differential Revision: https://reviews.llvm.org/D62983
llvm-svn: 362769
Any symbols defined in the LTO object are by definition the ones we
want in the final output so we skip the comdat group checking in those
cases.
This change makes the ELF code more explicit about this and means
that wasm and ELF do this in the same way.
Differential Revision: https://reviews.llvm.org/D62884
llvm-svn: 362625
Summary:
Make `wasm-ld --verbose` show data section start virtual address and name
as well, instead of just showing the size. This makes it much easier to
track which global variable is in which address when used in conjunction
with `--no-merge-data-sections`.
Patch by Guanzhong Chen
Reviewers: tlively, aheejin, sbc100, ruiu
Reviewed By: sbc100, ruiu
Subscribers: ruiu, dschuff, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62834
llvm-svn: 362548
Summary:
Add the names of the input files responsible for each error to the
messages.
Reviewers: sbc100, azakai
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62704
llvm-svn: 362162
This data structure is only needed temporarily while symbols are being
created.
This is a followup on rL361678.
Differential Revision: https://reviews.llvm.org/D62548
llvm-svn: 361977
When function signatures don't match and the undefined function is not
called directly (i.e. only has its address taken) we don't issue a
warning or create a runtime thunk for the undefined function.
Instead in this case we simply use the defined version of the function.
This is possible since checking signatures of dynamic calls happens
at runtime so any invalid usage will still result in a runtime error.
This is needed to allow C++ programs to link without generating
warnings. Its not uncommon in C++ for vtables to be populated by
function address whee the signature of the function is not known in the
compilation unit. In this case clang declares the method as void(void)
and relies on the vtable caller casting the data back to the correct
signature.
Fixes: https://bugs.llvm.org/show_bug.cgi?id=40412
Differential Revision: https://reviews.llvm.org/D62153
llvm-svn: 361678
This can be useful for post-link tools and for testing. Sometimes
it can be useful to produces a regular executable but with relocations
preserved.
Differential Revision: https://reviews.llvm.org/D62378
llvm-svn: 361635
Summary:
Before we can assign entries in the function of global index space
we need to know the total number of function and global imports
respectively.
To avoid programmer error this change seals that imports section before
assigned function and global index space. Any attempt to add an import
after the section is sealed will assert.
The lack this such as check caused https://reviews.llvm.org/D61876
to be reverted. I'm also trying to craft a test case the this
failure.
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62240
llvm-svn: 361470
This reverts commit 7804dbddcc.
This change broke a bunch of tests of the WebAssembly waterfall.
Will hopefully reland with increased test coverage.
llvm-svn: 361273
--reproduce is a convenient option for debugging. If you invoke lld
with `--reproduce=repro.tar`, it creates `repro.tar` with all input
files and the command line options given to the linker, so that it is
very easy to run lld with the exact same inputs.
ELF and Windows lld have this option.
This patch add that option to lld/wasm.
Differential Revision: https://reviews.llvm.org/D62170
llvm-svn: 361244
Major refactor to better match the structure of the ELF linker.
- Split out relocation processing into scanRelocations
- Split out synthetic sections into their own classes.
Differential Revision: https://reviews.llvm.org/D61811
llvm-svn: 361233
Previously these sections were being generated during their
constructors. This moves the work to finalizeContent, and also does
the same for the relocation sections because their contents depends
on the final layout too.
This change is part of a larger refactor to how we deal with synthetic
sections: https://reviews.llvm.org/D61811
Differential Revision: https://reviews.llvm.org/D61971
llvm-svn: 360941
But don't apply comdat groups when loading the LTO object files.
This is basically the same logic used by the ELF linker.
Differential Revision: https://reviews.llvm.org/D61924
llvm-svn: 360782
Guanzhong Chen