This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
down to pass builder in ltobackend.
Currently CodeGenOpts like UnrollLoops/VectorizeLoop/VectorizeSLP in clang
are not passed down to pass builder in ltobackend when new pass manager is
used. This is inconsistent with the behavior when new pass manager is used
and thinlto is not used. Such inconsistency causes slp vectorization pass
not being enabled in ltobackend for O3 + thinlto right now. This patch
fixes that.
Differential Revision: https://reviews.llvm.org/D72386
One instance looks like a false positive:
lld/ELF/Relocations.cpp:1622:14: note: use reference type 'const std::pair<ThunkSection *, uint32_t> &' (aka 'cons
t pair<lld:🧝:ThunkSection *, unsigned int> &') to prevent copying
for (const std::pair<ThunkSection *, uint32_t> ts : isd->thunkSections)
It is not changed in this commit.
This is equivalent to the existing `import_name` and `import_module`
attributes which control the import names in the final wasm binary
produced by lld.
This maps the existing
This attribute currently requires a string rather than using the
symbol name for a couple of reasons:
1. Avoid confusion with static and dynamic linking which is
based on symbol name. Exporting a function from a wasm module using
this directive is orthogonal to both static and dynamic linking.
2. Avoids name mangling.
Differential Revision: https://reviews.llvm.org/D70520
Remove the lld::enableColors function, as it just obscures which
stream it's affecting, and replace with explicit calls to the stream's
enable_colors.
Also, assign the stderrOS and stdoutOS globals first in link function,
just to ensure nothing might use them.
(Either change individually fixes the issue of using the old
stream, but both together seems best.)
Follow-up to b11386f9be.
Differential Revision: https://reviews.llvm.org/D70492
This change is for those who use lld as a library. Context:
https://reviews.llvm.org/D70287
This patch adds a new parmeter to lld::*::link() so that we can pass
an raw_ostream object representing stdout. Previously, lld::*::link()
took only an stderr object.
Justification for making stdoutOS and stderrOS mandatory: I wanted to
make link() functions to take stdout and stderr in that order.
However, if we change the function signature from
bool link(ArrayRef<const char *> args, bool canExitEarly,
raw_ostream &stderrOS = llvm::errs());
to
bool link(ArrayRef<const char *> args, bool canExitEarly,
raw_ostream &stdoutOS = llvm::outs(),
raw_ostream &stderrOS = llvm::errs());
, then the meaning of existing code that passes stderrOS silently
changes (stderrOS would be interpreted as stdoutOS). So, I chose to
make existing code not to compile, so that developers can fix their
code.
Differential Revision: https://reviews.llvm.org/D70292
When statically linking PIC code we create an internalized __memory_base
so that memory-base-relative relocation work correctly. The value of
this global should be zero, and not the globalBase since the globalBase
offset is already taken into account by getVirtualAddress.
Fixes: https://github.com/emscripten-core/emscripten/issues/9013
Differential Revision: https://reviews.llvm.org/D69600
Undefined symbols in WebAssembly can come with custom `import-module`
and `import-field` attributes. However when reading symbols from
bitcode object files during LTO those curtom attributes are not
available.
Once we compile the LTO object and read in the symbol table from the
object file we have access to these custom attributes. In this case,
when undefined symbols are added and a symbol already exists in the
SymbolTable we can't simple return it, we may need to update the
symbol's attributes.
Fixes: PR43211
Differential Revision: https://reviews.llvm.org/D68959
llvm-svn: 375081
Fix a bug where were not handling relocations against weakly undefined
data symbol. Add a test for this case. Also ensure that the weak
references to data symbols are not pulled in from archive files by
default (but are if `-u <name>` is added to the command line).
Fixes: PR43696
Differential Revision: https://reviews.llvm.org/D69073
llvm-svn: 375077
Summary:
WebAssembly memories are zero-initialized, so when module does not
import its memory initializing .bss sections is guaranteed to be a
no-op. To reduce binary size and initialization time, .bss sections
are simply not emitted into the final binary unless the memory is
imported.
Reviewers: sbc100
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68965
llvm-svn: 374940
This pattern matches the ELF implementation add if also useful as
part of a planned change where running `mark` more than once is needed.
Differential Revision: https://reviews.llvm.org/D68749
llvm-svn: 374275
Instead of returning an optional, just return the input string if
demangling fails, as that's what all callers use anyway.
Differential Revision: https://reviews.llvm.org/D68015
llvm-svn: 373077
Summary:
This was always the intended behavior, but had not been
implemented. This ordering is important for Emscripten when generating
.mem files while compiling to JS, since only zeros at the end of
initialized memory can be dropped.
Fixes https://github.com/emscripten-core/emscripten/issues/8999
Reviewers: sbc100
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67736
llvm-svn: 372284
Summary:
- `__wasm_init_memory` is now the WebAssembly start function instead
of being called from `__wasm_call_ctors` or called directly by the
runtime.
- Adds a new synthetic data symbol `__wasm_init_memory_flag` that is
atomically incremented from zero to one by the thread responsible
for initializing memory.
- All threads now unconditionally perform data.drop on all passive
segments.
- Removes --passive-segments and --active-segments flags and controls
segment type based on --shared-memory instead. The deleted flags
were only present to ameliorate the upgrade path in Emscripten.
Reviewers: sbc100, aheejin
Subscribers: dschuff, jgravelle-google, sunfish, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65783
llvm-svn: 370965
This patch implements support for the NO_STRIP flag, which will allow
__attribute__((used)) to be implemented.
This accompanies https://reviews.llvm.org/D62542, which moves to setting the
NO_STRIP flag, and will continue to set EXPORTED for Emscripten targets for
compatibility.
Differential Revision: https://reviews.llvm.org/D66968
llvm-svn: 370416
Adds --growable-table flag to handle building wasm modules with tables
that can grow.
Wasm tables that we use to store function pointers. In order to add functions
to that table at runtime, we need to either preallocate space, or grow the table.
In order to specify a table with no maximum size, we need some flag to handle
that case, separately from a potential --max-table-size= flag.
Note that the number of elements in the table isn't knowable until link-time,
so it's unclear if we will want a --max-table-size= flag in the future.
llvm-svn: 370127
Handling of --export/--undefined can pull in lazy symbols which in turn
can pull in referenced to optional symbols. We need to delay the
creation of optional symbols until all possible references to them have
been created.
Differential Revision: https://reviews.llvm.org/D66768
llvm-svn: 370012
Debug sections are special in that they can contain relocations against
symbols that are not present in the final output (i.e. not live).
However it is also possible to have R_WASM_TABLE_INDEX relocations
against symbols that don't have a table index assigned (since they are
not address taken by actual code.
Fixes: https://github.com/emscripten-core/emscripten/issues/9023
Differential Revision: https://reviews.llvm.org/D66435
llvm-svn: 369423
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
Differential revision: https://reviews.llvm.org/D66259
llvm-svn: 368936
Summary:
Emscripten expects `__data_end` to show up in PIC code as long as it's not
linked with `--shared`.
Currently, Emscripten breaks with latest LLVM because `__data_end` is controlled
by `config->isPic` instead of `config->shared`.`
Reviewers: tlively, sbc100
Reviewed By: sbc100
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65980
llvm-svn: 368361
This allows undefined references in input files be resolved by the
optional symbols. Previously we were doing this before input file
reading which means it was working only for command line symbols
references (i.e. -u or --export).
Also use addOptionalDataSymbol for __dso_handle and make all optional
symbols hidden by default.
Differential Revision: https://reviews.llvm.org/D65920
llvm-svn: 368310
Summary:
`createSyntheticSymbols`, which creates `WasmSym::InitTLS`, is only called
when `!config->relocatable`, but this condition is not checked when calling
`createInitTLSFunction`.
This diff checks `!config->relocatable` before calling `createInitTLSFunction`.
Fixes https://github.com/emscripten-core/emscripten/issues/9155.
Reviewers: tlively, aheejin, kripken, sbc100
Subscribers: dschuff, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65785
llvm-svn: 368078
1. raw_ostream supports ANSI colors so that you can write messages to
the termina with colors. Previously, in order to change and reset
color, you had to call `changeColor` and `resetColor` functions,
respectively.
So, if you print out "error: " in red, for example, you had to do
something like this:
OS.changeColor(raw_ostream::RED);
OS << "error: ";
OS.resetColor();
With this patch, you can write the same code as follows:
OS << raw_ostream::RED << "error: " << raw_ostream::RESET;
2. Add a boolean flag to raw_ostream so that you can disable colored
output. If you disable colors, changeColor, operator<<(Color),
resetColor and other color-related functions have no effect.
Most LLVM tools automatically prints out messages using colors, and
you can disable it by passing a flag such as `--disable-colors`.
This new flag makes it easy to write code that works that way.
Differential Revision: https://reviews.llvm.org/D65564
llvm-svn: 367649
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
The current PIC model for WebAssembly is more like ELF in that it
allows symbol interposition.
This means that more functions end up being addressed via the GOT
and fewer directly added to the wasm table.
One effect is a reduction in the number of wasm table entries similar
to the previous attempt in https://reviews.llvm.org/D61539 which was
reverted.
Differential Revision: https://reviews.llvm.org/D61772
llvm-svn: 360402
When generating PIC output only relocations of type
R_WASM_TABLE_INDEX_REL_SLEB should generate table entries.
R_WASM_TABLE_INDEX_I32 get resolved at runtime via the auto-generated
__wasm_apply_relocs functions.
R_WASM_TABLE_INDEX_SLEB are not allowed in PIC code.
Differential Revision: https://reviews.llvm.org/D61539
llvm-svn: 360165
The code we generate for applying data relocations at runtime omitted
the symbols with GOT entries.
Also refactor the code to reduce duplication.
Differential Revision: https://reviews.llvm.org/D61111
llvm-svn: 359207
Make some small adjustment while touching the code: make parameters
const, use less_first(), etc.
Differential Revision: https://reviews.llvm.org/D60989
llvm-svn: 358943
We can't (currently) meaningfully resolve certain types of relocations
against undefined data symbols. Previously when `--allow-undefined` was
used we were treating such relocation much like weak data symbols and
simply inserting zeros. This change turns such use cases in to an
error.
This means that `--allow-undefined` is no longer effective for data
symbols.
Fixes https://bugs.llvm.org/show_bug.cgi?id=40364
Differential Revision: https://reviews.llvm.org/D60882
llvm-svn: 358899
We were incorrectly used the symbol table version of the function rather
than the object-local version when checking the existing relocation
value.
This was causing erroneous warnings for comat symbols defined in
multiple object.s
Fixes: https://bugs.llvm.org/show_bug.cgi?id=40503
Differential Revision: https://reviews.llvm.org/D60928
llvm-svn: 358871
Summary:
The DataCount section is necessary for the bulk memory operations
memory.init and data.drop to validate, but it is not recognized by
engines that do not support bulk memory, so emit the section only if
bulk-memory is enabled.
Reviewers: aheejin, dschuff, sbc100
Subscribers: jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60637
llvm-svn: 358798
This should have been part of rL357710 but was overlooked because
in our test code the function in question was also used in other
relocations that caused it to be added to the table anyway.
Differential Revision: https://reviews.llvm.org/D60296
llvm-svn: 357737
See https://reviews.llvm.org/D59860
The initial version of this change effected more than just the
error message. This version is scoped down to only effect the error
itself.
llvm-svn: 357328
Summary:
Makes it a linker error if the "atomics" feature is used but the user
does not opt in to shared memory or if "atomics" is disallowed but the
user does opt in to shared memory. Also check that an appropriate max
memory size is supplied if shared memory is used.
Reviewers: sbc100, aheejin
Subscribers: dschuff, jgravelle-google, sunfish, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59281
llvm-svn: 357310
Also Revert "[WebAssembly] Fix typo from rL357143"
This reverts commit 0805ec5f7b and
a9958fc30d
(rL357143 and rL357144)
They cause failures with address-taken extern (JS) functions
in emscripten.
llvm-svn: 357224
This change implements lowering of references global symbols in PIC
mode.
This change implements lowering of global references in PIC mode using a
new @GOT reference type. @GOT references can be used with function or
data symbol names combined with the get_global instruction. In this case
the linker will insert the wasm global that stores the address of the
symbol (either in memory for data symbols or in the wasm table for
function symbols).
For now I'm continuing to use the R_WASM_GLOBAL_INDEX_LEB relocation
type for this type of reference which means that this relocation type
can refer to either a global or a function or data symbol. We could
choose to introduce specific relocation types for GOT entries in the
future. See the current dynamic linking proposal:
https://github.com/WebAssembly/tool-conventions/blob/master/DynamicLinking.md
Differential Revision: https://reviews.llvm.org/D54647
llvm-svn: 357022
Do not pipe binary data between processes in lit tests this time,
since it turns out that can break on Windows.
This reverts commit 84c8652fc3.
llvm-svn: 356975
Summary:
Adds --check-features and --no-check-features. The default for now is
to enable the checking, but this might change in the future.
Also adds --features=foo,bar for precisely controlling the features
used in the output binary.
Depends on D59173.
Reviewers: sbc100, aheejin
Subscribers: dschuff, jgravelle-google, sunfish, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59274
llvm-svn: 356805
Summary:
Implements a new target features section in assembly and object files
that records what features are used, required, and disallowed in
WebAssembly objects. The linker uses this information to ensure that
all objects participating in a link are feature-compatible and records
the set of used features in the output binary for use by optimizers
and other tools later in the toolchain.
The "atomics" feature is always required or disallowed to prevent
linking code with stripped atomics into multithreaded binaries. Other
features are marked used if they are enabled globally or on any
function in a module.
Future CLs will add linker flags for ignoring feature compatibility
checks and for specifying the set of allowed features, implement using
the presence of the "atomics" feature to control the type of memory
and segments in the linked binary, and add front-end flags for
relaxing the linkage policy for atomics.
Reviewers: aheejin, sbc100, dschuff
Subscribers: jgravelle-google, hiraditya, sunfish, mgrang, jfb, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59173
llvm-svn: 356610
For these types of relocations an absolute memory address is
required which is not possible for undefined data symbols. For symbols
that can be undefined at link time (i.e. external data symbols in
shared libraries) a different type of relocation (i.e. via a GOT) will
be needed.
Differential Revision: https://reviews.llvm.org/D59337
llvm-svn: 356310
When linking shared libraries, we import a mutable wasm global
to represent the address of each undefined data symbol.
This is a step towards supporting dynamic linking and shared
libraries.
Differential Revision: https://reviews.llvm.org/D59270
llvm-svn: 355988
This matches the ELF does. Update the comment in ELF/Symbols.h and
duplicate it in wasm/Symbols.h
This a followup on rL355580 and rL355577.
Differential Revision: https://reviews.llvm.org/D59075
llvm-svn: 355737
Summary:
In the clang UI, replaces -mthread-model posix with -matomics as the
source of truth on threading. In the backend, replaces
-thread-model=posix with the atomics target feature, which is now
collected on the WebAssemblyTargetMachine along with all other used
features. These collected features will also be used to emit the
target features section in the future.
The default configuration for the backend is thread-model=posix and no
atomics, which was previously an invalid configuration. This change
makes the default valid because the thread model is ignored.
A side effect of this change is that objects are never emitted with
passive segments. It will instead be up to the linker to decide
whether sections should be active or passive based on whether atomics
are used in the final link.
Reviewers: aheejin, sbc100, dschuff
Subscribers: mehdi_amini, jgravelle-google, hiraditya, sunfish, steven_wu, dexonsmith, rupprecht, jfb, jdoerfert, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D58742
llvm-svn: 355112
The code for encoding the symbols signature into its name
was not actually being used in the final version of this change.
Differential Revision: https://reviews.llvm.org/D58482
llvm-svn: 354539
Previously we could emit a warning and generate a potentially invalid
wasm module (due to call sites and functions having conflicting
signatures). Now, rather than create invalid binaries we handle such
cases by creating stub functions containing unreachable, effectively
turning these into runtime errors rather than validation failures.
Differential Revision: https://reviews.llvm.org/D57909
llvm-svn: 354528
Add a flag to allow symbols to have a wasm import name which differs from the
linker symbol name, allowing the linker to link code using the import_module
attribute.
Differential Revision: https://reviews.llvm.org/D57632
llvm-svn: 353473
Summary:
This patch fixes clang-tidy warnings on wasm-only files.
The list of checks used is:
`-*,clang-diagnostic-*,llvm-*,misc-*,-misc-unused-parameters,readability-identifier-naming,modernize-*`
(LLVM's default .clang-tidy list is the same except it does not have
`modernize-*`.)
The list of fixes are:
- Variable names start with an uppercase letter
- Function names start with a lowercase letter
- Use `auto` when you use casts so the type is evident
Reviewers: sbc100
Subscribers: dschuff, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D57499
llvm-svn: 353076
Fixes: https://bugs.llvm.org/show_bug.cgi?id=37168
This is only a first pass at supporting these custom import
modules. In the long run we most likely want to treat these
kinds of symbols very differently. For example, it should not
be possible to resolve such as symbol at static link type.
Differential Revision: https://reviews.llvm.org/D45796
llvm-svn: 352828
Previously we were never setting this which means it was always being
set to Default (-O2/-Os).
Differential Revision: https://reviews.llvm.org/D57422
llvm-svn: 352667
Change the way we create the symbol table to be closer to how its done
on ELF. Now the output symbol table matches the internal symtab order
and includes local and undefined symbols.
Fixes PR40204
Differential Revision: https://reviews.llvm.org/D56947
llvm-svn: 352645
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
This reverts commit 71eaf61c6c121c8c3bcaf3490557e92cf81599cb. One of
the lld tests was breaking, so revert this change until it is fixed.
llvm-svn: 351409
Jonas Devlieghere