[NFC] This patch fixes URLs containing "master". Old URLs were either broken or
redirecting to the new URL.
Reviewed By: #libc, ldionne, mehdi_amini
Differential Revision: https://reviews.llvm.org/D113186
Previously relocations were only generated for PIC output, but
relocations for TLS GOT entries are always needed when shared
memory is enabled, not just in PIC mode.
This means that the `__wasm_apply_global_tls_relocs` is now
generated even for statically linked (non-PIC) output. Without
this the globals that hold the addresses of TLS symbols are
not set correctly.
Differential Revision: https://reviews.llvm.org/D112833
This makes Wasm EH work with dynamic linking. So far we were only able
to handle destructors, which do not use any tags or LSDA info.
1. This uses `TargetExternalSymbol` for `GCC_except_tableN` symbols,
which points to the address of per-function LSDA info. It is more
convenient to use than `MCSymbol` because it can take additional
target flags.
2. When lowering `wasm_lsda` intrinsic, if PIC is enabled, make the
symbol relative to `__memory_base` and generate the `add` node. If
PIC is disabled, continue to use the absolute address.
3. Make tag symbols (`__cpp_exception` and `__c_longjmp`) undefined in
the backend, because it is hard to make it work with dynamic
linking's loading order. Instead, we make all tag symbols undefined
in the LLVM backend and import it from JS.
4. Add support for undefined tags to the linker.
Companion patches:
- https://github.com/WebAssembly/binaryen/pull/4223
- https://github.com/emscripten-core/emscripten/pull/15266
Reviewed By: sbc100
Differential Revision: https://reviews.llvm.org/D111388
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
Leave the name section in the output when using the --strip-debug
flag. This treats it more like ELF symbol tables, as the name
section has similar uses at runtime (e.g. wasm engines understand
it and it can be used for symbolization at runtime).
Fixes https://github.com/emscripten-core/emscripten/issues/14623
Differential Revision: https://reviews.llvm.org/D106728
MVP object files may import at most one table, and if they do, it must
be assigned table number zero in the output, as the references to that
table are not relocatable. Ensure that this is the case, even if some
inputs define other tables.
Differential Revision: https://reviews.llvm.org/D96001
The code previously assumed that `getChunk` would return a non-null pointer for
every symbol, but in fact it only returns non-null pointers for DefinedFunction
and DefinedData symbols. This patch fixes the segfault by checking whether
`getChunk` returns a null for each symbol and skipping the mapping output for
any symbols for which it does.
Differential Revision: https://reviews.llvm.org/D88369
This patch adds support to wasm-ld for linking multiple table references
together, in a manner similar to wasm globals. The indirect function
table is synthesized as needed.
To manage the transitional period in which the compiler doesn't yet
produce TABLE_NUMBER relocations and doesn't residualize table symbols,
the linker will detect object files which have table imports or
definitions, but no table symbols. In that case it will synthesize
symbols for the defined and imported tables.
As a change, relocatable objects are now written with table symbols,
which can cause symbol renumbering in some of the tests. If no object
file requires an indirect function table, none will be written to the
file. Note that for legacy ObjFile inputs, this test is conservative: as
we don't have relocs for each use of the indirecy function table, we
just assume that any incoming indirect function table should be
propagated to the output.
Differential Revision: https://reviews.llvm.org/D91870
This patch adds support to wasm-ld for linking multiple table references
together, in a manner similar to wasm globals. The indirect function
table is synthesized as needed.
To manage the transitional period in which the compiler doesn't yet
produce TABLE_NUMBER relocations and doesn't residualize table symbols,
the linker will detect object files which have table imports or
definitions, but no table symbols. In that case it will synthesize
symbols for the defined and imported tables.
As a change, relocatable objects are now written with table symbols,
which can cause symbol renumbering in some of the tests. If no object
file requires an indirect function table, none will be written to the
file. Note that for legacy ObjFile inputs, this test is conservative: as
we don't have relocs for each use of the indirecy function table, we
just assume that any incoming indirect function table should be
propagated to the output.
Differential Revision: https://reviews.llvm.org/D91870
This commit adds table symbol support in a partial way, while still
including some special cases for the __indirect_function_table symbol.
No change in tests.
Differential Revision: https://reviews.llvm.org/D94075
We have two types of relocations that we apply on startup:
1. Relocations that apply to wasm globals
2. Relocations that apply to wasm memory
The first set of relocations use only the `__memory_base` import to
update a set of internal globals. Because wasm globals are thread local
these need to run on each thread. Memory relocations, like static
constructors, must only be run once.
To ensure global relocations run on all threads and because the only
depend on the immutable `__memory_base` import we can run them during
the WebAssembly start functions, instead of waiting until the
post-instantiation __wasm_call_ctors.
Differential Revision: https://reviews.llvm.org/D93066
This flag works in a similar way to the ELF linker in that it
will resolve any defined symbols to their local definition with
a shared library or -pie executable.
This flag has no effect on static linking.
Differential Revision: https://reviews.llvm.org/D89152
With https://reviews.llvm.org/D87537 we made it an error
to import or export a mutable global with the +mutable-globals
feature present. However the scan was of the entire symbol
table rather than just the imports or exports and the filter
didn't match exaclyt meaning the `__stack_pointer` (a mutable
global) was always triggering with error when the `--export-all`
flag was used.
This also revealed that we didn't have any test coverage for
the `--export-all` flag.
This change fixes the current breakage on the emscripten-releases
roller.
Differential Revision: https://reviews.llvm.org/D87663
Summary:
This patch fixes a bug where initialization code for .bss segments was
emitted in the memory initialization function even though the .bss
segments were discounted in the datacount section and omitted in the
data section. This was producing invalid binaries due to out-of-bounds
segment indices on the memory.init and data.drop instructions that
were trying to operate on the nonexistent .bss segments.
Reviewers: sbc100
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80354
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.
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
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 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 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
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
Quinn Pham