Commit Graph

63 Commits

Author SHA1 Message Date
Rui Ueyama 136d27ab4d [Coding style change][lld] Rename variables for non-ELF ports
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
2019-07-11 05:40:30 +00:00
Thomas Lively 6004d9a13d [WebAssembly] Add option to emit passive segments
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
2019-07-03 22:04:54 +00:00
Guanzhong Chen e15dc95466 [wasm-ld] Add __global_base symbol to mark the value of --global-base
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
2019-06-26 20:12:33 +00:00
Sam Clegg fd54fa5d72 [WebAssembly] Fix for discarded init functions
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
2019-06-07 06:00:46 +00:00
Sam Clegg 7991b68284 [lld] Trace all references with lld --trace-symbol
Previously undefined symbol references were only traced if they were
seen before that definition.

Fixes https://bugs.llvm.org/show_bug.cgi?id=41878

Differential Revision: https://reviews.llvm.org/D61929

llvm-svn: 361636
2019-05-24 13:29:17 +00:00
Sam Clegg 8fcf012693 [WebAssembly] Refactor synthetic sections and relocation processing. NFC.
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
2019-05-21 09:13:09 +00:00
Sam Clegg b685ddf288 [WebAssembly] Always take into account added when applying runtime relocations
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
2019-04-25 17:11:54 +00:00
Sam Clegg 09137be7f8 [WebAssembly] Apply data relocations at runtime in shared objects
See: https://github.com/WebAssembly/tool-conventions/blob/master/DynamicLinking.md

Data section relocations in wasm shared libraries are applied by the
library itself at static constructor time.  This change adds a new
synthetic function that applies relocations to relevant memory locations
on startup.

Differential Revision: https://reviews.llvm.org/D59278

llvm-svn: 357715
2019-04-04 18:40:51 +00:00
Sam Clegg 492f752969 [WebAssembly] Initial implementation of PIC code generation
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
2019-03-26 19:46:15 +00:00
Sam Clegg 6540e57002 [WebAssembly] Don't generate invalid modules when function signatures mismatch
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
2019-02-20 23:19:31 +00:00
Sam Clegg af3b9d0570 [WebAssembly] Honor WASM_SYMBOL_EXPORT symbol flag
This flag means that symbol should be exported in the final binary.

The reason for this change is to allow source level annotations to
trigger a given symbol to be exported:
https://github.com/emscripten-core/emscripten/issues/7702

Differential Revision: https://reviews.llvm.org/D57869

llvm-svn: 353364
2019-02-07 01:53:50 +00:00
Sam Clegg 1f3f774f10 [WebAssembly] Implement --trace and --trace-symbol
Differential Revision: https://reviews.llvm.org/D57725

llvm-svn: 353264
2019-02-06 02:35:18 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
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
2019-01-19 08:50:56 +00:00
Heejin Ahn e915a71f18 [WebAssembly] Add support for the event section
Summary:
This adds support for the 'event section' specified in the exception
handling proposal.

Wasm exception handling binary model spec:
https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md#changes-to-the-binary-model

Reviewers: sbc100, ruiu

Subscribers: dschuff, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D54875

llvm-svn: 348703
2018-12-08 06:17:43 +00:00
Sam Clegg 2dad4e2c6d [WebAssembly] Import the stack pointer when building shared libraries
Differential Revision: https://reviews.llvm.org/D54558

llvm-svn: 346974
2018-11-15 18:15:54 +00:00
Sam Clegg bfb75348e2 [WebAssembly] Initial support for shared objects (-shared)
Based on the initial spec proposal:
https://github.com/WebAssembly/tool-conventions/blob/master/DynamicLinking.md

The llvm/codegen side of this is still missing but I believe this change is
still worth landing as an incremental step

Differential Revision: https://reviews.llvm.org/D54249

llvm-svn: 346918
2018-11-15 00:37:21 +00:00
Sam Clegg 37125f080f [WebAssembly] Respect `--no-mangle` in more locations
`--no-demangle` now also applies to the name section.  This change
was motivated by the rust team that have a slightly different name
mangling scheme to the standard C++ itanium one and prefer to do their
de-mangling as a post-link setp.

Patch by Alex Crichton!

Differential Revision: https://reviews.llvm.org/D54279

llvm-svn: 346516
2018-11-09 16:57:41 +00:00
Sam Clegg 305b0343ce [WebAssembly] Add --[no]-export-dynamic to replace --export-default
In a very recent change I introduced a --no-export-default flag
but after conferring with others it seems that this feature already
exists in gnu GNU ld and lld in the form the --export-dynamic flag
which is off by default.

This change replaces export-default with export-dynamic and also
changes the default to match the traditional linker behaviour.

Now, by default, only the entry point is exported.  If other symbols
are required by the embedder then --export-dynamic or --export can
be used to export all visibility hidden symbols or individual
symbols respectively.

This change touches a lot of tests that were relying on symbols
being exported by default.  I imagine it will also effect many
users but do think the change is worth it match of the traditional
behaviour and flag names.

Differential Revision: https://reviews.llvm.org/D52587

llvm-svn: 343265
2018-09-27 21:06:25 +00:00
Sam Clegg 4e62418b25 [WebAssembly] Add --export-default/--no-export-default options
These option control weather or not symbols marked as visibility
default are exported in the output binary.

By default this is true, but emscripten prefers to control the
exported symbol list explicitly at link time and ignore the
symbol attributes.

Differential Revision: https://reviews.llvm.org/D52003

llvm-svn: 343034
2018-09-25 21:50:15 +00:00
Sam Clegg 52b2456a95 [WebAssembly] Fix --export of LTO symbols
Differential Revision: https://reviews.llvm.org/D48697

llvm-svn: 335881
2018-06-28 17:21:46 +00:00
Sam Clegg ce004bfe35 [WebAssembly] Add support for bitcode archive members
This change effects the behavior of --export-all. Previously
--export-all would only effect symbols that survived GC. Now
--export-all will prevent any non-local symbols from being GCed.

Differential Revision: https://reviews.llvm.org/D48673

llvm-svn: 335878
2018-06-28 17:04:58 +00:00
Nicola Zaghen e7245b429b [lld] Update uses of DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM

Differential Revision: https://reviews.llvm.org/D44977

llvm-svn: 332351
2018-05-15 13:36:20 +00:00
Sam Clegg 3876d89a1b [WebAssembly] Update to match llvm changes
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D46849

llvm-svn: 332306
2018-05-14 22:42:33 +00:00
Sam Clegg d177ab2a5f [WebAssembly] Add support for debug (DWARF) sections
Specifically add support for custom sections that contain
relocations, and for the two new relocation types needed
by DWARF sections.

See: https://reviews.llvm.org/D44184

Patch by Yury Delendik!

Differential Revision: https://reviews.llvm.org/D44184

llvm-svn: 331566
2018-05-04 23:14:42 +00:00
Roman Lebedev d338222a8c [LLD][WASM] Handle WASM_SYMBOL_TYPE_SECTION in toString().
Fixes build. If this is not the desired solution, please revert.
WasmSymbolType was changed in rL330982 / D44184

llvm-svn: 330984
2018-04-26 20:00:11 +00:00
Nicholas Wilson a1e299f58b [WebAssembly] Implement GC for imports
Differential Revision: https://reviews.llvm.org/D44313

llvm-svn: 330454
2018-04-20 17:18:06 +00:00
Sam Clegg e3f3ccf886 [WebAssembly] Refactor to avoid conflating global and fucntion index space. NFC
Differential Revision: https://reviews.llvm.org/D44358

llvm-svn: 327326
2018-03-12 19:56:23 +00:00
Rui Ueyama 72a9a2321f [WebAssembly] Remove a second parameter from toString().
toString(T) is a stringize function for an object of type T. Each type
that has that function defined should know how to stringize itself, and
there should be one string representation of an object. Passing a
"supplemental" argument to toString() breaks that princple. We shouldn't
add a second parameter to that function.

Differential Revision: https://reviews.llvm.org/D44323

llvm-svn: 327182
2018-03-09 22:59:34 +00:00
Nicholas Wilson 2e55ee77e2 [WebAssembly] Handle weak undefined functions with a synthetic stub
This error case is described in Linking.md. The operand for call requires
generation of a synthetic stub.

Differential Revision: https://reviews.llvm.org/D44028

llvm-svn: 327151
2018-03-09 17:06:38 +00:00
Rui Ueyama b961abc886 [WebAssembly] Reduce code repetition. NFC.
Differential Revision: https://reviews.llvm.org/D43910

llvm-svn: 326379
2018-02-28 22:51:51 +00:00
Rui Ueyama 5420dd098b [WebAssembly] Simplify Symbol::getWasmType. NFC.
Differential Revision: https://reviews.llvm.org/D43717

llvm-svn: 326293
2018-02-28 01:10:50 +00:00
Rui Ueyama b911f12211 [WebAssembly] Inline translateVA as it's trivial.
The problem I want to address now is that chunks have too many data
members for "offsets", and their origins are not well defined.
For example, InputSegment has OutputSegmentOffset, but it's base class
also has OutputOffset. That's very confusing.

Differential Revision: https://reviews.llvm.org/D43726

llvm-svn: 326291
2018-02-28 01:01:34 +00:00
Rui Ueyama 28f3b20db5 [WebAssembly] Remove trivial accessors.
{set,get}OutputSegment don't hide anything, so remove them.

Differential Revision: https://reviews.llvm.org/D43724

llvm-svn: 326276
2018-02-28 00:20:29 +00:00
Sam Clegg 9310297438 [WebAssembly] Add explicit symbol table
This change modified lld to in response the llvm change which
moved to a more explicit symbol table in the object format.

Based on patches by Nicholas Wilson:
 1. https://reviews.llvm.org/D41955
 2. https://reviews.llvm.org/D42585

The primary difference that we see in the test output is that
for relocatable (-r) output we now have symbol table which
replaces exports/imports and globals.

See: https://github.com/WebAssembly/tool-conventions/issues/38
Differential Revision: https://reviews.llvm.org/D43264

llvm-svn: 325861
2018-02-23 05:08:53 +00:00
Sam Clegg 00245539b6 [WebAssembly] Rename GlobalSymbol types. NFC.
Purely a rename in preparation for adding new global symbol type.

We want to use GlobalSymbol to represent real wasm globals and
DataSymbol for pointers to things in linear memory (what ELF would
call STT_OBJECT).

This reduces the size the patch to add the explicit symbol table
which is coming soon!

Differential Revision: https://reviews.llvm.org/D43476

llvm-svn: 325645
2018-02-20 23:38:27 +00:00
Sam Clegg 3141ddc58d Consistent (non) use of empty lines in include blocks
The profailing style in lld seem to be to not include such empty lines.
Clang-tidy/clang-format seem to handle this just fine.

Differential Revision: https://reviews.llvm.org/D43528

llvm-svn: 325629
2018-02-20 21:53:18 +00:00
Sam Clegg 4f61714fd6 [WebAssembly] Remove InputChunk from Symbol baseclass
Instead include InputFuction and InputSegment directly
in the subclasses that use them (DefinedFunction and
DefinedGlobal).

Differential Revision: https://reviews.llvm.org/D43493

llvm-svn: 325603
2018-02-20 17:45:38 +00:00
Sam Clegg caca8d5db3 [WebAssembly] Remove unneeded classifer methods from Symbol class. NFC.
We already have isa<> for this, and these methods were simply
duplicating those redundantly.

Differential Revision: https://reviews.llvm.org/D43422

llvm-svn: 325418
2018-02-17 00:44:21 +00:00
Sam Clegg 3f8db98807 [WebAssembly] Simplify FunctionSymbol::get/set/hasFunctionType. NFC.
Differential Revision: https://reviews.llvm.org/D43416

llvm-svn: 325415
2018-02-16 23:50:23 +00:00
Sam Clegg c484ee0a9c [WebAssebmly] Remove use of Optional to fix assertion in gcc
This was causing GCC builds with fail with:
Symbols.h:240:3: error: static assertion failed: Symbol types must be
trivially destructible
  static_assert(std::is_trivially_destructible<T>(

The reason this is a gcc-only failure is that OptionalStorage has
as specialization for POD types that isn't built under GCC.

Differential Revision: https://reviews.llvm.org/D43317

llvm-svn: 325185
2018-02-14 22:55:38 +00:00
Sam Clegg dfb0b2c78f [WebAssembly] Use a Symbol class heirarchy. NFC.
This brings wasm into line with ELF and COFF in terms of
symbol types are represented.

Differential Revision: https://reviews.llvm.org/D43112

llvm-svn: 325150
2018-02-14 18:27:59 +00:00
Sam Clegg 37a4a8a4b1 [WebAssembly] Add __data_end link-sythentic symbol.
This is similar to _end (See https://linux.die.net/man/3/edata for more)
but using our own unique name since our use cases will most likely be
different and we want to keep our options open WRT to memory layout.

This change will allow is to remove the DataSize from the linking
metadata section which is currently being used by emscripten to derive
the end of the data.

Differential Revision: https://reviews.llvm.org/D42867

llvm-svn: 324443
2018-02-07 03:04:53 +00:00
Sam Clegg f0d433d0c6 [WebAssembly] Refactor linker-generated symbols. NFC.
Group all synthetic symbols in the in single struct to match
the ELF linker.

This change is part of a larger change to add more linker
symbols such as `_end` and `_edata`.

Differential Revision: https://reviews.llvm.org/D42866

llvm-svn: 324157
2018-02-02 22:59:56 +00:00
Sam Clegg fc50c62311 clang format
llvm-svn: 323622
2018-01-28 19:57:02 +00:00
Sam Clegg 24b3dcd4bf [WebAssemly] Associate symbol with InputChunk in which they are defined. NFC.
Summary:
Rather than explicit Function or InputSegment points store a
pointer to the base class (InputChunk) and use llvm dynamic
casts when we need a subtype.

This change is useful for add the upcoming gc-section support
wants to deal with all input chunks.

Subscribers: aheejin, llvm-commits

Differential Revision: https://reviews.llvm.org/D42625

llvm-svn: 323621
2018-01-28 19:57:01 +00:00
Sam Clegg 67abf53961 [WebAssembly] Don't duplicate functions in table output
Previously, we were ensuring that the "output index" for
InputFunctions was unique across all symbols that referenced
a function body, but allowing the same function body to have
multiple table indexes.

Now, we use the same mechanism for table indexes as we already
do for output indexes, ensuring that each InputFunction is only
placed in the table once.

This makes the LLD output table denser and smaller, but should
not change the behaviour.

Note that we still need the `Symbol::TableIndex` member, to
store the table index for function Symbols that don't have an
InputFunction, i.e. for address-taken imports.

Patch by Nicholas Wilson!

Differential Revision: https://reviews.llvm.org/D42476

llvm-svn: 323379
2018-01-24 21:45:25 +00:00
Sam Clegg 0f0a428738 [WebAssembly] Remove special handling of entry point export.
Its much easier to export it via setHidden(false), now that
that is a thing.

As a side effect the start function is not longer always exports first
(becuase its being exported just like all the other function).

Differential Revision: https://reviews.llvm.org/D42321

llvm-svn: 323025
2018-01-20 01:44:45 +00:00
Sam Clegg 2a06afae16 [WebAssembly] Add --export flag to force a symbol to be exported
This is useful for emscripten or other tools that want to
selectively exports symbols without necessarily changing the
source code.

Differential Revision: https://reviews.llvm.org/D42003

llvm-svn: 322408
2018-01-12 22:10:35 +00:00
Sam Clegg 408064ef1e [WebAssembly] Don't allow functions to be named more than once
Even though a function can have multiple names in the
linking standards (i.e. due to aliases), there can only
be one name for a given function in the NAME section.

Differential Revision: https://reviews.llvm.org/D41975

llvm-svn: 322383
2018-01-12 17:56:15 +00:00
Sam Clegg 5fa274bea4 [WebAssembly] Add InputChunk as common base class for InputSegment and InputFunction. NFC.
Differential Revision: https://reviews.llvm.org/D41419

llvm-svn: 322148
2018-01-10 01:13:34 +00:00