Commit Graph

46 Commits

Author SHA1 Message Date
Fangrui Song 33fdf82dda [WebAssembly] Rename variale references in comments after VariableName -> variableName change
llvm-svn: 366192
2019-07-16 08:08:17 +00:00
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
Sam Clegg 9abe8c4805 [lld][WebAssembly] Report undefined symbols during scanRelocations
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
2019-07-09 20:45:20 +00:00
Sam Clegg 7d4ec5af6c [WebAssembly] Don't export __data_end and __heap_base by default.
These can still be exported via --export if needed.

Differential Revision: https://reviews.llvm.org/D62744

llvm-svn: 362276
2019-05-31 22:51:59 +00:00
Sam Clegg 59f959ff33 [WebAssembly] Relax signature checking for undefined functions that are not called directly
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
2019-05-24 22:45:08 +00:00
Sam Clegg a5ca34e6b3 [WebAssebmly] Add support for --wrap
The code for implementing this features is taken almost verbatim
from the ELF backend.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=41681

Differential Revision: https://reviews.llvm.org/D62380

llvm-svn: 361639
2019-05-24 14:14:25 +00:00
Sam Clegg 4bce63a0e7 Reland: [WebAssembly] Add __start_/_stop_ symbols for data sections
This is a reland of rL361235.

Fixes https://bugs.llvm.org/show_bug.cgi?id=41565

Differential Revision: https://reviews.llvm.org/D61876

llvm-svn: 361476
2019-05-23 10:06:03 +00:00
Sam Clegg c0a4f45bcb Revert "[WebAssembly] Add __start_/_stop_ symbols for data sections"
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
2019-05-21 17:16:33 +00:00
Sam Clegg 7804dbddcc [WebAssembly] Add __start_/_stop_ symbols for data sections
Fixes https://bugs.llvm.org/show_bug.cgi?id=41565

Differential Revision: https://reviews.llvm.org/D61876

llvm-svn: 361236
2019-05-21 10:07:30 +00:00
Sam Clegg 697f2149f1 [WebAssembly] LTO: Honor comdat groups when loading bitcode files
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
2019-05-15 16:03:28 +00:00
Sam Clegg 0cfaa2470f [WebAssembly] Ensure ArchiveName is set even in the presence of --whole-archive.
Differential Revision: https://reviews.llvm.org/D60431

llvm-svn: 357966
2019-04-09 05:41:52 +00:00
Sam Clegg a688a42cdd [WebAssembly] Improve support for "needed" list in dylink section
This change adds basic support for shared library dependencies
via the dylink section.

See https://github.com/WebAssembly/tool-conventions/pull/77

Differential Revision: https://reviews.llvm.org/D59237

llvm-svn: 356102
2019-03-13 21:29:20 +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 230dc11d24 [WebAssembly] Refactor handling of weak undefined functions. NFC.
Also add to the docs.

This is refactor in preparation for https://reviews.llvm.org/D57909

Differential Revision: https://reviews.llvm.org/D57920

llvm-svn: 353478
2019-02-07 22:42:16 +00:00
Dan Gohman 9b84eeaa3e [WebAssembly] Fix imported function symbol names that differ from their import names in the .o format
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
2019-02-07 22:00:48 +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
Sam Clegg 7cc0753118 [WebAssembly] Support imports from custom module names
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
2019-02-01 02:29:57 +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 45218f4af9 [WebAssembly] Remove `using` statements from header files. NFC.
Differential Revision: https://reviews.llvm.org/D54758

llvm-svn: 347621
2018-11-27 01:08:16 +00:00
Sam Clegg 4c2cbfe68d Set IsUsedInRegularObj in a consistent manor between COFF, ELF and wasm. NFC
Differential Revision: https://reviews.llvm.org/D49147

llvm-svn: 338767
2018-08-02 20:39:19 +00:00
Sam Clegg c729c1b47d [WebAssembly] Initial support for LTO
Differential Revision: https://reviews.llvm.org/D47162

llvm-svn: 333570
2018-05-30 18:07:52 +00:00
Nicholas Wilson c4d9aa1b5f [WebAssembly] Avoid COMDAT hashmap lookup for each symbol. NFC
This reduces the number of lookups to one per COMDAT group, rather than
one per symbol in a COMDAT group.

Differential Revision: https://reviews.llvm.org/D44344

llvm-svn: 327523
2018-03-14 15:45:11 +00:00
Nicholas Wilson ebda41f812 [WebAssembly] Refactor order of creation for SyntheticFunction
Previously we created __wasm_call_ctors with null InputFunction, and
added the InputFunction later. Now we create the SyntheticFunction with
null body, and set the body later.

Differential Revision: https://reviews.llvm.org/D44206

llvm-svn: 327149
2018-03-09 16:43:05 +00:00
Nicholas Wilson dbd90bf8d1 [WebAssembly] Run clang-format. NFC
llvm-svn: 326896
2018-03-07 13:28:16 +00:00
Rui Ueyama dcf6234dad [WebAssembly] Simplify COMDAT handling.
Differential Revision: https://reviews.llvm.org/D43966

llvm-svn: 326509
2018-03-01 23:29:05 +00:00
Rui Ueyama c61b834f31 [WebAssembly] Do not use default arguments for SymbolTable.
Differential Revision: https://reviews.llvm.org/D43727

llvm-svn: 326282
2018-02-28 00:37:03 +00:00
Rui Ueyama e3498ec562 [WebAssembly] Separate addUndefined into addUndefined{Function,Data,Global}.
Previously, one function adds all types of undefined symbols. That
doesn't fit to the wasm's undefined symbol semantics well because
different types of undefined symbols are very different in wasm.
As a result, separate control flows merge in this addUndefined function
and then separate again for each type. That wasn't easy to read.

This patch separates the function into three functions. Now it is pretty
clear what we are doing for each undefined symbol type.

Differential Revision: https://reviews.llvm.org/D43697

llvm-svn: 326271
2018-02-28 00:09:22 +00:00
Rui Ueyama a6a0616508 Remove dead code.
llvm-svn: 325955
2018-02-23 20:33:43 +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 93e559b138 [WebAssembly] Split addDefined into two different methods. NFC.
Subscribers: jfb, dschuff, jgravelle-google, aheejin, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D43496

llvm-svn: 325613
2018-02-20 18:55:06 +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 a189230bf5 [WebAssembly] Cleanup methods for add synthetic symbols to symbtab. NFC.
These were duplicating (incorrectly) some of the logic for
handling conflicts, but since they are only ever added right
at the start we can assume no existing symbols.

Also rename these methods for clarity.

Differential Revision: https://reviews.llvm.org/D43252

llvm-svn: 325045
2018-02-13 20:14:26 +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 e0f6fcd0d9 [WebAssembly] Add COMDAT support
See https://bugs.llvm.org/show_bug.cgi?id=35533, and D40844

Things covered:
* Removing duplicate data segments (as determined by COMDATs emitted
  by the frontend)
* Removing duplicate globals and functions in COMDATs
* Checking that each time a COMDAT is seen it has the same symbols
  as at other times (ie it's a stronger check than simply giving all
  the symbols in the COMDAT weak linkage)

Patch by Nicholas Wilson!

Differential Revision: https://reviews.llvm.org/D40845

llvm-svn: 322415
2018-01-12 22:25:17 +00:00
Sam Clegg 5068685678 [WebAssembly] Create synthetic __wasm_call_ctors function
This change create a new synthetic function in the final
output binary which calls the static constructors in sequence.

See: https://github.com/WebAssembly/tool-conventions/issues/25

Differential Revision: https://reviews.llvm.org/D41893

llvm-svn: 322388
2018-01-12 18:35:13 +00:00
Sam Clegg 20db381b90 [WebAssembly] Refactor symbol and symbol table to remove WasmSymbol references
This WasmSymbol types comes directly from the input objects
but we want to be able to represent synthetic symbols too.

This is more in line with how the ELF linker represents symbols.

This change also removes the logic from Symbol::getVirtualAddress
for finding the global address and instead has the InputFile
provide this.

Differential Revision: https://reviews.llvm.org/D41426

llvm-svn: 322145
2018-01-10 00:52:20 +00:00
Sam Clegg 8d146bbc0c [WebAssembly] Output functions individually
The code section is now written out one function
at a time rather than all the functions in a given
objects being serialized at once.

This change lays the groundwork for supporting
--gc-sections.

Differential Revision: https://reviews.llvm.org/D41315

llvm-svn: 322138
2018-01-09 23:56:44 +00:00
Sam Clegg 5b1216c41e [WebAssembly] Remove used member from SymbolTable
Patch by Nicholas Wilson

llvm-svn: 321096
2017-12-19 18:32:13 +00:00
Sam Clegg 74fe0ba105 [WebAssembly] Fix symbol exports under -r/--relocatable
This change cleans up the way wasm exports and globals
are generated, particualrly for -r/--relocatable where
globals need to be created and exported in order for
output relocations which reference them.

Remove the need for a per file GlobalIndexOffset and
instead set the output index for each symbol directly.
This simplifies the code in several places.

Differential Revision: https://reviews.llvm.org/D40859

llvm-svn: 320001
2017-12-07 01:51:24 +00:00
Sam Clegg b862159683 [WebAssembly] Allow function signature checking at link time
This change allows checking of function signatures but
does not yes enable it by default.  In this mode, linking
two objects that were compiled with a different signatures
for the same function will produce a link error.

New options for enabling and disabling this feature have been
added: (--check-signatures/--no-check-signatures).

Differential Revision: https://reviews.llvm.org/D40371

llvm-svn: 319396
2017-11-30 01:40:08 +00:00
Sam Clegg a80d94d52b Rename `Symtab` private memory to avoid confusion with global `Symtab`
This is also consistent with SymVector that exists in COFF port
and soon to be added to the wasm port.

Split off as part of https://reviews.llvm.org/D40371

Differential Revision: https://reviews.llvm.org/D40525

llvm-svn: 319113
2017-11-27 23:16:06 +00:00
Sam Clegg c94d393ad5 [WebAssembly] Initial wasm linker implementation
This linker backend is still a work in progress but is
enough to link simple programs including linking against
library archives.

Differential Revision: https://reviews.llvm.org/D34851

llvm-svn: 318539
2017-11-17 18:14:09 +00:00