Commit Graph

22 Commits

Author SHA1 Message Date
Wouter van Oortmerssen 29f8c9f6c2 [WebAssembly] Triple::wasm64 related cleanup
Differential Revision: https://reviews.llvm.org/D83713
2020-07-16 12:01:10 -07:00
Wouter van Oortmerssen 4d135b0446 [WebAssembly] 64-bit memory limits 2020-07-06 12:40:45 -07:00
Wouter van Oortmerssen 3b29376e3f [WebAssembly] Adding 64-bit version of R_WASM_MEMORY_ADDR_* relocs
This adds 4 new reloc types.

A lot of code that previously assumed any memory or offset values could be contained in a uint32_t (and often truncated results from functions returning 64-bit values) have been upgraded to uint64_t. This is not comprehensive: it is only the values that come in contact with the new relocation values and their dependents.

A new tablegen mapping was added to automatically upgrade loads/stores in the assembler, which otherwise has no way to select for these instructions (since they are indentical other than for the offset immediate). It follows a similar technique to https://reviews.llvm.org/D53307

Differential Revision: https://reviews.llvm.org/D81704
2020-06-15 10:07:42 -07:00
Thomas Lively d851fce4cb [lld][WebAssembly] Do not emit initialization for .bss segments
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
2020-05-21 11:33:25 -07:00
Heejin Ahn f93426c5b9 [WebAssembly] Move event section before global section
Summary:
https://github.com/WebAssembly/exception-handling/issues/98

Also this moves many parts of code to make code align with the section
order, even if they don't affect the output.

Reviewers: tlively

Subscribers: dschuff, sbc100, hiraditya, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D76752
2020-03-25 11:49:03 -07:00
Sam Clegg a57f1a5435 [lld][WebAssembly] Handle mixed strong and weak undefined symbols
When there are both strong and weak references to an undefined
symbol ensure that the strong reference prevails in the output symbol
generating the correct error.

Test case copied from lld/test/ELF/weak-and-strong-undef.s

Differential Revision: https://reviews.llvm.org/D75322
2020-02-28 10:16:10 -08:00
Sam Clegg bd4812776b [WebAssembly] Use llvm::Optional to store optional symbol attributes. NFC.
The changes the in-memory representation of wasm symbols such that their
optional ImportName and ImportModule use llvm::Optional.

ImportName is set whenever WASM_SYMBOL_EXPLICIT_NAME flag is set.
ImportModule (for imports) is currently always set since it defaults to
"env".

In the future we can possibly extent to binary format distingish
import which have explit module names.

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74109
2020-02-19 17:25:33 -08:00
Thomas Lively 190dacc3cc [WebAssembly] Elide data segments for .bss sections
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
2019-10-15 19:05:11 +00:00
James Clarke 1ab27c74d4 [lld][WebAssembly] Fix static linking of -fPIC code with external undefined data
Reviewers: ruiu, sbc100

Reviewed By: sbc100

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68991

llvm-svn: 374913
2019-10-15 17:05:42 +00:00
Fangrui Song 33c59abf5c [WebAssembly] Wrap definitions in namespace lld { namespace wasm {. NFC
Similar to D68323, but for wasm.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D68759

llvm-svn: 374279
2019-10-10 05:25:39 +00:00
Sam Clegg 937b955837 [lld][WebAssembly] Fix static linking of -fPIC code with external undefined functions
Differential Revision: https://reviews.llvm.org/D66784

llvm-svn: 372779
2019-09-24 20:52:12 +00:00
Sam Clegg f6f4b98f03 [lld][WebAssembly] Preserve symbol flags in --relocatable output
Fixes https://github.com/emscripten-core/emscripten/issues/8879

Differential Revision: https://reviews.llvm.org/D67729

llvm-svn: 372660
2019-09-23 21:28:29 +00:00
Thomas Lively 09768c5d7a [WebAssembly] Initialize memory in start function
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
2019-09-04 19:50:39 +00:00
Jacob Gravelle 92ed86d239 [lld][WebAssembly] Support for growable tables
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
2019-08-27 22:58:21 +00:00
Sam Clegg 1a1df72a43 [lld][WebAssembly] Store table base in config rather than passing it around. NFC.
I've got another change that makes more use of this value in other
places.

Differential Revision: https://reviews.llvm.org/D66777

llvm-svn: 370010
2019-08-27 04:19:34 +00:00
Sam Clegg 7185a7301e [lld][WebAssembly] Allow linking of pic code into static binaries
Summary: See https://github.com/emscripten-core/emscripten/issues/9013

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65922

llvm-svn: 368719
2019-08-13 17:02:02 +00:00
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
Rui Ueyama 7e296adec7 Make functions and member variables distinguishable even after the name style change. NFC.
llvm-svn: 365605
2019-07-10 09:10:01 +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
Sam Clegg b9889bbacb [WebAssembly] Seal imports section before counting imports
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
2019-05-23 09:41:03 +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