Commit Graph

54 Commits

Author SHA1 Message Date
Dan Gohman 66bfbedbdf [WebAssembly] Support wasm exports with zero-length names.
Zero-length strings are valid export names in WebAssembly, so allow
users to specify them.

Differential Revision: https://reviews.llvm.org/D71793
2020-03-26 16:20:43 -07:00
Kazuaki Ishizaki 7ae3d33546 [lld] Fix trivial typos in comments
Reviewed By: ruiu, MaskRay

Differential Revision: https://reviews.llvm.org/D72196
2020-01-06 10:25:48 -08:00
Sam Clegg 881d877846 [WebAssembly] Add new `export_name` clang attribute for controlling wasm export names
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
2019-12-11 11:54:57 -08:00
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
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 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 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 e3a845e25e Re-land "[WebAssembly] Improve invalid relocation error message""
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
2019-03-29 22:56:39 +00:00
Derek Schuff 0c9ea10530 Revert "[WebAssembly] Improve invalid relocation error message"
This reverts commit 0805ec5f7b.

llvm-svn: 357225
2019-03-29 00:05:00 +00:00
Derek Schuff ac727e8647 Revert "[WebAssembly] Improve invalid relocation error message"
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
2019-03-29 00:04:58 +00:00
Sam Clegg a9958fc30d [WebAssembly] Fix typo from rL357143
llvm-svn: 357144
2019-03-28 02:04:31 +00:00
Sam Clegg 0805ec5f7b [WebAssembly] Improve invalid relocation error message
This message now matches the equivalent message in the ELF linker.

Differential Revision: https://reviews.llvm.org/D59860

llvm-svn: 357143
2019-03-28 02:02:07 +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
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 4aad12ce0b [WebAssembly] Update Config member to match command line option
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D50976

llvm-svn: 343157
2018-09-27 00:46:54 +00:00
Sam Clegg 47078f56f2 [WebAssembly] Optimise relocation processing. NFC.
This is a rebased version https://reviews.llvm.org/D42176 which is patch
by Nicolas Wilson.

Addresses issue:
https://github.com/WebAssembly/tool-conventions/issues/32, and
https://bugs.llvm.org/show_bug.cgi?id=38650

Previously, for each function/segment we iterated over every relocation
to find the relevant ones, which is an n^2 operation. Now, we just make
a single pass.

Differential Revision: https://reviews.llvm.org/D51063

llvm-svn: 340428
2018-08-22 17:50:51 +00:00
Sam Clegg fb983cda8a [WebAssembly] Add option to remove LEB padding at relocate sites
This change adds the ability for lld to remove LEB padding from
code section. This effectively shrinks the size of the resulting
binary in proportion to the number of code relocations.

Since there will be a performance cost this is currently only active for
-O1 and above. Some toolchains may instead want to perform this
compression as a post linker step (for example running a binary through
binaryen will automatically compress these values).

I imagine we might want to make this the default in the future.

Differential Revision: https://reviews.llvm.org/D46416

llvm-svn: 332783
2018-05-18 23:28:05 +00:00
Sam Clegg cfeb646f80 [WebAssembly] Fix R_WEBASSEMBLY_FUNCTION_OFFSET_I32 relocation entries
Fixes: lld: warning: unexpected existing value for R_WEBASSEMBLY_FUNCTION_OFFSET_I32: existing=839 expected=838

The existing solution is trying to erroneously recover correct offset of
the function code from the body (which is not a function segment that
includes its size, locals, and code).

The D46763 is trying to maintain the offset of the function code
allowing properly calculate the new relocation entry.

Patch by Yury Delendik

Differential Revision: https://reviews.llvm.org/D46765

llvm-svn: 332412
2018-05-15 22:27:50 +00:00
Sam Clegg c1953144ac [WebAssembly] Only perform sanity checking of relocation targets in debug builds
Also:
- Reduce the error to a warning so that debug and release
  versions can still link the same inputs.
- Add another check to verify the input LEB is padded to 5 bytes

Differential Revision: https://reviews.llvm.org/D46479

llvm-svn: 331571
2018-05-05 00:18:43 +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
Nicholas Wilson 6c7fe30a1c [WebAssembly] Implement --print-gc-sections for synthetic functions
Enables cleaning up confusion between which name variables are mangled
and which are unmangled, and --print-gc-sections then excersises and
tests that.

Differential Revision: https://reviews.llvm.org/D44440

llvm-svn: 330449
2018-04-20 17:09:18 +00:00
Sam Clegg 225c4697b4 [WebAssembly] Match llvm change to custom section size
Summary:
The content of custome sections no longer includes the
name itself.

See: https://reviews.llvm.org/D45579

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

Differential Revision: https://reviews.llvm.org/D45580

llvm-svn: 329948
2018-04-12 20:31:35 +00:00
Sam Clegg 80ba43872e [WebAssembly] Add support for custom sections
Copy user-defined custom sections into the output, concatenating
sections with the same name.

Differential Revision: https://reviews.llvm.org/D45340

llvm-svn: 329717
2018-04-10 16:12:49 +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
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
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
Nicholas Wilson 8269f37ce6 [WebAssembly] Use StringSaver to retain ownership of ctor function body. NFC
Differential Revision: https://reviews.llvm.org/D44149

llvm-svn: 326885
2018-03-07 10:37:50 +00:00
Nicholas Wilson f6dbc2edee [WebAssembly] Pass ownership of body to SyntheticFunction. NFC
This avoids the Writer unnecessarily having a member to retain ownership
of the function body.

Differential Revision: https://reviews.llvm.org/D43933

llvm-svn: 326580
2018-03-02 14:48:50 +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 b92b6b532f [WebAssembly] Remove unused header
This header used to be needed here for the `OutRelocation` struct
but that no longer exists.

Differential Revision: https://reviews.llvm.org/D43516

llvm-svn: 325608
2018-02-20 18:40:05 +00:00
Rui Ueyama bf450d905d Do not create a temporary data structure for relocations.
This patch removes `OutRelocations` vector from the InputChunk and
directly consume `Relocations` vector instead. This should make the linker
faster because we don't create a temporary data structure, and it matches
the lld's design principle that we don't create temporary data structures
for object files but instead directly consume mmap'ed data whenever possible.

Differential Revision: https://reviews.llvm.org/D43491

llvm-svn: 325549
2018-02-20 04:26:26 +00:00
Rui Ueyama 81bee04bf9 [WebAssembly] Define toString(wasm::InputChunk *) and use that in MarkLive.cpp.
Define toString(wasm::InputChunk *) and use that in MarkLive.cpp.

Differential Revision: https://reviews.llvm.org/D43434

llvm-svn: 325535
2018-02-19 22:29:48 +00:00
Sam Clegg 6d83fb4c07 [WebAssembly] Remove unneeded Chunk::getFileName() method. NFC.
Differential Revision: https://reviews.llvm.org/D43405

llvm-svn: 325414
2018-02-16 23:46:51 +00:00
Sam Clegg 447ae4044d [WebAssembly] Unify concepts of discarded and non-live input chunks. NFC.
It seems redundant to store this information twice.  None of the
locations where this bit is checked care about the distinction.

Differential Revision: https://reviews.llvm.org/D43250

llvm-svn: 325046
2018-02-13 20:29:38 +00:00
Sam Clegg 3dc44a66af [WebAssebmly] Remvoe trailing semicolon. NFC.
llvm-svn: 324716
2018-02-09 07:12:29 +00:00
Sam Clegg 8f6d2def2b [WebAssembly] Write minimal types section
Don't include type signatures that are not referenced by
some relocation.

We don't include this in the -gc-sections settings since
we are always building the type section from scratch,
just like we do the table elements.

In the future we might want to unify the relocation
processing which is currently done once for gc-sections
and then again for building the sympathetic type and
table sections.

Differential Revision: https://reviews.llvm.org/D42747

llvm-svn: 323931
2018-01-31 23:48:14 +00:00
Sam Clegg 0362633fd2 [WebAssembly] Add support for --gc-sections
In this initial version we only GC symbols with `hidden` visibility since
other symbols we export to the embedder.

We could potentially modify this the future and only use symbols
explicitly passed via `--export` as GC roots.

This version of the code only does GC of data and code. GC for the
types section is coming soon.

Differential Revision: https://reviews.llvm.org/D42511

llvm-svn: 323842
2018-01-31 01:45:47 +00:00
Sam Clegg fadf51886a [WebAssembly] Add getName and getFileName methods to InputChunk base class. NFC.
Summary: These are useful to upcoming addition of --gc-sections support.

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

Differential Revision: https://reviews.llvm.org/D42626

llvm-svn: 323623
2018-01-28 19:57:03 +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 ab604a9882 [WebAssembly] Update to match llvm changes to TABLE relocations
TABLE relocations now store the function that is being refered
to indirectly.

See rL323165.

Also extend the call-indirect.ll a little.

Based on a patch by Nicholas Wilson!

llvm-svn: 323168
2018-01-23 01:25:56 +00:00
Sam Clegg 1963d71cb8 [WebAssembly] Simplify generation of "names" section
Simplify generation of "names" section by simply iterating
over the DefinedFunctions array.

This even fixes some bugs, judging by the test changes required.
Some tests are asserting that functions are named multiple times,
other tests are asserting that the "names" section contains the
function's alias rather than its original name

Patch by Nicholas Wilson!

Differential Revision: https://reviews.llvm.org/D42076

llvm-svn: 322751
2018-01-17 20:19:04 +00:00
Sam Clegg fc0723c73f [WebAssembly] Refactor InputChunk.getSize(). NFC
Also, remove trailing semicolons.

Patch by Nicholas Wilson!

llvm-svn: 322726
2018-01-17 18:49:11 +00:00
Sam Clegg 4a379c3dd8 [WebAssembly] Use ArrayRef over raw pointers
Differential Revision: https://reviews.llvm.org/D42013

llvm-svn: 322423
2018-01-13 00:22:00 +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