Commit Graph

58 Commits

Author SHA1 Message Date
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 cf2b8722d4 [WebAssembly][lld] Fix crash when applying relocations to debug sections
Debug sections are special in that they can contain relocations against
symbols that are not present in the final output (i.e. not live).
However it is also possible to have R_WASM_TABLE_INDEX relocations
against symbols that don't have a table index assigned (since they are
not address taken by actual code.

Fixes: https://github.com/emscripten-core/emscripten/issues/9023

Differential Revision: https://reviews.llvm.org/D66435

llvm-svn: 369423
2019-08-20 18:39:24 +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 15006469bf [lld][WebAssembly] Fix __start/__stop symbols when combining input segments
We should be generating one __start/__stop pair per output segment
not per input segment.  The test wasn't catching this because it was
only linking a single object file.

Fixes PR41565

Differential Revision: https://reviews.llvm.org/D64148

llvm-svn: 365308
2019-07-08 10:35:08 +00:00
Keno Fischer cadcb9eb61 [WebAssembly] Fix list of relocations with addends in lld
Summary:
The list of relocations with addend in lld was missing `R_WASM_MEMORY_ADDR_REL_SLEB`,
causing `wasm-ld` to generate corrupted output. This fixes that problem and while
we're at it pulls the list of such relocations into the Wasm.h header, to avoid
duplicating it in multiple places.

Reviewers: sbc100
Differential Revision: https://reviews.llvm.org/D63696

llvm-svn: 364367
2019-06-26 00:52:42 +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 0d9f609d82 [WebAssembly] Assign GOT entries symbols used in data relocations
Differential Revision: https://reviews.llvm.org/D60492

llvm-svn: 358090
2019-04-10 15:06:17 +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 2a7cac932b [WebAssembly] Add new explicit relocation types for PIC relocations
See https://github.com/WebAssembly/tool-conventions/pull/106

Differential Revision: https://reviews.llvm.org/D59907

llvm-svn: 357710
2019-04-04 17:43:50 +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
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
Heejin Ahn a1cc4ea7bb [WebAssembly] clang-tidy (NFC)
Summary:
This patch fixes clang-tidy warnings on wasm-only files.
The list of checks used is:
`-*,clang-diagnostic-*,llvm-*,misc-*,-misc-unused-parameters,readability-identifier-naming,modernize-*`
(LLVM's default .clang-tidy list is the same except it does not have
`modernize-*`.)

The list of fixes are:
- Variable names start with an uppercase letter
- Function names start with a lowercase letter
- Use `auto` when you use casts so the type is evident

Reviewers: sbc100

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

Differential Revision: https://reviews.llvm.org/D57499

llvm-svn: 353076
2019-02-04 19:13:46 +00:00
Sam Clegg 79e33171d6 [WebAssembly] Update relocation naming to match llvm change. NFC.
Differential Revision: https://reviews.llvm.org/D57698

llvm-svn: 353066
2019-02-04 17:49:33 +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 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
Heejin Ahn 4821ebf73f [WebAssembly] clang-format (NFC)
Summary: This patch runs clang-format on all wasm-only files.

Reviewers: sbc100

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

Differential Revision: https://reviews.llvm.org/D51449

llvm-svn: 340970
2018-08-29 21:03:16 +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
Nicola Zaghen 5c4fb4566d Replace last DEBUG occurrence with LLVM_DEBUG in lld.
llvm-svn: 333084
2018-05-23 14:03:01 +00:00
Sam Clegg f377030a95 [WebAssembly] Remove dead code from LEB compression pass.
There are only certain relocation types that can exist in the
wasm code section and they are all LEB types.  Remove the dead
code for handling the other (I32) reloc types.

Differential Revision: https://reviews.llvm.org/D47226

llvm-svn: 333030
2018-05-22 20:52:20 +00:00
Sam Clegg 65a91288fc [WebAssembly] Fix two bugs in LEB compression: properly calculate function body offset, and write I32 values.
* Gets function size field from right location
* Writes I32 values during compression

Patch by Yury Delendik

Differential Revision: https://reviews.llvm.org/D47204

llvm-svn: 333002
2018-05-22 17:06:55 +00:00
Richard Trieu 6ac211667d Fix unused variable warning in non-debug builds.
llvm-svn: 332789
2018-05-19 00:37:23 +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
Benjamin Kramer 5455038d98 [lld] Make helpers static. NFC.
llvm-svn: 332408
2018-05-15 22:01:54 +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 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
Sam Clegg 0dbe57e752 [WebAssembly] Fix bug where reloc addends were written as unsigned
Relocation addends can be negative so should be written as
signed LEBs. This bug meant that writing value between 64
and 128 would be incorrectly interpreted as negative by the
object file readers.

Differential Revision: https://reviews.llvm.org/D45825

llvm-svn: 330374
2018-04-19 22:48:03 +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 37fbfc6815 [WebAssembly] Fix expected contents of relocations with addends
This fixes issues found on the wasm waterfall related to relocations
with addends. Undefined symbols, even those with addends should
always have a provisional value of zero. At least this is what llvm
emits (and I believe this is true for ELF too).

Differential Revision: https://reviews.llvm.org/D44451

llvm-svn: 327468
2018-03-14 00:53:34 +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
Sam Clegg dbd33b80b7 [WebAssembly] Verify contents of relocation target before writing it
Verify that the location where a relocation is about the be
applied contains the expected existing value.

This is essentially a sanity check to catch bugs in the compiler
and the linker.

Differential Revision: https://reviews.llvm.org/D44349

llvm-svn: 327325
2018-03-12 19:54:26 +00:00
Sam Clegg c1be8230ef [WebAssembly] Improve logging and comments around relocations. NFC.
Differential Revision: https://reviews.llvm.org/D44350

llvm-svn: 327232
2018-03-11 01:35:02 +00:00
Nicholas Wilson dbd90bf8d1 [WebAssembly] Run clang-format. NFC
llvm-svn: 326896
2018-03-07 13:28:16 +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
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
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 c1e5c218e6 Merge two small functions and add comments.
Differential Revision: https://reviews.llvm.org/D43406

llvm-svn: 325538
2018-02-19 22:44:18 +00:00
Rui Ueyama c06d94aa31 Removed a variable that is used only once.
llvm-svn: 325537
2018-02-19 22:39:52 +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
Rui Ueyama e351c3a438 Use write32le instead of write32<little>.
llvm-svn: 325384
2018-02-16 20:38:15 +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 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