Commit Graph

219 Commits

Author SHA1 Message Date
Thomas Lively 26a6b95da9 [WebAssembly] i32.const operands should be signed
Summary:
This was causing large addresses to be emitted as negative numbers,
which rightfully caused crashes in binaryen.

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64612

llvm-svn: 365930
2019-07-12 17:55:07 +00:00
Sam Clegg fd11ce32bb [WebAssembly] Import __stack_pointer when building -pie binaries
The -pie binary doesn't know that layout ahead of time so needs to
import the stack pointer from the embedder, just like we do already
for shared libraries.

This change is needed in order to address:
https://github.com/emscripten-core/emscripten/issues/8915

Differential Revision: https://reviews.llvm.org/D64516

llvm-svn: 365771
2019-07-11 13:13:25 +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 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
Sam Clegg d0e1d00397 [lld][WebAssembly] Fix typo in error message
Differential Revision: https://reviews.llvm.org/D64315

llvm-svn: 365304
2019-07-08 09:34:30 +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
Keno Fischer c5b8e1c538 [lld/WebAssembly] Slightly nicer error message for malformed input files
Summary:
Before:
```
wasm-ld: error: Relocations not in offset order
```
After
```
wasm-ld: error: While processing `libjulia.so`: Relocations not in offset order
```

At least this way you get to find out which input file is malformed.

Reviewers: sbc100
Differential Revision: https://reviews.llvm.org/D63694

llvm-svn: 364368
2019-06-26 00:52:46 +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 61d70e4a93 [WebAssembly] Error on archives without a symbol index
This is fairly common with wasm since GNU ar (most likely the system ar)
doesn't support the wasm object format so user who don't override AR
will end up with archives without an index.  We don't want to silently
ignore this issue.

In the future we could choose to instead behave like the ELF backend and
read the symbols from each object file in the archive if they are all of
the same type.  However, error'ing out seem like a conservative approach
for now.

Fixes: PR42376

Differential Revision: https://reviews.llvm.org/D63739

llvm-svn: 364338
2019-06-25 17:49:35 +00:00
Sam Clegg 53211aa9f1 [lld] Allow args::getInterger to parse args larger than 2^31-1
Differential Revision: https://reviews.llvm.org/D62933

llvm-svn: 362770
2019-06-07 06:05:26 +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 7c663cde14 [WebAssembly] Improve lto/comdat.ll test. NFC.
We were not previously testing the comdat exclusion in bitcode objects
because we were linking two copies of the .bc file and the
`linkonce_odr` linkage type was removing the duplicate `_start` at
the LTO stage.

Now we link an bitcode and non-bitcode version both of which contains a
copy of _start.  We link them in both orders, which means this test will
fail if comdat exclusion is not working correctly in bitcode parsing.

Differential Revision: https://reviews.llvm.org/D62923

llvm-svn: 362650
2019-06-05 21:08:30 +00:00
Dan Gohman ba86f2a22e [WebAssembly] Use Emscripten triples in PIC tests.
With r362638, llc doesn't support -relocation-model=pic with non-Emscripten
triples. Update these tests in lld which use -relocation-model=pic to also
use Emscripten triples.

llvm-svn: 362645
2019-06-05 20:59:20 +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
Thomas Lively 86e73f51d7 [WebAssembly] Improve feature validation error messages
Summary:
Add the names of the input files responsible for each error to the
messages.

Reviewers: sbc100, azakai

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62704

llvm-svn: 362162
2019-05-30 21:57:23 +00:00
Sam Clegg d506b0a484 [WebAssembly] Fix signatures of undefined function in LTO object which are not called directly.
We recently added special handling for function that are not called
directly but failed to add testing for the LTO case.

See https://reviews.llvm.org/D62153

Differential Revision: https://reviews.llvm.org/D62561

llvm-svn: 361975
2019-05-29 15:36:42 +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 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 35be7ff80c [WebAssembly] Add support for -emit-relocs
This can be useful for post-link tools and for testing.  Sometimes
it can be useful to produces a regular executable but with relocations
preserved.

Differential Revision: https://reviews.llvm.org/D62378

llvm-svn: 361635
2019-05-24 13:28:27 +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
Richard Smith 32591ca4e2 Fix test to put its outputs into the temp directory.
llvm-svn: 361297
2019-05-21 19:41:19 +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
Rui Ueyama d3f27f2bf4 Fix test failure.
I forgot to submit a last-minute change to the last patch.

llvm-svn: 361249
2019-05-21 12:01:16 +00:00
Rui Ueyama 35150bb534 [WebAssembly] Add --reproduce.
--reproduce is a convenient option for debugging. If you invoke lld
with `--reproduce=repro.tar`, it creates `repro.tar` with all input
files and the command line options given to the linker, so that it is
very easy to run lld with the exact same inputs.

ELF and Windows lld have this option.

This patch add that option to lld/wasm.

Differential Revision: https://reviews.llvm.org/D62170

llvm-svn: 361244
2019-05-21 11:52:14 +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 1a53ff2a13 [WebAssembly] Don't generate empty type sections.
Differential Revision: https://reviews.llvm.org/D61991

llvm-svn: 360940
2019-05-16 21:22:43 +00:00
Sam Clegg 5e6ea24497 [lld] Remove 2>&1 from --trace-symbol tests
The tracing goes to stdout so this is not needed.

Also remove the "not" from the final check in ELF/trace-symbols.s.
According the comment the check is that we don't crash, so we should
be checking for success here. Previously this step is error'ing with
undefined symbols because it didn't include all the needed objects.

Differential Revision: https://reviews.llvm.org/D61928

llvm-svn: 360794
2019-05-15 19:01:51 +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 ea38ac5ba3 [WebAssembly] Don't assume that strongly defined symbols are DSO-local
The current PIC model for WebAssembly is more like ELF in that it
allows symbol interposition.

This means that more functions end up being addressed via the GOT
and fewer directly added to the wasm table.

One effect is a reduction in the number of wasm table entries similar
to the previous attempt in https://reviews.llvm.org/D61539 which was
reverted.

Differential Revision: https://reviews.llvm.org/D61772

llvm-svn: 360402
2019-05-10 01:52:08 +00:00
Sam Clegg 08fa01a9b7 Revert "[WebAssembly] Don't generate unused table entries."
This reverts commit b33fdb7768.

This change apparently broke am emscripten test.

llvm-svn: 360367
2019-05-09 19:34:32 +00:00
Sam Clegg b33fdb7768 [WebAssembly] Don't generate unused table entries.
When generating PIC output only relocations of type
R_WASM_TABLE_INDEX_REL_SLEB should generate table entries.

R_WASM_TABLE_INDEX_I32 get resolved at runtime via the auto-generated
__wasm_apply_relocs functions.

R_WASM_TABLE_INDEX_SLEB are not allowed in PIC code.

Differential Revision: https://reviews.llvm.org/D61539

llvm-svn: 360165
2019-05-07 15:46:30 +00:00
Sam Clegg 5f8c2edef3 [WebAssembly] Add more test coverage for reloctions against section symbols
The only known user of this relocation type and symbol type is
the debug info sections, but we were not testing the `--relocatable`
output path.

This change adds a minimal test case to cover relocations against
section symbols includes `--relocatable` output.

Differential Revision: https://reviews.llvm.org/D61623

llvm-svn: 360110
2019-05-07 03:53:16 +00:00
Fangrui Song b159906a9a [test] Change llvm-readobj -long-option to --long-option or well-known short options. NFC
Also change some options that have different semantics (cause confusion) in llvm-readelf mode:

-s => -S
-t => --symbols
-sd => --section-data

llvm-svn: 359651
2019-05-01 05:49:01 +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 99cf58339f [WebAssembly] Fix typo in relocation checking
Runtime relocation are generated for relocations of type
R_WASM_MEMORY_ADDR_I32 when in PIC mode (either -shared or -pie).

Followup on https://reviews.llvm.org/D60882.

Differential Revision: https://reviews.llvm.org/D60992

llvm-svn: 358995
2019-04-23 14:49:38 +00:00
Sam Clegg 7cdec273dd [WebAssembly] Error on relocations against undefined data symbols.
We can't (currently) meaningfully resolve certain types of relocations
against undefined data symbols.  Previously when `--allow-undefined` was
used we were treating such relocation much like weak data symbols and
simply inserting zeros.  This change turns such use cases in to an
error.

This means that `--allow-undefined` is no longer effective for data
symbols.

Fixes https://bugs.llvm.org/show_bug.cgi?id=40364

Differential Revision: https://reviews.llvm.org/D60882

llvm-svn: 358899
2019-04-22 16:12:54 +00:00
Thomas Lively 84771e2d21 [WebAssembly] Emit the DataCount section when bulk memory is enabled
Summary:
The DataCount section is necessary for the bulk memory operations
memory.init and data.drop to validate, but it is not recognized by
engines that do not support bulk memory, so emit the section only if
bulk-memory is enabled.

Reviewers: aheejin, dschuff, sbc100

Subscribers: jgravelle-google, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60637

llvm-svn: 358798
2019-04-19 23:40:36 +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 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 a116d91ba2 [WebAssembly] Include function in wasm table when used in R_WASM_TABLE_INDEX_REL_SLEB
This should have been part of rL357710 but was overlooked because
in our test code the function in question was also used in other
relocations that caused it to be added to the table anyway.

Differential Revision: https://reviews.llvm.org/D60296

llvm-svn: 357737
2019-04-05 00:35:12 +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
Thomas Lively 06391f34bd [WebAssembly] "atomics" feature requires shared memory
Summary:
Makes it a linker error if the "atomics" feature is used but the user
does not opt in to shared memory or if "atomics" is disallowed but the
user does opt in to shared memory. Also check that an appropriate max
memory size is supplied if shared memory is used.

Reviewers: sbc100, aheejin

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59281

llvm-svn: 357310
2019-03-29 20:43:49 +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
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
Andrew Ng e6b6ab2c66 [LLD] Restore tests that use "-" as output
No longer require workarounds for output to "-" (stdout) for
Windows. These workarounds were just hiding the actual problem which has
been fixed in r357058.

Differential Revision: https://reviews.llvm.org/D59824

llvm-svn: 357072
2019-03-27 15:30:52 +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
Thomas Lively 82de51a3ae Reland "[WebAssembly] Add linker options to control feature checking"
Do not pipe binary data between processes in lit tests this time,
since it turns out that can break on Windows.

This reverts commit 84c8652fc3.

llvm-svn: 356975
2019-03-26 04:11:05 +00:00