Commit Graph

347 Commits

Author SHA1 Message Date
Wouter van Oortmerssen 62eeb3e57e [WebAssembly] fix __stack_pointer being added to .debug_aranges
When emitting a reloc for the Wasm global __stack_pointer, it was inadvertedly added to the symbols used for generating aranges, which caused some aranges to use it as the end symbol in a symbol diff, which caused a reloc for it to be emitted, which then caused an assert in `wasm64` since we have no 64-bit relocs for Wasm globals.
Fixes: https://bugs.llvm.org/show_bug.cgi?id=52376
Differential Revision: https://reviews.llvm.org/D113438
2021-11-08 16:30:31 -08:00
Wouter van Oortmerssen ac65366485 [WebAssembly] support "return" and unreachable code in asm type checker
To support return (it not being supported well was the ground cause for
https://github.com/WebAssembly/wasi-sdk/issues/200) we also have to have
at least a basic notion of unreachable, which in this case just means to stop
type checking until there is an end_block (an incoming control flow edge).
This is conservative (may miss on some type checking opportunities) but is
simple and an improvement over what we had before.

Differential Revision: https://reviews.llvm.org/D112953
2021-11-01 15:42:58 -07:00
Sam Clegg 3b039c68f2 Revert "[WebAssembly] Fix debug locations for ExplicitLocals pass"
This reverts commit a66451ebbe.

This caused a failure when integrated with emscripten:
https://ci.chromium.org/ui/p/emscripten-releases/builders/try/linux/b8832019855439718609/overview
2021-10-29 13:34:18 -07:00
Thomas Lively fb67f3d969 [WebAssembly] Add prototype relaxed float to int trunc instructions
Add i32x4.relaxed_trunc_f32x4_s, i32x4.relaxed_trunc_f32x4_u,
i32x4.relaxed_trunc_f64x2_s_zero, i32x4.relaxed_trunc_f64x2_u_zero.

These are only exposed as builtins, and require user opt-in.

Differential Revision: https://reviews.llvm.org/D112186
2021-10-28 14:01:53 -07:00
Wouter van Oortmerssen a66451ebbe [WebAssembly] Fix debug locations for ExplicitLocals pass
Differential Revision: https://reviews.llvm.org/D112487
2021-10-28 12:35:46 -07:00
Wouter van Oortmerssen 5694dbccc3 [WebAssembly] support Memory64 in target_features section
Differential Revision: https://reviews.llvm.org/D112266
2021-10-25 09:31:45 -07:00
Zhi An Ng e1fb13401e [WebAssembly] Add prototype relaxed float min max instructions
Add relaxed. f32x4.min, f32x4.max, f64x2.min, f64x2.max. These are only
exposed as builtins, and require user opt-in.

Differential Revision: https://reviews.llvm.org/D112146
2021-10-20 09:41:51 -07:00
Zhi An Ng 2542bfa43a [WebAssembly] Add prototype relaxed swizzle instructions
Add i8x16 relaxed_swizzle instructions. These are only
exposed as builtins, and require user opt-in.

Differential Revision: https://reviews.llvm.org/D112022
2021-10-19 17:53:04 -07:00
Yuta Saito 1813fde9cc [WebAssembly] Emit clangast in custom section aligned by 4 bytes
Emit __clangast in custom section instead of named data segment
to find it while iterating sections.
This could be avoided if all data segements (the wasm sense) were
represented as their own sections (in the llvm sense).
This can be resolved by https://github.com/WebAssembly/tool-conventions/issues/138

And the on-disk hashtable in clangast needs to be aligned by 4 bytes,
so add paddings in name length field in custom section header.

The length of clangast section name can be represented in 1 byte
by leb128, and possible maximum pads are 3 bytes, so the section
name length won't be invalid in theory.

Fixes https://bugs.llvm.org/show_bug.cgi?id=35928

Differential Revision: https://reviews.llvm.org/D74531
2021-10-19 15:50:08 -07:00
Zhi An Ng da07942834 [WebAssembly] Add prototype relaxed laneselect instructions
Add i8x16, i16x8, i32x4, i64x2 laneselect instructions. These are only
exposed as builtins, and require user opt-in.
2021-10-15 17:45:09 -07:00
Heejin Ahn 3ec1760d91 [WebAssembly] Remove WasmTagType
This removes `WasmTagType`. `WasmTagType` contained an attribute and a
signature index:
```
struct WasmTagType {
  uint8_t Attribute;
  uint32_t SigIndex;
};
```

Currently the attribute field is not used and reserved for future use,
and always 0. And that this class contains `SigIndex` as its property is
a little weird in the place, because the tag type's signature index is
not an inherent property of a tag but rather a reference to another
section that changes after linking. This makes tag handling in the
linker also weird that tag-related methods are taking both `WasmTagType`
and `WasmSignature` even though `WasmTagType` contains a signature
index. This is because the signature index changes in linking so it
doesn't have any info at this point. This instead moves `SigIndex` to
`struct WasmTag` itself, as we did for `struct WasmFunction` in D111104.

In this CL, in lib/MC and lib/Object, this now treats tag types in the
same way as function types. Also in YAML, this removes `struct Tag`,
because now it only contains the tag index. Also tags set `SigIndex` in
`WasmImport` union, as functions do.

I think this makes things simpler and makes tag handling more in line
with function handling. These two shares similar properties in that both
of them have signatures, but they are kind of nominal so having the same
signature doesn't mean they are the same element.

Also a drive-by fix: the reserved 'attirubute' part's encoding changed
from uleb32 to uint8 a while ago. This was fixed in lib/MC and
lib/Object but not in YAML. This doesn't change object files because the
field's value is always 0 and its encoding is the same for the both
encoding.

This is effectively NFC; I didn't mark it as such just because it
changed YAML test results.

Reviewed By: sbc100, tlively

Differential Revision: https://reviews.llvm.org/D111086
2021-10-05 17:11:22 -07:00
Thomas Lively 2f519825ba [WebAssembly] Add prototype relaxed SIMD fma/fms instructions
Add experimental clang builtins, LLVM intrinsics, and backend definitions for
the new {f32x4,f64x2}.{fma,fms} instructions in the relaxed SIMD proposal:
https://github.com/WebAssembly/relaxed-simd/blob/main/proposals/relaxed-simd/Overview.md.
Do not allow these instructions to be selected without explicit user opt-in.

Differential Revision: https://reviews.llvm.org/D110295
2021-09-23 11:01:36 -07:00
Sam Clegg ef8c9135ef [WebAssembly] Allow import and export of TLS symbols between DSOs
We previously had a limitation that TLS variables could not
be exported (and therefore could also not be imported).  This
change removed that limitation.

Differential Revision: https://reviews.llvm.org/D108877
2021-09-14 06:47:37 -07:00
Sam Clegg 44177e5fb2 [WebAssembly] Add explict TLS symbol flag
As before we maintain backwards compat with older object files
by also infering the TLS flag based on the name of the segment.

This change is was split out from https://reviews.llvm.org/D108877.

Differential Revision: https://reviews.llvm.org/D109426
2021-09-09 10:03:30 -04:00
Wouter van Oortmerssen a99fb86c65 [WebAssembly] Change WebAssemblyMCLowerPrePass to ModulePass
It was a FunctionPass before, which subverted its purpose to collect ALL symbols before MCLowering, depending on how LLVM schedules function passes.
Fixes https://bugs.llvm.org/show_bug.cgi?id=51555

Differential Revision: https://reviews.llvm.org/D109202
2021-09-08 10:47:43 -07:00
David Blaikie 40f1593558 DebugInfo: Correct/improve type formatting (pointers to function types especially)
This does add some extra superfluous whitespace (eg: "int *") intended
to make the Simplified Template Names work easier - this makes the
DIE-based names match more exactly the clang-generated names, so it's
easier to identify cases that don't generate matching names.

(arguably we could change clang to skip that whitespace or add some
fuzzy matching to accommodate differences in certain whitespace - but
this seemed easier and fairly low-impact)
2021-09-03 12:22:28 -07:00
Heejin Ahn 77b921b870 [WebAssembly] Tidy up EH/SjLj options
This CL is small, but the description can be a little long because I'm
trying to sum up the status quo for Emscripten/Wasm EH/SjLj options.

First, this CL adds an option for Wasm SjLj (`-wasm-enable-sjlj`), which
handles SjLj using Wasm EH. The implementation for this will be added as
a followup CL, but this adds the option first to do error checking.

This also adds an option for Wasm EH (`-wasm-enable-eh`), which has been
already implemented. Before we used `-exception-model=wasm` as the same
meaning as enabling Wasm EH, but after we add Wasm SjLj, it will be
possible to use Wasm EH instructions for Wasm SjLj while not enabling
EH, so going forward, to use Wasm EH, `opt` and `llc` will need this
option. This only affects `opt` and `llc` command lines and does not
affect Emscripten user interface.

Now we have two modes of EH (Emscripten/Wasm) and also two modes of SjLj
(also Emscripten/Wasm). The options corresponding to each of are:
- Emscripten EH: `-enable-emscripten-cxx-exceptions`
- Emscripten SjLj: `-enable-emscripten-sjlj`
- Wasm EH: `-wasm-enable-eh -exception-model=wasm`
           `-mattr=+exception-handling`
- Wasm SjLj: `-wasm-enable-sjlj -exception-model=wasm`
             `-mattr=+exception-handling`
The reason Wasm EH/SjLj's options are a little complicated are
`-exception-model` and `-mattr` are common LLVM options ane not under
our control. (`-mattr` can be omitted if it is embedded within the
bitcode file.)

And we have the following rules of the option composition:
- Emscripten EH and Wasm EH cannot be turned on at the same itme
- Emscripten SjLj and Wasm SjLj cannot be turned on at the same time
- Wasm SjLj should be used with Wasm EH

Which means we now allow these combinations:
- Emscripten EH + Emscripten SjLj: the current default in `emcc`
- Wasm EH + Emscripten SjLj:
  This is allowed, but only as an interim step in which we are testing
  Wasm EH but not yet have a working implementation of Wasm SjLj. This
  will error out (D107687) in compile time if `setjmp` is called in a
  function in which Wasm exception is used.
- Wasm EH + Wasm SjLj:
  This will be the default mode later when using Wasm EH. Currently Wasm
  SjLj implementation doesn't exist, so it doesn't work.
- Emscripten EH + Wasm SjLj will not work.

This CL moves these error checking routines to
`WebAssemblyPassConfig::addIRPasses`. Not sure if this is an ideal place
to do this, but I couldn't find elsewhere. Currently some checking is
done within LowerEmscriptenEHSjLj, but these checks only run if
LowerEmscriptenEHSjLj runs so it may not run when Wasm EH is used. This
moves that to `addIRPasses` and adds some more checks.

Currently LowerEmscriptenEHSjLj pass is responsible for Emscripten EH
and Emscripten SjLj. Wasm EH transformations are done in multiple
places, including WasmEHPrepare, LateEHPrepare, and CFGStackify. But in
the followup CL, LowerEmscriptenEHSjLj pass will be also responsible for
a part of Wasm SjLj transformation, because WasmSjLj will also be using
several Emscripten library functions, and we will be sharing more than
half of the transformation to do that between Emscripten SjLj and Wasm
SjLj.

Currently we have `-enable-emscripten-cxx-exceptions` and
`-enable-emscripten-sjlj` but these only work for `llc`, because for
`llc` we feed these options to the pass but when we run the pass using
`opt` the pass will be created with no options and the default options
will be used, which turns both Emscripten EH and Emscripten SjLj on.

Now we have one more SjLj option to care for, LowerEmscriptenEHSjLj pass
needs a finer way to control these options. This CL removes those
default parameters and make LowerEmscriptenEHSjLj pass read directly
from command line options specified. So if we only run
`opt -wasm-lower-em-ehsjlj`, currently both Emscripten EH and Emscripten
SjLj will run, but with this CL, none will run unless we additionally
pass `-enable-emscripten-cxx-exceptions` or `-enable-emscripten-sjlj`,
or both. This does not affect users; this only affects our `opt` tests
because `emcc` will not call either `opt` or `llc`. As a result of this,
our existing Emscripten EH/SjLj tests gained one or both of those
options in their `RUN` lines.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D107685
2021-08-24 17:54:39 -07:00
Derek Schuff ad1f5457d2 [WebAssembly] Generate R_WASM_FUNCTION_OFFSET relocs in debuginfo sections
Debug info sections need R_WASM_FUNCTION_OFFSET_I32 relocs (with FK_Data_4 fixup
kinds) to refer to functions (instead of R_WASM_TABLE_INDEX as is used in data
sections). Usually this is done in a convoluted way, with unnamed temp data
symbols which target the start of the function, in which case
WasmObjectWriter::recordRelocation converts it to use the section symbol
instead. However in some cases the function can actually be undefined; in this
case the dwarf generator uses the function symbol (a named undefined function
symbol) instead. In that case the section-symbol transform doesn't work and we
need to generate the correct reloc type a different way. In this change
WebAssemblyWasmObjectWriter::getRelocType takes the fixup section type into
account to choose the correct reloc type.

Fixes PR50408
Differential Revision: https://reviews.llvm.org/D103557
2021-07-19 14:02:33 -07:00
Wouter van Oortmerssen 670944fb20 [WebAssembly] Support R_WASM_MEMORY_ADDR_TLS_SLEB64 for wasm64
Also fixed TLS tests swapping addr & value in store op
Differential Revision: https://reviews.llvm.org/D106096
2021-07-19 10:22:43 -07:00
Fangrui Song aa3df8ddcd [test] Avoid llvm-readelf/llvm-readobj one-dash long options and deprecated aliases (e.g. --file-headers) 2021-07-15 10:26:21 -07:00
Thomas Lively 122b0220fd [WebAssembly] Remove datalayout strings from llc tests
The data layout strings do not have any effect on llc tests and will become
misleadingly out of date as we continue to update the canonical data layout, so
remove them from the tests.

Differential Revision: https://reviews.llvm.org/D105842
2021-07-14 11:17:08 -07:00
Wouter van Oortmerssen 9647a6f719 [WebAssembly] Added initial type checker to MC Assembler
This to protect against non-sensical instruction sequences being assembled,
which would either cause asserts/crashes further down, or a Wasm module being output that doesn't validate.

Unlike a validator, this type checker is able to give type-errors as part of the parsing process, which makes the assembler much friendlier to be used by humans writing manual input.

Because the MC system is single pass (instructions aren't even stored in MC format, they are directly output) the type checker has to be single pass as well, which means that from now on .globaltype and .functype decls must come before their use. An extra pass is added to Codegen to collect information for this purpose, since AsmPrinter is normally single pass / streaming as well, and would otherwise generate this information on the fly.

A `-no-type-check` flag was added to llvm-mc (and any other tools that take asm input) that surpresses type errors, as a quick escape hatch for tests that were not intended to be type correct.

This is a first version of the type checker that ignores control flow, i.e. it checks that types are correct along the linear path, but not the branch path. This will still catch most errors. Branch checking could be added in the future.

Differential Revision: https://reviews.llvm.org/D104945
2021-07-09 14:07:25 -07:00
Heejin Ahn 1d891d44f3 [WebAssembly] Rename event to tag
We recently decided to change 'event' to 'tag', and 'event section' to
'tag section', out of the rationale that the section contains a
generalized tag that references a type, which may be used for something
other than exceptions, and the name 'event' can be confusing in the web
context.

See
- https://github.com/WebAssembly/exception-handling/issues/159#issuecomment-857910130
- https://github.com/WebAssembly/exception-handling/pull/161

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D104423
2021-06-17 20:34:19 -07:00
serge-sans-paille 4ab3041acb Revert "[NFC] remove explicit default value for strboolattr attribute in tests"
This reverts commit bda6e5bee0.

See https://lab.llvm.org/buildbot/#/builders/109/builds/15424 for instance
2021-05-24 19:43:40 +02:00
serge-sans-paille bda6e5bee0 [NFC] remove explicit default value for strboolattr attribute in tests
Since d6de1e1a71, no attributes is quivalent to
setting attribute to false.

This is a preliminary commit for https://reviews.llvm.org/D99080
2021-05-24 19:31:04 +02:00
Wouter van Oortmerssen 3a293cbf13 [WebAssembly] Fix PIC/GOT codegen for wasm64
__table_base is know 64-bit, since in LLVM it represents a function pointer offset
__table_base32 is a copy in wasm32 for use in elem init expr, since no truncation may be used there.
New reloc R_WASM_TABLE_INDEX_REL_SLEB64 added

Differential Revision: https://reviews.llvm.org/D101784
2021-05-20 09:59:31 -07:00
Sam Clegg 3041b16f73 [WebAssembly] Add TLS data segment flag: WASM_SEG_FLAG_TLS
Previously the linker was relying solely on the name of the segment
to imply TLS.

Differential Revision: https://reviews.llvm.org/D102202
2021-05-12 13:31:02 -07:00
Sam Clegg 3b8d2be527 Reland: "[lld][WebAssembly] Initial support merging string data"
This change was originally landed in: 5000a1b4b9
It was reverted in: 061e071d8c

This change adds support for a new WASM_SEG_FLAG_STRINGS flag in
the object format which works in a similar fashion to SHF_STRINGS
in the ELF world.

Unlike the ELF linker this support is currently limited:
- No support for SHF_MERGE (non-string merging)
- Always do full tail merging ("lo" can be merged with "hello")
- Only support single byte strings (p2align 0)

Like the ELF linker merging is only performed at `-O1` and above.

This fixes part of https://bugs.llvm.org/show_bug.cgi?id=48828,
although crucially it doesn't not currently support debug sections
because they are not represented by data segments (they are custom
sections)

Differential Revision: https://reviews.llvm.org/D97657
2021-05-10 16:03:38 -07:00
Nico Weber 061e071d8c Revert "[lld][WebAssembly] Initial support merging string data"
This reverts commit 5000a1b4b9.
Breaks tests, see https://reviews.llvm.org/D97657#2749151

Easily repros locally with `ninja check-llvm-mc-webassembly`.
2021-05-10 18:28:28 -04:00
Sam Clegg 5000a1b4b9 [lld][WebAssembly] Initial support merging string data
This change adds support for a new WASM_SEG_FLAG_STRINGS flag in
the object format which works in a similar fashion to SHF_STRINGS
in the ELF world.

Unlike the ELF linker this support is currently limited:
- No support for SHF_MERGE (non-string merging)
- Always do full tail merging ("lo" can be merged with "hello")
- Only support single byte strings (p2align 0)

Like the ELF linker merging is only performed at `-O1` and above.

This fixes part of https://bugs.llvm.org/show_bug.cgi?id=48828,
although crucially it doesn't not currently support debug sections
because they are not represented by data segments (they are custom
sections)

Differential Revision: https://reviews.llvm.org/D97657
2021-05-10 13:15:12 -07:00
Thomas Lively cc86a8aa53 [WebAssembly] Test i64x2.abs encoding
This test was disabled despite the instruction having been implemented for a
long time. This commit just enables the test.

Differential Revision: https://reviews.llvm.org/D100345
2021-04-13 00:06:25 -07:00
Thomas Lively ea8dd3ee2e [WebAssembly] Update v128.any_true
In the final SIMD spec, there is only a single v128.any_true instruction, rather
than one for each lane interpretation because the semantics do not depend on the
lane interpretation.

Differential Revision: https://reviews.llvm.org/D100241
2021-04-11 11:13:16 -07:00
Thomas Lively 45783d0e8a [WebAssembly] Implement i64x2 comparisons
Removes the prototype builtin and intrinsic for i64x2.eq and implements that
instruction as well as the other i64x2 comparison instructions in the final SIMD
spec. Unsigned comparisons were not included in the final spec, so they still
need to be scalarized via a custom lowering.

Differential Revision: https://reviews.llvm.org/D99623
2021-03-31 10:46:17 -07:00
Heejin Ahn f38a9d6340 [WebAssembly] Raname a test and fix comments
D99627 fixed a decoding bug, not an encoding bug. This renames the test
to correct it and fix comments.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D99644
2021-03-31 09:13:08 -07:00
Alex Richardson 8fa570c969 [WebAssembly] Fix incorrect DW_TAG_pointer_type size in test
It should be 64 bits not 32 for wasm64-unknown-unknown. I noticed this
because this test was failing in our CHERI fork of LLVM due to a larger
.debug_abbrev section size. It turns out this happens because we add
DW_AT_byte_size for non-default pointer sizes to allow debugging our
hybrid compilation mode where we can have two different kinds of pointers.

Reviewed By: aardappel

Differential Revision: https://reviews.llvm.org/D99410
2021-03-31 09:17:45 +01:00
Heejin Ahn 144ec1c38e [WebAssembly] Encode numbers in ULEB128 in event section
The number of events and the type index should be encoded in ULEB128,
but they were incorrctly encoded in LEB128. The smallest number with
which its LEB128 and ULEB128 encodings are different is 64.
There's no way we can generate 64 events in the C++ toolchain
implementation so we can't test that, but the attached test tests when
the type index is 64.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D99627
2021-03-30 16:21:58 -07:00
Thomas Lively a1b8b0739a [WebAssembly] Fix i8x16.popcnt opcode
When I updated the SIMD opcodes in f5764a8654, I accidentally missed updating
i8x16.popcnt. This patch fixes the omission.

Differential Revision: https://reviews.llvm.org/D99536
2021-03-29 17:23:15 -07:00
Andy Wingo c9801db2eb [WebAssembly][MC] Record limit constraints for table sizes
This commit adds a full WasmTableType to MCSymbolWasm, differing from
the current situation (just an ElemType) in that it additionally records
a WasmLimits.

We add support for specifying the limits in .S files also, via the
following syntax variations:

  .tabletype SYM, ELEMTYPE
  .tabletype SYM, ELEMTYPE, MINSIZE
  .tabletype SYM, ELEMTYPE, MINSIZE, MAXSIZE

Depends on D99186.

Differential Revision: https://reviews.llvm.org/D99191
2021-03-24 09:44:22 +01:00
Andy Wingo 9ac5620cb8 [WebAssembly] Rename WasmLimits::Initial to ::Minimum. NFC.
This patch renames the "Initial" member of WasmLimits to the name used
in the spec, "Minimum".

In the core WebAssembly specification, the Limits data type has one
required "min" member and one optional "max" member, indicating the
minimum required size of the corresponding table or memory, and the
maximum size, if any.

Although the WebAssembly spec does instantiate locally-defined tables
and memories with the initial size being equal to the minimum size, it
can't impose such a requirement for imports.  It doesn't make sense to
require an initial size for a memory import, for example.  The compiler
can only sensibly express the minimum and maximum sizes.

See
https://github.com/WebAssembly/js-types/blob/master/proposals/js-types/Overview.md#naming-of-size-limits
for a related discussion that agrees that the right name of "initial" is
"minimum" when querying the type of a table or memory from JavaScript.
(Of course it still makes sense for JS to speak in terms of an initial
size when it explicitly instantiates memories and tables.)

Differential Revision: https://reviews.llvm.org/D99186
2021-03-24 09:10:11 +01:00
Thomas Lively f5764a8654 [WebAssembly] Finalize SIMD names and opcodes
Updates the names (e.g. widen => extend, saturate => sat) and opcodes of all
SIMD instructions to match the finalized SIMD spec. Deliberately does not change
the public interface in wasm_simd128.h yet; that will require more care.

Depends on D98466.

Differential Revision: https://reviews.llvm.org/D98676
2021-03-18 11:21:25 -07:00
Thomas Lively 2f2ae08da9 [WebAssembly] Remove experimental SIMD instructions
Removes the instruction definitions, intrinsics, and builtins for qfma/qfms,
signselect, and prefetch instructions, which were not included in the final
WebAssembly SIMD spec.

Depends on D98457.

Differential Revision: https://reviews.llvm.org/D98466
2021-03-18 11:21:24 -07:00
Thomas Lively 8638c897f4 [WebAssembly] Remove unimplemented-simd target feature
Now that the WebAssembly SIMD specification is finalized and engines are
generally up-to-date, there is no need for a separate target feature for gating
SIMD instructions that engines have not implemented. With this change,
v128.const is now enabled by default with the simd128 target feature.

Differential Revision: https://reviews.llvm.org/D98457
2021-03-18 10:23:12 -07:00
Yuta Saito aa0c571a5f [WebAssembly] Add new relocation for location relative data
This `R_WASM_MEMORY_ADDR_SELFREL_I32` relocation represents an offset
between its relocating address and the symbol address. It's very similar
to `R_X86_64_PC32` but restricted to be used for only data segments.

```
S + A - P
```

A: Represents the addend used to compute the value of the relocatable
field.
P: Represents the place of the storage unit being relocated.
S: Represents the value of the symbol whose index resides in the
relocation entry.

Proposal: https://github.com/WebAssembly/tool-conventions/issues/162

Differential Revision: https://reviews.llvm.org/D96659
2021-03-08 11:34:10 -08:00
Andy Wingo 4307069df4 [WebAssembly] Swap operand order of call_indirect in text format
The WebAssembly text and binary formats have different operand orders
for the "type" and "table" fields of call_indirect (and
return_call_indirect).  In LLVM we use the binary order for the MCInstr,
but when we produce or consume the text format we should use the text
order.  For compilation units targetting WebAssembly 1.0 (without the
reference types feature), we omit the table operand entirely.

Differential Revision: https://reviews.llvm.org/D97761
2021-03-03 08:51:21 +01:00
Wouter van Oortmerssen a0f4526836 [WebAssembly] Fix split-dwarf not emitting DW_OP_WASM_location correctly
It was using the regular path for target indices that uses uleb, but TI_GLOBAL_RELOC needs to be uint32_t.
Introduced here: https://reviews.llvm.org/D85685
Fixes: https://github.com/emscripten-core/emscripten/issues/13240

Differential Revision: https://reviews.llvm.org/D97564
2021-03-01 11:53:30 -08:00
Andy Wingo 2632ba6a35 [WebAssembly] call_indirect issues table number relocs
If the reference-types feature is enabled, call_indirect will explicitly
reference its corresponding function table via TABLE_NUMBER
relocations against a table symbol.

Also, as before, address-taken functions can also cause the function
table to be created, only with reference-types they additionally cause a
symbol table entry to be emitted.

Differential Revision: https://reviews.llvm.org/D90948
2021-03-01 16:49:00 +01:00
Andy Wingo 7dc98adbb0 Revert "[WebAssembly] call_indirect issues table number relocs"
This reverts commit 861dbe1a02.  It broke
emscripten -- see https://reviews.llvm.org/D90948#2578843.
2021-02-23 11:48:08 +01:00
Andy Wingo 861dbe1a02 [WebAssembly] call_indirect issues table number relocs
If the reference-types feature is enabled, call_indirect will explicitly
reference its corresponding function table via `TABLE_NUMBER`
relocations against a table symbol.

Also, as before, address-taken functions can also cause the function
table to be created, only with reference-types they additionally cause a
symbol table entry to be emitted.

We abuse the used-in-reloc flag on symbols to indicate which tables
should end up in the symbol table.  We do this because unfortunately
older wasm-ld will carp if it see a table symbol.

Differential Revision: https://reviews.llvm.org/D90948
2021-02-22 10:13:36 +01:00
Wouter van Oortmerssen 508aa69e9d [WebAssembly] Fix assert in lookup of section symbols
Fixes assert in: https://bugs.llvm.org/show_bug.cgi?id=49036

getWasmSection creates sections if they don't exist, but doesn't add them to the Symbols table. This may cause problems in subsequent calls to getOrCreateSymbol which checks this table, the calls createSymbol assuming it doesn't exist, which then checks UsedNames and finds out it does exist, causing an assert on trying to rename a non-temp symbol.

I tried also fixing the somewhat unintuitive forced suffixing (adding `0`), but it turns out that WasmObjectWriter currently assumes these section symbols are unique, so that may have to be a separate fix: https://bugs.llvm.org/show_bug.cgi?id=49252

Also worth noting is that getWasmSection calling createSymbol may not be correct to start with, given that createSymbol seems to assume it is creating non-section symbols. But again, for a future fix.

Related: where some of this was introduced: 8d396acac3

Differential Revision: https://reviews.llvm.org/D96473
2021-02-18 11:50:14 -08:00
Sam Clegg 7e7cfce0b6 [WebAssembly] Use data sections by default
This allows data sections that don't start with `.data` to be
used/created.

Without this, clang's `__attribute__((section("foo")))` would
generate assembly that would not parse.

Differential Revision: https://reviews.llvm.org/D96233
2021-02-09 11:03:06 -08:00