Commit Graph

17 Commits

Author SHA1 Message Date
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misleadingly out of date as we continue to update the canonical data layout, so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
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
Andy Wingo feac819e50 [MC][WebAssembly] Only emit indirect function table import if needed
The indirect function table, synthesized by the linker, is needed if and
only if there are TABLE_INDEX relocs.

Differential Revision: https://reviews.llvm.org/D91637
2020-11-25 08:38:43 -08:00
Georgii Rymar 9aa7898200 Reland "[lib/Support/YAMLTraits] - Don't print leading zeroes when dumping Hex8/Hex16/Hex32 types." (https://reviews.llvm.org/D90930).
This reverts reverting commit fc40a03323
and fixes LLD (MachO/wasm) tests that failed previously.
2020-11-18 13:08:46 +03:00
Georgii Rymar fc40a03323 Revert "[lib/Support/YAMLTraits] - Don't print leading zeroes when dumping Hex8/Hex16/Hex32 types."
This reverts commit 65fd17c241.

It breaks LLD/MachO tests that seems use obj2yaml the check the output.
2020-11-18 11:55:03 +03:00
Georgii Rymar 65fd17c241 [lib/Support/YAMLTraits] - Don't print leading zeroes when dumping Hex8/Hex16/Hex32 types.
When we produce an YAML output, we also print leading zeroes currently.
An output might look like this:

```
- Name:    .dynsym
  Type:    SHT_DYNSYM
  Address: 0x0000000000001000
  EntSize: 0x0000000000000018
```

There are probably no reason to print leading zeroes.
It just makes harder to read values. This patch stops printing them.
The output becomes like:

```
- Name:    .dynsym
  Type:    SHT_DYNSYM
  Address: 0x1000
  EntSize: 0x18
```

This affects obj2yaml mostly, but also dsymutil and llvm-xray tools output.

Differential revision: https://reviews.llvm.org/D90930
2020-11-18 11:31:00 +03:00
Paulo Matos 388fb67b0d [WebAssembly] Added .tabletype to asm and multiple table support in obj files
Adds more testing in basic-assembly.s and a new test tables.s.
Adds support to yaml reading and writing of tables as well.

Differential Revision: https://reviews.llvm.org/D88815
2020-10-13 07:52:23 -07:00
Thomas Lively 393d0f799f [WebAssembly] Allow multivalue signatures in object files
Summary:
Also changes the wasm YAML format to reflect the possibility of having
multiple return types and to put the returns after the params for
consistency with the binary encoding.

Reviewers: aheejin, sbc100

Subscribers: dschuff, jgravelle-google, hiraditya, sunfish, arphaman, rupprecht, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69156

llvm-svn: 375283
2019-10-18 20:27:30 +00:00
Thomas Lively 3f34e1b883 [WebAssembly] Merge used feature sets, update atomics linkage policy
Summary:
It does not currently make sense to use WebAssembly features in some functions
but not others, so this CL adds an IR pass that takes the union of all used
feature sets and applies it to each function in the module. This allows us to
prevent atomics from being lowered away if some function has opted in to using
them. When atomics is not enabled anywhere, we detect whether there exists any
atomic operations or thread local storage that would be stripped and disallow
linking with objects that contain atomics if and only if atomics or tls are
stripped. When atomics is enabled, mark it as used but do not require it of
other objects in the link. These changes allow libraries that do not use atomics
to be built once and linked into both single-threaded and multithreaded
binaries.

Reviewers: aheejin, sbc100, dschuff

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59625

llvm-svn: 357226
2019-03-29 00:14:01 +00:00
Thomas Lively f6f4f84378 [WebAssembly] Target features section
Summary:
Implements a new target features section in assembly and object files
that records what features are used, required, and disallowed in
WebAssembly objects. The linker uses this information to ensure that
all objects participating in a link are feature-compatible and records
the set of used features in the output binary for use by optimizers
and other tools later in the toolchain.

The "atomics" feature is always required or disallowed to prevent
linking code with stripped atomics into multithreaded binaries. Other
features are marked used if they are enabled globally or on any
function in a module.

Future CLs will add linker flags for ignoring feature compatibility
checks and for specifying the set of allowed features, implement using
the presence of the "atomics" feature to control the type of memory
and segments in the linked binary, and add front-end flags for
relaxing the linkage policy for atomics.

Reviewers: aheejin, sbc100, dschuff

Subscribers: jgravelle-google, hiraditya, sunfish, mgrang, jfb, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59173

llvm-svn: 356610
2019-03-20 20:26:45 +00:00
Sam Clegg 8fffa1dfa3 [WebAssembly] Remove unneeded MCSymbolRefExpr variants
We record the type of the symbol (event/function/data/global) in the
MCWasmSymbol and so it should always be clear how to handle a relocation
based on the symbol itself.

The exception is a function which still needs the special @TYPEINDEX
then the relocation contains the signature rather than the address
of the functions.

Differential Revision: https://reviews.llvm.org/D58472

llvm-svn: 354697
2019-02-22 22:29:34 +00:00
Wouter van Oortmerssen 0b3cf247c4 [WebAssembly] Make segment/size/type directives optional in asm
Summary:
These were "boilerplate" that repeated information already present
in .functype and end_function, that needed to be repeated to Please
the particular way our object writing works, and missing them would
generate errors.

Instead, we generate the information for these automatically so the
user can concern itself with writing more canonical wasm functions
that always work as expected.

Reviewers: dschuff, sbc100

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

Differential Revision: https://reviews.llvm.org/D57546

llvm-svn: 353067
2019-02-04 18:03:11 +00:00
Sam Clegg d1152a267c [WebAssembly] Rename relocations from R_WEBASSEMBLY_ to R_WASM_
See https://github.com/WebAssembly/tool-conventions/pull/95.

This is less typing and IMHO more readable, and it also fits with
our naming around the binary format which tends to use the short name.
e.g.

include/llvm/BinaryFormat/Wasm.h
tools/llvm-objdump/WasmDump.cpp
etc..

Differential Revision: https://reviews.llvm.org/D57611

llvm-svn: 353062
2019-02-04 17:28:46 +00:00
Sam Clegg 56c587adfd [WebAssembly] Store section alignment as a power of 2
This change bumps for version number of the wasm object file
metadata.

See https://github.com/WebAssembly/tool-conventions/pull/92

Differential Revision: https://reviews.llvm.org/D56758

llvm-svn: 351285
2019-01-16 01:34:48 +00:00
Thomas Lively 6a87ddac9a [WebAssembly] Massive instruction renaming
Summary:
An automated renaming of all the instructions listed at
https://github.com/WebAssembly/spec/issues/884#issuecomment-426433329
as well as some similarly-named identifiers.

Reviewers: aheejin, dschuff, aardappel

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

Differential Revision: https://reviews.llvm.org/D56338

llvm-svn: 350609
2019-01-08 06:25:55 +00:00
Wouter van Oortmerssen c7b89f0f62 [WebAssembly] Enforce assembler emits to streamer in order.
Summary:
The assembler processes directives and instructions in whatever order
they are in the file, then directly emits them to the streamer. This
could cause badly written (or generated) .s files to produce
incorrect binaries.

It now has state that tracks what it has most recently seen, to
enforce they are emitted in a given order that always produces
correct wasm binaries.

Also added a new test that compares obj2yaml output from llc (the
backend) to that going via .s and the assembler to ensure both paths
generate the same binaries.

The features this test covers could be extended.

Passes all wasm Lit tests.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=39557

Reviewers: sbc100, dschuff, aheejin

Subscribers: jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D55149

llvm-svn: 348185
2018-12-03 20:30:28 +00:00