Commit Graph

75 Commits

Author SHA1 Message Date
Heejin Ahn 9bd02c433b [WebAssembly] Misc. cosmetic changes in EH (NFC)
- Rename `wasm.catch` intrinsic to `wasm.catch.exn`, because we are
  planning to add a separate `wasm.catch.longjmp` intrinsic which
  returns two values.
- Rename several variables
- Remove an unnecessary parameter from `canLongjmp` and `isEmAsmCall`
  from LowerEmscriptenEHSjLj pass
- Add `-verify-machineinstrs` in a test for a safety measure
- Add more comments + fix some errors in comments
- Replace `std::vector` with `SmallVector` for cases likely with small
  number of elements
- Renamed `EnableEH`/`EnableSjLj` to `EnableEmEH`/`EnableEmSjLj`: We are
  soon going to add `EnableWasmSjLj`, so this makes the distincion
  clearer

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D107405
2021-08-03 21:03:46 -07:00
Paulo Matos 46667a1003 [WebAssembly] Implementation of global.get/set for reftypes in LLVM IR
Reland of 31859f896.

This change implements new DAG notes GLOBAL_GET/GLOBAL_SET, and
lowering methods for load and stores of reference types from IR
globals. Once the lowering creates the new nodes, tablegen pattern
matches those and converts them to Wasm global.get/set.

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D104797
2021-07-22 22:07:24 +02:00
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
Roman Lebedev c2c0d3ea89
Revert "[WebAssembly] Implementation of global.get/set for reftypes in LLVM IR"
This reverts commit 4facbf213c.

```
********************
FAIL: LLVM :: CodeGen/WebAssembly/funcref-call.ll (44466 of 44468)
******************** TEST 'LLVM :: CodeGen/WebAssembly/funcref-call.ll' FAILED ********************
Script:
--
: 'RUN: at line 1';   /builddirs/llvm-project/build-Clang12/bin/llc < /repositories/llvm-project/llvm/test/CodeGen/WebAssembly/funcref-call.ll --mtriple=wasm32-unknown-unknown -asm-verbose=false -mattr=+reference-types | /builddirs/llvm-project/build-Clang12/bin/FileCheck /repositories/llvm-project/llvm/test/CodeGen/WebAssembly/funcref-call.ll
--
Exit Code: 2

Command Output (stderr):
--
llc: /repositories/llvm-project/llvm/include/llvm/Support/LowLevelTypeImpl.h:44: static llvm::LLT llvm::LLT::scalar(unsigned int): Assertion `SizeInBits > 0 && "invalid scalar size"' failed.

```
2021-07-02 11:49:51 +03:00
Paulo Matos 4facbf213c [WebAssembly] Implementation of global.get/set for reftypes in LLVM IR
Reland of 31859f896.

This change implements new DAG notes GLOBAL_GET/GLOBAL_SET, and
lowering methods for load and stores of reference types from IR
globals. Once the lowering creates the new nodes, tablegen pattern
matches those and converts them to Wasm global.get/set.

Differential Revision: https://reviews.llvm.org/D104797
2021-07-02 09:46:28 +02:00
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
David Spickett 64de8763aa Revert "Implementation of global.get/set for reftypes in LLVM IR"
This reverts commit 31859f896c.

Causing SVE and RISCV-V test failures on bots.
2021-06-10 10:11:17 +00:00
Paulo Matos 31859f896c Implementation of global.get/set for reftypes in LLVM IR
This change implements new DAG notes GLOBAL_GET/GLOBAL_SET, and
lowering methods for load and stores of reference types from IR
globals. Once the lowering creates the new nodes, tablegen pattern
matches those and converts them to Wasm global.get/set.

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D95425
2021-06-10 10:07:45 +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
Andy Wingo b2f21b145a [CodeGen][WebAssembly] Better lowering for WASM_SYMBOL_TYPE_GLOBAL symbols
As we have been missing support for WebAssembly globals on the IR level,
the lowering of WASM_SYMBOL_TYPE_GLOBAL to IR was incomplete.  This
commit fleshes out the lowering support, lowering references to and
definitions of addrspace(1) values to correctly typed
WASM_SYMBOL_TYPE_GLOBAL symbols.

Depends on D101608.

Differential Revision: https://reviews.llvm.org/D101913
2021-05-11 11:47:40 +02:00
Heejin Ahn 0b2bc69ba2 [WebAssembly] Put utility functions in Utils directory (NFC)
This CL
1. Creates Utils/ directory under lib/Target/WebAssembly
2. Moves existing WebAssemblyUtilities.cpp|h into the Utils/ directory
3. Creates Utils/WebAssemblyTypeUtilities.cpp|h and put type
   declarataions and type conversion functions scattered in various
   places into this single place.

It has been suggested several times that it is not easy to share utility
functions between subdirectories (AsmParser, DIsassembler, MCTargetDesc,
...). Sometimes we ended up [[ https://reviews.llvm.org/D92840#2478863 | duplicating ]] the same function because of
this.

There are already other targets doing this: AArch64, AMDGPU, and ARM
have Utils/ subdirectory under their target directory.

This extracts the utility functions into a single directory Utils/ and
make them sharable among all passes in WebAssembly/ and its
subdirectories. Also I believe gathering all type-related conversion
functionalities into a single place makes it more usable. (Actually I
was working on another CL that uses various type conversion functions
scattered in multiple places, which became the motivation for this CL.)

Reviewed By: dschuff, aardappel

Differential Revision: https://reviews.llvm.org/D100995
2021-04-22 15:29:43 -07:00
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
Dan Gohman 698c6b0a09 [WebAssembly] Support single-floating-point immediate value
As mentioned in TODO comment, casting double to float causes NaNs to change bits.
To avoid the change, this patch adds support for single-floating-point immediate value on MachineCode.

Patch by Yuta Saito.

Differential Revision: https://reviews.llvm.org/D77384
2021-02-04 18:05:06 -08:00
Sam Clegg 96ef4f307d Revert "[WebAssembly] call_indirect issues table number relocs"
This reverts commit 418df4a6ab.

This change broke emscripten tests, I believe because it started
generating 5-byte a wide table index in the call_indirect instruction.
Neither v8 nor wabt seem to be able to handle that.  The spec
currently says that this is single 0x0 byte and:

"In future versions of WebAssembly, the zero byte occurring in the
encoding of the call_indirectcall_indirect instruction may be used to
index additional tables."

So we need to revisit this change.  For backwards compat I guess
we need to guarantee that __indirect_function_table is always at
address zero.   We could also consider making this a single-byte
relocation with and assert if have more than 127 tables (for now).

Differential Revision: https://reviews.llvm.org/D95005
2021-01-19 15:06:07 -08:00
Andy Wingo 418df4a6ab [WebAssembly] call_indirect issues table number relocs
This patch changes to make call_indirect explicitly refer to the
corresponding function table, residualizing TABLE_NUMBER relocs against
it.

With this change, wasm-ld now sees all references to tables, and can
link multiple tables.

Differential Revision: https://reviews.llvm.org/D90948
2021-01-19 09:32:45 +01:00
Sam Clegg a28a466210 [WebAssembly] Add new relocation type for TLS data symbols
These relocations represent offsets from the __tls_base symbol.

Previously we were just using normal MEMORY_ADDR relocations and relying
on the linker to select a segment-offset rather and absolute value in
Symbol::getVirtualAddress().  Using an explicit relocation type allows
allow us to clearly distinguish absolute from relative relocations based
on the relocation information alone.

One place this is useful is being able to reject absolute relocation in
the PIC case, but still accept TLS relocations.

Differential Revision: https://reviews.llvm.org/D91276
2020-11-13 07:59:29 -08:00
Jordan Rupprecht 980bf1d5d1 [NFC] Inline wasm assertion-only variable 2020-11-03 13:06:59 -08:00
Andy Wingo 107c3a12d6 [WebAssembly] Implement ref.null
This patch adds a new "heap type" operand kind to the WebAssembly MC
layer, used by ref.null. Currently the possible values are "extern" and
"func"; when typed function references come, though, this operand may be
a type index.

Note that the "heap type" production is still known as "refedtype" in
the draft proposal; changing its name in the spec is
ongoing (https://github.com/WebAssembly/reference-types/issues/123).

The register form of ref.null is still untested.

Differential Revision: https://reviews.llvm.org/D90608
2020-11-03 10:46:23 -08:00
Heejin Ahn 3bba91f64e [WebAssembly] Rename Emscripten EH functions
Renaming for some Emscripten EH functions has so far been done in
wasm-emscripten-finalize tool in Binaryen. But recently we decided to
make a compilation/linking path that does not rely on
wasm-emscripten-finalize for modifications, so here we move that
functionality to LLVM.

Invoke wrappers are generated in LowerEmscriptenEHSjLj pass, but final
wasm types are not available in the IR pass, we need to rename them at
the end of the pipeline.

This patch also removes uses of `emscripten_longjmp_jmpbuf` in
LowerEmscriptenEHSjLj pass, replacing that with `emscripten_longjmp`.
`emscripten_longjmp_jmpbuf` is lowered to `emscripten_longjmp`, but
previously we generated calls to `emscripten_longjmp_jmpbuf` in
LowerEmscriptenEHSjLj pass because it takes `jmp_buf*` instead of `i32`.
But we were able use `ptrtoint` to make it use `emscripten_longjmp`
directly here.

Addresses:
https://github.com/WebAssembly/binaryen/issues/3043
https://github.com/WebAssembly/binaryen/issues/3081

Companions:
https://github.com/WebAssembly/binaryen/pull/3191
https://github.com/emscripten-core/emscripten/pull/12399

Reviewed By: dschuff, tlively, sbc100

Differential Revision: https://reviews.llvm.org/D88697
2020-10-07 09:42:49 -07:00
Wouter van Oortmerssen b9a539c010 [WebAssembly] Adding 64-bit versions of __stack_pointer and other globals
We have 6 globals, all of which except for __table_base are 64-bit under wasm64.

Differential Revision: https://reviews.llvm.org/D82130
2020-06-25 15:52:44 -07:00
Wouter van Oortmerssen 3b29376e3f [WebAssembly] Adding 64-bit version of R_WASM_MEMORY_ADDR_* relocs
This adds 4 new reloc types.

A lot of code that previously assumed any memory or offset values could be contained in a uint32_t (and often truncated results from functions returning 64-bit values) have been upgraded to uint64_t. This is not comprehensive: it is only the values that come in contact with the new relocation values and their dependents.

A new tablegen mapping was added to automatically upgrade loads/stores in the assembler, which otherwise has no way to select for these instructions (since they are indentical other than for the offset immediate). It follows a similar technique to https://reviews.llvm.org/D53307

Differential Revision: https://reviews.llvm.org/D81704
2020-06-15 10:07:42 -07:00
Marek Kurdej 9301e3aaca [Target] Fix typos. NFC 2020-05-22 14:40:43 +02:00
Yuta Saito 08670d435b [WebAssembly] Support swiftself and swifterror for WebAssembly target
Summary:
Swift ABI is based on basic C ABI described here https://github.com/WebAssembly/tool-conventions/blob/master/BasicCABI.md
Swift Calling Convention on WebAssembly is a little deffer from swiftcc
on another architectures.

On non WebAssembly arch, swiftcc accepts extra parameters that are
attributed with swifterror or swiftself by caller. Even if callee
doesn't have these parameters, the invocation succeed ignoring extra
parameters.

But WebAssembly strictly checks that callee and caller signatures are
same. https://github.com/WebAssembly/design/blob/master/Semantics.md#calls
So at WebAssembly level, all swiftcc functions end up extra arguments
and all function definitions and invocations explicitly have additional
parameters to fill swifterror and swiftself.

This patch support signature difference for swiftself and swifterror cc
is swiftcc.

e.g.
```
declare swiftcc void @foo(i32, i32)
@data = global i8* bitcast (void (i32, i32)* @foo to i8*)
define swiftcc void @bar() {
  %1 = load i8*, i8** @data
  %2 = bitcast i8* %1 to void (i32, i32, i32)*
  call swiftcc void %2(i32 1, i32 2, i32 swiftself 3)
  ret void
}
```

For swiftcc, emit additional swiftself and swifterror parameters
if there aren't while lowering. These additional parameters are added
for both callee and caller.
They are necessary to match callee and caller signature for direct and
indirect function call.

Differential Revision: https://reviews.llvm.org/D76049
2020-03-19 17:39:52 -07:00
Thomas Lively ca9ba76481 [WebAssembly] Replace all calls with generalized multivalue calls
Summary:
Extends the multivalue call infrastructure to tail calls, removes all
legacy calls specialized for particular result types, and removes the
CallIndirectFixup pass, since all indirect call arguments are now
fixed up directly in the post-insertion hook.

In order to keep supporting pretty-printed defs and uses in test
expectations, MCInstLower now inserts an immediate containing the
number of defs for each call and call_indirect. The InstPrinter is
updated to query this immediate if it is present and determine which
MCOperands are defs and uses accordingly.

Depends on D72902.

Reviewers: aheejin

Subscribers: dschuff, mgorny, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74192
2020-02-18 15:55:20 -08:00
Thomas Lively 9d37f5afac [WebAssembly] Implement multivalue call_indirects
Summary:
Unlike normal calls, call_indirects have immediate arguments that
caused a MachineVerifier failure without a small tweak to loosen the
verifier's requirements for variadicOpsAreDefs instructions.

One nice thing about the new call_indirects is that they do not need
to participate in the PCALL_INDIRECT mechanism because their post-isel
hook handles moving the function pointer argument and adding the flags
and typeindex arguments itself.

Reviewers: aheejin

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74191
2020-02-18 13:49:46 -08:00
Thomas Lively 2cb27072ce [WebAssembly] Allow multivalue types in block signature operands
Summary:
Renames `ExprType` to the more apt `BlockType` and adds a variant for
multivalue blocks. Currently non-void blocks are only generated at the
end of functions where the block return type needs to agree with the
function return type, and that remains true for multivalue
blocks. That invariant means that the actual signature does not need
to be stored in the block signature `MachineOperand` because it can be
inferred by `WebAssemblyMCInstLower` from the return type of the
parent function. `WebAssemblyMCInstLower` continues to lower block
signature operands to immediates when possible but lowers multivalue
signatures to function type symbols. The AsmParser and Disassembler
are updated to handle multivalue block types as well.

Reviewers: aheejin, dschuff, aardappel

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68889

llvm-svn: 374933
2019-10-15 18:28:22 +00:00
Jonas Devlieghere 0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
2019-08-15 15:54:37 +00:00
Thomas Lively e0a9dce543 [WebAssembly] Do not emit tail calls with return type mismatch
Summary:
return_call and return_call_indirect are only valid if the return
types of the callee and caller match. We were previously not enforcing
that, which was producing invalid modules.

Reviewers: aheejin

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65246

llvm-svn: 367339
2019-07-30 18:08:39 +00:00
Guanzhong Chen 5204f7611f [WebAssembly] Compute and export TLS block alignment
Summary:
Add immutable WASM global `__tls_align` which stores the alignment
requirements of the TLS segment.

Add `__builtin_wasm_tls_align()` intrinsic to get this alignment in Clang.

The expected usage has now changed to:

    __wasm_init_tls(memalign(__builtin_wasm_tls_align(),
                             __builtin_wasm_tls_size()));

Reviewers: tlively, aheejin, sbc100, sunfish, alexcrichton

Reviewed By: tlively

Subscribers: dschuff, jgravelle-google, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D65028

llvm-svn: 366624
2019-07-19 23:34:16 +00:00
Guanzhong Chen 42bba4b852 [WebAssembly] Implement thread-local storage (local-exec model)
Summary:
Thread local variables are placed inside a `.tdata` segment. Their symbols are
offsets from the start of the segment. The address of a thread local variable
is computed as `__tls_base` + the offset from the start of the segment.

`.tdata` segment is a passive segment and `memory.init` is used once per thread
to initialize the thread local storage.

`__tls_base` is a wasm global. Since each thread has its own wasm instance,
it is effectively thread local. Currently, `__tls_base` must be initialized
at thread startup, and so cannot be used with dynamic libraries.

`__tls_base` is to be initialized with a new linker-synthesized function,
`__wasm_init_tls`, which takes as an argument a block of memory to use as the
storage for thread locals. It then initializes the block of memory and sets
`__tls_base`. As `__wasm_init_tls` will handle the memory initialization,
the memory does not have to be zeroed.

To help allocating memory for thread-local storage, a new compiler intrinsic
is introduced: `__builtin_wasm_tls_size()`. This instrinsic function returns
the size of the thread-local storage for the current function.

The expected usage is to run something like the following upon thread startup:

    __wasm_init_tls(malloc(__builtin_wasm_tls_size()));

Reviewers: tlively, aheejin, kripken, sbc100

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

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D64537

llvm-svn: 366272
2019-07-16 22:00:45 +00:00
Wouter van Oortmerssen d8ddf83950 [WebAssembly] refactored utilities to not depend on MachineInstr
Summary:
Most of these functions can work for MachineInstr and MCInst
equally now.

Reviewers: dschuff

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64643

llvm-svn: 365965
2019-07-12 22:08:25 +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 ef4c66c1c8 [WebAssembly] Remove unneeded target operand flags
This change is in preparation for the addition of new target
operand flags for new relocation types.  Have a symbol type as part
of the flag set makes it harder to use and AFAICT these are serving
no purpose.

Differential Revision: https://reviews.llvm.org/D60014

llvm-svn: 357548
2019-04-03 00:17:29 +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
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
Heejin Ahn 18c56a0762 [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-*`. But I've seen in multiple CLs in LLVM the modernize style
was recommended and code was fixed based on the style, so I added it as
well.)

The common 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
- Use inline initialization for class member variables
- Use `= default` for empty constructors / destructors
- Use `using` in place of `typedef`

Reviewers: sbc100, tlively, aardappel

Subscribers: dschuff, sunfish, jgravelle-google, yurydelendik, kripken, MatzeB, mgorny, rupprecht, llvm-commits

Differential Revision: https://reviews.llvm.org/D57500

llvm-svn: 353075
2019-02-04 19:13:39 +00:00
Heejin Ahn d6f487863d [WebAssembly] Exception handling: Switch to the new proposal
Summary:
This switches the EH implementation to the new proposal:
https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md
(The previous proposal was
 https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md)

- Instruction changes
  - Now we have one single `catch` instruction that returns a except_ref
    value
  - `throw` now can take variable number of operations
  - `rethrow` does not have 'depth' argument anymore
  - `br_on_exn` queries an except_ref to see if it matches the tag and
    branches to the given label if true.
  - `extract_exception` is a pseudo instruction that simulates popping
    values from wasm stack. This is to make `br_on_exn`, a very special
    instruction, work: `br_on_exn` puts values onto the stack only if it
    is taken, and the # of values can vay depending on the tag.

- Now there's only one `catch` per `try`, this patch removes all special
  handling for terminate pad with a call to `__clang_call_terminate`.
  Before it was the only case there are two catch clauses (a normal
  `catch` and `catch_all` per `try`).

- Make `rethrow` act as a terminator like `throw`. This splits BB after
  `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable`
  after `rethrow` in LateEHPrepare.

- Now we stop at all catchpads (because we add wasm `catch` instruction
  that catches all exceptions), this creates new
  `findWasmUnwindDestinations` function in SelectionDAGBuilder.

- Now we use `br_on_exn` instrution to figure out if an except_ref
  matches the current tag or not, LateEHPrepare generates this sequence
  for catch pads:
```
  catch
  block i32
  br_on_exn $__cpp_exception
  end_block
  extract_exception
```

- Branch analysis for `br_on_exn` in WebAssemblyInstrInfo

- Other various misc. changes to switch to the new proposal.

Reviewers: dschuff

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

Differential Revision: https://reviews.llvm.org/D57134

llvm-svn: 352598
2019-01-30 03:21:57 +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 da419bdb5e [WebAssembly] Add support for the event section
Summary:
This adds support for the 'event section' specified in the exception
handling proposal. (This was named 'exception section' first, but later
renamed to 'event section' to take possibilities of other kinds of
events into consideration. But currently we only store exception info in
this section.)

The event section is added between the global section and the export
section. This is for ease of validation per request of the V8 team.

This patch:
- Creates the event symbol type, which is a weak symbol
- Makes 'throw' instruction take the event symbol '__cpp_exception'
- Adds relocation support for events
- Adds WasmObjectWriter / WasmObjectFile (Reader) support
- Adds obj2yaml / yaml2obj support
- Adds '.eventtype' printing support

Reviewers: dschuff, sbc100, aardappel

Subscribers: jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D54096

llvm-svn: 346825
2018-11-14 02:46:21 +00:00
Heejin Ahn 24faf859e5 Reland "[WebAssembly] LSDA info generation"
Summary:
This adds support for LSDA (exception table) generation for wasm EH.
Wasm EH mostly follows the structure of Itanium-style exception tables,
with one exception: a call site table entry in wasm EH corresponds to
not a call site but a landing pad.

In wasm EH, the VM is responsible for stack unwinding. After an
exception occurs and the stack is unwound, the control flow is
transferred to wasm 'catch' instruction by the VM, after which the
personality function is called from the compiler-generated code. (Refer
to WasmEHPrepare pass for more information on this part.)

This patch:
- Changes wasm.landingpad.index intrinsic to take a token argument, to
make this 1:1 match with a catchpad instruction
- Stores landingpad index info and catch type info MachineFunction in
before instruction selection
- Lowers wasm.lsda intrinsic to an MCSymbol pointing to the start of an
exception table
- Adds WasmException class with overridden methods for table generation
- Adds support for LSDA section in Wasm object writer

Reviewers: dschuff, sbc100, rnk

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

Differential Revision: https://reviews.llvm.org/D52748

llvm-svn: 345345
2018-10-25 23:55:10 +00:00
Thomas Lively c63b5fcb2a [WebAssembly][NFC] Remove WebAssemblyStackifier TableGen backend
Summary:
Replace its functionality with a TableGen InstrInfo relational
instruction mapping. Although arguably more complex than the TableGen
backend, the relational mapping is a smaller maintenance burden than a
TableGen backend.

Reviewers: aardappel, aheejin, dschuff

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

Differential Revision: https://reviews.llvm.org/D53307

llvm-svn: 344962
2018-10-22 21:55:26 +00:00
Krasimir Georgiev 547d824da6 Revert "[WebAssembly] LSDA info generation"
This reverts commit r344575.
Newly introduced test eh-lsda.ll.test fails with use-after-free under
ASAN build.

llvm-svn: 344639
2018-10-16 18:50:09 +00:00
Heejin Ahn 0981eaab47 [WebAssembly] LSDA info generation
Summary:
This adds support for LSDA (exception table) generation for wasm EH.
Wasm EH mostly follows the structure of Itanium-style exception tables,
with one exception: a call site table entry in wasm EH corresponds to
not a call site but a landing pad.

In wasm EH, the VM is responsible for stack unwinding. After an
exception occurs and the stack is unwound, the control flow is
transferred to wasm 'catch' instruction by the VM, after which the
personality function is called from the compiler-generated code. (Refer
to WasmEHPrepare pass for more information on this part.)

This patch:
- Changes wasm.landingpad.index intrinsic to take a token argument, to
make this 1:1 match with a catchpad instruction
- Stores landingpad index info and catch type info MachineFunction in
before instruction selection
- Lowers wasm.lsda intrinsic to an MCSymbol pointing to the start of an
exception table
- Adds WasmException class with overridden methods for table generation
- Adds support for LSDA section in Wasm object writer

Reviewers: dschuff, sbc100, rnk

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

Differential Revision: https://reviews.llvm.org/D52748

llvm-svn: 344575
2018-10-16 00:09:12 +00:00
Derek Schuff 77a7a38006 [WebAssembly] Refactor WasmSignature and use it for MCSymbolWasm
MCContext does not destroy MCSymbols on shutdown. So, rather than putting
SmallVectors (which may heap-allocate) inside MCSymbolWasm, use unowned pointer
to a WasmSignature instead. The signatures are now owned by the AsmPrinter.
Also uses WasmSignature instead of param and result vectors in TargetStreamer,
and leaves some TODOs for further simplification.

 Differential Revision: https://reviews.llvm.org/D52580

llvm-svn: 343733
2018-10-03 22:22:48 +00:00
Derek Schuff 70ce1af9fa WebAssembly: Rename GetSignature to GetLibcallSignature [NFC]
llvm-svn: 343275
2018-09-27 22:20:33 +00:00
Thomas Lively 6f21a13675 [WebAssembly] Add V128 value type to binary format
Summary: Adds the necessary support to lib/ObjectYAML and fixes SIMD
calls to allow the tests to work. Also removes some dead code that
would otherwise have to have been updated.

Reviewers: aheejin, dschuff, sbc100

Subscribers: jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D52105

llvm-svn: 342689
2018-09-20 22:04:44 +00:00
Heejin Ahn f208f6311b [WebAssembly] clang-format (NFC)
Summary: This patch runs clang-format on all wasm-only files.

Reviewers: aardappel, dschuff, sunfish, tlively

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

Differential Revision: https://reviews.llvm.org/D51447

llvm-svn: 341439
2018-09-05 01:27:38 +00:00
Wouter van Oortmerssen 2d5fcf07a8 [WebAssembly] Fixed stale assert message in WebAssemblyMCInstLower
llvm-svn: 341423
2018-09-04 22:59:05 +00:00