Commit Graph

24 Commits

Author SHA1 Message Date
Sam Clegg 03e101f1b0 [WebAssembly] Use uint8_t for single byte values to match the spec
The original BinaryEncoding.md document used to specify that
these values were `varint7`, but the official spec lists them
explicitly as single byte values and not LEB.

A similar change for wabt is in flight:
 https://github.com/WebAssembly/wabt/pull/782

Differential Revision: https://reviews.llvm.org/D43921

llvm-svn: 326454
2018-03-01 18:06:21 +00:00
Sam Clegg 6c899ba6de [WebAssembly] Add first claass symbol table to wasm objects
This is combination of two patches by Nicholas Wilson:
  1. https://reviews.llvm.org/D41954
  2. https://reviews.llvm.org/D42495

Along with a few local modifications:
- One change I made was to add the UNDEFINED bit to the binary format
  to avoid the extra byte used when writing data symbols.  Although this
  bit is redundant for other symbols types (i.e. undefined can be
  implied if a function or global is a wasm import)
- I prefer to be explicit and consistent and not have derived flags.
- Some field renaming.
- Some reverting of unrelated minor changes.
- No test output differences.

Differential Revision: https://reviews.llvm.org/D43147

llvm-svn: 325860
2018-02-23 05:08:34 +00:00
Dan Gohman db1916a646 [WebAssembly] Add mechanisms for specifying an explicit import module name.
This adds a wasm-import-module function attribute and a .import_module
assembler directive, for specifying module import names for WebAssembly.
Currently these may only be used for function symbols; global variables
may be considered in the future.

WebAssembly has a two-level namespace scheme for symbols, and it's
normally the linker's job to assign the module name, which is the
first-level name. The attributes here allow users to specify their
own module names explicitly, which is useful for tools generating
bindings to modules defined in other languages.

This feature is not fully usable yet. It will evolve along with the
ongoing symbol table and lld changes.

Differential Revision: https://reviews.llvm.org/D42520

llvm-svn: 324778
2018-02-09 23:13:22 +00:00
Sam Clegg 6e7f1826c5 [WebAssembly] MC: Remove unused code for handling of wasm globals
For now, we are not using wasm globals, except for modeling of
the stack points.

Alos, factor out common struct WasmGlobalType, which matches the
name for that tuple in the Wasm spec and rename methods
to "isBindingGlobal", "isTypeGlobal" to avoid ambiguity.

Patch by Nicholas Wilson!

Differential Revision: https://reviews.llvm.org/D42750

llvm-svn: 323901
2018-01-31 19:50:14 +00:00
Dan Gohman ad19047d83 [WebAssembly] Remove WASM_STACK_POINTER.
WASM_STACK_POINTER and the .stack_pointer directive are no longer needed
now that the stack pointer global is an import.

llvm-svn: 319956
2017-12-06 20:56:40 +00:00
Dan Gohman c2c997718d [WebAssembly] Implement WASM_STACK_POINTER.
Use the .stack_pointer directive to implement WASM_STACK_POINTER for
specifying a global variable to be the stack pointer.

llvm-svn: 319797
2017-12-05 17:23:43 +00:00
Sam Clegg 12fd3da9d1 [WebAssembly] MC: Fix crash when -g specified.
At this point we don't output any debug sections or thier
relocations.

Differential Revision: https://reviews.llvm.org/D39076

llvm-svn: 316240
2017-10-20 21:28:38 +00:00
Sam Clegg 9bf73c078b [WebAssembly] Fix types for address taken functions
Differential Revision: https://reviews.llvm.org/D34966

llvm-svn: 307198
2017-07-05 20:25:08 +00:00
Dan Gohman 970d02c42d [WebAssembly] Initial linking metadata support
Add support for the new relocations and linking metadata section support in
https://github.com/WebAssembly/tool-conventions/blob/master/Linking.md. In
particular, this allows LLVM to indicate which variable is the stack pointer,
so that it can be linked with other objects.

This also adds support for emitting type relocations for call_indirect
instructions.

Right now, this is mainly tested by using wabt and hexdump to examine the
output on selected testcases. We'll add more tests as the design stablizes
and more of the pieces are in place.

llvm-svn: 299141
2017-03-30 23:58:19 +00:00
Derek Schuff b879539aac [WebAssembly] Fix some broken type encodings in wasm binary
A recent change switch the in-memory wasm value types
to be signed integers, but I missing a few cases where
these were being writing to the binary.

Differential Revision: https://reviews.llvm.org/D31014

Patch by Sam Clegg

llvm-svn: 297991
2017-03-16 20:49:48 +00:00
Derek Schuff e2688c432f [WebAssembly] Use LEB encoding for value types
Previously we were using the encoded LEB hex values
for the value types.  This change uses the decoded
negative value and the LEB encoder to write them out.

Differential Revision: https://reviews.llvm.org/D30847

Patch by Sam Clegg

llvm-svn: 297777
2017-03-14 20:23:22 +00:00
Dan Gohman 82607f56bd [WebAssembly] Add support for using a wasm global for the stack pointer.
This replaces the __stack_pointer variable which was allocated in linear
memory.

llvm-svn: 296201
2017-02-24 23:46:05 +00:00
Dan Gohman d934cb8806 [WebAssembly] Basic support for Wasm object file encoding.
With the "wasm32-unknown-unknown-wasm" triple, this allows writing out
simple wasm object files, and is another step in a larger series toward
migrating from ELF to general wasm object support. Note that this code
and the binary format itself is still experimental.

llvm-svn: 296190
2017-02-24 23:18:00 +00:00
Dan Gohman 18eafb6c68 [WebAssembly] Add skeleton MC support for the Wasm container format
This just adds the basic skeleton for supporting a new object file format.
All of the actual encoding will be implemented in followup patches.

Differential Revision: https://reviews.llvm.org/D26722

llvm-svn: 295803
2017-02-22 01:23:18 +00:00
Derek Schuff 7747d703e3 [WebAssembly] Emit .import_global assembler directives
Support a new assembler directive, .import_global, to declare imported
global variables (i.e. those with external linkage and no
initializer). The linker turns these into wasm imports.

Patch by Jacob Gravelle

Differential Revision: https://reviews.llvm.org/D26875

llvm-svn: 288296
2016-12-01 00:11:15 +00:00
Dan Gohman 3acb187d95 [WebAssembly] Implement more WebAssembly binary encoding.
This changes locals from being declared by the emitLocal hook in
WebAssemblyTargetStreamer, rather than with an instruction. After exploring
the infastructure in LLVM more, this seems to make more sense since
declaring locals doesn't use an encoded opcode.

This also adds more 0xd opcodes, type encodings, and miscellaneous
binary encoding bits.

llvm-svn: 285040
2016-10-24 23:27:49 +00:00
Dan Gohman 2726b88c03 [WebAssemby] Implement block signatures.
Per spec changes, this implements block signatures, and adds just enough
logic to produce correct block signatures at the ends of functions.

Differential Revision: https://reviews.llvm.org/D25144

llvm-svn: 283503
2016-10-06 22:29:32 +00:00
Derek Schuff c64d7655b2 [WebAssembly] Support CFI for WebAssembly target
Summary: This patch implements CFI for WebAssembly. It modifies the
LowerTypeTest pass to pre-assign table indexes to functions that are
called indirectly, and lowers type checks to test against the
appropriate table indexes. It also modifies the WebAssembly backend to
support a special ".indidx" assembly directive that propagates the table
index assignments out to the linker.

Patch by Dominic Chen

Differential Revision: https://reviews.llvm.org/D21768

llvm-svn: 277398
2016-08-01 22:25:02 +00:00
Derek Schuff 5859a9ed80 [WebAssembly] Emit type signatures for declared functions
Under emscripten, C code can take the address of a function implemented
in Javascript (which is exposed via an import in wasm). Because imports
do not have linear memory address in wasm, we need to generate a thunk
to be the target of the indirect call; it call the import directly.

To make this possible, LLVM needs to emit the type signatures for these
functions, because they may not be called directly or referred to other
than where the address is taken.

This uses s new .s directive (.functype) which specifies the signature.

Differential Revision: http://reviews.llvm.org/D20891

Re-apply r271599 but instead of bailing with an error when a declared
function has multiple returns, replace it with a pointer argument. Also
add the test case I forgot to 'git add' last time around.

llvm-svn: 271703
2016-06-03 18:34:36 +00:00
Derek Schuff f5bae9c1ce Revert "[WebAssembly] Emit type signatures for declared functions"
This reverts r271599, it broke the integration tests.
More places than I expected had nontrival return types in imports, or
else the check was wrong.

llvm-svn: 271606
2016-06-02 23:02:44 +00:00
Derek Schuff 23b7d65fe5 [WebAssembly] Emit type signatures for declared functions
Under emscripten, C code can take the address of a function implemented
in Javascript (which is exposed via an import in wasm). Because imports
do not have linear memory address in wasm, we need to generate a thunk
to be the target of the indirect call; it call the import directly.

To make this possible, LLVM needs to emit the type signatures for these
functions, because they may not be called directly or referred to other
than where the address is taken.

This uses s new .s directive (.functype) which specifies the signature.

Differential Revision: http://reviews.llvm.org/D20891

llvm-svn: 271599
2016-06-02 21:34:18 +00:00
Mehdi Amini b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
Benjamin Kramer 820f7548a1 Make some headers self-contained, remove unused includes that violate layering.
llvm-svn: 258937
2016-01-27 16:05:37 +00:00
Dan Gohman 3469ee120c [WebAssembly] Introduce a WebAssemblyTargetStreamer class.
Refactor .param, .result, .local, and .endfunc, as directives, using the
proper MCTargetStreamer mechanism, rather than fake instructions.

llvm-svn: 257511
2016-01-12 20:30:51 +00:00