Commit Graph

9 Commits

Author SHA1 Message Date
Sam Clegg 86c90f9bfd [lld][WebAssembly] Add --unresolved-symbols=import-dynamic
This is a new mode for handling unresolved symbols that allows all
symbols to be imported in the same that they would be in the case of
`-fpie` or `-shared`, but generting an otherwise fixed/non-relocatable
binary.

Code linked in this way should still be compiled with `-fPIC` so that
data symbols can be resolved via imports.

This essentially allows the building of static binaries that have
dynamic imports.  See:
https://github.com/emscripten-core/emscripten/issues/12682

As with other uses of the experimental dynamic linking ABI, this
behaviour will produce a warning unless run with `--experimental-pic`.

Differential Revision: https://reviews.llvm.org/D91577
2022-03-15 15:10:21 -07:00
Sam Clegg feddf11502 [lld][WebAssemlby] Convert test to check disassembly output. NFC
Differential Revision: https://reviews.llvm.org/D117739
2022-01-20 09:32:01 -08:00
Sam Clegg 6ee55f9ab5 Fix test failure created by ef8c9135ef
Followup to https://reviews.llvm.org/D108877 to fix test
failure.
2021-09-14 07:35:05 -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 b78c85a44a [WebAssembly] Convert to new "dylink.0" section format
This format is based on sub-sections (like the "linking" and "name"
sections) and is therefore easier to extend going forward.

spec change: https://github.com/WebAssembly/tool-conventions/pull/170
binaryen change: https://github.com/WebAssembly/binaryen/pull/4141
wabt change:  https://github.com/WebAssembly/wabt/pull/1707
emscripten change: https://github.com/emscripten-core/emscripten/pull/15019

Differential Revision: https://reviews.llvm.org/D109595
2021-09-12 05:30:38 -07:00
Sam Clegg e4888be74e [WebAssembly] Avoid unused function imports in PIC mode
In PIC mode we import function address via `GOT.mem` imports but for
direct function calls we still import the first class function.
However, if the function is never directly called we can avoid the first
class import completely.

Differential Revision: https://reviews.llvm.org/D108345
2021-08-18 22:31:04 -04:00
Wouter van Oortmerssen 4157b6033d [WebAssembly] Fixed LLD generation of 64-bit __wasm_apply_data_relocs
Differential Revision: https://reviews.llvm.org/D105863
2021-07-15 10:02:02 -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
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