Commit Graph

12 Commits

Author SHA1 Message Date
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
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 1a9b6e4a32 [WebAssembly][lld] Fix call-indirect.s test to validate
Add missing address operand, so that we can validate the output files.

Depends on D92315.

Differential Revision: https://reviews.llvm.org/D92320
2021-01-19 16:12:38 +01:00
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 fd1c894a4a [lld][WebAssembly] Convert some lld tests to assembly
When we originally wrote these tests we didn't have a stable and
fleshed out assembly format.  Now we do so we should prefer that
over llvm ir for lld tests to avoid including more part of llvm
than necessary in order to run the test.

This change converts just 30 out of about 130 test files. More to
come when I have some more time.

Differential Revision: https://reviews.llvm.org/D80361
2020-05-28 16:52:01 -07:00
Sam Clegg 305b0343ce [WebAssembly] Add --[no]-export-dynamic to replace --export-default
In a very recent change I introduced a --no-export-default flag
but after conferring with others it seems that this feature already
exists in gnu GNU ld and lld in the form the --export-dynamic flag
which is off by default.

This change replaces export-default with export-dynamic and also
changes the default to match the traditional linker behaviour.

Now, by default, only the entry point is exported.  If other symbols
are required by the embedder then --export-dynamic or --export can
be used to export all visibility hidden symbols or individual
symbols respectively.

This change touches a lot of tests that were relying on symbols
being exported by default.  I imagine it will also effect many
users but do think the change is worth it match of the traditional
behaviour and flag names.

Differential Revision: https://reviews.llvm.org/D52587

llvm-svn: 343265
2018-09-27 21:06:25 +00:00
Sam Clegg 30161dc28d [WebAssembly] Don't compress LEBs by default
LEB compression breaks debug info so we don't want to enable
it by default, even at high optimization levels.

Differential Revision: https://reviews.llvm.org/D50729

llvm-svn: 340073
2018-08-17 19:42:46 +00:00
Richard Smith 5a778aa79f Revert r339490 to match revert of llvm r339474 in r339630.
llvm-svn: 339635
2018-08-14 01:23:54 +00:00
Richard Trieu f1342bb8b8 Fix WebAssembly tests after r339474
Add flags to llc RUN lines to keep tests passing.

llvm-svn: 339490
2018-08-10 23:58:11 +00:00
Sam Clegg fb983cda8a [WebAssembly] Add option to remove LEB padding at relocate sites
This change adds the ability for lld to remove LEB padding from
code section. This effectively shrinks the size of the resulting
binary in proportion to the number of code relocations.

Since there will be a performance cost this is currently only active for
-O1 and above. Some toolchains may instead want to perform this
compression as a post linker step (for example running a binary through
binaryen will automatically compress these values).

I imagine we might want to make this the default in the future.

Differential Revision: https://reviews.llvm.org/D46416

llvm-svn: 332783
2018-05-18 23:28:05 +00:00