When weak aliases are used with in same translation
unit we need to be able to directly reference to alias
and not just the thing it is aliases. We do this by
defining both a wasm import and a wasm export in this
case that result in a single Symbol. This change is
a partial revert of rL314245. A corresponding lld
change address the previous issues we had with this.
See: https://github.com/WebAssembly/tool-conventions/issues/34
Differential Revision: https://reviews.llvm.org/D41472
llvm-svn: 321242
Summary:
- lowers @llvm.global_dtors by adding @llvm.global_ctors
functions which register the destructors with `__cxa_atexit`.
- impements @llvm.global_ctors with wasm start functions and linker metadata
See [here](https://github.com/WebAssembly/tool-conventions/issues/25) for more background.
Subscribers: jfb, dschuff, mgorny, jgravelle-google, aheejin, sunfish
Differential Revision: https://reviews.llvm.org/D41211
llvm-svn: 320774
Currently, when creating a named section, the Wasm
frontend forces it to use `SectionKind::Data`, whereas
in fact C++ does generate code sections with custom
names.
Patch by Nicholas Wilson
Differential Revision: https://reviews.llvm.org/D40906
llvm-svn: 320002
Instead of having .o files contain linear-memory and function table
definitions, use imports. This is more consistent with the stack pointer
being imported, and it's consistent with the linker being the one to
decide whether linear memory and function table are imported or defined
in the linked output. This implements tool-conventions #23.
Differential Revision: https://reviews.llvm.org/D40875
llvm-svn: 319989
Original change was rL319488.
This was reverted rL319602 due to a gcc 7.1 warning.
Differential Revision: https://reviews.llvm.org/D40772
llvm-svn: 319626
Summary:
Support was added in rL319488 but these tests were not
updated.
Subscribers: jfb, dschuff, jgravelle-google, aheejin, sunfish
Differential Revision: https://reviews.llvm.org/D40693
llvm-svn: 319510
The LLVM "hidden" flag needs to be passed through the Wasm
intermediate objects in order for the linker to apply
it to the final Wasm object.
The corresponding change in LLD is here: https://github.com/WebAssembly/lld/pull/14
Patch by Nicholas Wilson
Differential Revision: https://reviews.llvm.org/D40442
llvm-svn: 319488
This ensures that each segment has a unique address.
Without this, consecutive zero sized symbols would
end up with the same address and the linker cannot
map symbols to unique data segments.
Differential Revision: https://reviews.llvm.org/D39107
llvm-svn: 316717
Previously these were being included as both imports and
exports, with the import being satisfied by the export
(or some strong symbol) at runtime. However proved
unnecessary and actually complicated linking as it meant
there was not a 1-to-1 mapping between a wasm function
/global index and a linker symbol.
Differential Revision: https://reviews.llvm.org/D38246
llvm-svn: 314245
Summary:
This manifested itself in lld since it meant that weak
symbols were not appearing in archive symbol tables.
Subscribers: jfb, dschuff, jgravelle-google, aheejin
Differential Revision: https://reviews.llvm.org/D38111
llvm-svn: 313838
Add adds support for naming data segments. This is useful
useful linkers so that they can merge similar sections.
Differential Revision: https://reviews.llvm.org/D37886
llvm-svn: 313795
Add adds support for naming data segments. This is useful
useful linkers so that they can merge similar sections.
Differential Revision: https://reviews.llvm.org/D37886
llvm-svn: 313692
This means that we can honor -fdata-sections rather than
always creating a segment for each symbol.
It also allows for a followup change to add .init_array and friends.
Differential Revision: https://reviews.llvm.org/D37876
llvm-svn: 313395
- Create helper function for resolving weak references.
- Add test that preproduces the crash.
Differential Revision: https://reviews.llvm.org/D37916
llvm-svn: 313381
This is stepping stone towards honoring -fdata-sections
and letting the assembler decide how many wasm data
segments to create.
Differential Revision: https://reviews.llvm.org/D37834
llvm-svn: 313313
This change only treats imported and exports functions and globals
as symbol table entries the object has a "linking" section (i.e. it is
relocatable object file).
In this case all globals must be of type I32 and initialized with
i32.const. This was previously being assumed but not checked for and
was causing a failure on big endian machines due to using the wrong
value of then union.
See: https://bugs.llvm.org/show_bug.cgi?id=34487
Differential Revision: https://reviews.llvm.org/D37497
llvm-svn: 312674
Summary:
This allows tools like lld that process relocations
to apply data relocation correctly. This information
is required because relocation are stored as section
offset.
Subscribers: jfb, dschuff, jgravelle-google, aheejin
Differential Revision: https://reviews.llvm.org/D35234
llvm-svn: 307741
Summary: When implementing MCFillFragment, use the size of the fragment,
rather than the size of the section.
Patch by Dan Gohman
Differential Revision: https://reviews.llvm.org/D35090
llvm-svn: 307565
Model weakly defined symbols as symbols that are both
exports and imported and marked as weak. Local references
to the symbols refer to the import but the linker can
resolve this to the weak export if not strong symbol
is found at link time.
Differential Revision: https://reviews.llvm.org/D35029
llvm-svn: 307348
Previously we were generating a void(void) function type
for a weak alias. Update the weak-alias test case to
catch this.
Differential Revision: https://reviews.llvm.org/D34734
llvm-svn: 307194
The overal size of the data section (including BSS)
is otherwise not included in the wasm binary.
Differential Revision: https://reviews.llvm.org/D34657
llvm-svn: 306459
This ensures that symbolic relocations are generated for stack
pointer manipulations.
These relocations are of type R_WEBASSEMBLY_GLOBAL_INDEX_LEB.
This change also adds support for reading relocations of this
type in WasmObjectFile.cpp.
Since its a globally imported symbol this does mean that
the get_global/set_global instruction won't be valid until
the objects are linked that global used in no longer an
imported global.
Differential Revision: https://reviews.llvm.org/D34172
llvm-svn: 305616
These symbols were previously not being marked as functions
so were appearing as globals instead, and with the incorrect
relocation type.
Without this fix, objects that take address of external
functions include them as global imports rather than function
imports which then fails at link time.
Differential Revision: https://reviews.llvm.org/D34068
llvm-svn: 305263
Previously we were writing the value function index space
value but for these types of relocations we want to be
writing the table element index space value.
Add a test case for these relocation types that fails
without this change.
Differential Revision: https://reviews.llvm.org/D33962
llvm-svn: 305253
The change cleans up and unifies the handling of relocation
entries in WasmObjectWriter. Type index relocation no longer
need to be handled separately.
The only externally visible change should be that type
index relocations are no longer grouped at the end.
Differential Revision: https://reviews.llvm.org/D33918
llvm-svn: 304816
Undefined externals don't need to have a size or an offset.
This was broken by r303915. Added a test for this case.
This fixes the "Compile LLVM Torture (o)" step on the wasm
waterfall.
Differential Revision: https://reviews.llvm.org/D33803
llvm-svn: 304505
Also, include global entries for all data symbols, not
just external ones, since these are referenced by the
relocation records.
Add a test case that includes unnamed data.
Differential Revision: https://reviews.llvm.org/D33079
llvm-svn: 303915
Also, add test for data relocations and fix addend to
be signed.
Subscribers: jfb, dschuff
Differential Revision: https://reviews.llvm.org/D32513
llvm-svn: 301690
Sam Clegg