With r362638, llc doesn't support -relocation-model=pic with non-Emscripten
triples. Update these tests in lld which use -relocation-model=pic to also
use Emscripten triples.
llvm-svn: 362645
The current PIC model for WebAssembly is more like ELF in that it
allows symbol interposition.
This means that more functions end up being addressed via the GOT
and fewer directly added to the wasm table.
One effect is a reduction in the number of wasm table entries similar
to the previous attempt in https://reviews.llvm.org/D61539 which was
reverted.
Differential Revision: https://reviews.llvm.org/D61772
llvm-svn: 360402
When generating PIC output only relocations of type
R_WASM_TABLE_INDEX_REL_SLEB should generate table entries.
R_WASM_TABLE_INDEX_I32 get resolved at runtime via the auto-generated
__wasm_apply_relocs functions.
R_WASM_TABLE_INDEX_SLEB are not allowed in PIC code.
Differential Revision: https://reviews.llvm.org/D61539
llvm-svn: 360165
The code we generate for applying data relocations at runtime omitted
the symbols with GOT entries.
Also refactor the code to reduce duplication.
Differential Revision: https://reviews.llvm.org/D61111
llvm-svn: 359207
This should have been part of rL357710 but was overlooked because
in our test code the function in question was also used in other
relocations that caused it to be added to the table anyway.
Differential Revision: https://reviews.llvm.org/D60296
llvm-svn: 357737
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
For these types of relocations an absolute memory address is
required which is not possible for undefined data symbols. For symbols
that can be undefined at link time (i.e. external data symbols in
shared libraries) a different type of relocation (i.e. via a GOT) will
be needed.
Differential Revision: https://reviews.llvm.org/D59337
llvm-svn: 356310
When linking shared libraries, we import a mutable wasm global
to represent the address of each undefined data symbol.
This is a step towards supporting dynamic linking and shared
libraries.
Differential Revision: https://reviews.llvm.org/D59270
llvm-svn: 355988
Summary:
Rename MemoryIndex to InitFlags and implement logic for determining
data segment layout in ObjectYAML and MC. Also adds a "passive" flag
for the .section assembler directive although this cannot be assembled
yet because the assembler does not support data sections.
Reviewers: sbc100, aardappel, aheejin, dschuff
Subscribers: jgravelle-google, hiraditya, sunfish, rupprecht, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57938
llvm-svn: 354397
Dan Gohman