llvm-project/llvm
Heejin Ahn 9261ee32dc [WebAssembly] Make EH work with dynamic linking
This makes Wasm EH work with dynamic linking. So far we were only able
to handle destructors, which do not use any tags or LSDA info.

1. This uses `TargetExternalSymbol` for `GCC_except_tableN` symbols,
   which points to the address of per-function LSDA info. It is more
   convenient to use than `MCSymbol` because it can take additional
   target flags.

2. When lowering `wasm_lsda` intrinsic, if PIC is enabled, make the
   symbol relative to `__memory_base` and generate the `add` node. If
   PIC is disabled, continue to use the absolute address.

3. Make tag symbols (`__cpp_exception` and `__c_longjmp`) undefined in
   the backend, because it is hard to make it work with dynamic
   linking's loading order. Instead, we make all tag symbols undefined
   in the LLVM backend and import it from JS.

4. Add support for undefined tags to the linker.

Companion patches:
- https://github.com/WebAssembly/binaryen/pull/4223
- https://github.com/emscripten-core/emscripten/pull/15266

Reviewed By: sbc100

Differential Revision: https://reviews.llvm.org/D111388
2021-10-12 23:28:27 -07:00
..
benchmarks
bindings
cmake Add .cmt and .cmti files for OCaml bindings 2021-10-05 19:36:12 +05:30
docs [docs] [NFC] Clarify the datalayout documentation 2021-10-12 23:21:48 +05:30
examples Re-apply e50aea58d5, "Major JITLinkMemoryManager refactor". with fixes. 2021-10-11 21:39:00 -07:00
include [instcombine] propagate freeze through single use poison producing flag instruction 2021-10-12 13:52:41 -07:00
lib [WebAssembly] Make EH work with dynamic linking 2021-10-12 23:28:27 -07:00
projects
resources
runtimes [runtimes] Ensure required deps for tests targets are actually built 2021-09-29 14:41:33 -07:00
test [WebAssembly] Make EH work with dynamic linking 2021-10-12 23:28:27 -07:00
tools Re-apply e50aea58d5, "Major JITLinkMemoryManager refactor". with fixes. 2021-10-11 21:39:00 -07:00
unittests [X86] Remove little support we had for MPX 2021-10-12 16:18:51 -07:00
utils [gn build] Port 9cf995be6b 2021-10-12 17:32:05 +00:00
.clang-format
.clang-tidy
.gitattributes
.gitignore
CMakeLists.txt Revert "[CMake] Enable LLVM_ENABLE_PER_TARGET_RUNTIME_DIR by default on Linux" 2021-09-28 18:23:43 +03:00
CODE_OWNERS.TXT
CREDITS.TXT
LICENSE.TXT
README.txt
RELEASE_TESTERS.TXT
configure
llvm.spec.in

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