Under emscripten, C code can take the address of a function implemented
in Javascript (which is exposed via an import in wasm). Because imports
do not have linear memory address in wasm, we need to generate a thunk
to be the target of the indirect call; it call the import directly.
To make this possible, LLVM needs to emit the type signatures for these
functions, because they may not be called directly or referred to other
than where the address is taken.
This uses s new .s directive (.functype) which specifies the signature.
Differential Revision: http://reviews.llvm.org/D20891
Re-apply r271599 but instead of bailing with an error when a declared
function has multiple returns, replace it with a pointer argument. Also
add the test case I forgot to 'git add' last time around.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271703 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts r271599, it broke the integration tests.
More places than I expected had nontrival return types in imports, or
else the check was wrong.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271606 91177308-0d34-0410-b5e6-96231b3b80d8
Under emscripten, C code can take the address of a function implemented
in Javascript (which is exposed via an import in wasm). Because imports
do not have linear memory address in wasm, we need to generate a thunk
to be the target of the indirect call; it call the import directly.
To make this possible, LLVM needs to emit the type signatures for these
functions, because they may not be called directly or referred to other
than where the address is taken.
This uses s new .s directive (.functype) which specifies the signature.
Differential Revision: http://reviews.llvm.org/D20891
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271599 91177308-0d34-0410-b5e6-96231b3b80d8
