Explanation: There was an inconsistency between non-const and const FRT
pointers. The former used Direct_Unowned the latter used Indirect
calling convention. We want to use Direct_Unowned for both cases. The
crash was the result of a calling convention mismatch between the
SILFunctionType of a Swift closure and the SILFunctionType of the C++
function's formal parameter that is taking a function pointer. The
compiler tried to insert a conversion between the two function types
that does not exist and caused an assertion in debug compilers and
miscompilation in production compilers.
Issue: rdar://149398905
Risk: Low, the fix is targeted and we change to a well-tested behavior
with non-const FRT pointers.
Testing: Regression test added.
Original PR: #81070
Reviewer: @j-hui
The thunk's parameter needs the @in_guaranteed convention if it's a
const reference parameter. However, that convention wasn't being used
because clang importer was removing the const reference from the
type and SILGen was computing the type of the parameter based on the
type without const reference.
This commit fixes the bug by passing the clang function type to
SILDeclRef so that it can be used to compute the correct thunk type.
This fixes a crash when a closure is passed to a C function taking a
pointer to a function that has a const reference struct parameter.
This recommits e074426 with fixes to
serialization/deserialization of function types. The fixes prevent clang
types of functions from being dropped during serialization.
rdar://131321096
The thunk's parameter needs the @in_guaranteed convention if it's a
const reference parameter. However, that convention wasn't being used
because clang importer was removing the const reference from the
type and SILGen was computing the type of the parameter based on the
type without const reference.
This commit fixes the bug by passing the clang function type to
SILDeclRef so that it can be used to compute the correct thunk type.
This fixes a crash when a closure is passed to a C function taking a
pointer to a function that has a const reference struct parameter.
rdar://131321096
This corresponds to the parameter-passing convention of the Itanium C++
ABI, in which the argument is passed indirectly and possibly modified,
but not destroyed, by the callee.
@in_cxx is handled the same way as @in in callers and @in_guaranteed in
callees. OwnershipModelEliminator emits the call to destroy_addr that is
needed to destroy the argument in the caller.
rdar://122707697
emitManagedParameter assumes the passed value has an address type and
calls forBorrowedAddressRValue when the parameter convention is
Indirect_In_Guaranteed.
Call forBorrowedObjectRValue instead when the type isn't an address
type.
rdar://130456931
When emitting a native-to-foreign thunk, pass the thunk's result address parameter to the native function if both the thunk and the native function return their results indirectly and the thunk is not for an async function.
Also, remove an outdated assertion.
rdar://124501345
