This was needed to access UEFI boot services in my new Boot2Rust experiment.
I also realized that Rust functions declared as extern always use the C calling convention regardless of how they were declared, so this pull request fixes that as well.
This adds an other ABI option which allows a custom selection over the target
architecture and OS. The only current candidate for this change is that kernel32
on win32 uses stdcall, but on win64 it uses the cdecl calling convention.
Otherwise everywhere else this is defined as using the Cdecl calling convention.
cc #10049Closes#8774
This commit resumes management of the stack boundaries and limits when switching
between tasks. This additionally leverages the __morestack function to run code
on "stack overflow". The current behavior is to abort the process, but this is
probably not the best behavior in the long term (for deails, see the comment I
wrote up in the stack exhaustion routine).
I borrow some ideas from clang's ABIInfo.h and TargetInfo.cpp.
LLVMType is replaced with ArgType, which is similar to clang's ABIArgInfo,
and I also merge attrs of FnType into it.
Now ABI implementation doesn't need to insert hidden return pointer
to arg_tys of FnType. Instead it is handled in foreign.rs.
This change also fixes LLVM assertion failure when compiling MIPS target.
This fixes two existing bugs along the way:
* The `transmute` intrinsic did not correctly handle casts of immediate
aggregates like newtype structs and tuples.
* The code for calling foreign functions used the wrong type to create
an `alloca` temporary
enum Foo { A, B }
fn foo() -> Foo { A }
Before:
; Function Attrs: nounwind uwtable
define void @_ZN3foo18hbedc642d5d9cf5aag4v0.0E(%enum.Foo* noalias nocapture sret, { i64, %tydesc*, i8*, i8*, i8 }* nocapture readnone) #0 {
"function top level":
%2 = getelementptr inbounds %enum.Foo* %0, i64 0, i32 0
store i64 0, i64* %2, align 8
ret void
}
After:
; Function Attrs: nounwind readnone uwtable
define %enum.Foo @_ZN3foo18hbedc642d5d9cf5aag4v0.0E({ i64, %tydesc*, i8*, i8*, i8 }* nocapture readnone) #0 {
"function top level":
ret %enum.Foo zeroinitializer
}
The `noalias` attributes were being set only on function definitions,
not on all declarations. This is harmless for `noalias`, but prevented
some optimization opportunities and is *not* harmless for other
attributes like `sret` with ABI implications.
Closes#9104
Beforehand it was assumed that the standard cdecl abi was used for all extern
fns of extern crates, but this reads the abi of the extern fn type and declares
the function in the local crate with the appropriate type.
I was trying to think of how to write a test for this, but I was just drawing up blanks :(. Are there standard functions in libc which are not of the cdecl abi? If so we could try linking to them and make sure that the cal completes successfully.
Otherwise, I manually verified that the function was declared correctly by looking at the llvm assembly.
cc #9055 (I'm not sure if this will fix that issue)
Beforehand it was assumed that the standard cdecl abi was used for all extern
fns of extern crates, but this reads the abi of the extern fn type and declares
the function in the local crate with the appropriate type.
Since function pointers do not carry along the function attributes with
them in the type, this needs to be set on the call instruction itself.
Closes#9152
- Made naming schemes consistent between Option, Result and Either
- Changed Options Add implementation to work like the maybe monad (return None if any of the inputs is None)
- Removed duplicate Option::get and renamed all related functions to use the term `unwrap` instead
The code to build the transmute intrinsic currently makes the invalid
assumption that if the in-type is non-immediate, the out-type is
non-immediate as well. But this is wrong, for example when transmuting
[int, ..1] to int. So we need to handle this fourth case as well.
Fixes#7988
