diff options
Diffstat (limited to 'compiler/rustc_llvm/src')
| -rw-r--r-- | compiler/rustc_llvm/src/lib.rs | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/compiler/rustc_llvm/src/lib.rs b/compiler/rustc_llvm/src/lib.rs new file mode 100644 index 00000000000..eda9b2b1fc0 --- /dev/null +++ b/compiler/rustc_llvm/src/lib.rs @@ -0,0 +1,251 @@ +// tidy-alphabetical-start +#![allow(internal_features)] +#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")] +#![doc(rust_logo)] +#![feature(extern_types)] +#![feature(rustdoc_internals)] +#![warn(unreachable_pub)] +// tidy-alphabetical-end + +use std::cell::RefCell; +use std::{ptr, slice}; + +use libc::size_t; + +unsafe extern "C" { + /// Opaque type that allows C++ code to write bytes to a Rust-side buffer, + /// in conjunction with `RawRustStringOstream`. Use this as `&RustString` + /// (Rust) and `RustStringRef` (C++) in FFI signatures. + pub type RustString; +} + +impl RustString { + pub fn build_byte_buffer(closure: impl FnOnce(&Self)) -> Vec<u8> { + let buf = RustStringInner::default(); + closure(buf.as_opaque()); + buf.into_inner() + } +} + +/// Underlying implementation of [`RustString`]. +/// +/// Having two separate types makes it possible to use the opaque [`RustString`] +/// in FFI signatures without `improper_ctypes` warnings. This is a workaround +/// for the fact that there is no way to opt out of `improper_ctypes` when +/// _declaring_ a type (as opposed to using that type). +#[derive(Default)] +struct RustStringInner { + bytes: RefCell<Vec<u8>>, +} + +impl RustStringInner { + fn as_opaque(&self) -> &RustString { + let ptr: *const RustStringInner = ptr::from_ref(self); + // We can't use `ptr::cast` here because extern types are `!Sized`. + let ptr = ptr as *const RustString; + unsafe { &*ptr } + } + + fn from_opaque(opaque: &RustString) -> &Self { + // SAFETY: A valid `&RustString` must have been created via `as_opaque`. + let ptr: *const RustString = ptr::from_ref(opaque); + let ptr: *const RustStringInner = ptr.cast(); + unsafe { &*ptr } + } + + fn into_inner(self) -> Vec<u8> { + self.bytes.into_inner() + } +} + +/// Appends the contents of a byte slice to a [`RustString`]. +/// +/// This function is implemented in `rustc_llvm` so that the C++ code in this +/// crate can link to it directly, without an implied link-time dependency on +/// `rustc_codegen_llvm`. +#[unsafe(no_mangle)] +pub unsafe extern "C" fn LLVMRustStringWriteImpl( + buf: &RustString, + slice_ptr: *const u8, // Same ABI as `*const c_char` + slice_len: size_t, +) { + let slice = unsafe { slice::from_raw_parts(slice_ptr, slice_len) }; + RustStringInner::from_opaque(buf).bytes.borrow_mut().extend_from_slice(slice); +} + +/// Initialize targets enabled by the build script via `cfg(llvm_component = "...")`. +/// N.B., this function can't be moved to `rustc_codegen_llvm` because of the `cfg`s. +pub fn initialize_available_targets() { + macro_rules! init_target( + ($cfg:meta, $($method:ident),*) => { { + #[cfg($cfg)] + fn init() { + unsafe extern "C" { + $(fn $method();)* + } + unsafe { + $($method();)* + } + } + #[cfg(not($cfg))] + fn init() { } + init(); + } } + ); + init_target!( + llvm_component = "x86", + LLVMInitializeX86TargetInfo, + LLVMInitializeX86Target, + LLVMInitializeX86TargetMC, + LLVMInitializeX86AsmPrinter, + LLVMInitializeX86AsmParser + ); + init_target!( + llvm_component = "arm", + LLVMInitializeARMTargetInfo, + LLVMInitializeARMTarget, + LLVMInitializeARMTargetMC, + LLVMInitializeARMAsmPrinter, + LLVMInitializeARMAsmParser + ); + init_target!( + llvm_component = "aarch64", + LLVMInitializeAArch64TargetInfo, + LLVMInitializeAArch64Target, + LLVMInitializeAArch64TargetMC, + LLVMInitializeAArch64AsmPrinter, + LLVMInitializeAArch64AsmParser + ); + init_target!( + llvm_component = "amdgpu", + LLVMInitializeAMDGPUTargetInfo, + LLVMInitializeAMDGPUTarget, + LLVMInitializeAMDGPUTargetMC, + LLVMInitializeAMDGPUAsmPrinter, + LLVMInitializeAMDGPUAsmParser + ); + init_target!( + llvm_component = "avr", + LLVMInitializeAVRTargetInfo, + LLVMInitializeAVRTarget, + LLVMInitializeAVRTargetMC, + LLVMInitializeAVRAsmPrinter, + LLVMInitializeAVRAsmParser + ); + init_target!( + llvm_component = "m68k", + LLVMInitializeM68kTargetInfo, + LLVMInitializeM68kTarget, + LLVMInitializeM68kTargetMC, + LLVMInitializeM68kAsmPrinter, + LLVMInitializeM68kAsmParser + ); + init_target!( + llvm_component = "csky", + LLVMInitializeCSKYTargetInfo, + LLVMInitializeCSKYTarget, + LLVMInitializeCSKYTargetMC, + LLVMInitializeCSKYAsmPrinter, + LLVMInitializeCSKYAsmParser + ); + init_target!( + llvm_component = "loongarch", + LLVMInitializeLoongArchTargetInfo, + LLVMInitializeLoongArchTarget, + LLVMInitializeLoongArchTargetMC, + LLVMInitializeLoongArchAsmPrinter, + LLVMInitializeLoongArchAsmParser + ); + init_target!( + llvm_component = "mips", + LLVMInitializeMipsTargetInfo, + LLVMInitializeMipsTarget, + LLVMInitializeMipsTargetMC, + LLVMInitializeMipsAsmPrinter, + LLVMInitializeMipsAsmParser + ); + init_target!( + llvm_component = "powerpc", + LLVMInitializePowerPCTargetInfo, + LLVMInitializePowerPCTarget, + LLVMInitializePowerPCTargetMC, + LLVMInitializePowerPCAsmPrinter, + LLVMInitializePowerPCAsmParser + ); + init_target!( + llvm_component = "systemz", + LLVMInitializeSystemZTargetInfo, + LLVMInitializeSystemZTarget, + LLVMInitializeSystemZTargetMC, + LLVMInitializeSystemZAsmPrinter, + LLVMInitializeSystemZAsmParser + ); + init_target!( + llvm_component = "jsbackend", + LLVMInitializeJSBackendTargetInfo, + LLVMInitializeJSBackendTarget, + LLVMInitializeJSBackendTargetMC + ); + init_target!( + llvm_component = "msp430", + LLVMInitializeMSP430TargetInfo, + LLVMInitializeMSP430Target, + LLVMInitializeMSP430TargetMC, + LLVMInitializeMSP430AsmPrinter, + LLVMInitializeMSP430AsmParser + ); + init_target!( + llvm_component = "riscv", + LLVMInitializeRISCVTargetInfo, + LLVMInitializeRISCVTarget, + LLVMInitializeRISCVTargetMC, + LLVMInitializeRISCVAsmPrinter, + LLVMInitializeRISCVAsmParser + ); + init_target!( + llvm_component = "sparc", + LLVMInitializeSparcTargetInfo, + LLVMInitializeSparcTarget, + LLVMInitializeSparcTargetMC, + LLVMInitializeSparcAsmPrinter, + LLVMInitializeSparcAsmParser + ); + init_target!( + llvm_component = "nvptx", + LLVMInitializeNVPTXTargetInfo, + LLVMInitializeNVPTXTarget, + LLVMInitializeNVPTXTargetMC, + LLVMInitializeNVPTXAsmPrinter + ); + init_target!( + llvm_component = "hexagon", + LLVMInitializeHexagonTargetInfo, + LLVMInitializeHexagonTarget, + LLVMInitializeHexagonTargetMC, + LLVMInitializeHexagonAsmPrinter, + LLVMInitializeHexagonAsmParser + ); + init_target!( + llvm_component = "xtensa", + LLVMInitializeXtensaTargetInfo, + LLVMInitializeXtensaTarget, + LLVMInitializeXtensaTargetMC, + LLVMInitializeXtensaAsmParser + ); + init_target!( + llvm_component = "webassembly", + LLVMInitializeWebAssemblyTargetInfo, + LLVMInitializeWebAssemblyTarget, + LLVMInitializeWebAssemblyTargetMC, + LLVMInitializeWebAssemblyAsmPrinter, + LLVMInitializeWebAssemblyAsmParser + ); + init_target!( + llvm_component = "bpf", + LLVMInitializeBPFTargetInfo, + LLVMInitializeBPFTarget, + LLVMInitializeBPFTargetMC, + LLVMInitializeBPFAsmPrinter, + LLVMInitializeBPFAsmParser + ); +} |