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Diffstat (limited to 'compiler/rustc_abi/src/extern_abi.rs')
| -rw-r--r-- | compiler/rustc_abi/src/extern_abi.rs | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/compiler/rustc_abi/src/extern_abi.rs b/compiler/rustc_abi/src/extern_abi.rs new file mode 100644 index 00000000000..f3cf7f583ce --- /dev/null +++ b/compiler/rustc_abi/src/extern_abi.rs @@ -0,0 +1,235 @@ +use std::fmt; + +use rustc_macros::{Decodable, Encodable, HashStable_Generic}; + +#[cfg(test)] +mod tests; + +use ExternAbi as Abi; + +#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy, Debug)] +#[derive(HashStable_Generic, Encodable, Decodable)] +pub enum ExternAbi { + // Some of the ABIs come first because every time we add a new ABI, we have to re-bless all the + // hashing tests. These are used in many places, so giving them stable values reduces test + // churn. The specific values are meaningless. + Rust, + C { + unwind: bool, + }, + Cdecl { + unwind: bool, + }, + Stdcall { + unwind: bool, + }, + Fastcall { + unwind: bool, + }, + Vectorcall { + unwind: bool, + }, + Thiscall { + unwind: bool, + }, + Aapcs { + unwind: bool, + }, + Win64 { + unwind: bool, + }, + SysV64 { + unwind: bool, + }, + PtxKernel, + Msp430Interrupt, + X86Interrupt, + /// An entry-point function called by the GPU's host + // FIXME: should not be callable from Rust on GPU targets, is for host's use only + GpuKernel, + EfiApi, + AvrInterrupt, + AvrNonBlockingInterrupt, + CCmseNonSecureCall, + CCmseNonSecureEntry, + System { + unwind: bool, + }, + RustIntrinsic, + RustCall, + /// *Not* a stable ABI, just directly use the Rust types to describe the ABI for LLVM. Even + /// normally ABI-compatible Rust types can become ABI-incompatible with this ABI! + Unadjusted, + /// For things unlikely to be called, where reducing register pressure in + /// `extern "Rust"` callers is worth paying extra cost in the callee. + /// Stronger than just `#[cold]` because `fn` pointers might be incompatible. + RustCold, + RiscvInterruptM, + RiscvInterruptS, +} + +impl Abi { + pub fn supports_varargs(self) -> bool { + // * C and Cdecl obviously support varargs. + // * C can be based on Aapcs, SysV64 or Win64, so they must support varargs. + // * EfiApi is based on Win64 or C, so it also supports it. + // * System falls back to C for functions with varargs. + // + // * Stdcall does not, because it would be impossible for the callee to clean + // up the arguments. (callee doesn't know how many arguments are there) + // * Same for Fastcall, Vectorcall and Thiscall. + // * Other calling conventions are related to hardware or the compiler itself. + match self { + Self::C { .. } + | Self::Cdecl { .. } + | Self::System { .. } + | Self::Aapcs { .. } + | Self::Win64 { .. } + | Self::SysV64 { .. } + | Self::EfiApi => true, + _ => false, + } + } +} + +#[derive(Copy, Clone)] +pub struct AbiData { + pub abi: Abi, + + /// Name of this ABI as we like it called. + pub name: &'static str, +} + +#[allow(non_upper_case_globals)] +pub const AbiDatas: &[AbiData] = &[ + AbiData { abi: Abi::Rust, name: "Rust" }, + AbiData { abi: Abi::C { unwind: false }, name: "C" }, + AbiData { abi: Abi::C { unwind: true }, name: "C-unwind" }, + AbiData { abi: Abi::Cdecl { unwind: false }, name: "cdecl" }, + AbiData { abi: Abi::Cdecl { unwind: true }, name: "cdecl-unwind" }, + AbiData { abi: Abi::Stdcall { unwind: false }, name: "stdcall" }, + AbiData { abi: Abi::Stdcall { unwind: true }, name: "stdcall-unwind" }, + AbiData { abi: Abi::Fastcall { unwind: false }, name: "fastcall" }, + AbiData { abi: Abi::Fastcall { unwind: true }, name: "fastcall-unwind" }, + AbiData { abi: Abi::Vectorcall { unwind: false }, name: "vectorcall" }, + AbiData { abi: Abi::Vectorcall { unwind: true }, name: "vectorcall-unwind" }, + AbiData { abi: Abi::Thiscall { unwind: false }, name: "thiscall" }, + AbiData { abi: Abi::Thiscall { unwind: true }, name: "thiscall-unwind" }, + AbiData { abi: Abi::Aapcs { unwind: false }, name: "aapcs" }, + AbiData { abi: Abi::Aapcs { unwind: true }, name: "aapcs-unwind" }, + AbiData { abi: Abi::Win64 { unwind: false }, name: "win64" }, + AbiData { abi: Abi::Win64 { unwind: true }, name: "win64-unwind" }, + AbiData { abi: Abi::SysV64 { unwind: false }, name: "sysv64" }, + AbiData { abi: Abi::SysV64 { unwind: true }, name: "sysv64-unwind" }, + AbiData { abi: Abi::PtxKernel, name: "ptx-kernel" }, + AbiData { abi: Abi::Msp430Interrupt, name: "msp430-interrupt" }, + AbiData { abi: Abi::X86Interrupt, name: "x86-interrupt" }, + AbiData { abi: Abi::GpuKernel, name: "gpu-kernel" }, + AbiData { abi: Abi::EfiApi, name: "efiapi" }, + AbiData { abi: Abi::AvrInterrupt, name: "avr-interrupt" }, + AbiData { abi: Abi::AvrNonBlockingInterrupt, name: "avr-non-blocking-interrupt" }, + AbiData { abi: Abi::CCmseNonSecureCall, name: "C-cmse-nonsecure-call" }, + AbiData { abi: Abi::CCmseNonSecureEntry, name: "C-cmse-nonsecure-entry" }, + AbiData { abi: Abi::System { unwind: false }, name: "system" }, + AbiData { abi: Abi::System { unwind: true }, name: "system-unwind" }, + AbiData { abi: Abi::RustIntrinsic, name: "rust-intrinsic" }, + AbiData { abi: Abi::RustCall, name: "rust-call" }, + AbiData { abi: Abi::Unadjusted, name: "unadjusted" }, + AbiData { abi: Abi::RustCold, name: "rust-cold" }, + AbiData { abi: Abi::RiscvInterruptM, name: "riscv-interrupt-m" }, + AbiData { abi: Abi::RiscvInterruptS, name: "riscv-interrupt-s" }, +]; + +#[derive(Copy, Clone, Debug)] +pub struct AbiUnsupported {} +/// Returns the ABI with the given name (if any). +pub fn lookup(name: &str) -> Result<Abi, AbiUnsupported> { + AbiDatas + .iter() + .find(|abi_data| name == abi_data.name) + .map(|&x| x.abi) + .ok_or_else(|| AbiUnsupported {}) +} + +pub fn all_names() -> Vec<&'static str> { + AbiDatas.iter().map(|d| d.name).collect() +} + +impl Abi { + /// Default ABI chosen for `extern fn` declarations without an explicit ABI. + pub const FALLBACK: Abi = Abi::C { unwind: false }; + + #[inline] + pub fn index(self) -> usize { + // N.B., this ordering MUST match the AbiDatas array above. + // (This is ensured by the test indices_are_correct().) + use Abi::*; + let i = match self { + // Cross-platform ABIs + Rust => 0, + C { unwind: false } => 1, + C { unwind: true } => 2, + // Platform-specific ABIs + Cdecl { unwind: false } => 3, + Cdecl { unwind: true } => 4, + Stdcall { unwind: false } => 5, + Stdcall { unwind: true } => 6, + Fastcall { unwind: false } => 7, + Fastcall { unwind: true } => 8, + Vectorcall { unwind: false } => 9, + Vectorcall { unwind: true } => 10, + Thiscall { unwind: false } => 11, + Thiscall { unwind: true } => 12, + Aapcs { unwind: false } => 13, + Aapcs { unwind: true } => 14, + Win64 { unwind: false } => 15, + Win64 { unwind: true } => 16, + SysV64 { unwind: false } => 17, + SysV64 { unwind: true } => 18, + PtxKernel => 19, + Msp430Interrupt => 20, + X86Interrupt => 21, + GpuKernel => 22, + EfiApi => 23, + AvrInterrupt => 24, + AvrNonBlockingInterrupt => 25, + CCmseNonSecureCall => 26, + CCmseNonSecureEntry => 27, + // Cross-platform ABIs + System { unwind: false } => 28, + System { unwind: true } => 29, + RustIntrinsic => 30, + RustCall => 31, + Unadjusted => 32, + RustCold => 33, + RiscvInterruptM => 34, + RiscvInterruptS => 35, + }; + debug_assert!( + AbiDatas + .iter() + .enumerate() + .find(|(_, AbiData { abi, .. })| *abi == self) + .map(|(index, _)| index) + .expect("abi variant has associated data") + == i, + "Abi index did not match `AbiDatas` ordering" + ); + i + } + + #[inline] + pub fn data(self) -> &'static AbiData { + &AbiDatas[self.index()] + } + + pub fn name(self) -> &'static str { + self.data().name + } +} + +impl fmt::Display for Abi { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!(f, "\"{}\"", self.name()) + } +} |