Rollup merge of rust-lang#65809 - roblabla:eficall-abi, r=nagisa

Add new EFIAPI ABI

Fixes rust-lang#54527

Adds a new ABI, "efiapi", which reflects the calling convention as specified by [the current spec UEFI spec](https://uefi.org/sites/default/files/resources/UEFI%20Spec%202_7_A%20Sept%206.pdf#G6.999903). When compiling for x86_64, we should select the `win64` ABI, while on all other architectures (Itanium, x86, ARM and ARM64 and RISC-V), we should select the `C` ABI.

Currently, this is done by just turning it into the C ABI everywhere except on x86_64, where it's turned into the win64 ABI. Should we prevent this ABI from being used on unsupported architectures, and if so, how would this be done?

src/librustc/ich/impls_syntax.rs

@@ -80,6 +80,7 @@ impl_stable_hash_for!(enum ::rustc_target::spec::abi::Abi {
     Msp430Interrupt,
     X86Interrupt,
     AmdGpuKernel,
+    EfiApi,
     Rust,
     C,
     System,

src/librustc/ty/layout.rs

@@ -2596,6 +2596,7 @@ where
 
             // It's the ABI's job to select this, not ours.
             System => bug!("system abi should be selected elsewhere"),
+            EfiApi => bug!("eficall abi should be selected elsewhere"),
 
             Stdcall => Conv::X86Stdcall,
             Fastcall => Conv::X86Fastcall,

src/librustc_target/spec/abi.rs

@@ -21,6 +21,7 @@ pub enum Abi {
     Msp430Interrupt,
     X86Interrupt,
     AmdGpuKernel,
+    EfiApi,
 
     // Multiplatform / generic ABIs
     Rust,
@@ -58,6 +59,7 @@ const AbiDatas: &[AbiData] = &[
     AbiData {abi: Abi::Msp430Interrupt, name: "msp430-interrupt", generic: false },
     AbiData {abi: Abi::X86Interrupt, name: "x86-interrupt", generic: false },
     AbiData {abi: Abi::AmdGpuKernel, name: "amdgpu-kernel", generic: false },
+    AbiData {abi: Abi::EfiApi, name: "efiapi", generic: false },
 
     // Cross-platform ABIs
     AbiData {abi: Abi::Rust, name: "Rust", generic: true },

src/librustc_target/spec/mod.rs

@@ -905,6 +905,13 @@ impl Target {
                     abi
                 }
             },
+            Abi::EfiApi => {
+                if self.arch == "x86_64" {
+                    Abi::Win64
+                } else {
+                    Abi::C
+                }
+            },
             abi => abi
         }
     }

src/libsyntax/feature_gate/active.rs

@@ -533,6 +533,9 @@ declare_features! (
     /// casts in safe Rust to `dyn Trait` for such a `Trait` is also forbidden.
     (active, object_safe_for_dispatch, "1.40.0", Some(43561), None),
 
+    /// Allows using the `efiapi` ABI.
+    (active, abi_efiapi, "1.40.0", Some(65815), None),
+
     // -------------------------------------------------------------------------
     // feature-group-end: actual feature gates
     // -------------------------------------------------------------------------

src/libsyntax/feature_gate/check.rs

@@ -227,6 +227,10 @@ impl<'a> PostExpansionVisitor<'a> {
                 gate_feature_post!(&self, abi_amdgpu_kernel, span,
                                    "amdgpu-kernel ABI is experimental and subject to change");
             },
+            Abi::EfiApi => {
+                gate_feature_post!(&self, abi_efiapi, span,
+                                   "efiapi ABI is experimental and subject to change");
+            },
             // Stable
             Abi::Cdecl |
             Abi::Stdcall |

src/libsyntax_pos/symbol.rs

@@ -110,6 +110,7 @@ symbols! {
         aarch64_target_feature,
         abi,
         abi_amdgpu_kernel,
+        abi_efiapi,
         abi_msp430_interrupt,
         abi_ptx,
         abi_sysv64,

src/test/codegen/abi-efiapi.rs

@@ -0,0 +1,31 @@
+// Checks if the correct annotation for the efiapi ABI is passed to llvm.
+
+// revisions:x86_64 i686 aarch64 arm riscv
+
+// min-llvm-version 9.0
+
+//[x86_64] compile-flags: --target x86_64-unknown-uefi
+//[i686] compile-flags: --target i686-unknown-linux-musl
+//[aarch64] compile-flags: --target aarch64-unknown-none
+//[arm] compile-flags: --target armv7r-none-eabi
+//[riscv] compile-flags: --target riscv64gc-unknown-none-elf
+// compile-flags: -C no-prepopulate-passes
+
+#![crate_type = "lib"]
+#![feature(no_core, lang_items, abi_efiapi)]
+#![no_core]
+
+#[lang="sized"]
+trait Sized { }
+#[lang="freeze"]
+trait Freeze { }
+#[lang="copy"]
+trait Copy { }
+
+//x86_64: define win64cc void @has_efiapi
+//i686: define void @has_efiapi
+//aarch64: define void @has_efiapi
+//arm: define void @has_efiapi
+//riscv: define void @has_efiapi
+#[no_mangle]
+pub extern "efiapi" fn has_efiapi() {}

src/test/ui/codemap_tests/unicode.stderr

@@ -4,7 +4,7 @@ error[E0703]: invalid ABI: found `路濫狼á́́`
 LL | extern "路濫狼á́́" fn foo() {}
    |        ^^^^^^^^^ invalid ABI
    |
-   = help: valid ABIs: cdecl, stdcall, fastcall, vectorcall, thiscall, aapcs, win64, sysv64, ptx-kernel, msp430-interrupt, x86-interrupt, amdgpu-kernel, Rust, C, system, rust-intrinsic, rust-call, platform-intrinsic, unadjusted
+   = help: valid ABIs: cdecl, stdcall, fastcall, vectorcall, thiscall, aapcs, win64, sysv64, ptx-kernel, msp430-interrupt, x86-interrupt, amdgpu-kernel, efiapi, Rust, C, system, rust-intrinsic, rust-call, platform-intrinsic, unadjusted
 
 error: aborting due to previous error
 

src/test/ui/feature-gates/feature-gate-abi.rs

@@ -7,6 +7,7 @@
 // gate-test-abi_ptx
 // gate-test-abi_x86_interrupt
 // gate-test-abi_amdgpu_kernel
+// gate-test-abi_efiapi
 
 // Functions
 extern "rust-intrinsic" fn f1() {} //~ ERROR intrinsics are subject to change
@@ -20,6 +21,7 @@ extern "ptx-kernel" fn f6() {} //~ ERROR PTX ABIs are experimental and subject t
 extern "x86-interrupt" fn f7() {} //~ ERROR x86-interrupt ABI is experimental
 extern "thiscall" fn f8() {} //~ ERROR thiscall is experimental and subject to change
 extern "amdgpu-kernel" fn f9() {} //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+extern "efiapi" fn f10() {} //~ ERROR efiapi ABI is experimental and subject to change
 
 // Methods in trait definition
 trait Tr {
@@ -34,6 +36,7 @@ trait Tr {
     extern "x86-interrupt" fn m7(); //~ ERROR x86-interrupt ABI is experimental
     extern "thiscall" fn m8(); //~ ERROR thiscall is experimental and subject to change
     extern "amdgpu-kernel" fn m9(); //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+    extern "efiapi" fn m10(); //~ ERROR efiapi ABI is experimental and subject to change
 
     extern "vectorcall" fn dm3() {} //~ ERROR vectorcall is experimental and subject to change
     extern "rust-call" fn dm4() {} //~ ERROR rust-call ABI is subject to change
@@ -42,6 +45,7 @@ trait Tr {
     extern "x86-interrupt" fn dm7() {} //~ ERROR x86-interrupt ABI is experimental
     extern "thiscall" fn dm8() {} //~ ERROR thiscall is experimental and subject to change
     extern "amdgpu-kernel" fn dm9() {} //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+    extern "efiapi" fn dm10() {} //~ ERROR efiapi ABI is experimental and subject to change
 }
 
 struct S;
@@ -59,6 +63,7 @@ impl Tr for S {
     extern "x86-interrupt" fn m7() {} //~ ERROR x86-interrupt ABI is experimental
     extern "thiscall" fn m8() {} //~ ERROR thiscall is experimental and subject to change
     extern "amdgpu-kernel" fn m9() {} //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+    extern "efiapi" fn m10() {} //~ ERROR efiapi ABI is experimental and subject to change
 }
 
 // Methods in inherent impl
@@ -74,6 +79,7 @@ impl S {
     extern "x86-interrupt" fn im7() {} //~ ERROR x86-interrupt ABI is experimental
     extern "thiscall" fn im8() {} //~ ERROR thiscall is experimental and subject to change
     extern "amdgpu-kernel" fn im9() {} //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+    extern "efiapi" fn im10() {} //~ ERROR efiapi ABI is experimental and subject to change
 }
 
 // Function pointer types
@@ -86,6 +92,7 @@ type A6 = extern "ptx-kernel" fn (); //~ ERROR PTX ABIs are experimental and sub
 type A7 = extern "x86-interrupt" fn(); //~ ERROR x86-interrupt ABI is experimental
 type A8 = extern "thiscall" fn(); //~ ERROR thiscall is experimental and subject to change
 type A9 = extern "amdgpu-kernel" fn(); //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+type A10 = extern "efiapi" fn(); //~ ERROR efiapi ABI is experimental and subject to change
 
 // Foreign modules
 extern "rust-intrinsic" {} //~ ERROR intrinsics are subject to change
@@ -97,5 +104,6 @@ extern "ptx-kernel" {} //~ ERROR PTX ABIs are experimental and subject to change
 extern "x86-interrupt" {} //~ ERROR x86-interrupt ABI is experimental
 extern "thiscall" {} //~ ERROR thiscall is experimental and subject to change
 extern "amdgpu-kernel" {} //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+extern "efiapi" {} //~ ERROR efiapi ABI is experimental and subject to change
 
 fn main() {}