diff --git a/src/tools/compiletest/src/directives/directive_names.rs b/src/tools/compiletest/src/directives/directive_names.rs index 7fc76a42e0ca1..cc4e81c357ada 100644 --- a/src/tools/compiletest/src/directives/directive_names.rs +++ b/src/tools/compiletest/src/directives/directive_names.rs @@ -193,6 +193,7 @@ pub(crate) const KNOWN_DIRECTIVE_NAMES: &[&str] = &[ "only-bpf", "only-cdb", "only-dist", + "only-eabihf", "only-elf", "only-emscripten", "only-gnu", diff --git a/tests/ui/c-variadic/same-program-multiple-abis-arm.rs b/tests/ui/c-variadic/same-program-multiple-abis-arm.rs new file mode 100644 index 0000000000000..1b0bdecabfbc8 --- /dev/null +++ b/tests/ui/c-variadic/same-program-multiple-abis-arm.rs @@ -0,0 +1,77 @@ +#![feature(extended_varargs_abi_support)] +//@ run-pass +//@ only-arm +//@ ignore-thumb (this test uses arm assembly) +//@ only-eabihf (the assembly below requires float hardware support) + +// Check that multiple c-variadic calling conventions can be used in the same program. +// +// Clang and gcc reject defining functions with a non-default calling convention and a variable +// argument list, so C programs that use multiple c-variadic calling conventions are unlikely +// to come up. Here we validate that our codegen backends do in fact generate correct code. + +extern "C" { + fn variadic_c(_: f64, _: ...) -> f64; +} + +extern "aapcs" { + fn variadic_aapcs(_: f64, _: ...) -> f64; +} + +fn main() { + unsafe { + assert_eq!(variadic_c(1.0, 2.0, 3.0), 1.0 + 2.0 + 3.0); + assert_eq!(variadic_aapcs(1.0, 2.0, 3.0), 1.0 + 2.0 + 3.0); + } +} + +// This assembly was generated using https://godbolt.org/z/xcW6a1Tj5, and corresponds to the +// following code compiled for the `armv7-unknown-linux-gnueabihf` target: +// +// ```rust +// #![feature(c_variadic)] +// +// #[unsafe(no_mangle)] +// unsafe extern "C" fn variadic(a: f64, mut args: ...) -> f64 { +// let b = args.arg::(); +// let c = args.arg::(); +// +// a + b + c +// } +// ``` +// +// This function uses floats (and passes one normal float argument) because the aapcs and C calling +// conventions differ in how floats are passed, e.g. https://godbolt.org/z/sz799f51x. However, for +// c-variadic functions, both ABIs actually behave the same, based on: +// +// https://github.com/ARM-software/abi-aa/blob/main/aapcs32/aapcs32.rst#65parameter-passing +// +// > A variadic function is always marshaled as for the base standard. +// +// https://github.com/ARM-software/abi-aa/blob/main/aapcs32/aapcs32.rst#7the-standard-variants +// +// > This section applies only to non-variadic functions. For a variadic function the base standard +// > is always used both for argument passing and result return. +core::arch::global_asm!( + r#" +{variadic_c}: +{variadic_aapcs}: + sub sp, sp, #12 + stmib sp, {{r2, r3}} + vmov d0, r0, r1 + add r0, sp, #4 + vldr d1, [sp, #4] + add r0, r0, #15 + bic r0, r0, #7 + vadd.f64 d0, d0, d1 + add r1, r0, #8 + str r1, [sp] + vldr d1, [r0] + vadd.f64 d0, d0, d1 + vmov r0, r1, d0 + add sp, sp, #12 + bx lr + "#, + variadic_c = sym variadic_c, + variadic_aapcs = sym variadic_aapcs, +); diff --git a/tests/ui/c-variadic/same-program-multiple-abis.rs b/tests/ui/c-variadic/same-program-multiple-abis-x86_64.rs similarity index 100% rename from tests/ui/c-variadic/same-program-multiple-abis.rs rename to tests/ui/c-variadic/same-program-multiple-abis-x86_64.rs