diff --git a/compiler/rustc_mir/src/transform/inline.rs b/compiler/rustc_mir/src/transform/inline.rs index 2ccb9b3709f..aae98f5b6d8 100644 --- a/compiler/rustc_mir/src/transform/inline.rs +++ b/compiler/rustc_mir/src/transform/inline.rs @@ -206,6 +206,11 @@ impl Inliner<'tcx> { debug!("should_inline({:?})", callsite); let tcx = self.tcx; + if callsite.fn_sig.c_variadic() { + debug!("callee is variadic - not inlining"); + return false; + } + let codegen_fn_attrs = tcx.codegen_fn_attrs(callsite.callee.def_id()); let self_features = &self.codegen_fn_attrs.target_features; diff --git a/src/test/mir-opt/inline/inline-compatibility.rs b/src/test/mir-opt/inline/inline-compatibility.rs index 2e9edf5260f..30aff0a64ef 100644 --- a/src/test/mir-opt/inline/inline-compatibility.rs +++ b/src/test/mir-opt/inline/inline-compatibility.rs @@ -5,6 +5,7 @@ #![crate_type = "lib"] #![feature(no_sanitize)] #![feature(target_feature_11)] +#![feature(c_variadic)] // EMIT_MIR inline_compatibility.inlined_target_feature.Inline.diff #[target_feature(enable = "sse2")] @@ -35,3 +36,20 @@ pub unsafe fn target_feature() {} #[inline] #[no_sanitize(address)] pub unsafe fn no_sanitize() {} + +// EMIT_MIR inline_compatibility.not_inlined_c_variadic.Inline.diff +pub unsafe fn not_inlined_c_variadic() { + let s = sum(4u32, 4u32, 30u32, 200u32, 1000u32); +} + +#[no_mangle] +#[inline(always)] +unsafe extern "C" fn sum(n: u32, mut vs: ...) -> u32 { + let mut s = 0; + let mut i = 0; + while i != n { + s += vs.arg::(); + i += 1; + } + s +}