diff --git a/src/librustc_codegen_ssa/mir/block.rs b/src/librustc_codegen_ssa/mir/block.rs index 98da07a905e25..26442faa3215c 100644 --- a/src/librustc_codegen_ssa/mir/block.rs +++ b/src/librustc_codegen_ssa/mir/block.rs @@ -20,7 +20,7 @@ use syntax_pos::Pos; use super::{FunctionCx, LocalRef}; use super::place::PlaceRef; -use super::operand::{OperandValue, OperandRef}; +use super::operand::OperandRef; use super::operand::OperandValue::{Pair, Ref, Immediate}; /// Used by `FunctionCx::codegen_terminator` for emitting common patterns @@ -695,18 +695,7 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { // an "spoofed" `VaList`. This argument is ignored, but we need to // populate it with a dummy operand so that the users real arguments // are not overwritten. - let i = if sig.c_variadic && last_arg_idx.map(|x| x == i).unwrap_or(false) { - let layout = match self.cx.tcx().lang_items().va_list() { - Some(did) => bx.cx().layout_of(bx.tcx().type_of(did)), - None => bug!("`va_list` language item required for C-variadics"), - }; - let op = OperandRef { - val: OperandValue::Immediate( - bx.cx().const_undef(bx.cx().immediate_backend_type(layout) - )), - layout: layout, - }; - self.codegen_argument(&mut bx, op, &mut llargs, &fn_ty.args[i]); + let i = if sig.c_variadic && last_arg_idx.map(|x| i >= x).unwrap_or(false) { if i + 1 < fn_ty.args.len() { i + 1 } else { diff --git a/src/test/codegen/issue-58881.rs b/src/test/codegen/issue-58881.rs new file mode 100644 index 0000000000000..de451324f03c4 --- /dev/null +++ b/src/test/codegen/issue-58881.rs @@ -0,0 +1,21 @@ +// compile-flags: -C no-prepopulate-passes +// +// only-x86_64 +// ignore-windows + +#![crate_type = "lib"] + +extern "C" { + fn variadic_fn(_: i32, ...); +} + +#[repr(C)] +struct Foo(u8); +#[repr(C)] +struct Bar(u64, u64, u64); + +// Ensure that emit arguments of the correct type. +pub unsafe fn test_call_variadic() { + // CHECK: call void (i32, ...) @variadic_fn(i32 0, i8 {{.*}}, %Bar* {{.*}}) + variadic_fn(0, Foo(0), Bar(0, 0, 0)) +}