diff --git a/compiler/rustc_attr/src/builtin.rs b/compiler/rustc_attr/src/builtin.rs index 2fd625c2a6c2..364a3a1eeb5e 100644 --- a/compiler/rustc_attr/src/builtin.rs +++ b/compiler/rustc_attr/src/builtin.rs @@ -67,7 +67,7 @@ fn handle_errors(sess: &ParseSess, span: Span, error: AttrError) { } } -#[derive(Clone, PartialEq, Encodable, Decodable)] +#[derive(Copy, Clone, PartialEq, Encodable, Decodable)] pub enum InlineAttr { None, Hint, diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs index 9a2fbf359ea1..62a7986c194f 100644 --- a/compiler/rustc_codegen_llvm/src/attributes.rs +++ b/compiler/rustc_codegen_llvm/src/attributes.rs @@ -25,7 +25,7 @@ use crate::value::Value; /// Mark LLVM function to use provided inline heuristic. #[inline] -fn inline(cx: &CodegenCx<'ll, '_>, val: &'ll Value, inline: InlineAttr, requires_inline: bool) { +fn inline(cx: &CodegenCx<'ll, '_>, val: &'ll Value, inline: InlineAttr) { use self::InlineAttr::*; match inline { Hint => Attribute::InlineHint.apply_llfn(Function, val), @@ -35,7 +35,6 @@ fn inline(cx: &CodegenCx<'ll, '_>, val: &'ll Value, inline: InlineAttr, requires Attribute::NoInline.apply_llfn(Function, val); } } - None if requires_inline => Attribute::InlineHint.apply_llfn(Function, val), None => {} }; } @@ -226,7 +225,14 @@ pub fn from_fn_attrs(cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value, instance: ty:: } } - inline(cx, llfn, codegen_fn_attrs.inline.clone(), instance.def.requires_inline(cx.tcx)); + let inline_attr = if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NAKED) { + InlineAttr::Never + } else if codegen_fn_attrs.inline == InlineAttr::None && instance.def.requires_inline(cx.tcx) { + InlineAttr::Hint + } else { + codegen_fn_attrs.inline + }; + inline(cx, llfn, inline_attr); // The `uwtable` attribute according to LLVM is: // diff --git a/compiler/rustc_mir/src/transform/inline.rs b/compiler/rustc_mir/src/transform/inline.rs index 094c15131186..4eeb8969bb11 100644 --- a/compiler/rustc_mir/src/transform/inline.rs +++ b/compiler/rustc_mir/src/transform/inline.rs @@ -254,6 +254,11 @@ impl Inliner<'tcx> { self.tcx.sess.opts.debugging_opts.inline_mir_threshold }; + if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NAKED) { + debug!("#[naked] present - not inlining"); + return false; + } + if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::COLD) { debug!("#[cold] present - not inlining"); return false; diff --git a/src/test/codegen/naked-noinline.rs b/src/test/codegen/naked-noinline.rs new file mode 100644 index 000000000000..2a2208d4fce3 --- /dev/null +++ b/src/test/codegen/naked-noinline.rs @@ -0,0 +1,30 @@ +// Checks that naked functions are never inlined. +// compile-flags: -O -Zmir-opt-level=2 +// ignore-wasm32 +#![crate_type = "lib"] +#![feature(asm)] +#![feature(naked_functions)] + +#[inline(always)] +#[naked] +#[no_mangle] +pub unsafe extern "C" fn f() { +// Check that f has naked and noinline attributes. +// +// CHECK: define void @f() unnamed_addr [[ATTR:#[0-9]+]] +// CHECK-NEXT: start: +// CHECK-NEXT: call void asm + asm!("", options(noreturn)); +} + +#[no_mangle] +pub unsafe fn g() { +// Check that call to f is not inlined. +// +// CHECK-LABEL: define void @g() +// CHECK-NEXT: start: +// CHECK-NEXT: call void @f() + f(); +} + +// CHECK: attributes [[ATTR]] = { naked noinline{{.*}} }