From c2fb99984c2ed4b54f5b8baff26fcc04af71d032 Mon Sep 17 00:00:00 2001 From: Tomasz Miąsko Date: Fri, 20 Nov 2020 00:00:00 +0000 Subject: Never inline naked functions The `#[naked]` attribute disabled prologue / epilogue emission for the function and it is responsibility of a developer to provide them. The compiler is no position to inline such functions correctly. Disable inlining of naked functions at LLVM and MIR level. --- compiler/rustc_codegen_llvm/src/attributes.rs | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'compiler/rustc_codegen_llvm/src') diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs index 9a2fbf359ea..62a7986c194 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: // -- cgit 1.4.1-3-g733a5