Address review feedback

Author: wesleywiser

src/librustc_codegen_llvm/abi.rs

@@ -396,6 +396,11 @@ impl<'tcx> FnAbiLlvmExt<'tcx> for FnAbi<'tcx, Ty<'tcx>> {
             llvm::Attribute::NoReturn.apply_llfn(llvm::AttributePlace::Function, llfn);
         }
 
+        // FIXME(eddyb, wesleywiser): apply this to callsites as well?
+        if !self.can_unwind {
+            llvm::Attribute::NoUnwind.apply_llfn(llvm::AttributePlace::Function, llfn);
+        }
+
         let mut i = 0;
         let mut apply = |attrs: &ArgAttributes, ty: Option<&Type>| {
             attrs.apply_llfn(llvm::AttributePlace::Argument(i), llfn, ty);
@@ -431,6 +436,8 @@ impl<'tcx> FnAbiLlvmExt<'tcx> for FnAbi<'tcx, Ty<'tcx>> {
     }
 
     fn apply_attrs_callsite(&self, bx: &mut Builder<'a, 'll, 'tcx>, callsite: &'ll Value) {
+        // FIXME(wesleywiser, eddyb): We should apply `nounwind` and `noreturn` as appropriate to this callsite.
+
         let mut i = 0;
         let mut apply = |attrs: &ArgAttributes, ty: Option<&Type>| {
             attrs.apply_callsite(llvm::AttributePlace::Argument(i), callsite, ty);

src/librustc_codegen_llvm/attributes.rs

@@ -10,11 +10,10 @@ use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc_middle::ty::layout::HasTyCtxt;
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::ty::{self, TyCtxt};
 use rustc_session::config::{OptLevel, Sanitizer};
 use rustc_session::Session;
 
-use crate::abi::FnAbi;
 use crate::attributes;
 use crate::llvm::AttributePlace::Function;
 use crate::llvm::{self, Attribute};
@@ -75,12 +74,6 @@ pub fn emit_uwtable(val: &'ll Value, emit: bool) {
     Attribute::UWTable.toggle_llfn(Function, val, emit);
 }
 
-/// Tell LLVM whether the function can or cannot unwind.
-#[inline]
-fn unwind(val: &'ll Value, can_unwind: bool) {
-    Attribute::NoUnwind.toggle_llfn(Function, val, !can_unwind);
-}
-
 /// Tell LLVM if this function should be 'naked', i.e., skip the epilogue and prologue.
 #[inline]
 fn naked(val: &'ll Value, is_naked: bool) {
@@ -244,12 +237,7 @@ pub(crate) fn default_optimisation_attrs(sess: &Session, llfn: &'ll Value) {
 
 /// Composite function which sets LLVM attributes for function depending on its AST (`#[attribute]`)
 /// attributes.
-pub fn from_fn_attrs(
-    cx: &CodegenCx<'ll, 'tcx>,
-    llfn: &'ll Value,
-    instance: ty::Instance<'tcx>,
-    fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
-) {
+pub fn from_fn_attrs(cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value, instance: ty::Instance<'tcx>) {
     let codegen_fn_attrs = cx.tcx.codegen_fn_attrs(instance.def_id());
 
     match codegen_fn_attrs.optimize {
@@ -313,8 +301,6 @@ pub fn from_fn_attrs(
     }
     sanitize(cx, codegen_fn_attrs.flags, llfn);
 
-    unwind(llfn, fn_abi.can_unwind);
-
     // Always annotate functions with the target-cpu they are compiled for.
     // Without this, ThinLTO won't inline Rust functions into Clang generated
     // functions (because Clang annotates functions this way too).

src/librustc_codegen_llvm/callee.rs

@@ -78,7 +78,7 @@ pub fn get_fn(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'tcx>) -> &'ll Value
         let llfn = cx.declare_fn(&sym, &fn_abi);
         debug!("get_fn: not casting pointer!");
 
-        attributes::from_fn_attrs(cx, llfn, instance, &fn_abi);
+        attributes::from_fn_attrs(cx, llfn, instance);
 
         let instance_def_id = instance.def_id();
 

src/librustc_codegen_llvm/mono_item.rs

@@ -77,7 +77,7 @@ impl PreDefineMethods<'tcx> for CodegenCx<'ll, 'tcx> {
 
         debug!("predefine_fn: instance = {:?}", instance);
 
-        attributes::from_fn_attrs(self, lldecl, instance, &fn_abi);
+        attributes::from_fn_attrs(self, lldecl, instance);
 
         self.instances.borrow_mut().insert(instance, lldecl);
     }