Rename variadic to c_variadic

Function signatures with the `variadic` member set are actually
C-variadic functions. Make this a little more explicit by renaming the
`variadic` boolean value, `c_variadic`.

43 files changed, 119 insertions, 119 deletions

diff --git a/src/librustc/hir/lowering.rs b/src/librustc/hir/lowering.rs
index 0e2b34d4fac..6e96054bea9 100644
--- a/src/librustc/hir/lowering.rs
+++ b/src/librustc/hir/lowering.rs
@@ -954,7 +954,7 @@ impl<'a> LoweringContext<'a> {
         let decl = FnDecl {
             inputs: vec![],
             output,
-            variadic: false
+            c_variadic: false
         };
         let body_id = self.record_body(body_expr, Some(&decl));
         self.is_generator = prev_is_generator;
@@ -2118,7 +2118,7 @@ impl<'a> LoweringContext<'a> {
         P(hir::FnDecl {
             inputs,
             output,
-            variadic: decl.variadic,
+            c_variadic: decl.c_variadic,
             implicit_self: decl.inputs.get(0).map_or(
                 hir::ImplicitSelfKind::None,
                 |arg| {
@@ -3973,7 +3973,7 @@ impl<'a> LoweringContext<'a> {
                     let outer_decl = FnDecl {
                         inputs: decl.inputs.clone(),
                         output: FunctionRetTy::Default(fn_decl_span),
-                        variadic: false,
+                        c_variadic: false,
                     };
                     // We need to lower the declaration outside the new scope, because we
                     // have to conserve the state of being inside a loop condition for the
diff --git a/src/librustc/hir/mod.rs b/src/librustc/hir/mod.rs
index 205109d18fe..d8169d05dd4 100644
--- a/src/librustc/hir/mod.rs
+++ b/src/librustc/hir/mod.rs
@@ -1868,7 +1868,7 @@ pub struct Arg {
 pub struct FnDecl {
     pub inputs: HirVec<Ty>,
     pub output: FunctionRetTy,
-    pub variadic: bool,
+    pub c_variadic: bool,
     /// Does the function have an implicit self?
     pub implicit_self: ImplicitSelfKind,
 }
diff --git a/src/librustc/hir/print.rs b/src/librustc/hir/print.rs
index 8c252b0d027..dab4b9c824d 100644
--- a/src/librustc/hir/print.rs
+++ b/src/librustc/hir/print.rs
@@ -2007,7 +2007,7 @@ impl<'a> State<'a> {
             s.print_type(ty)?;
             s.end()
         })?;
-        if decl.variadic {
+        if decl.c_variadic {
             self.s.word(", ...")?;
         }
         self.pclose()?;
diff --git a/src/librustc/ich/impls_hir.rs b/src/librustc/ich/impls_hir.rs
index b7ec5889d6a..77582278690 100644
--- a/src/librustc/ich/impls_hir.rs
+++ b/src/librustc/ich/impls_hir.rs
@@ -368,7 +368,7 @@ impl_stable_hash_for!(enum hir::TyKind {
 impl_stable_hash_for!(struct hir::FnDecl {
     inputs,
     output,
-    variadic,
+    c_variadic,
     implicit_self
 });
 
diff --git a/src/librustc/ich/impls_ty.rs b/src/librustc/ich/impls_ty.rs
index cce1273b7f0..f77a88128f2 100644
--- a/src/librustc/ich/impls_ty.rs
+++ b/src/librustc/ich/impls_ty.rs
@@ -232,7 +232,7 @@ impl_stable_hash_for!(struct ty::GenSig<'tcx> {
 
 impl_stable_hash_for!(struct ty::FnSig<'tcx> {
     inputs_and_output,
-    variadic,
+    c_variadic,
     unsafety,
     abi
 });
diff --git a/src/librustc/traits/select.rs b/src/librustc/traits/select.rs
index e85b84bce43..e7cc9618080 100644
--- a/src/librustc/traits/select.rs
+++ b/src/librustc/traits/select.rs
@@ -1944,7 +1944,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                 if let ty::FnSig {
                     unsafety: hir::Unsafety::Normal,
                     abi: Abi::Rust,
-                    variadic: false,
+                    c_variadic: false,
                     ..
                 } = self_ty.fn_sig(self.tcx()).skip_binder()
                 {
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index b37b632f4be..9767396147c 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -2453,7 +2453,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             self.mk_fn_sig(
                 params_iter,
                 s.output(),
-                s.variadic,
+                s.c_variadic,
                 hir::Unsafety::Normal,
                 abi::Abi::Rust,
             )
@@ -2779,7 +2779,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     pub fn mk_fn_sig<I>(self,
                         inputs: I,
                         output: I::Item,
-                        variadic: bool,
+                        c_variadic: bool,
                         unsafety: hir::Unsafety,
                         abi: abi::Abi)
         -> <I::Item as InternIteratorElement<Ty<'tcx>, ty::FnSig<'tcx>>>::Output
@@ -2788,7 +2788,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     {
         inputs.chain(iter::once(output)).intern_with(|xs| ty::FnSig {
             inputs_and_output: self.intern_type_list(xs),
-            variadic, unsafety, abi
+            c_variadic, unsafety, abi
         })
     }
 
diff --git a/src/librustc/ty/instance.rs b/src/librustc/ty/instance.rs
index 709dce4589f..49ebd202813 100644
--- a/src/librustc/ty/instance.rs
+++ b/src/librustc/ty/instance.rs
@@ -65,7 +65,7 @@ impl<'a, 'tcx> Instance<'tcx> {
                 sig.map_bound(|sig| tcx.mk_fn_sig(
                     iter::once(*env_ty.skip_binder()).chain(sig.inputs().iter().cloned()),
                     sig.output(),
-                    sig.variadic,
+                    sig.c_variadic,
                     sig.unsafety,
                     sig.abi
                 ))
diff --git a/src/librustc/ty/relate.rs b/src/librustc/ty/relate.rs
index b15aa862901..2940757fa90 100644
--- a/src/librustc/ty/relate.rs
+++ b/src/librustc/ty/relate.rs
@@ -147,9 +147,9 @@ impl<'tcx> Relate<'tcx> for ty::FnSig<'tcx> {
     {
         let tcx = relation.tcx();
 
-        if a.variadic != b.variadic {
+        if a.c_variadic != b.c_variadic {
             return Err(TypeError::VariadicMismatch(
-                expected_found(relation, &a.variadic, &b.variadic)));
+                expected_found(relation, &a.c_variadic, &b.c_variadic)));
         }
         let unsafety = relation.relate(&a.unsafety, &b.unsafety)?;
         let abi = relation.relate(&a.abi, &b.abi)?;
@@ -171,7 +171,7 @@ impl<'tcx> Relate<'tcx> for ty::FnSig<'tcx> {
             });
         Ok(ty::FnSig {
             inputs_and_output: tcx.mk_type_list(inputs_and_output)?,
-            variadic: a.variadic,
+            c_variadic: a.c_variadic,
             unsafety,
             abi,
         })
diff --git a/src/librustc/ty/structural_impls.rs b/src/librustc/ty/structural_impls.rs
index a81d5c9d86e..f1a465e1f17 100644
--- a/src/librustc/ty/structural_impls.rs
+++ b/src/librustc/ty/structural_impls.rs
@@ -396,7 +396,7 @@ impl<'a, 'tcx> Lift<'tcx> for ty::FnSig<'a> {
         tcx.lift(&self.inputs_and_output).map(|x| {
             ty::FnSig {
                 inputs_and_output: x,
-                variadic: self.variadic,
+                c_variadic: self.c_variadic,
                 unsafety: self.unsafety,
                 abi: self.abi,
             }
@@ -832,7 +832,7 @@ BraceStructTypeFoldableImpl! {
 
 BraceStructTypeFoldableImpl! {
     impl<'tcx> TypeFoldable<'tcx> for ty::FnSig<'tcx> {
-        inputs_and_output, variadic, unsafety, abi
+        inputs_and_output, c_variadic, unsafety, abi
     }
 }
 
diff --git a/src/librustc/ty/sty.rs b/src/librustc/ty/sty.rs
index 7ade035ce89..3fd2e38a3d3 100644
--- a/src/librustc/ty/sty.rs
+++ b/src/librustc/ty/sty.rs
@@ -979,11 +979,11 @@ impl<'tcx> PolyGenSig<'tcx> {
 ///
 /// - `inputs`: is the list of arguments and their modes.
 /// - `output`: is the return type.
-/// - `variadic`: indicates whether this is a C-variadic function.
+/// - `c_variadic`: indicates whether this is a C-variadic function.
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable)]
 pub struct FnSig<'tcx> {
     pub inputs_and_output: &'tcx List<Ty<'tcx>>,
-    pub variadic: bool,
+    pub c_variadic: bool,
     pub unsafety: hir::Unsafety,
     pub abi: abi::Abi,
 }
@@ -1016,8 +1016,8 @@ impl<'tcx> PolyFnSig<'tcx> {
     pub fn output(&self) -> ty::Binder<Ty<'tcx>> {
         self.map_bound_ref(|fn_sig| fn_sig.output())
     }
-    pub fn variadic(&self) -> bool {
-        self.skip_binder().variadic
+    pub fn c_variadic(&self) -> bool {
+        self.skip_binder().c_variadic
     }
     pub fn unsafety(&self) -> hir::Unsafety {
         self.skip_binder().unsafety
diff --git a/src/librustc/util/ppaux.rs b/src/librustc/util/ppaux.rs
index fbe9e3359bf..aecef3c5ec7 100644
--- a/src/librustc/util/ppaux.rs
+++ b/src/librustc/util/ppaux.rs
@@ -360,7 +360,7 @@ impl PrintContext {
     fn fn_sig<F: fmt::Write>(&mut self,
                              f: &mut F,
                              inputs: &[Ty<'_>],
-                             variadic: bool,
+                             c_variadic: bool,
                              output: Ty<'_>)
                              -> fmt::Result {
         write!(f, "(")?;
@@ -370,7 +370,7 @@ impl PrintContext {
             for &ty in inputs {
                 print!(f, self, write(", "), print_display(ty))?;
             }
-            if variadic {
+            if c_variadic {
                 write!(f, ", ...")?;
             }
         }
@@ -1074,10 +1074,10 @@ define_print! {
             }
 
             write!(f, "fn")?;
-            cx.fn_sig(f, self.inputs(), self.variadic, self.output())
+            cx.fn_sig(f, self.inputs(), self.c_variadic, self.output())
         }
         debug {
-            write!(f, "({:?}; variadic: {})->{:?}", self.inputs(), self.variadic, self.output())
+            write!(f, "({:?}; c_variadic: {})->{:?}", self.inputs(), self.c_variadic, self.output())
         }
     }
 }
diff --git a/src/librustc_codegen_llvm/abi.rs b/src/librustc_codegen_llvm/abi.rs
index aea62360651..49c9555a2c6 100644
--- a/src/librustc_codegen_llvm/abi.rs
+++ b/src/librustc_codegen_llvm/abi.rs
@@ -422,7 +422,7 @@ impl<'tcx> FnTypeExt<'tcx> for FnType<'tcx, Ty<'tcx>> {
 
         let mut inputs = sig.inputs();
         let extra_args = if sig.abi == RustCall {
-            assert!(!sig.variadic && extra_args.is_empty());
+            assert!(!sig.c_variadic && extra_args.is_empty());
 
             match sig.inputs().last().unwrap().sty {
                 ty::Tuple(ref tupled_arguments) => {
@@ -435,7 +435,7 @@ impl<'tcx> FnTypeExt<'tcx> for FnType<'tcx, Ty<'tcx>> {
                 }
             }
         } else {
-            assert!(sig.variadic || extra_args.is_empty());
+            assert!(sig.c_variadic || extra_args.is_empty());
             extra_args
         };
 
@@ -531,7 +531,7 @@ impl<'tcx> FnTypeExt<'tcx> for FnType<'tcx, Ty<'tcx>> {
             // If this is a C-variadic function, this is not the return value,
             // and there is one or more fixed arguments; ensure that the `VaList`
             // is ignored as an argument.
-            if sig.variadic {
+            if sig.c_variadic {
                 match (last_arg_idx, arg_idx) {
                     (Some(last_idx), Some(cur_idx)) if last_idx == cur_idx => {
                         let va_list_did = match cx.tcx.lang_items().va_list() {
@@ -589,7 +589,7 @@ impl<'tcx> FnTypeExt<'tcx> for FnType<'tcx, Ty<'tcx>> {
             args: inputs.iter().chain(extra_args).enumerate().map(|(i, ty)| {
                 arg_of(ty, Some(i))
             }).collect(),
-            variadic: sig.variadic,
+            c_variadic: sig.c_variadic,
             conv,
         };
         fn_ty.adjust_for_abi(cx, sig.abi);
@@ -717,7 +717,7 @@ impl<'tcx> FnTypeExt<'tcx> for FnType<'tcx, Ty<'tcx>> {
             llargument_tys.push(llarg_ty);
         }
 
-        if self.variadic {
+        if self.c_variadic {
             cx.type_variadic_func(&llargument_tys, llreturn_ty)
         } else {
             cx.type_func(&llargument_tys, llreturn_ty)
diff --git a/src/librustc_codegen_llvm/debuginfo/type_names.rs b/src/librustc_codegen_llvm/debuginfo/type_names.rs
index 176c9b8c542..8b218ab39d9 100644
--- a/src/librustc_codegen_llvm/debuginfo/type_names.rs
+++ b/src/librustc_codegen_llvm/debuginfo/type_names.rs
@@ -143,7 +143,7 @@ pub fn push_debuginfo_type_name<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>,
                 output.pop();
             }
 
-            if sig.variadic {
+            if sig.c_variadic {
                 if !sig.inputs().is_empty() {
                     output.push_str(", ...");
                 } else {
diff --git a/src/librustc_codegen_ssa/mir/block.rs b/src/librustc_codegen_ssa/mir/block.rs
index 684dfac991b..627380ee38f 100644
--- a/src/librustc_codegen_ssa/mir/block.rs
+++ b/src/librustc_codegen_ssa/mir/block.rs
@@ -232,7 +232,7 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         &mut self,
         mut bx: Bx,
     ) {
-        if self.fn_ty.variadic {
+        if self.fn_ty.c_variadic {
             if let Some(va_list) = self.va_list_ref {
                 bx.va_end(va_list.llval);
             }
@@ -507,7 +507,7 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
         // The "spoofed" `VaList` added to a C-variadic functions signature
         // should not be included in the `extra_args` calculation.
-        let extra_args_start_idx = sig.inputs().len() - if sig.variadic { 1 } else { 0 };
+        let extra_args_start_idx = sig.inputs().len() - if sig.c_variadic { 1 } else { 0 };
         let extra_args = &args[extra_args_start_idx..];
         let extra_args = extra_args.iter().map(|op_arg| {
             let op_ty = op_arg.ty(self.mir, bx.tcx());
@@ -695,7 +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.variadic && last_arg_idx.map(|x| x == i).unwrap_or(false) {
+            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"),
diff --git a/src/librustc_codegen_ssa/mir/mod.rs b/src/librustc_codegen_ssa/mir/mod.rs
index 95cf8cfe2d0..dc77d4673cd 100644
--- a/src/librustc_codegen_ssa/mir/mod.rs
+++ b/src/librustc_codegen_ssa/mir/mod.rs
@@ -585,7 +585,7 @@ fn arg_local_refs<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
             indirect_operand.store(bx, tmp);
             tmp
         } else {
-            if fx.fn_ty.variadic && last_arg_idx.map(|idx| arg_index == idx).unwrap_or(false) {
+            if fx.fn_ty.c_variadic && last_arg_idx.map(|idx| arg_index == idx).unwrap_or(false) {
                 let va_list_impl = match arg_decl.ty.ty_adt_def() {
                     Some(adt) => adt.non_enum_variant(),
                     None => bug!("`va_list` language item improperly constructed")
diff --git a/src/librustc_lint/types.rs b/src/librustc_lint/types.rs
index fb279a5d9b8..35489ab42e7 100644
--- a/src/librustc_lint/types.rs
+++ b/src/librustc_lint/types.rs
@@ -766,7 +766,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
         let def_id = self.cx.tcx.hir().local_def_id(id);
         let sig = self.cx.tcx.fn_sig(def_id);
         let sig = self.cx.tcx.erase_late_bound_regions(&sig);
-        let inputs = if sig.variadic {
+        let inputs = if sig.c_variadic {
             // Don't include the spoofed `VaList` in the functions list
             // of inputs.
             &sig.inputs()[..sig.inputs().len() - 1]
diff --git a/src/librustc_mir/borrow_check/nll/type_check/mod.rs b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
index f897795d86f..df035aab54c 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
@@ -1604,12 +1604,12 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
         debug!("check_call_inputs({:?}, {:?})", sig, args);
         // Do not count the `VaList` argument as a "true" argument to
         // a C-variadic function.
-        let inputs = if sig.variadic {
+        let inputs = if sig.c_variadic {
             &sig.inputs()[..sig.inputs().len() - 1]
         } else {
             &sig.inputs()[..]
         };
-        if args.len() < inputs.len() || (args.len() > inputs.len() && !sig.variadic) {
+        if args.len() < inputs.len() || (args.len() > inputs.len() && !sig.c_variadic) {
             span_mirbug!(self, term, "call to {:?} with wrong # of args", sig);
         }
         for (n, (fn_arg, op_arg)) in inputs.iter().zip(args).enumerate() {
diff --git a/src/librustc_mir/monomorphize/item.rs b/src/librustc_mir/monomorphize/item.rs
index a26a1a7861e..059af2dbba9 100644
--- a/src/librustc_mir/monomorphize/item.rs
+++ b/src/librustc_mir/monomorphize/item.rs
@@ -353,7 +353,7 @@ impl<'a, 'tcx> DefPathBasedNames<'a, 'tcx> {
                     output.pop();
                 }
 
-                if sig.variadic {
+                if sig.c_variadic {
                     if !sig.inputs().is_empty() {
                         output.push_str(", ...");
                     } else {
diff --git a/src/librustc_target/abi/call/arm.rs b/src/librustc_target/abi/call/arm.rs
index 52d7f3ac3dc..e3fee8e5700 100644
--- a/src/librustc_target/abi/call/arm.rs
+++ b/src/librustc_target/abi/call/arm.rs
@@ -99,7 +99,7 @@ pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<'a, Ty>)
     // `extern "aapcs"`, then we must use the VFP registers for homogeneous aggregates.
     let vfp = cx.target_spec().llvm_target.ends_with("hf")
         && fty.conv != Conv::ArmAapcs
-        && !fty.variadic;
+        && !fty.c_variadic;
 
     if !fty.ret.is_ignore() {
         classify_ret_ty(cx, &mut fty.ret, vfp);
diff --git a/src/librustc_target/abi/call/mod.rs b/src/librustc_target/abi/call/mod.rs
index 8ada328a158..fbbd120f934 100644
--- a/src/librustc_target/abi/call/mod.rs
+++ b/src/librustc_target/abi/call/mod.rs
@@ -531,7 +531,7 @@ pub struct FnType<'a, Ty> {
     /// LLVM return type.
     pub ret: ArgType<'a, Ty>,
 
-    pub variadic: bool,
+    pub c_variadic: bool,
 
     pub conv: Conv,
 }
diff --git a/src/librustc_traits/chalk_context/program_clauses.rs b/src/librustc_traits/chalk_context/program_clauses.rs
index 4d8a67ca638..3f88d0e08b4 100644
--- a/src/librustc_traits/chalk_context/program_clauses.rs
+++ b/src/librustc_traits/chalk_context/program_clauses.rs
@@ -105,7 +105,7 @@ fn assemble_builtin_sized_impls<'tcx>(
             let fn_ptr = generic_types::fn_ptr(
                 tcx,
                 fn_ptr.inputs_and_output.len(),
-                fn_ptr.variadic,
+                fn_ptr.c_variadic,
                 fn_ptr.unsafety,
                 fn_ptr.abi
             );
@@ -190,11 +190,11 @@ fn wf_clause_for_raw_ptr<'tcx>(
 fn wf_clause_for_fn_ptr<'tcx>(
     tcx: ty::TyCtxt<'_, '_, 'tcx>,
     arity_and_output: usize,
-    variadic: bool,
+    c_variadic: bool,
     unsafety: hir::Unsafety,
     abi: abi::Abi
 ) -> Clauses<'tcx> {
-    let fn_ptr = generic_types::fn_ptr(tcx, arity_and_output, variadic, unsafety, abi);
+    let fn_ptr = generic_types::fn_ptr(tcx, arity_and_output, c_variadic, unsafety, abi);
 
     let wf_clause = ProgramClause {
         goal: DomainGoal::WellFormed(WellFormed::Ty(fn_ptr)),
@@ -503,7 +503,7 @@ impl ChalkInferenceContext<'cx, 'gcx, 'tcx> {
                         wf_clause_for_fn_ptr(
                             self.infcx.tcx,
                             fn_ptr.inputs_and_output.len(),
-                            fn_ptr.variadic,
+                            fn_ptr.c_variadic,
                             fn_ptr.unsafety,
                             fn_ptr.abi
                         )
diff --git a/src/librustc_traits/generic_types.rs b/src/librustc_traits/generic_types.rs
index 634c024b064..f2ce9631f35 100644
--- a/src/librustc_traits/generic_types.rs
+++ b/src/librustc_traits/generic_types.rs
@@ -24,7 +24,7 @@ crate fn raw_ptr(tcx: TyCtxt<'_, '_, 'tcx>, mutbl: hir::Mutability) -> Ty<'tcx>
 crate fn fn_ptr(
     tcx: ty::TyCtxt<'_, '_, 'tcx>,
     arity_and_output: usize,
-    variadic: bool,
+    c_variadic: bool,
     unsafety: hir::Unsafety,
     abi: abi::Abi
 ) -> Ty<'tcx> {
@@ -37,7 +37,7 @@ crate fn fn_ptr(
 
     let fn_sig = ty::Binder::bind(ty::FnSig {
         inputs_and_output,
-        variadic,
+        c_variadic,
         unsafety,
         abi,
     });
diff --git a/src/librustc_typeck/astconv.rs b/src/librustc_typeck/astconv.rs
index 1d99584eec4..b3694752204 100644
--- a/src/librustc_typeck/astconv.rs
+++ b/src/librustc_typeck/astconv.rs
@@ -18,7 +18,7 @@ use rustc::ty::subst::{Kind, Subst, InternalSubsts, SubstsRef};
 use rustc::ty::wf::object_region_bounds;
 use rustc_data_structures::sync::Lrc;
 use rustc_target::spec::abi;
-use crate::require_c_abi_if_variadic;
+use crate::require_c_abi_if_c_variadic;
 use smallvec::SmallVec;
 use syntax::ast;
 use syntax::feature_gate::{GateIssue, emit_feature_err};
@@ -1768,7 +1768,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> dyn AstConv<'gcx, 'tcx> + 'o {
                 tcx.mk_tup(fields.iter().map(|t| self.ast_ty_to_ty(&t)))
             }
             hir::TyKind::BareFn(ref bf) => {
-                require_c_abi_if_variadic(tcx, &bf.decl, bf.abi, ast_ty.span);
+                require_c_abi_if_c_variadic(tcx, &bf.decl, bf.abi, ast_ty.span);
                 tcx.mk_fn_ptr(self.ty_of_fn(bf.unsafety, bf.abi, &bf.decl))
             }
             hir::TyKind::TraitObject(ref bounds, ref lifetime) => {
@@ -1913,7 +1913,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> dyn AstConv<'gcx, 'tcx> + 'o {
         let bare_fn_ty = ty::Binder::bind(tcx.mk_fn_sig(
             input_tys,
             output_ty,
-            decl.variadic,
+            decl.c_variadic,
             unsafety,
             abi
         ));
diff --git a/src/librustc_typeck/check/callee.rs b/src/librustc_typeck/check/callee.rs
index aeb43635eb7..0a4c0eb3aff 100644
--- a/src/librustc_typeck/check/callee.rs
+++ b/src/librustc_typeck/check/callee.rs
@@ -368,7 +368,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             .0;
         let fn_sig = self.normalize_associated_types_in(call_expr.span, &fn_sig);
 
-        let inputs = if fn_sig.variadic {
+        let inputs = if fn_sig.c_variadic {
             if fn_sig.inputs().len() > 1 {
                 &fn_sig.inputs()[..fn_sig.inputs().len() - 1]
             } else {
@@ -391,7 +391,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             inputs,
             &expected_arg_tys[..],
             arg_exprs,
-            fn_sig.variadic,
+            fn_sig.c_variadic,
             TupleArgumentsFlag::DontTupleArguments,
             def_span,
         );
@@ -424,7 +424,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             fn_sig.inputs(),
             &expected_arg_tys,
             arg_exprs,
-            fn_sig.variadic,
+            fn_sig.c_variadic,
             TupleArgumentsFlag::TupleArguments,
             None,
         );
diff --git a/src/librustc_typeck/check/closure.rs b/src/librustc_typeck/check/closure.rs
index 2a4b17a6399..db89b32be7b 100644
--- a/src/librustc_typeck/check/closure.rs
+++ b/src/librustc_typeck/check/closure.rs
@@ -141,7 +141,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             self.tcx.mk_fn_sig(
                 iter::once(self.tcx.intern_tup(sig.inputs())),
                 sig.output(),
-                sig.variadic,
+                sig.c_variadic,
                 sig.unsafety,
                 sig.abi,
             )
@@ -386,7 +386,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         // Watch out for some surprises and just ignore the
         // expectation if things don't see to match up with what we
         // expect.
-        if expected_sig.sig.variadic != decl.variadic {
+        if expected_sig.sig.c_variadic != decl.c_variadic {
             return self.sig_of_closure_no_expectation(expr_def_id, decl, body);
         } else if expected_sig.sig.inputs_and_output.len() != decl.inputs.len() + 1 {
             return self.sig_of_closure_with_mismatched_number_of_arguments(
@@ -404,7 +404,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         let bound_sig = ty::Binder::bind(self.tcx.mk_fn_sig(
             expected_sig.sig.inputs().iter().cloned(),
             expected_sig.sig.output(),
-            decl.variadic,
+            decl.c_variadic,
             hir::Unsafety::Normal,
             Abi::RustCall,
         ));
@@ -586,7 +586,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         let result = ty::Binder::bind(self.tcx.mk_fn_sig(
             supplied_arguments,
             supplied_return,
-            decl.variadic,
+            decl.c_variadic,
             hir::Unsafety::Normal,
             Abi::RustCall,
         ));
@@ -621,7 +621,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         let result = ty::Binder::bind(self.tcx.mk_fn_sig(
             supplied_arguments,
             self.tcx.types.err,
-            decl.variadic,
+            decl.c_variadic,
             hir::Unsafety::Normal,
             Abi::RustCall,
         ));
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index 202d8bec4e9..3a430f77b6c 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -130,7 +130,7 @@ use std::mem::replace;
 use std::ops::{self, Deref};
 use std::slice;
 
-use crate::require_c_abi_if_variadic;
+use crate::require_c_abi_if_c_variadic;
 use crate::session::{CompileIncomplete, Session};
 use crate::session::config::EntryFnType;
 use crate::TypeAndSubsts;
@@ -1072,7 +1072,7 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>,
     fn_sig = fcx.tcx.mk_fn_sig(
         fn_sig.inputs().iter().cloned(),
         revealed_ret_ty,
-        fn_sig.variadic,
+        fn_sig.c_variadic,
         fn_sig.unsafety,
         fn_sig.abi
     );
@@ -1426,7 +1426,7 @@ pub fn check_item_type<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, it: &'tcx hir::Ite
                     }
 
                     if let hir::ForeignItemKind::Fn(ref fn_decl, _, _) = item.node {
-                        require_c_abi_if_variadic(tcx, fn_decl, m.abi, item.span);
+                        require_c_abi_if_c_variadic(tcx, fn_decl, m.abi, item.span);
                     }
                 }
             }
@@ -2783,7 +2783,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             &method.sig.inputs()[1..]
         );
         self.check_argument_types(sp, expr_sp, &method.sig.inputs()[1..], &expected_arg_tys[..],
-                                  args_no_rcvr, method.sig.variadic, tuple_arguments,
+                                  args_no_rcvr, method.sig.c_variadic, tuple_arguments,
                                   self.tcx.hir().span_if_local(method.def_id));
         method.sig.output()
     }
@@ -2862,7 +2862,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                             fn_inputs: &[Ty<'tcx>],
                             mut expected_arg_tys: &[Ty<'tcx>],
                             args: &'gcx [hir::Expr],
-                            variadic: bool,
+                            c_variadic: bool,
                             tuple_arguments: TupleArgumentsFlag,
                             def_span: Option<Span>) {
         let tcx = self.tcx;
@@ -2886,11 +2886,11 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         let param_count_error = |expected_count: usize,
                                  arg_count: usize,
                                  error_code: &str,
-                                 variadic: bool,
+                                 c_variadic: bool,
                                  sugg_unit: bool| {
             let mut err = tcx.sess.struct_span_err_with_code(sp,
                 &format!("this function takes {}{} but {} {} supplied",
-                    if variadic {"at least "} else {""},
+                    if c_variadic { "at least " } else { "" },
                     potentially_plural_count(expected_count, "parameter"),
                     potentially_plural_count(arg_count, "parameter"),
                     if arg_count == 1 {"was"} else {"were"}),
@@ -2910,7 +2910,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                     Applicability::MachineApplicable);
             } else {
                 err.span_label(sp, format!("expected {}{}",
-                                           if variadic {"at least "} else {""},
+                                           if c_variadic { "at least " } else { "" },
                                            potentially_plural_count(expected_count, "parameter")));
             }
             err.emit();
@@ -2944,7 +2944,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             }
         } else if expected_arg_count == supplied_arg_count {
             fn_inputs.to_vec()
-        } else if variadic {
+        } else if c_variadic {
             if supplied_arg_count >= expected_arg_count {
                 fn_inputs.to_vec()
             } else {
@@ -2991,10 +2991,10 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                 self.select_obligations_where_possible(false);
             }
 
-            // For variadic functions, we don't have a declared type for all of
+            // For C-variadic functions, we don't have a declared type for all of
             // the arguments hence we only do our usual type checking with
             // the arguments who's types we do know.
-            let t = if variadic {
+            let t = if c_variadic {
                 expected_arg_count
             } else if tuple_arguments == TupleArguments {
                 args.len()
@@ -3043,7 +3043,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
 
         // We also need to make sure we at least write the ty of the other
         // arguments which we skipped above.
-        if variadic {
+        if c_variadic {
             fn variadic_error<'tcx>(s: &Session, span: Span, t: Ty<'tcx>, cast_ty: &str) {
                 use crate::structured_errors::{VariadicError, StructuredDiagnostic};
                 VariadicError::new(s, span, t, cast_ty).diagnostic().emit();
diff --git a/src/librustc_typeck/lib.rs b/src/librustc_typeck/lib.rs
index 419796a2014..2095c81d0fb 100644
--- a/src/librustc_typeck/lib.rs
+++ b/src/librustc_typeck/lib.rs
@@ -136,14 +136,14 @@ fn check_type_alias_enum_variants_enabled<'a, 'gcx, 'tcx>(tcx: TyCtxt<'a, 'gcx,
     }
 }
 
-fn require_c_abi_if_variadic(tcx: TyCtxt<'_, '_, '_>,
-                             decl: &hir::FnDecl,
-                             abi: Abi,
-                             span: Span) {
-    if decl.variadic && !(abi == Abi::C || abi == Abi::Cdecl) {
+fn require_c_abi_if_c_variadic(tcx: TyCtxt<'_, '_, '_>,
+                               decl: &hir::FnDecl,
+                               abi: Abi,
+                               span: Span) {
+    if decl.c_variadic && !(abi == Abi::C || abi == Abi::Cdecl) {
         let mut err = struct_span_err!(tcx.sess, span, E0045,
-            "variadic function must have C or cdecl calling convention");
-        err.span_label(span, "variadics require C or cdecl calling convention").emit();
+            "C-variadic function must have C or cdecl calling convention");
+        err.span_label(span, "C-variadics require C or cdecl calling convention").emit();
     }
 }
 
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 5bae00b9cb8..b4bf6665d4e 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -1804,7 +1804,7 @@ impl Arg {
 pub struct FnDecl {
     pub inputs: Vec<Arg>,
     pub output: FunctionRetTy,
-    pub variadic: bool,
+    pub c_variadic: bool,
 }
 
 impl FnDecl {
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index 27b0cfb1630..0bdc7fd60cb 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -985,7 +985,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
         P(ast::FnDecl {
             inputs,
             output,
-            variadic: false
+            c_variadic: false
         })
     }
 
diff --git a/src/libsyntax/mut_visit.rs b/src/libsyntax/mut_visit.rs
index 8efc4689cac..032a0e993ae 100644
--- a/src/libsyntax/mut_visit.rs
+++ b/src/libsyntax/mut_visit.rs
@@ -673,7 +673,7 @@ pub fn noop_visit_asyncness<T: MutVisitor>(asyncness: &mut IsAsync, vis: &mut T)
 }
 
 pub fn noop_visit_fn_decl<T: MutVisitor>(decl: &mut P<FnDecl>, vis: &mut T) {
-    let FnDecl { inputs, output, variadic: _ } = decl.deref_mut();
+    let FnDecl { inputs, output, c_variadic: _ } = decl.deref_mut();
     visit_vec(inputs, |input| vis.visit_arg(input));
     match output {
         FunctionRetTy::Default(span) => vis.visit_span(span),
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index b58091b57da..5f3b08bf942 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -1457,12 +1457,12 @@ impl<'a> Parser<'a> {
         };
 
         self.expect_keyword(keywords::Fn)?;
-        let (inputs, variadic) = self.parse_fn_args(false, true)?;
+        let (inputs, c_variadic) = self.parse_fn_args(false, true)?;
         let ret_ty = self.parse_ret_ty(false)?;
         let decl = P(FnDecl {
             inputs,
             output: ret_ty,
-            variadic,
+            c_variadic,
         });
         Ok(TyKind::BareFn(P(BareFnTy {
             abi,
@@ -1635,7 +1635,7 @@ impl<'a> Parser<'a> {
     }
 
     fn parse_ty_common(&mut self, allow_plus: bool, allow_qpath_recovery: bool,
-                       allow_variadic: bool) -> PResult<'a, P<Ty>> {
+                       allow_c_variadic: bool) -> PResult<'a, P<Ty>> {
         maybe_whole!(self, NtTy, |x| x);
 
         let lo = self.span;
@@ -1773,12 +1773,12 @@ impl<'a> Parser<'a> {
                 }
             }
         } else if self.check(&token::DotDotDot) {
-            if allow_variadic {
+            if allow_c_variadic {
                 self.eat(&token::DotDotDot);
                 TyKind::CVarArgs
             } else {
                 return Err(self.fatal(
-                    "only foreign functions are allowed to be variadic"
+                    "only foreign functions are allowed to be C-variadic"
                 ));
             }
         } else {
@@ -1969,7 +1969,7 @@ impl<'a> Parser<'a> {
 
     /// This version of parse arg doesn't necessarily require identifier names.
     fn parse_arg_general(&mut self, require_name: bool, is_trait_item: bool,
-                         allow_variadic: bool) -> PResult<'a, Arg> {
+                         allow_c_variadic: bool) -> PResult<'a, Arg> {
         maybe_whole!(self, NtArg, |x| x);
 
         if let Ok(Some(_)) = self.parse_self_arg() {
@@ -2018,12 +2018,12 @@ impl<'a> Parser<'a> {
             }
 
             self.eat_incorrect_doc_comment("a method argument's type");
-            (pat, self.parse_ty_common(true, true, allow_variadic)?)
+            (pat, self.parse_ty_common(true, true, allow_c_variadic)?)
         } else {
             debug!("parse_arg_general ident_to_pat");
             let parser_snapshot_before_ty = self.clone();
             self.eat_incorrect_doc_comment("a method argument's type");
-            let mut ty = self.parse_ty_common(true, true, allow_variadic);
+            let mut ty = self.parse_ty_common(true, true, allow_c_variadic);
             if ty.is_ok() && self.token != token::Comma &&
                self.token != token::CloseDelim(token::Paren) {
                 // This wasn't actually a type, but a pattern looking like a type,
@@ -2042,7 +2042,7 @@ impl<'a> Parser<'a> {
                     (pat, ty)
                 }
                 Err(mut err) => {
-                    // If this is a variadic argument and we hit an error, return the
+                    // If this is a C-variadic argument and we hit an error, return the
                     // error.
                     if self.token == token::DotDotDot {
                         return Err(err);
@@ -6122,12 +6122,12 @@ impl<'a> Parser<'a> {
         Ok(where_clause)
     }
 
-    fn parse_fn_args(&mut self, named_args: bool, allow_variadic: bool)
+    fn parse_fn_args(&mut self, named_args: bool, allow_c_variadic: bool)
                      -> PResult<'a, (Vec<Arg> , bool)> {
         self.expect(&token::OpenDelim(token::Paren))?;
 
         let sp = self.span;
-        let mut variadic = false;
+        let mut c_variadic = false;
         let (args, recovered): (Vec<Option<Arg>>, bool) =
             self.parse_seq_to_before_end(
                 &token::CloseDelim(token::Paren),
@@ -6141,14 +6141,14 @@ impl<'a> Parser<'a> {
                         named_args
                     };
                     match p.parse_arg_general(enforce_named_args, false,
-                                              allow_variadic) {
+                                              allow_c_variadic) {
                         Ok(arg) => {
                             if let TyKind::CVarArgs = arg.ty.node {
-                                variadic = true;
+                                c_variadic = true;
                                 if p.token != token::CloseDelim(token::Paren) {
                                     let span = p.span;
                                     p.span_err(span,
-                                        "`...` must be last in argument list in variadic function");
+                                        "`...` must be the last argument of a C-variadic function");
                                     Ok(None)
                                 } else {
                                     Ok(Some(arg))
@@ -6176,24 +6176,24 @@ impl<'a> Parser<'a> {
 
         let args: Vec<_> = args.into_iter().filter_map(|x| x).collect();
 
-        if variadic && args.is_empty() {
+        if c_variadic && args.is_empty() {
             self.span_err(sp,
-                          "variadic function must be declared with at least one named argument");
+                          "C-variadic function must be declared with at least one named argument");
         }
 
-        Ok((args, variadic))
+        Ok((args, c_variadic))
     }
 
     /// Parses the argument list and result type of a function declaration.
-    fn parse_fn_decl(&mut self, allow_variadic: bool) -> PResult<'a, P<FnDecl>> {
+    fn parse_fn_decl(&mut self, allow_c_variadic: bool) -> PResult<'a, P<FnDecl>> {
 
-        let (args, variadic) = self.parse_fn_args(true, allow_variadic)?;
+        let (args, c_variadic) = self.parse_fn_args(true, allow_c_variadic)?;
         let ret_ty = self.parse_ret_ty(true)?;
 
         Ok(P(FnDecl {
             inputs: args,
             output: ret_ty,
-            variadic,
+            c_variadic,
         }))
     }
 
@@ -6340,7 +6340,7 @@ impl<'a> Parser<'a> {
         Ok(P(FnDecl {
             inputs: fn_inputs,
             output: self.parse_ret_ty(true)?,
-            variadic: false
+            c_variadic: false
         }))
     }
 
@@ -6366,7 +6366,7 @@ impl<'a> Parser<'a> {
         Ok(P(FnDecl {
             inputs: inputs_captures,
             output,
-            variadic: false
+            c_variadic: false
         }))
     }
 
@@ -6398,8 +6398,8 @@ impl<'a> Parser<'a> {
                      abi: Abi)
                      -> PResult<'a, ItemInfo> {
         let (ident, mut generics) = self.parse_fn_header()?;
-        let allow_variadic = abi == Abi::C && unsafety == Unsafety::Unsafe;
-        let decl = self.parse_fn_decl(allow_variadic)?;
+        let allow_c_variadic = abi == Abi::C && unsafety == Unsafety::Unsafe;
+        let decl = self.parse_fn_decl(allow_c_variadic)?;
         generics.where_clause = self.parse_where_clause()?;
         let (inner_attrs, body) = self.parse_inner_attrs_and_block()?;
         let header = FnHeader { unsafety, asyncness, constness, abi };
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index b3964d0ce9c..4f4336c5b27 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -2814,7 +2814,7 @@ impl<'a> State<'a> {
         -> io::Result<()> {
         self.popen()?;
         self.commasep(Inconsistent, &decl.inputs, |s, arg| s.print_arg(arg, false))?;
-        if decl.variadic {
+        if decl.c_variadic {
             self.s.word(", ...")?;
         }
         self.pclose()?;
@@ -3241,7 +3241,7 @@ mod tests {
             let decl = ast::FnDecl {
                 inputs: Vec::new(),
                 output: ast::FunctionRetTy::Default(syntax_pos::DUMMY_SP),
-                variadic: false
+                c_variadic: false
             };
             let generics = ast::Generics::default();
             assert_eq!(
diff --git a/src/test/run-pass-fulldeps/pprust-expr-roundtrip.rs b/src/test/run-pass-fulldeps/pprust-expr-roundtrip.rs
index 956bc5ad862..80e0b0102af 100644
--- a/src/test/run-pass-fulldeps/pprust-expr-roundtrip.rs
+++ b/src/test/run-pass-fulldeps/pprust-expr-roundtrip.rs
@@ -112,7 +112,7 @@ fn iter_exprs(depth: usize, f: &mut FnMut(P<Expr>)) {
                 let decl = P(FnDecl {
                     inputs: vec![],
                     output: FunctionRetTy::Default(DUMMY_SP),
-                    variadic: false,
+                    c_variadic: false,
                 });
                 iter_exprs(depth - 1, &mut |e| g(
                         ExprKind::Closure(CaptureBy::Value,
diff --git a/src/test/ui/c-variadic/variadic-ffi-1.stderr b/src/test/ui/c-variadic/variadic-ffi-1.stderr
index 52d7394d6af..61d55ce0d3e 100644
--- a/src/test/ui/c-variadic/variadic-ffi-1.stderr
+++ b/src/test/ui/c-variadic/variadic-ffi-1.stderr
@@ -1,8 +1,8 @@
-error[E0045]: variadic function must have C or cdecl calling convention
+error[E0045]: C-variadic function must have C or cdecl calling convention
   --> $DIR/variadic-ffi-1.rs:5:5
    |
 LL |     fn printf(_: *const u8, ...); //~ ERROR: variadic function must have C or cdecl calling
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ variadics require C or cdecl calling convention
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ C-variadics require C or cdecl calling convention
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/c-variadic/variadic-ffi-2.stderr b/src/test/ui/c-variadic/variadic-ffi-2.stderr
index cb2a9f874b7..4c8b8d2b2e1 100644
--- a/src/test/ui/c-variadic/variadic-ffi-2.stderr
+++ b/src/test/ui/c-variadic/variadic-ffi-2.stderr
@@ -1,8 +1,8 @@
-error[E0045]: variadic function must have C or cdecl calling convention
+error[E0045]: C-variadic function must have C or cdecl calling convention
   --> $DIR/variadic-ffi-2.rs:3:11
    |
 LL | fn baz(f: extern "stdcall" fn(usize, ...)) {
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ variadics require C or cdecl calling convention
+   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ C-variadics require C or cdecl calling convention
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/error-codes/E0045.stderr b/src/test/ui/error-codes/E0045.stderr
index b38bbc169bd..0ce91f0a401 100644
--- a/src/test/ui/error-codes/E0045.stderr
+++ b/src/test/ui/error-codes/E0045.stderr
@@ -1,8 +1,8 @@
-error[E0045]: variadic function must have C or cdecl calling convention
+error[E0045]: C-variadic function must have C or cdecl calling convention
   --> $DIR/E0045.rs:1:17
    |
 LL | extern "Rust" { fn foo(x: u8, ...); }   //~ ERROR E0045
-   |                 ^^^^^^^^^^^^^^^^^^^ variadics require C or cdecl calling convention
+   |                 ^^^^^^^^^^^^^^^^^^^ C-variadics require C or cdecl calling convention
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/invalid/invalid-variadic-function.rs b/src/test/ui/invalid/invalid-variadic-function.rs
index aea630e7c26..8d23f0e4770 100644
--- a/src/test/ui/invalid/invalid-variadic-function.rs
+++ b/src/test/ui/invalid/invalid-variadic-function.rs
@@ -1,3 +1,3 @@
 extern "C" fn foo(x: u8, ...);
-//~^ ERROR only foreign functions are allowed to be variadic
+//~^ ERROR only foreign functions are allowed to be C-variadic
 //~| ERROR expected one of `->`, `where`, or `{`, found `;`
diff --git a/src/test/ui/invalid/invalid-variadic-function.stderr b/src/test/ui/invalid/invalid-variadic-function.stderr
index 7a0b8066fd5..b2dbf8b9190 100644
--- a/src/test/ui/invalid/invalid-variadic-function.stderr
+++ b/src/test/ui/invalid/invalid-variadic-function.stderr
@@ -1,4 +1,4 @@
-error: only foreign functions are allowed to be variadic
+error: only foreign functions are allowed to be C-variadic
   --> $DIR/invalid-variadic-function.rs:1:26
    |
 LL | extern "C" fn foo(x: u8, ...);
diff --git a/src/test/ui/parser/variadic-ffi-3.rs b/src/test/ui/parser/variadic-ffi-3.rs
index 13bce27bb83..ce83cc87abe 100644
--- a/src/test/ui/parser/variadic-ffi-3.rs
+++ b/src/test/ui/parser/variadic-ffi-3.rs
@@ -1,5 +1,5 @@
 fn foo(x: isize, ...) {
-    //~^ ERROR: only foreign functions are allowed to be variadic
+    //~^ ERROR: only foreign functions are allowed to be C-variadic
 }
 
 fn main() {}
diff --git a/src/test/ui/parser/variadic-ffi-3.stderr b/src/test/ui/parser/variadic-ffi-3.stderr
index 150de9e63d3..8ea4d194396 100644
--- a/src/test/ui/parser/variadic-ffi-3.stderr
+++ b/src/test/ui/parser/variadic-ffi-3.stderr
@@ -1,4 +1,4 @@
-error: only foreign functions are allowed to be variadic
+error: only foreign functions are allowed to be C-variadic
   --> $DIR/variadic-ffi-3.rs:1:18
    |
 LL | fn foo(x: isize, ...) {
diff --git a/src/test/ui/parser/variadic-ffi-4.rs b/src/test/ui/parser/variadic-ffi-4.rs
index 812ed256a5d..5f8b3f8f539 100644
--- a/src/test/ui/parser/variadic-ffi-4.rs
+++ b/src/test/ui/parser/variadic-ffi-4.rs
@@ -1,5 +1,5 @@
 extern "C" fn foo(x: isize, ...) {
-    //~^ ERROR: only foreign functions are allowed to be variadic
+    //~^ ERROR: only foreign functions are allowed to be C-variadic
 }
 
 fn main() {}
diff --git a/src/test/ui/parser/variadic-ffi-4.stderr b/src/test/ui/parser/variadic-ffi-4.stderr
index 2d036b0cf37..69fbf84869c 100644
--- a/src/test/ui/parser/variadic-ffi-4.stderr
+++ b/src/test/ui/parser/variadic-ffi-4.stderr
@@ -1,4 +1,4 @@
-error: only foreign functions are allowed to be variadic
+error: only foreign functions are allowed to be C-variadic
   --> $DIR/variadic-ffi-4.rs:1:29
    |
 LL | extern "C" fn foo(x: isize, ...) {