Remove the decl arg from FnAbi::llvm_type

We can apply the `c_variadic` fix all the time, rather than trying to
distinguish between declarations and any other use.

compiler/rustc_codegen_llvm/src/abi.rs

@@ -344,18 +344,18 @@ impl ArgAbiMethods<'tcx> for Builder<'a, 'll, 'tcx> {
 }
 
 pub trait FnAbiLlvmExt<'tcx> {
-    fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>, decl: bool) -> &'ll Type;
+    fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type;
     fn ptr_to_llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type;
     fn llvm_cconv(&self) -> llvm::CallConv;
     fn apply_attrs_llfn(&self, cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value);
     fn apply_attrs_callsite(&self, bx: &mut Builder<'a, 'll, 'tcx>, callsite: &'ll Value);
 }
 
 impl<'tcx> FnAbiLlvmExt<'tcx> for FnAbi<'tcx, Ty<'tcx>> {
-    fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>, decl: bool) -> &'ll Type {
-        // Ignore extra args when calling C variadic functions.
-        let args =
-            if decl && self.c_variadic { &self.args[..self.fixed_count] } else { &self.args };
+    fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type {
+        // Ignore "extra" args from the call site for C variadic functions.
+        // Only the "fixed" args are part of the LLVM function signature.
+        let args = if self.c_variadic { &self.args[..self.fixed_count] } else { &self.args };
 
         let args_capacity: usize = args.iter().map(|arg|
             if arg.pad.is_some() { 1 } else { 0 } +
@@ -414,7 +414,7 @@ impl<'tcx> FnAbiLlvmExt<'tcx> for FnAbi<'tcx, Ty<'tcx>> {
     fn ptr_to_llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type {
         unsafe {
             llvm::LLVMPointerType(
-                self.llvm_type(cx, false),
+                self.llvm_type(cx),
                 cx.data_layout().instruction_address_space.0 as c_uint,
             )
         }

compiler/rustc_codegen_llvm/src/declare.rs

@@ -90,7 +90,7 @@ impl CodegenCx<'ll, 'tcx> {
             name,
             fn_abi.llvm_cconv(),
             llvm::UnnamedAddr::Global,
-            fn_abi.llvm_type(self, false),
+            fn_abi.llvm_type(self),
         );
         fn_abi.apply_attrs_llfn(self, llfn);
         llfn

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -712,7 +712,7 @@ fn gen_fn<'ll, 'tcx>(
     codegen: &mut dyn FnMut(Builder<'_, 'll, 'tcx>),
 ) -> (&'ll Type, &'ll Value) {
     let fn_abi = FnAbi::of_fn_ptr(cx, rust_fn_sig, &[]);
-    let llty = fn_abi.llvm_type(cx, false);
+    let llty = fn_abi.llvm_type(cx);
     let llfn = cx.declare_fn(name, &fn_abi);
     cx.set_frame_pointer_type(llfn);
     cx.apply_target_cpu_attr(llfn);

compiler/rustc_codegen_llvm/src/type_.rs

@@ -276,8 +276,7 @@ impl LayoutTypeMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         ty.llvm_type(self)
     }
     fn fn_decl_backend_type(&self, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> &'ll Type {
-        // This does not include extra args when calling C variadic functions.
-        fn_abi.llvm_type(self, true)
+        fn_abi.llvm_type(self)
     }
     fn fn_ptr_backend_type(&self, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> &'ll Type {
         fn_abi.ptr_to_llvm_type(self)