Method check_call

crates/rustc_codegen_nvvm/src/builder.rs:1199–1250

(
        &mut self,
        typ: &str,
        llfn: &'ll Value,
        args: &'b [&'ll Value],
    )

    }

    fn check_call<'b>(
        &mut self,
        typ: &str,
        llfn: &'ll Value,
        args: &'b [&'ll Value],
    ) -> Cow<'b, [&'ll Value]> {
        let mut fn_ty = self.cx.val_ty(llfn);
        // Strip off pointers
        while self.cx.type_kind(fn_ty) == TypeKind::Pointer {
            fn_ty = self.cx.element_type(fn_ty);
        }

        assert!(
            self.cx.type_kind(fn_ty) == TypeKind::Function,
            "builder::{} not passed a function, but {:?}",
            typ,
            fn_ty
        );

        let param_tys = self.cx.func_params_types(fn_ty);

        let all_args_match = param_tys
            .iter()
            .zip(args.iter().map(|&v| self.val_ty(v)))
            .all(|(expected_ty, actual_ty)| *expected_ty == actual_ty);

        if all_args_match {
            return Cow::Borrowed(args);
        }

        let casted_args: Vec<_> = param_tys
            .into_iter()
            .zip(args.iter())
            .enumerate()
            .map(|(_, (expected_ty, &actual_val))| {
                let actual_ty = self.val_ty(actual_val);

                if expected_ty != actual_ty {
                    trace!(
                        "Expected arg to be {:?} but instead found {:?}, bitcasting the pain away",
                        expected_ty,
                        actual_ty
                    );
                    self.bitcast(actual_val, expected_ty)
                } else {
                    actual_val
                }
            })
            .collect();

        Cow::Owned(casted_args)
    }

    pub fn va_arg(&mut self, list: &'ll Value, ty: &'ll Type) -> &'ll Value {
        unsafe { llvm::LLVMBuildVAArg(self.llbuilder, list, ty, unnamed()) }