1 // Copyright 2024 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 //! Implementation of the `call_method!` series of macros. These macros are meant to be used as
16 //! function-like macros and implement a statically type-safe way to call Java methods while also
17 //! caching the method id. The macro arguments are implemented in [`mod ast`](mod@ast) and the
18 //! generated code is implemented in [`mod codegen`](mod@codegen).
19
20 use proc_macro2::TokenStream;
21 use syn::parse_quote;
22
23 use ast::{ConstructorArgs, InstanceArgs, StaticArgs};
24 use codegen::{MethodCall, MethodInfo, Receiver};
25
26 mod ast;
27 mod codegen;
28
29 /// See [`crate::call_method!`] for usage.
call_method(args: TokenStream) -> syn::Result<TokenStream>30 pub fn call_method(args: TokenStream) -> syn::Result<TokenStream> {
31 let args = syn::parse2::<InstanceArgs>(args)?;
32
33 let method_info = MethodInfo::new(args.cls, args.name, args.sig);
34 let receiver = Receiver::Instance(args.this);
35 let method_call = MethodCall::new(
36 args.env,
37 method_info,
38 receiver,
39 args.args.into_iter().collect(),
40 );
41
42 method_call.generate().map_err(syn::Error::from)
43 }
44
45 /// See [`crate::call_static_method!`] for usage.
call_static_method(args: TokenStream) -> syn::Result<TokenStream>46 pub fn call_static_method(args: TokenStream) -> syn::Result<TokenStream> {
47 let args = syn::parse2::<StaticArgs>(args)?;
48
49 let method_info = MethodInfo::new(args.cls, args.name, args.sig);
50 let receiver = Receiver::Static;
51 let method_call = MethodCall::new(
52 args.env,
53 method_info,
54 receiver,
55 args.args.into_iter().collect(),
56 );
57
58 method_call.generate().map_err(syn::Error::from)
59 }
60
61 /// See [`crate::call_constructor!`] for usage.
call_constructor(args: TokenStream) -> syn::Result<TokenStream>62 pub fn call_constructor(args: TokenStream) -> syn::Result<TokenStream> {
63 let args = syn::parse2::<ConstructorArgs>(args)?;
64
65 let name = parse_quote!["<init>"];
66 let method_info = MethodInfo::new(args.cls, name, args.sig);
67 let receiver = Receiver::Constructor;
68 let method_call = MethodCall::new(
69 args.env,
70 method_info,
71 receiver,
72 args.args.into_iter().collect(),
73 );
74
75 method_call.generate().map_err(syn::Error::from)
76 }
77
78 #[cfg(test)]
79 mod test {
80 use super::*;
81 use quote::quote;
82
83 #[test]
call_method_error()84 fn call_method_error() {
85 let out = call_method(quote![&mut env, &CLS, "method", "INVALID", &this_obj]);
86 assert!(out.is_err());
87 }
88
89 #[test]
call_static_method_error()90 fn call_static_method_error() {
91 let out = call_static_method(quote![&mut env, &CLS, "method", "INVALID"]);
92 assert!(out.is_err());
93 }
94
95 #[test]
call_constructor_error()96 fn call_constructor_error() {
97 let out = call_constructor(quote![&mut env, &CLS, "INVALID"]);
98 assert!(out.is_err());
99 }
100 }
101