try assuming macros are fn call-like, emit warning if not

alecmocatta · Oct 15, 2019 · 10aa536 · 10aa536
1 parent 9b4a894
commit 10aa536
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Showing 2 changed files with 20 additions and 8 deletions.
diff --git a/serde_closure_derive/src/lib.rs b/serde_closure_derive/src/lib.rs
@@ -10,6 +10,7 @@
 //! documentation.
 
 #![doc(html_root_url = "https://docs.rs/serde_closure_derive/0.2.2")]
+#![feature(proc_macro_diagnostic)]
 #![allow(non_snake_case)] // due to proc-macro-hack can't apply this directly
 
 extern crate proc_macro;
@@ -19,7 +20,7 @@ use proc_macro_hack::proc_macro_hack;
 use quote::{quote, ToTokens};
 use std::{collections::HashSet, iter, iter::successors, str};
 use syn::{
-	parse::{Parse, ParseStream}, parse2, token::Bracket, Arm, Block, Error, Expr, ExprArray, ExprAssign, ExprAssignOp, ExprAsync, ExprAwait, ExprBinary, ExprBlock, ExprBox, ExprBreak, ExprCall, ExprCast, ExprClosure, ExprField, ExprForLoop, ExprGroup, ExprIf, ExprIndex, ExprLet, ExprLoop, ExprMatch, ExprMethodCall, ExprParen, ExprPath, ExprRange, ExprReference, ExprRepeat, ExprReturn, ExprStruct, ExprTry, ExprTryBlock, ExprTuple, ExprType, ExprUnary, ExprUnsafe, ExprWhile, ExprYield, FieldValue, Ident, Local, Member, Pat, PatBox, PatIdent, PatReference, PatSlice, PatTuple, PatTupleStruct, PatType, Path, PathArguments, PathSegment, Stmt, Type, TypeInfer, TypeReference, UnOp
+	parse::{Parse, ParseStream}, parse2, spanned::Spanned, token::Bracket, Arm, Block, Error, Expr, ExprArray, ExprAssign, ExprAssignOp, ExprAsync, ExprAwait, ExprBinary, ExprBlock, ExprBox, ExprBreak, ExprCall, ExprCast, ExprClosure, ExprField, ExprForLoop, ExprGroup, ExprIf, ExprIndex, ExprLet, ExprLoop, ExprMacro, ExprMatch, ExprMethodCall, ExprParen, ExprPath, ExprRange, ExprReference, ExprRepeat, ExprReturn, ExprStruct, ExprTry, ExprTryBlock, ExprTuple, ExprType, ExprUnary, ExprUnsafe, ExprWhile, ExprYield, FieldValue, Ident, Local, Member, Pat, PatBox, PatIdent, PatReference, PatSlice, PatTuple, PatTupleStruct, PatType, Path, PathArguments, PathSegment, Stmt, Type, TypeInfer, TypeReference, UnOp
 };
 
 #[proc_macro_hack]
@@ -730,6 +731,24 @@ impl<'a> State<'a> {
 				state.expr(cond);
 				state.block(&mut body.stmts);
 			}
+			Expr::Macro(ExprMacro { ref mut mac, .. }) => {
+				let tokens = &mac.tokens;
+				if let Ok(expr) = parse2::<ExprCall>(quote! { self::abc(#tokens) }) {
+					let mut expr = Expr::Call(expr);
+					self.expr(&mut expr);
+					let expr = if let Expr::Call(expr) = expr {
+						expr
+					} else {
+						unreachable!()
+					};
+					mac.tokens = expr.args.to_token_stream();
+				} else {
+					mac.span()
+						.unwrap()
+						.warning("See https://github.com/alecmocatta/serde_closure/issues/16")
+						.emit()
+				}
+			}
 			_ => (),
 		}
 	}

diff --git a/tests/test.rs b/tests/test.rs
@@ -81,7 +81,6 @@ fn fnonce() {
 			a += *e;
 			*h += (b.clone() + f.as_str() + g.as_str()).as_str();
 			b += h.as_str();
-			let (a, b) = (&a, &b);
 			format!("{}{}{}{}{}{}{}{}", a, b, c, d, e, f, g, h)
 		}
 	);
@@ -159,7 +158,6 @@ fn fnmut() {
 				// *a += *e;
 				*h += (b.clone() + f.as_str() + g.as_str()).as_str();
 				// *b += h.as_str();
-				let (a, b) = (&a, &b);
 				format!("{}{}{}{}{}{}{}{}", a, b, c, d, e, f, g, h)
 			})(
 				0,
@@ -180,7 +178,6 @@ fn fnmut() {
 			a += *e;
 			*h += (b.clone() + f.as_str() + g.as_str()).as_str();
 			b += h.as_str();
-			let (a, b) = (&a, &b);
 			format!("{}{}{}{}{}{}{}{}", a, b, c, d, e, f, g, h)
 		}
 	);
@@ -201,7 +198,6 @@ fn fnmut() {
 	let _ = unfold(0_usize, FnMut!(|acc: &mut _| Some(*acc)));
 	let x = 123_usize;
 	let c = FnMut!(move |arg: String| {
-		let x = &x;
 		println!("{} {}", x, arg);
 	});
 	let _ = (c, c);
@@ -308,7 +304,6 @@ fn fnref() {
 				// *a += *e;
 				*h += (b.clone() + f.as_str() + g.as_str()).as_str();
 				// *b += h.as_str();
-				let (a, b) = (&a, &b);
 				format!("{}{}{}{}{}{}{}{}", a, b, c, d, e, f, g, h)
 			})(
 				0,
@@ -336,7 +331,6 @@ fn fnref() {
 		// *a += *e;
 		*h += (b.clone() + f.as_str() + g.as_str()).as_str();
 		// *b += h.as_str();
-		let (a, b) = (&a, &b);
 		format!("{}{}{}{}{}{}{}{}", a, b, c, d, e, f, g, h)
 	});
 	test(x);
@@ -356,7 +350,6 @@ fn fnref() {
 	let _ = unfold(0_usize, Fn!(|acc: &mut _| Some(*acc)));
 	let x = 123_usize;
 	let c = Fn!(move |arg: String| {
-		let x = &x;
 		println!("{} {}", x, arg);
 	});
 	let _ = (c, c);