Fix parsing logic in proc_macro::quote

tests/ui/proc-macro/quote/auxiliary/basic.rs

@@ -11,6 +11,15 @@ use proc_macro::*;
 
 #[proc_macro]
 pub fn run_tests(_: TokenStream) -> TokenStream {
+    test_sep1();
+    test_sep2();
+    test_sep_group1();
+    test_sep_group2();
+    test_dollar_dollar1();
+    test_dollar_dollar2();
+    test_dollar_dollar3();
+    test_dollar_dollar4();
+
     test_quote_impl();
     test_substitution();
     test_iter();
@@ -50,6 +59,75 @@ pub fn run_tests(_: TokenStream) -> TokenStream {
     TokenStream::new()
 }
 
+fn test_sep1() {
+    let iter = ["a", "b"].into_iter();
+    let tokens = quote!($($iter) << *);
+
+    let expected = "\"a\" << \"b\"";
+    assert_eq!(expected, tokens.to_string());
+}
+
+fn test_sep2() {
+    let iter1 = ["a", "b"].into_iter();
+    let iter2 = [1, 2, 3];
+    let tokens = quote!($($iter1) ($($iter1) $($iter2),* A) *);
+
+    let expected = "\"a\" ($(\"b\") 1i32 , 2i32 , 3i32 A) \"b\"";
+    assert_eq!(expected, tokens.to_string());
+}
+
+fn test_sep_group1() {
+    let x = "X";
+    let iter = ["a", "b"].into_iter();
+    let tokens = quote!($($x) >> $($iter) << *);
+
+    let expected = "$(\"X\") >> \"a\" << \"b\"";
+    assert_eq!(expected, tokens.to_string());
+}
+
+fn test_sep_group2() {
+    let x = "X";
+    let iter = ["a", "b"].into_iter();
+    let tokens = quote!($($x) >> > $($iter) << *);
+
+    let expected = "$(\"X\") >> > \"a\" << \"b\"";
+    assert_eq!(expected, tokens.to_string());
+}
+
+fn test_dollar_dollar1() {
+    let iter = ["a", "b"].into_iter();
+    let tokens = quote!($$ x $($$ x $iter)*);
+
+    let expected = "$x $x \"a\" $x \"b\"";
+    assert_eq!(expected, tokens.to_string());
+}
+
+fn test_dollar_dollar2() {
+    let iter = ["a", "b", "c"].into_iter();
+    let tokens = quote!($($iter) $$ *);
+
+    let expected = "\"a\" $ \"b\" $ \"c\"";
+    assert_eq!(expected, tokens.to_string());
+}
+
+fn test_dollar_dollar3() {
+    let x = "X";
+    let iter = ["a", "b", "c"].into_iter();
+    let tokens = quote!($($x)$$($x),*);
+
+    let expected = "$(\"X\") $ (\"X\"),*";
+    assert_eq!(expected, tokens.to_string());
+}
+
+fn test_dollar_dollar4() {
+    let x = "X";
+    let iter = ["a", "b", "c"].into_iter();
+    let tokens = quote!($($x)$$y$($iter)*);
+
+    let expected = "$(\"X\") $y \"a\" \"b\" \"c\"";
+    assert_eq!(expected, tokens.to_string());
+}
+
 // Based on https://github.com/dtolnay/quote/blob/0245506323a3616daa2ee41c6ad0b871e4d78ae4/tests/test.rs
 //
 // FIXME(quote):
@@ -106,7 +184,7 @@ fn test_iter() {
 
     assert_eq!("X, X, X, X,", quote!($($primes,)*).to_string());
 
-    assert_eq!("X, X, X, X", quote!($($primes),*).to_string());
+    assert_eq!("X , X , X , X", quote!($($primes),*).to_string());
 }
 
 fn test_array() {
@@ -320,7 +398,7 @@ fn test_fancy_repetition() {
         $($foo: $bar),*
     };
 
-    let expected = r#""a" : true, "b" : false"#;
+    let expected = r#""a" : true , "b" : false"#;
     assert_eq!(expected, tokens.to_string());
 }
 
@@ -333,7 +411,7 @@ fn test_nested_fancy_repetition() {
         ),*
     };
 
-    let expected = "'a' 'b' 'c', 'x' 'y' 'z'";
+    let expected = "'a' 'b' 'c' , 'x' 'y' 'z'";
     assert_eq!(expected, tokens.to_string());
 }
 
@@ -345,7 +423,7 @@ fn test_duplicate_name_repetition() {
         $($foo: $foo),*
     };
 
-    let expected = r#""a" : "a", "b" : "b" "a" : "a", "b" : "b""#;
+    let expected = r#""a" : "a" , "b" : "b" "a" : "a" , "b" : "b""#;
     assert_eq!(expected, tokens.to_string());
 }
 
@@ -356,7 +434,7 @@ fn test_duplicate_name_repetition_no_copy() {
         $($foo: $foo),*
     };
 
-    let expected = r#""a" : "a", "b" : "b""#;
+    let expected = r#""a" : "a" , "b" : "b""#;
     assert_eq!(expected, tokens.to_string());
 }
 
@@ -369,7 +447,7 @@ fn test_btreeset_repetition() {
         $($set: $set),*
     };
 
-    let expected = r#""a" : "a", "b" : "b""#;
+    let expected = r#""a" : "a" , "b" : "b""#;
     assert_eq!(expected, tokens.to_string());
 }
 
@@ -378,7 +456,7 @@ fn test_variable_name_conflict() {
     // fine, if a little confusing when debugging.
     let _i = vec!['a', 'b'];
     let tokens = quote! { $($_i),* };
-    let expected = "'a', 'b'";
+    let expected = "'a' , 'b'";
     assert_eq!(expected, tokens.to_string());
 }
 
@@ -390,7 +468,7 @@ fn test_nonrep_in_repetition() {
         $($rep $rep : $nonrep $nonrep),*
     };
 
-    let expected = r#""a" "a" : "c" "c", "b" "b" : "c" "c""#;
+    let expected = r#""a" "a" : "c" "c" , "b" "b" : "c" "c""#;
     assert_eq!(expected, tokens.to_string());
 }
 

tests/ui/proc-macro/quote/not-quotable-repetition-group-brace.rs

@@ -0,0 +1,10 @@
+#![feature(proc_macro_quote)]
+
+extern crate proc_macro;
+
+use proc_macro::quote;
+
+fn main() {
+    let arr = [1, 2, 3];
+    quote! { ${$arr}* }; //~ ERROR the trait bound `[{integer}; 3]: ToTokens` is not satisfied [E0277]
+}

tests/ui/proc-macro/quote/not-quotable-repetition-group-brace.stderr

@@ -0,0 +1,23 @@
+error[E0277]: the trait bound `[{integer}; 3]: ToTokens` is not satisfied
+  --> $DIR/not-quotable-repetition-group-brace.rs:9:5
+   |
+LL |     quote! { ${$arr}* };
+   |     ^^^^^^^^^^^^^^^^^^^
+   |     |
+   |     the trait `ToTokens` is not implemented for `[{integer}; 3]`
+   |     required by a bound introduced by this call
+   |
+   = help: the following other types implement trait `ToTokens`:
+             &T
+             &mut T
+             Box<T>
+             CString
+             Cow<'_, T>
+             Option<T>
+             Rc<T>
+             bool
+           and 24 others
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.

tests/ui/proc-macro/quote/not-quotable-repetition-group-bracket.rs

@@ -0,0 +1,10 @@
+#![feature(proc_macro_quote)]
+
+extern crate proc_macro;
+
+use proc_macro::quote;
+
+fn main() {
+    let arr = [1, 2, 3];
+    quote! { $[$arr]* }; //~ ERROR the trait bound `[{integer}; 3]: ToTokens` is not satisfied [E0277]
+}

tests/ui/proc-macro/quote/not-quotable-repetition-group-bracket.stderr

@@ -0,0 +1,23 @@
+error[E0277]: the trait bound `[{integer}; 3]: ToTokens` is not satisfied
+  --> $DIR/not-quotable-repetition-group-bracket.rs:9:5
+   |
+LL |     quote! { $[$arr]* };
+   |     ^^^^^^^^^^^^^^^^^^^
+   |     |
+   |     the trait `ToTokens` is not implemented for `[{integer}; 3]`
+   |     required by a bound introduced by this call
+   |
+   = help: the following other types implement trait `ToTokens`:
+             &T
+             &mut T
+             Box<T>
+             CString
+             Cow<'_, T>
+             Option<T>
+             Rc<T>
+             bool
+           and 24 others
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.

tests/ui/proc-macro/quote/not-quotable-repetition-group-none.rs

@@ -0,0 +1,16 @@
+#![feature(proc_macro_quote)]
+
+extern crate proc_macro;
+
+use proc_macro::quote;
+
+macro_rules! do_quote {
+    ($dollar:tt $content:expr) => {
+        proc_macro::quote!($dollar $content *) //~ ERROR the trait bound `[{integer}; 3]: ToTokens` is not satisfied [E0277]
+    };
+}
+
+fn main() {
+    let arr = [1, 2, 3];
+    do_quote!($ f!($arr));
+}

tests/ui/proc-macro/quote/not-quotable-repetition-group-none.stderr

@@ -0,0 +1,27 @@
+error[E0277]: the trait bound `[{integer}; 3]: ToTokens` is not satisfied
+  --> $DIR/not-quotable-repetition-group-none.rs:9:9
+   |
+LL |         proc_macro::quote!($dollar $content *)
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `ToTokens` is not implemented for `[{integer}; 3]`
+...
+LL |     do_quote!($ f!($arr));
+   |     ---------------------
+   |     |
+   |     required by a bound introduced by this call
+   |     in this macro invocation
+   |
+   = help: the following other types implement trait `ToTokens`:
+             &T
+             &mut T
+             Box<T>
+             CString
+             Cow<'_, T>
+             Option<T>
+             Rc<T>
+             bool
+           and 24 others
+   = note: this error originates in the macro `proc_macro::quote` which comes from the expansion of the macro `do_quote` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.

tests/ui/proc-macro/quote/not-quotable-repetition-invalid-separator.rs

@@ -0,0 +1,10 @@
+#![feature(proc_macro_quote)]
+
+extern crate proc_macro;
+
+use proc_macro::quote;
+
+fn main() {
+    let arr = [1, 2, 3];
+    quote! { $($arr) $$ x .. false [] * }; //~ ERROR the trait bound `[{integer}; 3]: ToTokens` is not satisfied [E0277]
+}

tests/ui/proc-macro/quote/not-quotable-repetition-invalid-separator.stderr

@@ -0,0 +1,23 @@
+error[E0277]: the trait bound `[{integer}; 3]: ToTokens` is not satisfied
+  --> $DIR/not-quotable-repetition-invalid-separator.rs:9:5
+   |
+LL |     quote! { $($arr) $$ x .. false [] * };
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     |
+   |     the trait `ToTokens` is not implemented for `[{integer}; 3]`
+   |     required by a bound introduced by this call
+   |
+   = help: the following other types implement trait `ToTokens`:
+             &T
+             &mut T
+             Box<T>
+             CString
+             Cow<'_, T>
+             Option<T>
+             Rc<T>
+             bool
+           and 24 others
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.