Add more tests for cfg_select parsing

Signed-off-by: Jonathan Brouwer <jonathantbrouwer@gmail.com>

Author: JonathanBrouwer

tests/ui/macros/cfg_select.rs

@@ -60,3 +60,38 @@ cfg_select! {
 
 cfg_select! {}
 //~^ ERROR none of the predicates in this `cfg_select` evaluated to true
+
+cfg_select! {
+    => {}
+    //~^ ERROR expected unsuffixed literal, found `=>`
+}
+
+cfg_select! {
+    () => {}
+    //~^ ERROR expected unsuffixed literal, found `(`
+}
+
+cfg_select! { //~ ERROR none of the predicates in this `cfg_select` evaluated to true
+    "str" => {}
+    //~^ ERROR literal in `cfg` predicate value must be a boolean
+}
+
+cfg_select! {
+    a::b => {}
+    //~^ ERROR `cfg` predicate key must be an identifier
+}
+
+cfg_select! { //~ ERROR none of the predicates in this `cfg_select` evaluated to true
+    a() => {}
+    //~^ ERROR invalid predicate `a` [E0537]
+}
+
+cfg_select! {
+    a + 1 => {}
+    //~^ ERROR expected one of `(`, `::`, `=>`, or `=`, found `+`
+}
+
+cfg_select! {
+    cfg!() => {}
+    //~^ ERROR expected one of `(`, `::`, `=>`, or `=`, found `!`
+}

tests/ui/macros/cfg_select.stderr

@@ -21,5 +21,67 @@ error: none of the predicates in this `cfg_select` evaluated to true
 LL | cfg_select! {}
    | ^^^^^^^^^^^^^^
 
-error: aborting due to 2 previous errors; 1 warning emitted
+error: expected unsuffixed literal, found `=>`
+  --> $DIR/cfg_select.rs:65:5
+   |
+LL |     => {}
+   |     ^^
+
+error: expected unsuffixed literal, found `(`
+  --> $DIR/cfg_select.rs:70:5
+   |
+LL |     () => {}
+   |     ^
+
+error[E0565]: literal in `cfg` predicate value must be a boolean
+  --> $DIR/cfg_select.rs:75:5
+   |
+LL |     "str" => {}
+   |     ^^^^^
+
+error: none of the predicates in this `cfg_select` evaluated to true
+  --> $DIR/cfg_select.rs:74:1
+   |
+LL | / cfg_select! {
+LL | |     "str" => {}
+LL | |
+LL | | }
+   | |_^
+
+error: `cfg` predicate key must be an identifier
+  --> $DIR/cfg_select.rs:80:5
+   |
+LL |     a::b => {}
+   |     ^^^^
+
+error[E0537]: invalid predicate `a`
+  --> $DIR/cfg_select.rs:85:5
+   |
+LL |     a() => {}
+   |     ^^^
+
+error: none of the predicates in this `cfg_select` evaluated to true
+  --> $DIR/cfg_select.rs:84:1
+   |
+LL | / cfg_select! {
+LL | |     a() => {}
+LL | |
+LL | | }
+   | |_^
+
+error: expected one of `(`, `::`, `=>`, or `=`, found `+`
+  --> $DIR/cfg_select.rs:90:7
+   |
+LL |     a + 1 => {}
+   |       ^ expected one of `(`, `::`, `=>`, or `=`
+
+error: expected one of `(`, `::`, `=>`, or `=`, found `!`
+  --> $DIR/cfg_select.rs:95:8
+   |
+LL |     cfg!() => {}
+   |        ^ expected one of `(`, `::`, `=>`, or `=`
+
+error: aborting due to 11 previous errors; 1 warning emitted
 
+Some errors have detailed explanations: E0537, E0565.
+For more information about an error, try `rustc --explain E0537`.