Change cfg(version) error message wording

Author: mibac138

src/librustc_attr/builtin.rs

@@ -634,21 +634,21 @@ pub fn eval_condition(
                 [NestedMetaItem::Literal(Lit { span, .. })
                 | NestedMetaItem::MetaItem(MetaItem { span, .. })] => {
                     sess.span_diagnostic
-                        .struct_span_err(*span, &*format!("expected string literal"))
+                        .struct_span_err(*span, &*format!("expected a version literal"))
                         .emit();
                     return false;
                 }
                 [..] => {
                     sess.span_diagnostic
-                        .struct_span_err(cfg.span, "expected single string literal")
+                        .struct_span_err(cfg.span, "expected single version literal")
                         .emit();
                     return false;
                 }
             };
             let min_version = match Version::parse(&min_version.as_str()) {
                 Some(ver) => ver,
                 None => {
-                    sess.span_diagnostic.struct_span_err(*span, "invalid version string").emit();
+                    sess.span_diagnostic.struct_span_err(*span, "invalid version literal").emit();
                     return false;
                 }
             };

src/test/ui/feature-gates/feature-gate-cfg-version.rs

@@ -5,13 +5,16 @@ fn foo() -> bool { true }
 //~^ ERROR `cfg(version)` is experimental and subject to change
 fn foo() -> bool { false }
 
-#[cfg(version("1.43", "1.44", "1.45"))] //~ ERROR: expected single string literal
+#[cfg(version("1.43", "1.44", "1.45"))] //~ ERROR: expected single version literal
 //~^ ERROR `cfg(version)` is experimental and subject to change
 fn bar() -> bool  { false }
-#[cfg(version(false))] //~ ERROR: expected string literal
+#[cfg(version(false))] //~ ERROR: expected a version literal
 //~^ ERROR `cfg(version)` is experimental and subject to change
 fn bar() -> bool  { false }
-#[cfg(version("foo"))] //~ ERROR: invalid version string
+#[cfg(version("foo"))] //~ ERROR: invalid version literal
+//~^ ERROR `cfg(version)` is experimental and subject to change
+fn bar() -> bool  { false }
+#[cfg(version("999"))]
 //~^ ERROR `cfg(version)` is experimental and subject to change
 fn bar() -> bool  { false }
 #[cfg(version("999"))]

src/test/ui/feature-gates/feature-gate-cfg-version.stderr

@@ -25,7 +25,7 @@ LL | #[cfg(version("1.43", "1.44", "1.45"))]
    = note: see issue #64796 <https://github.com/rust-lang/rust/issues/64796> for more information
    = help: add `#![feature(cfg_version)]` to the crate attributes to enable
 
-error: expected single string literal
+error: expected single version literal
   --> $DIR/feature-gate-cfg-version.rs:8:7
    |
 LL | #[cfg(version("1.43", "1.44", "1.45"))]
@@ -40,7 +40,7 @@ LL | #[cfg(version(false))]
    = note: see issue #64796 <https://github.com/rust-lang/rust/issues/64796> for more information
    = help: add `#![feature(cfg_version)]` to the crate attributes to enable
 
-error: expected string literal
+error: expected a version literal
   --> $DIR/feature-gate-cfg-version.rs:11:15
    |
 LL | #[cfg(version(false))]
@@ -55,7 +55,7 @@ LL | #[cfg(version("foo"))]
    = note: see issue #64796 <https://github.com/rust-lang/rust/issues/64796> for more information
    = help: add `#![feature(cfg_version)]` to the crate attributes to enable
 
-error: invalid version string
+error: invalid version literal
   --> $DIR/feature-gate-cfg-version.rs:14:15
    |
 LL | #[cfg(version("foo"))]