Only apply procedural-masquerade back-compat hack to rental

Author: Aaron1011

compiler/rustc_expand/src/base.rs

@@ -1240,16 +1240,35 @@ pub(crate) fn pretty_printing_compatibility_hack(nt: &Nonterminal, sess: &ParseS
         if let ast::ItemKind::Enum(enum_def, _) = &item.kind {
             if let [variant] = &*enum_def.variants {
                 if variant.ident.name == sym::Input {
-                    sess.buffer_lint_with_diagnostic(
-                        &PROC_MACRO_BACK_COMPAT,
-                        item.ident.span,
-                        ast::CRATE_NODE_ID,
-                        "using `procedural-masquerade` crate",
-                        BuiltinLintDiagnostics::ProcMacroBackCompat(
-                        "The `procedural-masquerade` crate has been unnecessary since Rust 1.30.0. \
-                        Versions of this crate below 0.1.7 will eventually stop compiling.".to_string())
-                    );
-                    return true;
+                    let filename = sess.source_map().span_to_filename(variant.ident.span);
+                    let filename = filename.prefer_local();
+                    let filename = filename.to_string_lossy();
+                    let rental_prefix = "rental-";
+                    if let Some(pos) = filename.find(rental_prefix) {
+                        let mut digits = filename[(pos + rental_prefix.len())..].split(".");
+                        // Check for a version before `0.5.6`
+                        if digits.next().and_then(|d| d.parse().ok()) == Some(0usize)
+                            && digits
+                                .next()
+                                .and_then(|d| d.parse().ok())
+                                .map_or(false, |d: usize| d <= 5)
+                            && digits
+                                .next()
+                                .and_then(|d| d[..1].parse().ok())
+                                .map_or(false, |d: usize| d < 6)
+                        {
+                            sess.buffer_lint_with_diagnostic(
+                                &PROC_MACRO_BACK_COMPAT,
+                                item.ident.span,
+                                ast::CRATE_NODE_ID,
+                                "using outdated version of `rental` crate",
+                                BuiltinLintDiagnostics::ProcMacroBackCompat(
+                                "Versions of the `rental` crate below `0.5.6` will eventually stop compiling. \
+                                Please update to the latest version of `rental`".to_string())
+                            );
+                            return true;
+                        }
+                    }
                 }
             }
         }

src/test/ui/proc-macro/issue-73933-procedural-masquerade.rs

@@ -5,8 +5,7 @@
 extern crate test_macros;
 
 #[derive(Print)]
-enum ProceduralMasqueradeDummyType { //~ WARN using
-//~| WARN this was previously
+enum ProceduralMasqueradeDummyType {
     Input
 }
 

src/test/ui/proc-macro/issue-73933-procedural-masquerade.stdout

@@ -1,5 +1,4 @@
-PRINT-DERIVE INPUT (DISPLAY): enum ProceduralMasqueradeDummyType { Input, }
-PRINT-DERIVE RE-COLLECTED (DISPLAY): enum ProceduralMasqueradeDummyType { Input }
+PRINT-DERIVE INPUT (DISPLAY): enum ProceduralMasqueradeDummyType { Input }
 PRINT-DERIVE INPUT (DEBUG): TokenStream [
     Ident {
         ident: "enum",
@@ -14,9 +13,9 @@ PRINT-DERIVE INPUT (DEBUG): TokenStream [
         stream: TokenStream [
             Ident {
                 ident: "Input",
-                span: #0 bytes(186..191),
+                span: #0 bytes(141..146),
             },
         ],
-        span: #0 bytes(135..193),
+        span: #0 bytes(135..148),
     },
 ]

src/test/ui/proc-macro/issue-84428-rental-back-compat.rs

@@ -0,0 +1,4 @@
+// check-pass
+// aux-build:test-macros.rs
+
+include!("pretty-print-compat-hack/rental-0.5.5.rs");

src/test/ui/proc-macro/issue-73933-procedural-masquerade.stderr renamed to src/test/ui/proc-macro/issue-84428-rental-back-compat.stderr

@@ -1,25 +1,25 @@
-warning: using `procedural-masquerade` crate
-  --> $DIR/issue-73933-procedural-masquerade.rs:8:6
+warning: using outdated version of `rental` crate
+  --> $DIR/pretty-print-compat-hack/rental-0.5.5.rs:7:6
    |
 LL | enum ProceduralMasqueradeDummyType {
    |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(proc_macro_back_compat)]` on by default
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
-   = note: The `procedural-masquerade` crate has been unnecessary since Rust 1.30.0. Versions of this crate below 0.1.7 will eventually stop compiling.
+   = note: Versions of the `rental` crate below `0.5.6` will eventually stop compiling. Please update to the latest version of `rental`
 
 warning: 1 warning emitted
 
 Future incompatibility report: Future breakage date: None, diagnostic:
-warning: using `procedural-masquerade` crate
-  --> $DIR/issue-73933-procedural-masquerade.rs:8:6
+warning: using outdated version of `rental` crate
+  --> $DIR/pretty-print-compat-hack/rental-0.5.5.rs:7:6
    |
 LL | enum ProceduralMasqueradeDummyType {
    |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(proc_macro_back_compat)]` on by default
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
-   = note: The `procedural-masquerade` crate has been unnecessary since Rust 1.30.0. Versions of this crate below 0.1.7 will eventually stop compiling.
+   = note: Versions of the `rental` crate below `0.5.6` will eventually stop compiling. Please update to the latest version of `rental`
 

src/test/ui/proc-macro/issue-84428-rental-back-compat.stdout

@@ -0,0 +1,22 @@
+PRINT-DERIVE INPUT (DISPLAY): enum ProceduralMasqueradeDummyType { Input, }
+PRINT-DERIVE RE-COLLECTED (DISPLAY): enum ProceduralMasqueradeDummyType { Input }
+PRINT-DERIVE INPUT (DEBUG): TokenStream [
+    Ident {
+        ident: "enum",
+        span: #0 bytes(10794903..10794907),
+    },
+    Ident {
+        ident: "ProceduralMasqueradeDummyType",
+        span: #0 bytes(10794908..10794937),
+    },
+    Group {
+        delimiter: Brace,
+        stream: TokenStream [
+            Ident {
+                ident: "Input",
+                span: #0 bytes(10794944..10794949),
+            },
+        ],
+        span: #0 bytes(10794938..10794951),
+    },
+]

src/test/ui/proc-macro/pretty-print-compat-hack/rental-0.5.5.rs

@@ -0,0 +1,11 @@
+// ignore-test this is not a test
+
+#[macro_use]
+extern crate test_macros;
+
+#[derive(Print)]
+enum ProceduralMasqueradeDummyType {
+    Input
+}
+
+fn main() {}