Extend proc_macro_back_compat lint to actix-web

Aaron1011 · Aaron1011 · commit 390d1ef6d048 · 2021-03-18T12:09:14.000-04:00
Unlike the other cases of this lint, there's no simple way to detect if
an old version of the relevant crate (`syn`) is in use. The `actix-web`
crate only depends on `pin-project` v1.0.0, so checking the version of
`actix-web` does not guarantee that a new enough version of
`pin-project` (and therefore `syn`) is in use.

Instead, we rely on the fact that virtually all of the regressed crates
are pinned to a pre-1.0 version of `pin-project`. When this is the case,
bumping the `actix-web` dependency will pull in the *latest* version of
`pin-project`, which has an explicit dependency on a newer v dependency
on a newer version of `syn`.

The lint message tells users to update `actix-web`, since that's what
they're most likely to have control over. We could potentially tell them
to run `cargo update -p syn`, but I think it's more straightforward to
suggest an explicit change to the `Cargo.toml`

The `actori-web` fork had its last commit over a year ago, and appears
to just be a renamed fork of `actix-web`. Therefore, I've removed the
`actori-web` check entirely - any crates that actually get broken can
simply update `syn` themselves.
diff --git a/compiler/rustc_expand/src/proc_macro_server.rs b/compiler/rustc_expand/src/proc_macro_server.rs
@@ -53,11 +53,11 @@ impl ToInternal<token::DelimToken> for Delimiter {
     }
 }
 
-impl FromInternal<(TreeAndSpacing, &'_ ParseSess, &'_ mut Vec<Self>)>
+impl FromInternal<(TreeAndSpacing, &'_ mut Vec<Self>, &mut Rustc<'_>)>
     for TokenTree<Group, Punct, Ident, Literal>
 {
     fn from_internal(
-        ((tree, spacing), sess, stack): (TreeAndSpacing, &ParseSess, &mut Vec<Self>),
+        ((tree, spacing), stack, rustc): (TreeAndSpacing, &mut Vec<Self>, &mut Rustc<'_>),
     ) -> Self {
         use rustc_ast::token::*;
 
@@ -146,10 +146,10 @@ impl FromInternal<(TreeAndSpacing, &'_ ParseSess, &'_ mut Vec<Self>)>
             SingleQuote => op!('\''),
 
             Ident(name, false) if name == kw::DollarCrate => tt!(Ident::dollar_crate()),
-            Ident(name, is_raw) => tt!(Ident::new(sess, name, is_raw)),
+            Ident(name, is_raw) => tt!(Ident::new(rustc.sess, name, is_raw)),
             Lifetime(name) => {
                 let ident = symbol::Ident::new(name, span).without_first_quote();
-                stack.push(tt!(Ident::new(sess, ident.name, false)));
+                stack.push(tt!(Ident::new(rustc.sess, ident.name, false)));
                 tt!(Punct::new('\'', true))
             }
             Literal(lit) => tt!(Literal { lit }),
@@ -179,15 +179,15 @@ impl FromInternal<(TreeAndSpacing, &'_ ParseSess, &'_ mut Vec<Self>)>
             }
 
             Interpolated(nt) => {
-                if let Some((name, is_raw)) = ident_name_compatibility_hack(&nt, span, sess) {
-                    TokenTree::Ident(Ident::new(sess, name.name, is_raw, name.span))
+                if let Some((name, is_raw)) = ident_name_compatibility_hack(&nt, span, rustc) {
+                    TokenTree::Ident(Ident::new(rustc.sess, name.name, is_raw, name.span))
                 } else {
-                    let stream = nt_to_tokenstream(&nt, sess, CanSynthesizeMissingTokens::No);
+                    let stream = nt_to_tokenstream(&nt, rustc.sess, CanSynthesizeMissingTokens::No);
                     TokenTree::Group(Group {
                         delimiter: Delimiter::None,
                         stream,
                         span: DelimSpan::from_single(span),
-                        flatten: crate::base::pretty_printing_compatibility_hack(&nt, sess),
+                        flatten: crate::base::pretty_printing_compatibility_hack(&nt, rustc.sess),
                     })
                 }
             }
@@ -449,7 +449,7 @@ impl server::TokenStreamIter for Rustc<'_> {
         loop {
             let tree = iter.stack.pop().or_else(|| {
                 let next = iter.cursor.next_with_spacing()?;
-                Some(TokenTree::from_internal((next, self.sess, &mut iter.stack)))
+                Some(TokenTree::from_internal((next, &mut iter.stack, self)))
             })?;
             // A hack used to pass AST fragments to attribute and derive macros
             // as a single nonterminal token instead of a token stream.
@@ -719,11 +719,11 @@ impl server::Span for Rustc<'_> {
 fn ident_name_compatibility_hack(
     nt: &Nonterminal,
     orig_span: Span,
-    sess: &ParseSess,
+    rustc: &mut Rustc<'_>,
 ) -> Option<(rustc_span::symbol::Ident, bool)> {
     if let NtIdent(ident, is_raw) = nt {
         if let ExpnKind::Macro(_, macro_name) = orig_span.ctxt().outer_expn_data().kind {
-            let source_map = sess.source_map();
+            let source_map = rustc.sess.source_map();
             let filename = source_map.span_to_filename(orig_span);
             if let FileName::Real(RealFileName::Named(path)) = filename {
                 let matches_prefix = |prefix, filename| {
@@ -745,7 +745,7 @@ fn ident_name_compatibility_hack(
                     let snippet = source_map.span_to_snippet(orig_span);
                     if snippet.as_deref() == Ok("$name") {
                         if time_macros_impl {
-                            sess.buffer_lint_with_diagnostic(
+                            rustc.sess.buffer_lint_with_diagnostic(
                                 &PROC_MACRO_BACK_COMPAT,
                                 orig_span,
                                 ast::CRATE_NODE_ID,
@@ -759,13 +759,25 @@ fn ident_name_compatibility_hack(
                     }
                 }
 
-                if macro_name == sym::tuple_from_req
-                    && (matches_prefix("actix-web", "extract.rs")
-                        || matches_prefix("actori-web", "extract.rs"))
-                {
+                if macro_name == sym::tuple_from_req && matches_prefix("actix-web", "extract.rs") {
                     let snippet = source_map.span_to_snippet(orig_span);
                     if snippet.as_deref() == Ok("$T") {
-                        return Some((*ident, *is_raw));
+                        if let FileName::Real(RealFileName::Named(macro_path)) =
+                            source_map.span_to_filename(rustc.def_site)
+                        {
+                            if macro_path.to_string_lossy().contains("pin-project-internal-0.") {
+                                rustc.sess.buffer_lint_with_diagnostic(
+                                    &PROC_MACRO_BACK_COMPAT,
+                                    orig_span,
+                                    ast::CRATE_NODE_ID,
+                                    "using an old version of `actix-web`",
+                                    BuiltinLintDiagnostics::ProcMacroBackCompat(
+                                    "the version of `actix-web` you are using might stop compiling in future versions of Rust; \
+                                    please update to the latest version of the `actix-web` crate to avoid breakage".to_string())
+                                );
+                                return Some((*ident, *is_raw));
+                            }
+                        }
                     }
                 }
             }
diff --git a/src/test/ui/proc-macro/group-compat-hack/auxiliary/pin-project-internal-0.4.0.rs b/src/test/ui/proc-macro/group-compat-hack/auxiliary/pin-project-internal-0.4.0.rs
@@ -2,6 +2,10 @@
 // no-prefer-dynamic
 
 #![crate_type = "proc-macro"]
+#![crate_name = "group_compat_hack"]
+
+// This file has an unusual name in order to trigger the back-compat
+// code in the compiler
 
 extern crate proc_macro;
 use proc_macro::TokenStream;
diff --git a/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.rs b/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.rs
@@ -1,5 +1,5 @@
 // check-pass
-// aux-build:group-compat-hack.rs
+// aux-build:pin-project-internal-0.4.0.rs
 // compile-flags: -Z span-debug
 
 #![no_std] // Don't load unnecessary hygiene information from std
@@ -51,14 +51,16 @@ mod actix_web_test {
     include!("actix-web/src/extract.rs");
 
     struct Foo;
-    tuple_from_req!(Foo);
+    tuple_from_req!(Foo); //~ WARN using an old version
+    //~| WARN this was previously
 }
 
 mod actix_web_version_test {
     include!("actix-web-2.0.0/src/extract.rs");
 
     struct Foo;
-    tuple_from_req!(Foo);
+    tuple_from_req!(Foo); //~ WARN using an old version
+    //~| WARN this was previously
 }
 
 mod actori_web_test {
diff --git a/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.stderr b/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.stderr
@@ -31,7 +31,39 @@ LL |     impl_macros!(Foo);
    = note: the `time-macros-impl` crate will stop compiling in futures version of Rust. Please update to the latest version of the `time` crate to avoid breakage
    = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
-warning: 2 warnings emitted
+warning: using an old version of `actix-web`
+  --> $DIR/actix-web/src/extract.rs:5:34
+   |
+LL |         #[my_macro] struct Three($T);
+   |                                  ^^
+   | 
+  ::: $DIR/group-compat-hack.rs:54:5
+   |
+LL |     tuple_from_req!(Foo);
+   |     --------------------- in this macro invocation
+   |
+   = 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 version of `actix-web` you are using might stop compiling in future versions of Rust; please update to the latest version of the `actix-web` crate to avoid breakage
+   = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+warning: using an old version of `actix-web`
+  --> $DIR/actix-web-2.0.0/src/extract.rs:5:34
+   |
+LL |         #[my_macro] struct Three($T);
+   |                                  ^^
+   | 
+  ::: $DIR/group-compat-hack.rs:62:5
+   |
+LL |     tuple_from_req!(Foo);
+   |     --------------------- in this macro invocation
+   |
+   = 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 version of `actix-web` you are using might stop compiling in future versions of Rust; please update to the latest version of the `actix-web` crate to avoid breakage
+   = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+warning: 4 warnings emitted
 
 Future incompatibility report: Future breakage date: None, diagnostic:
 warning: using an old version of `time-macros-impl`
@@ -68,3 +100,37 @@ LL |     impl_macros!(Foo);
    = note: the `time-macros-impl` crate will stop compiling in futures version of Rust. Please update to the latest version of the `time` crate to avoid breakage
    = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
+Future breakage date: None, diagnostic:
+warning: using an old version of `actix-web`
+  --> $DIR/actix-web/src/extract.rs:5:34
+   |
+LL |         #[my_macro] struct Three($T);
+   |                                  ^^
+   | 
+  ::: $DIR/group-compat-hack.rs:54:5
+   |
+LL |     tuple_from_req!(Foo);
+   |     --------------------- in this macro invocation
+   |
+   = 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 version of `actix-web` you are using might stop compiling in future versions of Rust; please update to the latest version of the `actix-web` crate to avoid breakage
+   = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+Future breakage date: None, diagnostic:
+warning: using an old version of `actix-web`
+  --> $DIR/actix-web-2.0.0/src/extract.rs:5:34
+   |
+LL |         #[my_macro] struct Three($T);
+   |                                  ^^
+   | 
+  ::: $DIR/group-compat-hack.rs:62:5
+   |
+LL |     tuple_from_req!(Foo);
+   |     --------------------- in this macro invocation
+   |
+   = 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 version of `actix-web` you are using might stop compiling in future versions of Rust; please update to the latest version of the `actix-web` crate to avoid breakage
+   = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
diff --git a/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.stdout b/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.stdout
@@ -5,6 +5,6 @@ Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/tim
 Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/js-sys-0.3.17/src/lib.rs:5:21: 5:27 (#24) }, Ident { ident: "Two", span: $DIR/js-sys-0.3.17/src/lib.rs:5:28: 5:31 (#24) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:46:13: 46:16 (#0) }], span: $DIR/js-sys-0.3.17/src/lib.rs:5:31: 5:38 (#24) }, Punct { ch: ';', spacing: Alone, span: $DIR/js-sys-0.3.17/src/lib.rs:5:38: 5:39 (#24) }]
 Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/group-compat-hack.rs:39:25: 39:31 (#28) }, Ident { ident: "Three", span: $DIR/group-compat-hack.rs:39:32: 39:37 (#28) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:47:12: 47:15 (#0) }], span: $DIR/group-compat-hack.rs:39:38: 39:43 (#28) }], span: $DIR/group-compat-hack.rs:39:37: 39:44 (#28) }, Punct { ch: ';', spacing: Alone, span: $DIR/group-compat-hack.rs:39:44: 39:45 (#28) }]
 Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actix-web/src/extract.rs:5:21: 5:27 (#33) }, Ident { ident: "Three", span: $DIR/actix-web/src/extract.rs:5:28: 5:33 (#33) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:54:21: 54:24 (#0) }], span: $DIR/actix-web/src/extract.rs:5:33: 5:37 (#33) }, Punct { ch: ';', spacing: Alone, span: $DIR/actix-web/src/extract.rs:5:37: 5:38 (#33) }]
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actix-web-2.0.0/src/extract.rs:5:21: 5:27 (#38) }, Ident { ident: "Three", span: $DIR/actix-web-2.0.0/src/extract.rs:5:28: 5:33 (#38) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:61:21: 61:24 (#0) }], span: $DIR/actix-web-2.0.0/src/extract.rs:5:33: 5:37 (#38) }, Punct { ch: ';', spacing: Alone, span: $DIR/actix-web-2.0.0/src/extract.rs:5:37: 5:38 (#38) }]
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actori-web/src/extract.rs:5:21: 5:27 (#43) }, Ident { ident: "Four", span: $DIR/actori-web/src/extract.rs:5:28: 5:32 (#43) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:68:21: 68:24 (#0) }], span: $DIR/actori-web/src/extract.rs:5:32: 5:36 (#43) }, Punct { ch: ';', spacing: Alone, span: $DIR/actori-web/src/extract.rs:5:36: 5:37 (#43) }]
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actori-web-2.0.0/src/extract.rs:5:21: 5:27 (#48) }, Ident { ident: "Four", span: $DIR/actori-web-2.0.0/src/extract.rs:5:28: 5:32 (#48) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:75:21: 75:24 (#0) }], span: $DIR/actori-web-2.0.0/src/extract.rs:5:32: 5:36 (#48) }, Punct { ch: ';', spacing: Alone, span: $DIR/actori-web-2.0.0/src/extract.rs:5:36: 5:37 (#48) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actix-web-2.0.0/src/extract.rs:5:21: 5:27 (#38) }, Ident { ident: "Three", span: $DIR/actix-web-2.0.0/src/extract.rs:5:28: 5:33 (#38) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:62:21: 62:24 (#0) }], span: $DIR/actix-web-2.0.0/src/extract.rs:5:33: 5:37 (#38) }, Punct { ch: ';', spacing: Alone, span: $DIR/actix-web-2.0.0/src/extract.rs:5:37: 5:38 (#38) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actori-web/src/extract.rs:5:21: 5:27 (#43) }, Ident { ident: "Four", span: $DIR/actori-web/src/extract.rs:5:28: 5:32 (#43) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:70:21: 70:24 (#0) }], span: $DIR/actori-web/src/extract.rs:5:33: 5:35 (#43) }], span: $DIR/actori-web/src/extract.rs:5:32: 5:36 (#43) }, Punct { ch: ';', spacing: Alone, span: $DIR/actori-web/src/extract.rs:5:36: 5:37 (#43) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actori-web-2.0.0/src/extract.rs:5:21: 5:27 (#48) }, Ident { ident: "Four", span: $DIR/actori-web-2.0.0/src/extract.rs:5:28: 5:32 (#48) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:77:21: 77:24 (#0) }], span: $DIR/actori-web-2.0.0/src/extract.rs:5:33: 5:35 (#48) }], span: $DIR/actori-web-2.0.0/src/extract.rs:5:32: 5:36 (#48) }, Punct { ch: ';', spacing: Alone, span: $DIR/actori-web-2.0.0/src/extract.rs:5:36: 5:37 (#48) }]
