Ignore version = … and raise a warning instead of an error

Author: mo8it

crates/cargo-platform/src/cfg.rs

@@ -281,26 +281,6 @@ impl<'a> Parser<'a> {
 
     fn cfg(&mut self) -> Result<Cfg, ParseError> {
         match self.t.next() {
-            Some(Ok(Token::Ident(false, "version"))) => {
-                self.eat(&Token::LeftParen)?;
-                let token = self
-                    .t
-                    .next()
-                    .ok_or_else(|| ParseError::new(self.t.orig, InvalidVersion))??;
-                let Token::String(version_str) = token else {
-                    return Err(ParseError::new(
-                        self.t.orig,
-                        UnexpectedToken {
-                            expected: "a string",
-                            found: token.classify(),
-                        },
-                    ));
-                };
-                self.eat(&Token::RightParen)?;
-                let version = CfgRustVersion::parse(version_str)
-                    .ok_or_else(|| ParseError::new(self.t.orig, InvalidVersion))?;
-                Ok(Cfg::Version(version))
-            }
             Some(Ok(Token::Ident(raw, name))) => {
                 let e = if self.r#try(&Token::Equals) {
                     let val = match self.t.next() {
@@ -326,6 +306,25 @@ impl<'a> Parser<'a> {
                         },
                         val.to_string(),
                     )
+                } else if name == "version" {
+                    self.eat(&Token::LeftParen)?;
+                    let token = self
+                        .t
+                        .next()
+                        .ok_or_else(|| ParseError::new(self.t.orig, InvalidVersion))??;
+                    let Token::String(version_str) = token else {
+                        return Err(ParseError::new(
+                            self.t.orig,
+                            UnexpectedToken {
+                                expected: "a string",
+                                found: token.classify(),
+                            },
+                        ));
+                    };
+                    self.eat(&Token::RightParen)?;
+                    let version = CfgRustVersion::parse(version_str)
+                        .ok_or_else(|| ParseError::new(self.t.orig, InvalidVersion))?;
+                    Cfg::Version(version)
                 } else {
                     Cfg::Name(Ident {
                         name: name.to_string(),

crates/cargo-platform/src/lib.rs

@@ -88,14 +88,24 @@ impl Platform {
                             )),
                         _ => (),
                     },
-                    Cfg::KeyPair(name, _) => if name.as_str() == "feature" {
-                        warnings.push(String::from(
-                            "Found `feature = ...` in `target.'cfg(...)'.dependencies`. \
-                             This key is not supported for selecting dependencies \
-                             and will not work as expected. \
-                             Use the [features] section instead: \
-                             https://doc.rust-lang.org/cargo/reference/features.html"
-                        ))
+                    Cfg::KeyPair(name, _) => match name.as_str() {
+                        "feature" => {
+                            warnings.push(String::from(
+                                "Found `feature = ...` in `target.'cfg(...)'.dependencies`. \
+                                 This key is not supported for selecting dependencies \
+                                 and will not work as expected. \
+                                 Use the [features] section instead: \
+                                 https://doc.rust-lang.org/cargo/reference/features.html"
+                            ));
+                        },
+                        "version" => {
+                            warnings.push(String::from(
+                                "Found `version = ...` in `target.'cfg(...)'.dependencies`. \
+                                This format is ignored by Cargo. \
+                                Use the format `version(\"1.23.4\")` or `version(\"1.23\")` instead."
+                            ));
+                        },
+                        _ => {}
                     },
                     Cfg::Version(..) => {},
                 }

crates/cargo-platform/tests/test_cfg.rs

@@ -100,6 +100,7 @@ fn cfg_syntax() {
     good(" version(\"1.23.4\")", c!(version(23, 4)));
     good("version(\"1.23.4\") ", c!(version(23, 4)));
     good(" version(\"1.23.4\") ", c!(version(23, 4)));
+    good("version = \"1.23.4\"", c!(version = "1.23.4"));
 }
 
 #[test]
@@ -151,6 +152,7 @@ fn cfg_expr() {
     good("all(a, )", e!(all(a)));
     good("not(a = \"b\")", e!(not(a = "b")));
     good("not(all(a))", e!(not(all(a))));
+    good("not(version(\"1.23.4\"))", e!(not(version(23, 4))));
 }
 
 #[test]

tests/testsuite/cfg.rs

@@ -944,10 +944,17 @@ fn cfg_bad_version3() {
     p.cargo("check")
         .with_status(101)
         .with_stderr_data(str![[r#"
-[ERROR] failed to parse manifest at `[ROOT]/foo/Cargo.toml`
-
-Caused by:
-  failed to parse `version = "1.87.0"` as a cfg expression: expected `(`, found `=`
+[WARNING] Found `version = ...` in `target.'cfg(...)'.dependencies`. This format is ignored by Cargo. Use the format `version("1.23.4")` or `version("1.23")` instead.
+[LOCKING] 1 package to latest compatible version
+[CHECKING] foo v0.0.0 ([ROOT]/foo)
+error[E0463]: can't find crate for `b`
+ --> src/lib.rs:1:1
+  |
+1 | extern crate b;
+  | ^^^^^^^^^^^^^^^ can't find crate
+
+For more information about this error, try `rustc --explain E0463`.
+[ERROR] could not compile `foo` (lib) due to 1 previous error
 
 "#]])
         .run();