Support Rust 2024 language edition (#4063)

Author: ncave

src/Fable.Cli/CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 * [JS/TS] Add support for `CaseRules.LowerAll` on `StringEnums` (by @shayanhabibi)
+* [Rust] Support Rust 2024 language edition (by @ncave)
 
 ### Fixed
 

src/Fable.Compiler/CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 * [JS/TS] Add support for `CaseRules.LowerAll` on `StringEnums` (by @shayanhabibi)
+* [Rust] Support Rust 2024 language edition (by @ncave)
 
 ### Fixed
 

src/Fable.Transforms/FSharp2Fable.Util.fs

@@ -150,11 +150,11 @@ type FsAtt(att: FSharpAttribute) =
         member _.Entity = FsEnt.Ref att.AttributeType
         member _.ConstructorArgs = att.ConstructorArguments |> Seq.mapToList snd
 
-type FsGenParam(gen: FSharpGenericParameter) =
+type FsGenParam(p: FSharpGenericParameter) =
     interface Fable.GenericParam with
-        member _.Name = TypeHelpers.genParamName gen
-        member _.IsMeasure = gen.IsMeasure
-        member _.Constraints = FsGenParam.Constraints gen
+        member _.Name = TypeHelpers.genParamName p
+        member _.IsMeasure = p.IsMeasure
+        member _.Constraints = FsGenParam.Constraints p
 
     static member Constraint(c: FSharpGenericParameterConstraint) =
         if c.IsCoercesToConstraint then
@@ -203,8 +203,8 @@ type FsGenParam(gen: FSharpGenericParameter) =
         else
             None // TODO: Document these cases
 
-    static member Constraints(gen: FSharpGenericParameter) =
-        gen.Constraints |> Seq.chooseToList FsGenParam.Constraint
+    static member Constraints(p: FSharpGenericParameter) =
+        p.Constraints |> Seq.chooseToList FsGenParam.Constraint
 
 type FsParam(p: FSharpParameter, ?isNamed) =
     let isOptional = p.IsOptionalArg

src/Fable.Transforms/Rust/AST/Rust.AST.Helpers.fs

@@ -513,6 +513,8 @@ module Blocks =
             tokens = None
         }
 
+    let mkBodyBlock (expr: Expr) : Block = [ expr |> mkExprStmt ] |> mkBlock
+
     let mkExprBlock (expr: Expr) : Block =
         match expr.kind with
         | ExprKind.Block(block, None) -> block
@@ -787,6 +789,14 @@ module Exprs =
     let mkLabelBlockExpr name (statements: Stmt seq) : Expr =
         ExprKind.Block(mkBlock statements, Some(mkLabel name)) |> mkExpr
 
+    let mkUnsafeBlockExpr (expr: Expr) : Expr =
+        let block = mkExprBlock expr
+
+        let unsafeBlock =
+            { block with rules = BlockCheckMode.Unsafe(UnsafeSource.UserProvided) }
+
+        unsafeBlock |> mkBlockExpr
+
     let mkIfThenExpr ifExpr thenExpr : Expr =
         let thenBlock = mkSemiBlock thenExpr
         ExprKind.If(ifExpr, thenBlock, None) |> mkExpr
@@ -1410,6 +1420,10 @@ module Items =
         let def = Defaultness.Final
         ItemKind.Const(def, ty, exprOpt) |> mkItem attrs ident
 
+    let mkExternCrateItem attrs name (aliasOpt: Symbol option) : Item =
+        let ident = mkIdent name
+        ItemKind.ExternCrate(aliasOpt) |> mkItem attrs ident
+
     let mkImplItem attrs name ty generics items ofTrait : Item =
         let ident = mkIdent name
 

src/Fable.Transforms/Rust/AST/Rust.AST.State.fs

@@ -11,7 +11,7 @@ open type Macros
 module ast = Fable.Transforms.Rust.AST.Types
 module token = Fable.Transforms.Rust.AST.Types.token
 module kw = Fable.Transforms.Rust.AST.Symbols.kw
-module sym = Fable.Transforms.Rust.AST.Symbols.sym
+// module sym = Fable.Transforms.Rust.AST.Symbols.sym
 module pp = Fable.Transforms.Rust.AST.Pretty
 module parser = Fable.Transforms.Rust.AST.Parser
 

src/Fable.Transforms/Rust/AST/Rust.AST.Symbols.fs

@@ -5,8 +5,8 @@ module Fable.Transforms.Rust.AST.Symbols
 // After modifying this list adjust `is_special`, `is_used_keyword`/`is_unused_keyword`,
 // this should be rarely necessary though if the keywords are kept in alphabetic order.
 module kw =
-    // Special reserved identifiers used internally for elided lifetimes
-    // unnamed method parameters crate root module error recovery etc.
+    // Special reserved identifiers used internally for elided lifetimes,
+    // unnamed method parameters, crate root module, error recovery etc.
     let Empty = ""
     let PathRoot = "{{root}}"
     let DollarCrate = "$crate"
@@ -64,24 +64,31 @@ module kw =
     let Yield = "yield"
 
     // Edition-specific keywords that are used in stable Rust.
-    let Async = "async" // >=  2018 Edition only
-    let Await = "await" // >=  2018 Edition only
-    let Dyn = "dyn" // >=  2018 Edition only
+    let Async = "async" // >= 2018 Edition only
+    let Await = "await" // >= 2018 Edition only
+    let Dyn = "dyn" // >= 2018 Edition only
 
     // Edition-specific keywords that are used in unstable Rust or reserved for future use.
-    let Try = "try" // >=  2018 Edition only
+    let Gen = "gen" // >= 2024 Edition only
+    let Try = "try" // >= 2018 Edition only
 
-    // Special lifetime names
+    // "Lifetime keywords" =regular keywords with a leading `'`.
     let UnderscoreLifetime = "'_"
     let StaticLifetime = "'static"
 
-    // Weak keywords have special meaning only in specific contexts.
+    // Weak keywords, have special meaning only in specific contexts.
     let Auto = "auto"
+    let Builtin = "builtin"
     let Catch = "catch"
     let Default = "default"
     let MacroRules = "macro_rules"
     let Raw = "raw"
+    let Reuse = "reuse"
+    let ContractEnsures = "contract_ensures"
+    let ContractRequires = "contract_requires"
+    let Safe = "safe"
     let Union = "union"
+    let Yeet = "yeet"
 
     let RustKeywords =
         [
@@ -149,74 +156,127 @@ module kw =
             Dyn
 
             // Edition-specific keywords that are used in unstable Rust or reserved for future use.
+            Gen
             Try
 
-            // Special lifetime names
+            // "Lifetime keywords"
             UnderscoreLifetime
             StaticLifetime
 
             // Weak keywords have special meaning only in specific contexts.
             Auto
+            Builtin
             Catch
             Default
             MacroRules
             Raw
+            Reuse
+            ContractEnsures
+            ContractRequires
+            Safe
             Union
+            Yeet
         ]
 
     let RustPrelude =
         [
-            "Copy"
+            // Re-exported core operators
             "Send"
             "Sized"
             "Sync"
             "Unpin"
-            "drop"
             "Drop"
             "Fn"
             "FnMut"
             "FnOnce"
-            "Box"
-            "ToOwned"
-            "Clone"
-            "PartialEq"
-            "PartialOrd"
-            "Eq"
-            "Ord"
-            "AsRef"
+            "AsyncFn"
+            "AsyncFnMut"
+            "AsyncFnOnce"
+
+            // Re-exported types and traits
             "AsMut"
-            "Into"
+            "AsRef"
             "From"
-            "Default"
-            "Iterator"
-            "Extend"
-            "IntoIterator"
+            "Into"
             "DoubleEndedIterator"
             "ExactSizeIterator"
+            "Extend"
+            "IntoIterator"
+            "Iterator"
             "Option"
-            "Some"
             "None"
+            "Some"
             "Result"
-            "Ok"
             "Err"
+            "Ok"
+
+            // derive macros
+            "Clone"
+            "Copy"
+            // "Debug"
+            "Default"
+            "Eq"
+            // "Hash"
+            "Ord"
+            "PartialEq"
+            "PartialOrd"
+
+            // items from the alloc crate
+            "ToOwned"
+            "Box"
             "String"
             "ToString"
-            "TryFrom"
-            "TryInto"
             "Vec"
-            "FromIterator"
+
+        // // Re-exported functions
+        // "drop"
+        // "align_of"
+        // "align_of_val"
+        // "size_of"
+        // "size_of_val"
+
+        // // Re-exported built-in macros
+        // "assert"
+        // "cfg"
+        // "column"
+        // "compile_error"
+        // "concat"
+        // "concat_idents"
+        // "env"
+        // "file"
+        // "format_args"
+        // "format_args_nl"
+        // "include"
+        // "include_bytes"
+        // "include_str"
+        // "line"
+        // "log_syntax"
+        // "module_path"
+        // "option_env"
+        // "stringify"
+        // "trace_macros"
+
+        // "alloc_error_handler"
+        // "bench"
+        // "derive"
+        // "global_allocator"
+        // "test"
+        // "test_case"
+
         ]
 
+(*
+
 // Pre-interned symbols that can be referred to with `rustc_span::sym::*`.
 //
 // The symbol is the stringified identifier unless otherwise specified, in
 // which case the name should mention the non-identifier punctuation.
-// E.g. `sym::proc_dash_macro` represents "proc-macro", and it shouldn't be
+// E.g. `sym::proc_dash_macro` represents "proc-macro" and it shouldn't be
 // called `sym::proc_macro` because then it's easy to mistakenly think it
 // represents "proc_macro".
 //
 // As well as the symbols listed, there are symbols for the strings
-// "0", "1", ..., "9", which are accessible via `sym::integer`.
+// "0" "1" ..., "9" which are accessible via `sym::integer`.
 //
 // The proc macro will abort if symbols are not in alphabetical order (as
 // defined by `impl Ord for str`) or if any symbols are duplicated. Vim
@@ -1426,7 +1486,7 @@ module sym =
     let xmm_reg = "xmm_reg"
     let ymm_reg = "ymm_reg"
     let zmm_reg = "zmm_reg"
-
+*)
 (*
 
 type Symbol with

src/Fable.Transforms/Rust/Fable2Rust.fs

@@ -3563,7 +3563,7 @@ module Util =
 
             let fnBody = strBody |> Seq.map mkEmitSemiStmt |> mkBlock |> Some
 
-            let attrs = []
+            let attrs = [ mkAttr "cfg" [ "not(feature = \"no_std\")" ] ]
             let fnDecl = mkFnDecl [] VOID_RETURN_TY
             let fnKind = mkFnKind DEFAULT_FN_HEADER fnDecl NO_GENERICS fnBody
             let fnItem = mkFnItem attrs "main" fnKind
@@ -4125,8 +4125,13 @@ module Util =
             let returnType = memb.ReturnParameter.Type
             transformFunc com ctx parameters returnType (Some memb.FullName) decl.Args decl.Body
 
+        let isUnsafe =
+            memb.Attributes |> Seq.exists (fun a -> a.Entity.FullName = Atts.rustUnsafe)
+
         let fnBodyBlock =
-            if decl.Body.Type = Fable.Unit then
+            if isUnsafe then
+                fnBody |> mkUnsafeBlockExpr |> mkBodyBlock
+            else if decl.Body.Type = Fable.Unit then
                 mkSemiBlock fnBody
             else
                 mkExprBlock fnBody
@@ -5403,9 +5408,8 @@ module Compiler =
         let topAttrs =
             [
                 if isLastFileInProject com then
-                    // adds "no_std" for fable library crate if feature is enabled
-                    if isFableLibrary com then
-                        mkInnerAttr "cfg_attr" [ "feature = \"no_std\""; "no_std" ]
+                    // adds "no_std" to crate if feature is enabled
+                    mkInnerAttr "cfg_attr" [ "feature = \"no_std\""; "no_std" ]
 
                     // TODO: make some of those conditional on compiler options
                     mkInnerAttr "allow" [ "dead_code" ]
@@ -5419,6 +5423,7 @@ module Compiler =
                     mkInnerAttr "allow" [ "unused_parens" ]
                     mkInnerAttr "allow" [ "unused_variables" ]
                     mkInnerAttr "allow" [ "unused_assignments" ]
+                    mkInnerAttr "allow" [ "unused_unsafe" ]
 
             // these require nightly
             // mkInnerAttr "feature" ["stmt_expr_attributes"]

src/fable-library-dart/List.fs

@@ -262,9 +262,9 @@ let foldBack2<'T1, 'T2, 'State> (folder: 'T1 -> 'T2 -> 'State -> 'State) (xs: 'T
     // fold2 (fun acc x y -> folder x y acc) state (reverse xs) (reverse ys)
     Array.foldBack2 folder (toArray xs) (toArray ys) state
 
-let unfold<'T, 'State> (gen: 'State -> ('T * 'State) option) (state: 'State) =
+let unfold<'T, 'State> (generator: 'State -> ('T * 'State) option) (state: 'State) =
     let rec loop acc (node: 'T list) =
-        match gen acc with
+        match generator acc with
         | None -> node
         | Some(x, acc) -> loop acc (node.AppendConsNoTail x)
 

src/fable-library-py/fable_library/List.fs

@@ -285,9 +285,9 @@ let foldBack2<'T1, 'T2, 'State> (folder: 'T1 -> 'T2 -> 'State -> 'State) (xs: 'T
     // fold2 (fun acc x y -> folder x y acc) state (reverse xs) (reverse ys)
     Array.foldBack2 folder (toArray xs) (toArray ys) state
 
-let unfold (gen: 'State -> ('T * 'State) option) (state: 'State) =
+let unfold (generator: 'State -> ('T * 'State) option) (state: 'State) =
     let rec loop acc (node: 'T list) =
-        match gen acc with
+        match generator acc with
         | None -> node
         | Some(x, acc) -> loop acc (node.AppendConsNoTail x)
 

src/fable-library-rust/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "fable_library_rust"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 [features]
 atomic = []
@@ -22,7 +22,7 @@ default = ["bigint", "datetime", "decimal", "enum_func", "enum_string", "guid",
 chrono = { version = "0.4", optional = true }
 futures = { version = "0.3", features = ["executor", "thread-pool"], default-features = false, optional = true }
 futures-timer = { version = "3.0", optional = true }
-hashbrown = { version = "0.14", optional = true }
+hashbrown = { version = "0.15", optional = true }
 num-bigint = { version = "0.4", optional = true }
 num-integer = { version = "0.1", optional = true }
 num-traits = { version = "0.2", optional = true }
@@ -31,7 +31,7 @@ rust_decimal = { version = "1.36", features = ["maths"], default-features = fals
 startup = { version = "0.1", path = "vendored/startup", optional = true }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
-uuid = { version = "1.13", features = ["v4"], default-features = false, optional = true }
+uuid = { version = "1.14", features = ["v4"], default-features = false, optional = true }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
-uuid = { version = "1.13", features = ["v4", "js"], default-features = false, optional = true }
+uuid = { version = "1.14", features = ["v4", "js"], default-features = false, optional = true }