Update to syn 2 and darling 0.20.6 (#308)

* Update to syn 2

- Bump crates to 2018 edition; this is needed for generated code to
  produce usable error messages.
- Bump darling dependency to 0.20.6
- Remove support for `field(type = "...")` and leave only `field(ty = "...")`
- Update compiletest outputs
- Allow unquoted block expressions

derive_builder/Cargo.toml

@@ -7,6 +7,7 @@ authors = [
     "Jan-Erik Rediger <janerik@fnordig.de>",
     "Ted Driggs <ted.driggs@outlook.com>",
 ]
+edition = "2018"
 
 description = "Rust macro to automatically implement the builder pattern for arbitrary structs."
 repository = "https://github.com/colin-kiegel/rust-derive-builder"

derive_builder/src/lib.rs

@@ -728,7 +728,7 @@ pub use error::UninitializedFieldError;
 pub mod export {
     pub mod core {
         #[cfg(feature = "alloc")]
-        pub use alloc::string;
+        pub use ::alloc::string;
         #[cfg(not(feature = "std"))]
         pub use core::*;
         #[cfg(feature = "std")]

derive_builder/tests/builder_field_custom.rs

@@ -7,10 +7,10 @@ use std::num::ParseIntError;
 
 #[derive(Debug, PartialEq, Default, Builder, Clone)]
 pub struct Lorem {
-    #[builder(field(ty = "Option<usize>", build = "self.ipsum.unwrap_or(42) + 1"))]
+    #[builder(field(ty = "Option<usize>", build = self.ipsum.unwrap_or(42) + 1))]
     ipsum: usize,
 
-    #[builder(setter(into), field(ty = "String", build = "self.dolor.parse()?"))]
+    #[builder(setter(into), field(ty = "String", build = self.dolor.parse()?))]
     dolor: u32,
 }
 

derive_builder/tests/compile-fail/builder_field_custom.rs

@@ -10,11 +10,6 @@ pub struct Lorem {
     )]
     ipsum: usize,
 
-    // Both `ty` and `type` are temporarily allowed to ease the transition
-    // to syn 2.0, but they are mutually exclusive.
-    #[builder(field(ty = "usize", type = "usize"))]
-    dolor: usize,
-
     // `default` is incompatible with `field.ty`, even without `field.build`
     #[builder(default = "2", field(ty = "usize"))]
     sit: usize,

derive_builder/tests/compile-fail/builder_field_custom.stderr

@@ -4,26 +4,20 @@ error: #[builder(default)] and #[builder(field(build="..."))] cannot be used tog
 8 |         default = "1",
   |                   ^^^
 
-error: duplicate field - `type` is a deprecated alias for `ty`.
-  --> tests/compile-fail/builder_field_custom.rs:15:35
+error: #[builder(default)] and #[builder(field(ty="..."))] cannot be used together
+  --> tests/compile-fail/builder_field_custom.rs:14:25
    |
-15 |     #[builder(field(ty = "usize", type = "usize"))]
-   |                                   ^^^^
-
-error: #[builder(default)] and #[builder(field(type="..."))] cannot be used together
-  --> tests/compile-fail/builder_field_custom.rs:19:25
-   |
-19 |     #[builder(default = "2", field(ty = "usize"))]
+14 |     #[builder(default = "2", field(ty = "usize"))]
    |                         ^^^
 
 error: #[builder(default)] and #[builder(field(build="..."))] cannot be used together
-  --> tests/compile-fail/builder_field_custom.rs:23:25
+  --> tests/compile-fail/builder_field_custom.rs:18:25
    |
-23 |     #[builder(default = "3", field(ty = "usize", build = "self.ipsum + 42"))]
+18 |     #[builder(default = "3", field(ty = "usize", build = "self.ipsum + 42"))]
    |                         ^^^
 
-error: #[builder(default)] and #[builder(field(type="..."))] cannot be used together
-  --> tests/compile-fail/builder_field_custom.rs:23:25
+error: #[builder(default)] and #[builder(field(ty="..."))] cannot be used together
+  --> tests/compile-fail/builder_field_custom.rs:18:25
    |
-23 |     #[builder(default = "3", field(ty = "usize", build = "self.ipsum + 42"))]
+18 |     #[builder(default = "3", field(ty = "usize", build = "self.ipsum + 42"))]
    |                         ^^^

derive_builder/tests/compile-fail/crate_root.stderr

@@ -13,10 +13,16 @@ error[E0433]: failed to resolve: could not find `export` in `empty`
   |          ^^^^^^^ not found in `empty::export::core::option`
   |
   = note: this error originates in the derive macro `Builder` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: consider importing this enum
+help: consider importing one of these items
+  |
+5 | use core::option::Option;
   |
 5 | use derive_builder::export::core::option::Option;
   |
+5 | use serde::__private::Option;
+  |
+5 | use std::option::Option;
+  |
 
 error[E0433]: failed to resolve: could not find `export` in `empty`
  --> tests/compile-fail/crate_root.rs:7:10
@@ -25,10 +31,16 @@ error[E0433]: failed to resolve: could not find `export` in `empty`
   |          ^^^^^^^ not found in `empty::export::core::clone`
   |
   = note: this error originates in the derive macro `Builder` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: consider importing this trait
+help: consider importing one of these items
+  |
+5 | use core::clone::Clone;
   |
 5 | use derive_builder::export::core::clone::Clone;
   |
+5 | use serde::__private::Clone;
+  |
+5 | use std::clone::Clone;
+  |
 
 error[E0433]: failed to resolve: could not find `export` in `empty`
  --> tests/compile-fail/crate_root.rs:7:10
@@ -39,14 +51,15 @@ error[E0433]: failed to resolve: could not find `export` in `empty`
   = note: this error originates in the derive macro `Builder` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider importing one of these items
   |
-5 | use derive_builder::export::core::fmt::Result;
+5 | use core::fmt::Result;
   |
-5 | use derive_builder::export::core::io::Result;
+5 | use core::result::Result;
   |
-5 | use derive_builder::export::core::result::Result;
+5 | use derive_builder::export::core::fmt::Result;
   |
-5 | use derive_builder::export::core::thread::Result;
+5 | use derive_builder::export::core::io::Result;
   |
+    and 9 other candidates
 
 error[E0433]: failed to resolve: could not find `export` in `empty`
  --> tests/compile-fail/crate_root.rs:7:10
@@ -55,10 +68,16 @@ error[E0433]: failed to resolve: could not find `export` in `empty`
   |          ^^^^^^^ not found in `empty::export::core::convert`
   |
   = note: this error originates in the derive macro `Builder` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: consider importing this trait
+help: consider importing one of these items
+  |
+5 | use core::convert::Into;
   |
 5 | use derive_builder::export::core::convert::Into;
   |
+5 | use serde::__private::Into;
+  |
+5 | use std::convert::Into;
+  |
 
 error[E0433]: failed to resolve: could not find `UninitializedFieldError` in `empty`
  --> tests/compile-fail/crate_root.rs:7:10
@@ -79,10 +98,16 @@ error[E0433]: failed to resolve: could not find `export` in `empty`
   |          ^^^^^^^ not found in `empty::export::core::default`
   |
   = note: this error originates in the derive macro `Builder` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: consider importing this trait
+help: consider importing one of these items
+  |
+5 | use core::default::Default;
   |
 5 | use derive_builder::export::core::default::Default;
   |
+5 | use serde::__private::Default;
+  |
+5 | use std::default::Default;
+  |
 
 error[E0412]: cannot find type `UninitializedFieldError` in module `empty`
  --> tests/compile-fail/crate_root.rs:7:10

derive_builder_core/Cargo.toml

@@ -7,7 +7,7 @@ authors = [
     "Jan-Erik Rediger <janerik@fnordig.de>",
     "Ted Driggs <ted.driggs@outlook.com>",
 ]
-
+edition = "2018"
 description = "Internal helper library for the derive_builder crate."
 repository = "https://github.com/colin-kiegel/rust-derive-builder"
 documentation = "https://docs.rs/derive_builder_core"
@@ -21,10 +21,10 @@ clippy = []
 lib_has_std = []
 
 [dependencies]
-darling = "0.14.0"
+darling = "0.20.6"
 proc-macro2 = "1.0.37"
-quote = "1.0.18"
-syn = { version = "1.0.91", features = ["full", "extra-traits"] }
+quote = "1.0.35"
+syn = { version = "2.0.15", features = ["full", "extra-traits"] }
 
 [dev-dependencies]
 pretty_assertions = "1.2.1"

derive_builder_core/src/block.rs

@@ -1,6 +1,6 @@
 use std::convert::TryFrom;
 
-use proc_macro2::TokenStream;
+use proc_macro2::{Span, TokenStream};
 use quote::ToTokens;
 use syn::{self, spanned::Spanned, Block, LitStr};
 
@@ -16,6 +16,10 @@ impl BlockContents {
     pub fn is_empty(&self) -> bool {
         self.0.stmts.is_empty()
     }
+
+    pub fn span(&self) -> Span {
+        self.0.span()
+    }
 }
 
 impl ToTokens for BlockContents {
@@ -39,7 +43,7 @@ impl From<syn::Expr> for BlockContents {
     fn from(v: syn::Expr) -> Self {
         Self(Block {
             brace_token: syn::token::Brace(v.span()),
-            stmts: vec![syn::Stmt::Expr(v)],
+            stmts: vec![syn::Stmt::Expr(v, None)],
         })
     }
 }
@@ -57,6 +61,14 @@ impl darling::FromMeta for BlockContents {
             Err(darling::Error::unexpected_lit_type(value))
         }
     }
+
+    fn from_expr(expr: &syn::Expr) -> darling::Result<Self> {
+        if let syn::Expr::Lit(lit) = expr {
+            Self::from_value(&lit.lit)
+        } else {
+            Ok(Self::from(expr.clone()))
+        }
+    }
 }
 
 #[cfg(test)]
@@ -71,7 +83,7 @@ mod test {
     }
 
     #[test]
-    #[should_panic(expected = r#"lex error"#)]
+    #[should_panic(expected = r#"cannot parse"#)]
     fn block_invalid_token_trees() {
         parse("let x = 2; { x+1").unwrap();
     }

derive_builder_core/src/build_method.rs

@@ -1,15 +1,12 @@
 use std::borrow::Cow;
 
-use doc_comment_from;
 use proc_macro2::{Span, TokenStream};
 use quote::{ToTokens, TokenStreamExt};
-use syn;
 use syn::spanned::Spanned;
-use BuilderPattern;
-use Initializer;
-use DEFAULT_STRUCT_NAME;
 
-use crate::DefaultExpression;
+use crate::{
+    doc_comment_from, BuilderPattern, DefaultExpression, Initializer, DEFAULT_STRUCT_NAME,
+};
 
 /// Initializer for the struct fields in the build method, implementing
 /// `quote::ToTokens`.

derive_builder_core/src/builder.rs

@@ -5,12 +5,9 @@ use quote::{format_ident, ToTokens, TokenStreamExt};
 use syn::punctuated::Punctuated;
 use syn::{self, Path, TraitBound, TraitBoundModifier, TypeParamBound};
 
-use doc_comment_from;
-use BuildMethod;
-use BuilderField;
-use BuilderPattern;
-use DeprecationNotes;
-use Setter;
+use crate::{
+    doc_comment_from, BuildMethod, BuilderField, BuilderPattern, DeprecationNotes, Setter,
+};
 
 const ALLOC_NOT_ENABLED_ERROR: &str = r#"`alloc` is disabled within 'derive_builder', consider one of the following:
 * enable feature `alloc` on 'dervie_builder' if a `global_allocator` is present
@@ -858,7 +855,7 @@ mod tests {
 
                 add_simple_foo_builder(&mut result);
 
-                result.append_all(quote!(compile_error! { #ALLOC_NOT_ENABLED_ERROR }));
+                result.append_all(quote!(::core::compile_error! { #ALLOC_NOT_ENABLED_ERROR }));
 
                 result
             }

derive_builder_core/src/builder_field.rs

@@ -2,7 +2,6 @@ use std::borrow::Cow;
 
 use proc_macro2::TokenStream;
 use quote::{ToTokens, TokenStreamExt};
-use syn;
 
 /// Field for the builder struct, implementing `quote::ToTokens`.
 ///

derive_builder_core/src/default_expression.rs

@@ -23,6 +23,13 @@ impl DefaultExpression {
         }
     }
 
+    pub fn span(&self) -> Span {
+        match self {
+            DefaultExpression::Explicit(block) => block.span(),
+            DefaultExpression::Trait => Span::call_site(),
+        }
+    }
+
     #[cfg(test)]
     pub fn explicit<I: Into<BlockContents>>(content: I) -> Self {
         DefaultExpression::Explicit(content.into())
@@ -39,15 +46,6 @@ impl darling::FromMeta for DefaultExpression {
     }
 }
 
-impl syn::spanned::Spanned for DefaultExpression {
-    fn span(&self) -> Span {
-        match self {
-            DefaultExpression::Explicit(block) => block.span(),
-            DefaultExpression::Trait => Span::call_site(),
-        }
-    }
-}
-
 /// Wrapper for `DefaultExpression`
 struct DefaultExpressionWithCrateRoot<'a> {
     crate_root: &'a syn::Path,

derive_builder_core/src/deprecation_notes.rs

@@ -1,6 +1,5 @@
 use proc_macro2::{Span, TokenStream};
 use quote::{ToTokens, TokenStreamExt};
-use syn;
 
 /// Deprecation notes we want to emit to the user, implementing
 /// `quote::ToTokens`.

derive_builder_core/src/initializer.rs

@@ -1,10 +1,7 @@
 use proc_macro2::{Span, TokenStream};
 use quote::{ToTokens, TokenStreamExt};
-use syn;
-use BuilderPattern;
-use DEFAULT_STRUCT_NAME;
 
-use crate::{change_span, BlockContents, DefaultExpression};
+use crate::{change_span, BlockContents, BuilderPattern, DefaultExpression, DEFAULT_STRUCT_NAME};
 
 /// Initializer for the target struct fields, implementing `quote::ToTokens`.
 ///