darling_core: Remove nightly proc_macro_diagnostic feature

This commit adds a patch that removes the code for the diagnostics
feature from darling_core as it depends on the nightly
proc_macro_diagnostic feature of rustc.

diff --git a/src/darling-core/debian/patches/no-nightly.diff b/src/darling-core/debian/patches/no-nightly.diff
new file mode 100644 (file)
index 0000000..0d5f663
--- /dev/null
+++ b/src/darling-core/debian/patches/no-nightly.diff
@@ -0,0 +1,139 @@
+Index: darling-core/src/error/kind.rs
+===================================================================
+--- darling-core.orig/src/error/kind.rs
++++ darling-core/src/error/kind.rs
+@@ -128,23 +128,6 @@ impl ErrorUnknownField {
+     {
+         ErrorUnknownField::new(field, did_you_mean(field, alternates))
+     }
+-
+-    #[cfg(feature = "diagnostics")]
+-    pub fn to_diagnostic(self, span: Option<::proc_macro2::Span>) -> ::proc_macro::Diagnostic {
+-        let base = span
+-            .unwrap_or_else(::proc_macro2::Span::call_site)
+-            .unwrap()
+-            .error(self.top_line());
+-        match self.did_you_mean {
+-            Some(alt_name) => base.help(format!("did you mean `{}`?", alt_name)),
+-            None => base,
+-        }
+-    }
+-
+-    #[cfg(feature = "diagnostics")]
+-    fn top_line(&self) -> String {
+-        format!("Unknown field: `{}`", self.name)
+-    }
+ }
+ 
+ impl From<String> for ErrorUnknownField {
+Index: darling-core/src/error/mod.rs
+===================================================================
+--- darling-core.orig/src/error/mod.rs
++++ darling-core/src/error/mod.rs
+@@ -295,83 +295,18 @@ impl Error {
+     /// }
+     /// ```
+     pub fn write_errors(self) -> TokenStream {
+-        #[cfg(feature = "diagnostics")]
+-        {
+-            self.emit();
+-            quote!()
+-        }
+-
+-        #[cfg(not(feature = "diagnostics"))]
+-        {
+-            self.flatten()
+-                .into_iter()
+-                .map(|e| e.single_to_syn_error().to_compile_error())
+-                .collect()
+-        }
++        self.flatten()
++            .into_iter()
++            .map(|e| e.single_to_syn_error().to_compile_error())
++            .collect()
+     }
+ 
+-    #[cfg(not(feature = "diagnostics"))]
+     fn single_to_syn_error(self) -> ::syn::Error {
+         match self.span {
+             Some(span) => ::syn::Error::new(span, self.kind),
+             None => ::syn::Error::new(Span::call_site(), self),
+         }
+     }
+-
+-    #[cfg(feature = "diagnostics")]
+-    fn single_to_diagnostic(self) -> ::proc_macro::Diagnostic {
+-        use proc_macro::{Diagnostic, Level};
+-
+-        // Delegate to dedicated error formatters when applicable.
+-        //
+-        // If span information is available, don't include the error property path
+-        // since it's redundant and not consistent with native compiler diagnostics.
+-        match self.kind {
+-            ErrorKind::UnknownField(euf) => euf.to_diagnostic(self.span),
+-            _ => match self.span {
+-                Some(span) => span.unwrap().error(self.kind.to_string()),
+-                None => Diagnostic::new(Level::Error, self.to_string()),
+-            },
+-        }
+-    }
+-
+-    /// Transform this error and its children into a list of compiler diagnostics
+-    /// and emit them. If the `Error` has associated span information, the diagnostics
+-    /// will identify the correct location in source code automatically.
+-    ///
+-    /// # Stability
+-    /// This is only available on `nightly` until the compiler `proc_macro_diagnostic`
+-    /// feature stabilizes. Until then, it may break at any time.
+-    #[cfg(feature = "diagnostics")]
+-    pub fn emit(self) {
+-        for error in self.flatten() {
+-            error.single_to_diagnostic().emit()
+-        }
+-    }
+-
+-    /// Transform the error into a compiler diagnostic and - if the diagnostic points to
+-    /// a specific code location - add a spanned help child diagnostic that points to the
+-    /// parent derived trait.
+-    ///
+-    /// This is experimental and therefore not exposed outside the crate.
+-    #[cfg(feature = "diagnostics")]
+-    #[allow(dead_code)]
+-    fn emit_with_macro_help_span(self) {
+-        use proc_macro::Diagnostic;
+-
+-        for error in self.flatten() {
+-            let needs_help = error.has_span();
+-            let diagnostic = error.single_to_diagnostic();
+-            Diagnostic::emit(if needs_help {
+-                diagnostic.span_help(
+-                    Span::call_site().unwrap(),
+-                    "Encountered as part of this derive-mode-macro",
+-                )
+-            } else {
+-                diagnostic
+-            })
+-        }
+-    }
+ }
+ 
+ impl StdError for Error {
+Index: darling-core/src/lib.rs
+===================================================================
+--- darling-core.orig/src/lib.rs
++++ darling-core/src/lib.rs
+@@ -1,5 +1,4 @@
+ #![recursion_limit = "256"]
+-#![cfg_attr(feature = "diagnostics", feature(proc_macro_diagnostic))]
+ 
+ #[macro_use]
+ extern crate quote;
+@@ -7,8 +6,6 @@ extern crate quote;
+ extern crate syn;
+ extern crate fnv;
+ extern crate ident_case;
+-#[cfg(feature = "diagnostics")]
+-extern crate proc_macro;
+ extern crate proc_macro2;
+ #[cfg(feature = "suggestions")]
+ extern crate strsim;

diff --git a/src/darling-core/debian/patches/series b/src/darling-core/debian/patches/series
new file mode 100644 (file)
index 0000000..8e3f0d8
--- /dev/null
+++ b/src/darling-core/debian/patches/series
@@ -0,0 +1 @@
+no-nightly.diff