Updates workflows to use alloc and adds error when derive cannot use …

…alloc.
colin-kiegel · Jan 20, 2024 · 4c008cb · 4c008cb
1 parent 547cde6
commit 4c008cb
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Showing 8 changed files with 81 additions and 72 deletions.
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -15,7 +15,7 @@ jobs:
           - 1.56.0 # MSRV
         features:
           - ""
-          - --no-default-features
+          - --no-default-features --features alloc
           - --features clippy
 
     env:

diff --git a/derive_builder/Cargo.toml b/derive_builder/Cargo.toml
@@ -17,9 +17,9 @@ readme = "README.md"
 
 [features]
 default = ["std"]
-std = []
+std = ["derive_builder_macro/lib_has_std"]
 clippy = ["derive_builder_macro/clippy"]
-alloc = []
+alloc = ["derive_builder_macro/alloc"]
 
 [dependencies]
 derive_builder_macro = { version = "=0.12.0", path = "../derive_builder_macro" }

diff --git a/derive_builder_core/Cargo.toml b/derive_builder_core/Cargo.toml
@@ -14,7 +14,9 @@ license = "MIT OR Apache-2.0"
 readme = "README.md"
 
 [features]
+alloc = []
 clippy = []
+lib_has_std = []
 
 [dependencies]
 darling = "0.14.0"

diff --git a/derive_builder_core/src/builder.rs b/derive_builder_core/src/builder.rs
@@ -12,6 +12,11 @@ use BuilderPattern;
 use DeprecationNotes;
 use 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
+* use a custom error `#[builder(build_fn(error = "path::to::Error"))]
+* disable the validation error `#[builder(build_fn(error(validation_error = false)))]"#;
+
 /// Builder, implementing `quote::ToTokens`.
 ///
 /// # Examples
@@ -135,6 +140,8 @@ pub struct Builder<'a> {
     /// This would be `false` when `build_fn.error.as_validation_error() == Some((false, _))`. This
     /// has no effect when `generate_error` is `false`.
     pub generate_validation_error: bool,
+    /// Indicator of `cfg!(not(any(feature = "alloc", feature = "std")))`, as a field for tests
+    pub no_alloc: bool,
     /// Whether this builder must derive `Clone`.
     ///
     /// This is true even for a builder using the `owned` pattern if there is a field whose setter
@@ -233,7 +240,10 @@ impl<'a> ToTokens for Builder<'a> {
                 ));
             }
 
-            if self.generate_error {
+            if self.no_alloc && self.generate_error && self.generate_validation_error {
+                let err = syn::Error::new_spanned(&self.ident, ALLOC_NOT_ENABLED_ERROR);
+                tokens.append_all(err.to_compile_error());
+            } else if self.generate_error {
                 let builder_error_ident = format_ident!("{}Error", builder_ident);
                 let builder_error_doc = format!("Error type for {}", builder_ident);
 
@@ -385,6 +395,7 @@ macro_rules! default_builder {
             functions: vec![quote!(fn bar() -> { unimplemented!() })],
             generate_error: true,
             generate_validation_error: true,
+            no_alloc: false,
             must_derive_clone: true,
             doc_comment: None,
             deprecation_notes: DeprecationNotes::default(),
@@ -400,6 +411,43 @@ mod tests {
     use proc_macro2::TokenStream;
     use syn::Ident;
 
+    fn add_simple_foo_builder(result: &mut TokenStream) {
+        #[cfg(not(feature = "clippy"))]
+        result.append_all(quote!(#[allow(clippy::all)]));
+
+        result.append_all(quote!(
+            #[derive(Clone)]
+            pub struct FooBuilder {
+                foo: u32,
+            }
+        ));
+
+        #[cfg(not(feature = "clippy"))]
+        result.append_all(quote!(#[allow(clippy::all)]));
+
+        result.append_all(quote!(
+            #[allow(dead_code)]
+            impl FooBuilder {
+                fn bar () -> {
+                    unimplemented!()
+                }
+
+                /// Create an empty builder, with all fields set to `None` or `PhantomData`.
+                fn create_empty() -> Self {
+                    Self {
+                        foo: ::db::export::core::default::Default::default(),
+                    }
+                }
+            }
+
+            impl ::db::export::core::default::Default for FooBuilder {
+                fn default() -> Self {
+                    Self::create_empty()
+                }
+            }
+        ));
+    }
+
     fn add_generated_error(result: &mut TokenStream) {
         result.append_all(quote!(
             #[doc="Error type for FooBuilder"]
@@ -446,40 +494,7 @@ mod tests {
             {
                 let mut result = quote!();
 
-                #[cfg(not(feature = "clippy"))]
-                result.append_all(quote!(#[allow(clippy::all)]));
-
-                result.append_all(quote!(
-                    #[derive(Clone)]
-                    pub struct FooBuilder {
-                        foo: u32,
-                    }
-                ));
-
-                #[cfg(not(feature = "clippy"))]
-                result.append_all(quote!(#[allow(clippy::all)]));
-
-                result.append_all(quote!(
-                    #[allow(dead_code)]
-                    impl FooBuilder {
-                        fn bar () -> {
-                            unimplemented!()
-                        }
-
-                        /// Create an empty builder, with all fields set to `None` or `PhantomData`.
-                        fn create_empty() -> Self {
-                            Self {
-                                foo: ::db::export::core::default::Default::default(),
-                            }
-                        }
-                    }
-
-                    impl ::db::export::core::default::Default for FooBuilder {
-                        fn default() -> Self {
-                            Self::create_empty()
-                        }
-                    }
-                ));
+                add_simple_foo_builder(&mut result);
 
                 add_generated_error(&mut result);
 
@@ -797,40 +812,7 @@ mod tests {
             {
                 let mut result = quote!();
 
-                #[cfg(not(feature = "clippy"))]
-                result.append_all(quote!(#[allow(clippy::all)]));
-
-                result.append_all(quote!(
-                    #[derive(Clone)]
-                    pub struct FooBuilder {
-                        foo: u32,
-                    }
-                ));
-
-                #[cfg(not(feature = "clippy"))]
-                result.append_all(quote!(#[allow(clippy::all)]));
-
-                result.append_all(quote!(
-                    #[allow(dead_code)]
-                    impl FooBuilder {
-                        fn bar () -> {
-                            unimplemented!()
-                        }
-
-                        /// Create an empty builder, with all fields set to `None` or `PhantomData`.
-                        fn create_empty() -> Self {
-                            Self {
-                                foo: ::db::export::core::default::Default::default(),
-                            }
-                        }
-                    }
-
-                    impl ::db::export::core::default::Default for FooBuilder {
-                        fn default() -> Self {
-                            Self::create_empty()
-                        }
-                    }
-                ));
+                add_simple_foo_builder(&mut result);
 
                 result.append_all(quote!(
                     #[doc="Error type for FooBuilder"]
@@ -860,6 +842,26 @@ mod tests {
 
                 result
             }
+                .to_string()
+        );
+    }
+
+    #[test]
+    fn no_alloc_bug_using_string() {
+        let mut builder = default_builder!();
+        builder.no_alloc = true;
+
+        assert_eq!(
+            quote!(#builder).to_string(),
+            {
+                let mut result = quote!();
+
+                add_simple_foo_builder(&mut result);
+
+                result.append_all(quote!(compile_error! { #ALLOC_NOT_ENABLED_ERROR }));
+
+                result
+            }
             .to_string()
         );
     }

diff --git a/derive_builder_core/src/macro_options/darling_opts.rs b/derive_builder_core/src/macro_options/darling_opts.rs
@@ -803,6 +803,7 @@ impl Options {
                 .as_ref()
                 .and_then(BuildFnError::as_validation_error)
                 .map_or(true, |(b, _)| b),
+            no_alloc: cfg!(not(any(feature = "alloc", feature = "lib_has_std"))),
             must_derive_clone: self.requires_clone(),
             doc_comment: None,
             deprecation_notes: Default::default(),

diff --git a/derive_builder_macro/Cargo.toml b/derive_builder_macro/Cargo.toml
@@ -19,7 +19,9 @@ readme = "README.md"
 proc-macro = true
 
 [features]
+alloc = ["derive_builder_core/alloc"]
 clippy = ["derive_builder_core/clippy"]
+lib_has_std = ["derive_builder_core/lib_has_std"]
 
 [dependencies]
 syn = { version = "1.0.91", features = ["full", "extra-traits"] }

diff --git a/derive_builder_no_alloc_tests/Cargo.toml b/derive_builder_no_alloc_tests/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2018"
 publish = false
 
 [features]
+alloc = [] # To satify workflows which set `alloc`
 clippy = ["derive_builder/clippy"]
 
 [dependencies]

diff --git a/derive_builder_no_std_tests/Cargo.toml b/derive_builder_no_std_tests/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2018"
 publish = false
 
 [features]
+alloc = [] # To satify workflows which set `alloc`
 clippy = ["derive_builder/clippy"]
 
 [dependencies]