Add support for compiler experimental features

commit-id:480c1b28

review update

review update

fix docs, add todo

scarb-metadata/src/lib.rs

@@ -231,6 +231,9 @@ pub struct PackageMetadata {
     #[serde(flatten)]
     pub manifest_metadata: ManifestMetadata,
 
+    /// Compiler experimental features allowed for this package.
+    pub experimental_features: Vec<String>,
+
     /// Additional data not captured by deserializer.
     #[cfg_attr(feature = "builder", builder(default))]
     #[serde(flatten)]

scarb/src/compiler/db.rs

@@ -93,16 +93,21 @@ fn build_project_config(unit: &CompilationUnit) -> Result<ProjectConfig> {
         .components
         .iter()
         .map(|component| {
+            let experimental_features = component.package.manifest.experimental_features.clone();
             (
                 component.cairo_package_name(),
                 CrateSettings {
                     edition: component.package.manifest.edition,
-                    experimental_features: Default::default(),
+                    // TODO (#1040): replace this with a macro
+                    experimental_features: cairo_lang_filesystem::db::ExperimentalFeaturesConfig {
+                        negative_impls: experimental_features
+                            .unwrap_or_default()
+                            .contains(&SmolStr::new_inline("negative_impls")),
+                    },
                 },
             )
         })
         .collect();
-
     let crates_config = AllCratesConfig {
         override_map: crates_config,
         ..Default::default()

scarb/src/core/manifest/mod.rs

@@ -49,6 +49,9 @@ pub struct Manifest {
     pub compiler_config: ManifestCompilerConfig,
     #[builder(default)]
     pub scripts: BTreeMap<SmolStr, ScriptDefinition>,
+    /// Allow experimental features.
+    #[builder(default)]
+    pub experimental_features: Option<Vec<SmolStr>>,
 }
 
 /// Subset of a [`Manifest`] that contains package metadata.

scarb/src/core/manifest/toml_manifest.rs

@@ -198,6 +198,7 @@ pub struct TomlPackage {
     /// **UNSTABLE** This package does not depend on Cairo's `core`.
     pub no_core: Option<bool>,
     pub cairo_version: Option<MaybeWorkspaceField<VersionReq>>,
+    pub experimental_features: Option<Vec<SmolStr>>,
 }
 
 #[derive(Clone, Debug, Serialize, Eq, PartialEq)]
@@ -556,15 +557,17 @@ impl TomlManifest {
             .transpose()?
             .unwrap_or_default();
 
+        // TODO (#1040): add checking for fields that are not present in ExperimentalFeaturesConfig
+        let experimental_features = package.experimental_features.clone();
         let manifest = ManifestBuilder::default()
             .summary(summary)
             .targets(targets)
             .edition(edition)
             .metadata(metadata)
             .compiler_config(compiler_config)
             .scripts(scripts)
+            .experimental_features(experimental_features)
             .build()?;
-
         Ok(manifest)
     }
 

scarb/src/core/publishing/manifest_normalization.rs

@@ -75,6 +75,7 @@ fn generate_package(pkg: &Package) -> Box<TomlPackage> {
         repository: metadata.repository.clone().map(MaybeWorkspace::Defined),
         no_core: summary.no_core.then_some(true),
         cairo_version: metadata.cairo_version.clone().map(MaybeWorkspace::Defined),
+        experimental_features: pkg.manifest.experimental_features.clone(),
     })
 }
 

scarb/src/ops/metadata.rs

@@ -135,6 +135,15 @@ fn collect_package_metadata(package: &Package) -> m::PackageMetadata {
 
     let edition = edition_variant(package.manifest.edition);
 
+    let experimental_features: Vec<String> = package
+        .manifest
+        .experimental_features
+        .clone()
+        .unwrap_or_default()
+        .iter()
+        .map(|x| x.to_string())
+        .collect();
+
     m::PackageMetadataBuilder::default()
         .id(wrap_package_id(package.id))
         .name(package.id.name.clone())
@@ -146,6 +155,7 @@ fn collect_package_metadata(package: &Package) -> m::PackageMetadata {
         .dependencies(dependencies)
         .targets(targets)
         .manifest_metadata(manifest_metadata)
+        .experimental_features(experimental_features)
         .build()
         .unwrap()
 }

scarb/tests/metadata.rs

@@ -1287,3 +1287,28 @@ fn includes_edition() {
     }
     panic!("Package not found in metadata!");
 }
+
+#[test]
+fn includes_experimental_features() {
+    let t = assert_fs::TempDir::new().unwrap();
+    ProjectBuilder::start()
+        .name("hello")
+        .version("0.1.0")
+        .manifest_package_extra(r#"experimental-features = ["negative_impls"]"#)
+        .build(&t);
+
+    let metadata = Scarb::quick_snapbox()
+        .arg("--json")
+        .arg("metadata")
+        .arg("--format-version")
+        .arg("1")
+        .current_dir(&t)
+        .stdout_json::<Metadata>();
+
+    assert!(packages_by_name(metadata)
+        .get("hello")
+        .unwrap()
+        .clone()
+        .experimental_features
+        .contains(&String::from("negative_impls")))
+}

utils/scarb-test-support/src/project_builder.rs

@@ -24,6 +24,7 @@ pub struct ProjectBuilder {
     src: HashMap<Utf8PathBuf, String>,
     deps: Vec<(String, Value)>,
     dev_deps: Vec<(String, Value)>,
+    manifest_package_extra: String,
     manifest_extra: String,
 }
 
@@ -44,6 +45,7 @@ impl ProjectBuilder {
             )]),
             deps: Vec::new(),
             dev_deps: Vec::new(),
+            manifest_package_extra: String::new(),
             manifest_extra: String::new(),
         }
     }
@@ -95,6 +97,11 @@ impl ProjectBuilder {
         self.dep("starknet", Dep.version(CAIRO_VERSION))
     }
 
+    pub fn manifest_package_extra(mut self, extra: impl ToString) -> Self {
+        self.manifest_package_extra = extra.to_string();
+        self
+    }
+
     pub fn manifest_extra(mut self, extra: impl ToString) -> Self {
         self.manifest_extra = extra.to_string();
         self
@@ -111,6 +118,12 @@ impl ProjectBuilder {
         if let Some(cairo_version) = self.cairo_version.as_ref() {
             doc["package"]["cairo-version"] = Item::Value(Value::from(cairo_version.to_string()));
         }
+        let mut manifest = doc.to_string();
+        if !self.manifest_package_extra.is_empty() {
+            manifest.push_str(&self.manifest_package_extra);
+        }
+
+        let mut doc = manifest.parse::<Document>().unwrap();
         doc["dependencies"] = toml_edit::table();
         for (name, dep) in &self.deps {
             doc["dependencies"][name.clone()] = Item::Value(dep.clone());

website/docs/reference/manifest.md

@@ -209,6 +209,15 @@ Keys are human-readable link names, and values are URLs.
 "We're hiring" = "https://swmansion.com/careers/"
 ```
 
+### `experimental-features`
+
+This field is responsible for setting experimental flags to be used on the package for the compiler.
+
+```toml
+[package]
+experimental-features = ["negative_impls"]
+```
+
 ## `[dependencies]`
 
 See [Specifying Dependencies](./specifying-dependencies) page.