sway_core/semantic_analysis/namespace/

namespace.rs

use crate::{language::Visibility, Engines, Ident};

use super::{module::Module, root::Root, ModulePath, ModulePathBuf};

use sway_error::handler::{ErrorEmitted, Handler};
use sway_types::{
    constants::{CONTRACT_ID, PRELUDE, STD},
    span::Span,
};

/// The set of items that represent the namespace context passed throughout type checking.
#[derive(Clone, Debug)]
pub struct Namespace {
    /// The `root` of the project namespace.
    ///
    /// From the root, the entirety of the project's namespace can always be accessed.
    ///
    /// The root is initialised from the `init` namespace before type-checking begins.
    pub(crate) root: Root,
    /// An absolute path from the `root` that represents the module location.
    ///
    /// The path of the root module in a package is `[package_name]`. If a module `X` is a submodule
    /// of module `Y` which is a submodule of the root module in the package `P`, then the path is
    /// `[P, Y, X]`.
    pub(crate) current_mod_path: ModulePathBuf,
}

impl Namespace {
    /// Initialize the namespace
    /// See also the factory functions in contract_helpers.rs
    ///
    /// If `import_prelude_into_root` is true then and std::prelude::* will be
    /// imported into the root module, provided std is available in the external modules.
    pub fn new(
        handler: &Handler,
        engines: &Engines,
        package_root: Root,
        import_prelude_into_root: bool,
    ) -> Result<Self, ErrorEmitted> {
        let package_name = package_root.current_package_name().clone();
        let mut res = Self {
            root: package_root,
            current_mod_path: vec![package_name],
        };

        if import_prelude_into_root {
            res.import_implicits(handler, engines)?;
        }
        Ok(res)
    }

    pub fn root(self) -> Root {
        self.root
    }

    pub fn root_ref(&self) -> &Root {
        &self.root
    }

    pub fn current_module(&self) -> &Module {
        self.root
            .module_in_current_package(&self.current_mod_path)
            .unwrap_or_else(|| panic!("Could not retrieve submodule for mod_path."))
    }

    pub fn current_module_mut(&mut self) -> &mut Module {
        self.root
            .module_mut_in_current_package(&self.current_mod_path)
            .unwrap_or_else(|| panic!("Could not retrieve submodule for mod_path."))
    }

    pub(crate) fn current_module_has_submodule(&self, submod_name: &Ident) -> bool {
        self.current_module()
            .submodule(&[submod_name.clone()])
            .is_some()
    }

    pub fn current_package_name(&self) -> &Ident {
        self.root.current_package_name()
    }

    /// A reference to the path of the module currently being processed.
    pub fn current_mod_path(&self) -> &ModulePathBuf {
        &self.current_mod_path
    }

    /// Prepends the module path into the prefixes.
    pub fn prepend_module_path<'a>(
        &'a self,
        prefixes: impl IntoIterator<Item = &'a Ident>,
    ) -> ModulePathBuf {
        self.current_mod_path
            .iter()
            .chain(prefixes)
            .cloned()
            .collect()
    }

    /// Convert a parsed path to a full path.
    pub fn parsed_path_to_full_path(
        &self,
        _engines: &Engines,
        parsed_path: &ModulePathBuf,
        is_relative_to_package_root: bool,
    ) -> ModulePathBuf {
        if is_relative_to_package_root {
            // Path is relative to the root module in the current package. Prepend the package name
            let mut path = vec![self.current_package_name().clone()];
            for ident in parsed_path.iter() {
                path.push(ident.clone())
            }
            path
        } else if self.current_module_has_submodule(&parsed_path[0]) {
            // The first identifier is a submodule of the current module
            // The path is therefore assumed to be relative to the current module, so prepend the current module path.
            self.prepend_module_path(parsed_path)
        } else if self.module_is_external(parsed_path) {
            // The path refers to an external module, so the path is already a full path.
            parsed_path.to_vec()
        } else {
            // The first identifier is neither a submodule nor an external package. It must
            // therefore refer to a binding in the local environment
            self.prepend_module_path(parsed_path)
        }
    }

    pub fn current_package_root_module(&self) -> &Module {
        self.root.current_package_root_module()
    }

    pub fn module_from_absolute_path(&self, path: &ModulePathBuf) -> Option<&Module> {
        self.root.module_from_absolute_path(path)
    }

    // Like module_from_absolute_path, but throws an error if the module is not found
    pub fn require_module_from_absolute_path(
        &self,
        handler: &Handler,
        path: &ModulePathBuf,
    ) -> Result<&Module, ErrorEmitted> {
        self.root.require_module(handler, path)
    }

    /// Returns true if the current module being checked is a direct or indirect submodule of
    /// the module given by the `absolute_module_path`.
    ///
    /// The current module being checked is determined by `mod_path`.
    ///
    /// E.g., the `mod_path` `[fist, second, third]` of the root `foo` is a submodule of the module
    /// `[foo, first]`. Note that the `mod_path` does not contain the root name, while the
    /// `absolute_module_path` always contains it.
    ///
    /// If the current module being checked is the same as the module given by the `absolute_module_path`,
    /// the `true_if_same` is returned.
    pub(crate) fn module_is_submodule_of(
        &self,
        absolute_module_path: &ModulePath,
        true_if_same: bool,
    ) -> bool {
        if self.current_mod_path.len() < absolute_module_path.len() {
            return false;
        }

        let is_submodule = absolute_module_path
            .iter()
            .zip(self.current_mod_path.iter())
            .all(|(left, right)| left == right);

        if is_submodule {
            if self.current_mod_path.len() == absolute_module_path.len() {
                true_if_same
            } else {
                true
            }
        } else {
            false
        }
    }

    /// Returns true if the module given by the `absolute_module_path` is external
    /// to the current package. External modules are imported in the `Forc.toml` file.
    pub(crate) fn module_is_external(&self, absolute_module_path: &ModulePath) -> bool {
        assert!(!absolute_module_path.is_empty(), "Absolute module path must have at least one element, because it always contains the package name.");

        self.root.current_package_name() != &absolute_module_path[0]
    }

    pub fn package_exists(&self, name: &Ident) -> bool {
        self.module_from_absolute_path(&vec![name.clone()])
            .is_some()
    }

    pub(crate) fn module_has_binding(
        &self,
        engines: &Engines,
        mod_path: &ModulePathBuf,
        symbol: &Ident,
    ) -> bool {
        let dummy_handler = Handler::default();
        if let Some(module) = self.module_from_absolute_path(mod_path) {
            module
                .resolve_symbol(&dummy_handler, engines, symbol)
                .is_ok()
        } else {
            false
        }
    }

    // Import std::prelude::* and ::CONTRACT_ID as appropriate into the current module
    fn import_implicits(
        &mut self,
        handler: &Handler,
        engines: &Engines,
    ) -> Result<(), ErrorEmitted> {
        // Import preludes
        let package_name = self.current_package_name().to_string();
        let prelude_ident = Ident::new_no_span(PRELUDE.to_string());

        if package_name == STD {
            // Do nothing
        } else {
            // Import std::prelude::*
            let std_string = STD.to_string();
            // Only import std::prelude::* if std exists as a dependency
            if self.root.exists_as_external(&std_string) {
                self.root.star_import(
                    handler,
                    engines,
                    &[Ident::new_no_span(std_string), prelude_ident],
                    &self.current_mod_path,
                    Visibility::Private,
                )?
            }
        }

        // Import contract id. CONTRACT_ID is declared in the root module, so only import it into non-root modules
        if self.root.is_contract_package() && self.current_mod_path.len() > 1 {
            // import ::CONTRACT_ID
            self.root.item_import(
                handler,
                engines,
                &[Ident::new_no_span(package_name)],
                &Ident::new_no_span(CONTRACT_ID.to_string()),
                &self.current_mod_path,
                None,
                Visibility::Private,
            )?
        }

        Ok(())
    }

    pub(crate) fn enter_submodule(
        &mut self,
        handler: &Handler,
        engines: &Engines,
        mod_name: Ident,
        visibility: Visibility,
        module_span: Span,
    ) -> Result<(), ErrorEmitted> {
        let mut import_implicits = false;

        // Ensure the new module exists and is initialized properly
        if !self
            .current_module()
            .submodules()
            .contains_key(&mod_name.to_string())
        {
            // Entering a new module. Add a new one.
            self.current_module_mut()
                .add_new_submodule(&mod_name, visibility, Some(module_span));
            import_implicits = true;
        }

        // Update self to point to the new module
        self.current_mod_path.push(mod_name.clone());

        // Import implicits into the newly created module.
        if import_implicits {
            self.import_implicits(handler, engines)?;
        }

        Ok(())
    }

    /// Pushes a new submodule to the namespace's module hierarchy.
    pub fn push_submodule(
        &mut self,
        handler: &Handler,
        engines: &Engines,
        mod_name: Ident,
        visibility: Visibility,
        module_span: Span,
    ) -> Result<(), ErrorEmitted> {
        match self.enter_submodule(handler, engines, mod_name, visibility, module_span) {
            Ok(_) => Ok(()),
            Err(e) => Err(e),
        }
    }

    /// Pops the current submodule from the namespace's module hierarchy.
    pub fn pop_submodule(&mut self) {
        self.current_mod_path.pop();
    }

    pub(crate) fn star_import_to_current_module(
        &mut self,
        handler: &Handler,
        engines: &Engines,
        src: &ModulePath,
        visibility: Visibility,
    ) -> Result<(), ErrorEmitted> {
        self.root
            .star_import(handler, engines, src, &self.current_mod_path, visibility)
    }

    pub(crate) fn variant_star_import_to_current_module(
        &mut self,
        handler: &Handler,
        engines: &Engines,
        src: &ModulePath,
        enum_name: &Ident,
        visibility: Visibility,
    ) -> Result<(), ErrorEmitted> {
        self.root.variant_star_import(
            handler,
            engines,
            src,
            &self.current_mod_path,
            enum_name,
            visibility,
        )
    }

    pub(crate) fn self_import_to_current_module(
        &mut self,
        handler: &Handler,
        engines: &Engines,
        src: &ModulePath,
        alias: Option<Ident>,
        visibility: Visibility,
    ) -> Result<(), ErrorEmitted> {
        self.root.self_import(
            handler,
            engines,
            src,
            &self.current_mod_path,
            alias,
            visibility,
        )
    }

    pub(crate) fn item_import_to_current_module(
        &mut self,
        handler: &Handler,
        engines: &Engines,
        src: &ModulePath,
        item: &Ident,
        alias: Option<Ident>,
        visibility: Visibility,
    ) -> Result<(), ErrorEmitted> {
        self.root.item_import(
            handler,
            engines,
            src,
            item,
            &self.current_mod_path,
            alias,
            visibility,
        )
    }

    #[allow(clippy::too_many_arguments)]
    pub(crate) fn variant_import_to_current_module(
        &mut self,
        handler: &Handler,
        engines: &Engines,
        src: &ModulePath,
        enum_name: &Ident,
        variant_name: &Ident,
        alias: Option<Ident>,
        visibility: Visibility,
    ) -> Result<(), ErrorEmitted> {
        self.root.variant_import(
            handler,
            engines,
            src,
            enum_name,
            variant_name,
            &self.current_mod_path,
            alias,
            visibility,
        )
    }
}