feat(enum): add basic enum support

Fixes: #178
Refs: #302

Author: Xenira

Cargo.toml

@@ -38,9 +38,11 @@ native-tls = "0.2"
 zip = "4.0"
 
 [features]
+default = ["enum"]
 closure = []
 embed = []
 anyhow = ["dep:anyhow"]
+enum = []
 
 [workspace]
 members = [

allowed_bindings.rs

@@ -87,6 +87,8 @@ bind! {
     zend_declare_class_constant,
     zend_declare_property,
     zend_do_implement_interface,
+    zend_enum_add_case,
+    zend_enum_new,
     zend_execute_data,
     zend_function_entry,
     zend_hash_clean,
@@ -114,6 +116,7 @@ bind! {
     zend_register_bool_constant,
     zend_register_double_constant,
     zend_register_ini_entries,
+    zend_register_internal_enum,
     zend_ini_entry_def,
     zend_register_internal_class_ex,
     zend_register_long_constant,
@@ -191,6 +194,7 @@ bind! {
     ZEND_ACC_DEPRECATED,
     ZEND_ACC_DONE_PASS_TWO,
     ZEND_ACC_EARLY_BINDING,
+    ZEND_ACC_ENUM,
     ZEND_ACC_FAKE_CLOSURE,
     ZEND_ACC_FINAL,
     ZEND_ACC_GENERATOR,

build.rs

@@ -261,7 +261,7 @@ fn generate_bindings(defines: &[(&str, &str)], includes: &[PathBuf]) -> Result<S
     Ok(bindings)
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
 enum ApiVersion {
     Php80 = 2020_09_30,
     Php81 = 2021_09_02,
@@ -272,8 +272,15 @@ enum ApiVersion {
 
 impl ApiVersion {
     /// Returns the minimum API version supported by ext-php-rs.
-    pub const fn min() -> Self {
-        ApiVersion::Php80
+    pub fn min() -> Self {
+        [
+            ApiVersion::Php80,
+            #[cfg(feature = "enum")]
+            ApiVersion::Php81,
+        ]
+        .into_iter()
+        .max()
+        .unwrap_or(Self::max())
     }
 
     /// Returns the maximum API version supported by ext-php-rs.

crates/macros/Cargo.toml

@@ -6,7 +6,7 @@ homepage = "https://github.com/davidcole1340/ext-php-rs"
 license = "MIT OR Apache-2.0"
 version = "0.11.0"
 authors = ["David Cole <[email protected]>"]
-edition = "2018"
+edition = "2021"
 
 [lib]
 proc-macro = true
@@ -19,6 +19,7 @@ proc-macro2 = "1.0.26"
 lazy_static = "1.4.0"
 anyhow = "1.0"
 convert_case = "0.8.0"
+itertools = "0.14.0"
 
 [lints.rust]
 missing_docs = "warn"

crates/macros/src/enum_.rs

@@ -0,0 +1,263 @@
+use std::convert::TryFrom;
+
+use darling::FromAttributes;
+use itertools::Itertools;
+use proc_macro2::TokenStream;
+use quote::{quote, ToTokens};
+use syn::{Expr, Fields, Ident, ItemEnum, Lit};
+
+use crate::{
+    helpers::get_docs,
+    parsing::{PhpRename, RenameRule, Visibility},
+    prelude::*,
+};
+
+#[derive(FromAttributes, Default, Debug)]
+#[darling(default, attributes(php), forward_attrs(doc))]
+struct PhpEnumAttribute {
+    #[darling(flatten)]
+    rename: PhpRename,
+    #[darling(default)]
+    allow_discriminants: bool,
+    vis: Option<Visibility>,
+    attrs: Vec<syn::Attribute>,
+}
+
+#[derive(FromAttributes, Default, Debug)]
+#[darling(default, attributes(php), forward_attrs(doc))]
+struct PhpEnumVariantAttribute {
+    #[darling(flatten)]
+    rename: PhpRename,
+    discriminant: Option<Expr>,
+    // TODO: Implement doc support for enum variants
+    #[allow(dead_code)]
+    attrs: Vec<syn::Attribute>,
+}
+
+pub fn parser(mut input: ItemEnum) -> Result<TokenStream> {
+    let php_attr = PhpEnumAttribute::from_attributes(&input.attrs)?;
+    input.attrs.retain(|attr| !attr.path().is_ident("php"));
+
+    let docs = get_docs(&php_attr.attrs)?;
+    let mut cases = vec![];
+    let mut discriminant_type = DiscriminantType::None;
+
+    let mut variants = input.variants.clone();
+    for variant in &mut variants {
+        if variant.fields != Fields::Unit {
+            bail!("Enum cases must be unit variants, found: {:?}", variant);
+        }
+        if !php_attr.allow_discriminants && variant.discriminant.is_some() {
+            bail!(variant => "Native discriminants are currently not exported to PHP. To set a discriminant, use the `#[php(allow_discriminants)]` attribute on the enum. To export discriminants, set the #[php(discriminant = ...)] attribute on the enum case.");
+        }
+
+        let variant_attr = PhpEnumVariantAttribute::from_attributes(&variant.attrs)?;
+        let discriminant = variant_attr
+            .discriminant
+            .as_ref()
+            .map(TryInto::try_into)
+            .transpose()?;
+
+        if let Some(d) = &discriminant {
+            match d {
+                Discriminant::String(_) => {
+                    if discriminant_type != DiscriminantType::String {
+                        bail!(variant => "Mixed discriminants are not allowed in enums, found string and integer discriminants");
+                    }
+
+                    discriminant_type = DiscriminantType::String;
+                }
+                Discriminant::Integer(_) => {
+                    if discriminant_type != DiscriminantType::Integer {
+                        bail!(variant => "Mixed discriminants are not allowed in enums, found string and integer discriminants");
+                    }
+
+                    discriminant_type = DiscriminantType::Integer;
+                }
+            }
+        } else if discriminant_type != DiscriminantType::None {
+            bail!(variant => "Discriminant must be specified for all enum cases, found: {:?}", variant);
+        }
+
+        cases.push(EnumCase {
+            ident: &variant.ident,
+            discriminant,
+        });
+
+        if !cases
+            .iter()
+            .filter_map(|case| case.discriminant.as_ref())
+            .all_unique()
+        {
+            bail!(variant => "Enum cases must have unique discriminants, found duplicates in: {:?}", cases);
+        }
+    }
+
+    let enum_props = Enum {
+        ident: &input.ident,
+        attrs: php_attr,
+        docs,
+        cases,
+        flags: None, // TODO: Implement flags support
+    };
+
+    Ok(quote! {
+        #[allow(dead_code)]
+        #input
+
+        #enum_props
+    })
+}
+
+#[derive(Debug)]
+pub struct Enum<'a> {
+    ident: &'a Ident,
+    attrs: PhpEnumAttribute,
+    docs: Vec<String>,
+    cases: Vec<EnumCase<'a>>,
+    // TODO: Implement flags support
+    #[allow(dead_code)]
+    flags: Option<String>,
+}
+
+impl ToTokens for Enum<'_> {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        let ident = &self.ident;
+        let enum_name = self
+            .attrs
+            .rename
+            .rename(ident.to_string(), RenameRule::Pascal);
+        let flags = quote! { ::ext_php_rs::flags::ClassFlags::Enum };
+        let docs = &self.docs;
+        let cases = &self.cases;
+
+        let class = quote! {
+            impl ::ext_php_rs::class::RegisteredClass for #ident {
+                const CLASS_NAME: &'static str = #enum_name;
+                const BUILDER_MODIFIER: ::std::option::Option<
+                    fn(::ext_php_rs::builders::ClassBuilder) -> ::ext_php_rs::builders::ClassBuilder
+                > = None;
+                const EXTENDS: ::std::option::Option<
+                    ::ext_php_rs::class::ClassEntryInfo
+                > = None;
+                const IMPLEMENTS: &'static [::ext_php_rs::class::ClassEntryInfo] = &[];
+                const FLAGS: ::ext_php_rs::flags::ClassFlags = #flags;
+                const DOC_COMMENTS: &'static [&'static str] = &[
+                    #(#docs,)*
+                ];
+
+                fn get_metadata() -> &'static ::ext_php_rs::class::ClassMetadata<Self> {
+                    static METADATA: ::ext_php_rs::class::ClassMetadata<#ident> =
+                        ::ext_php_rs::class::ClassMetadata::new();
+                    &METADATA
+                }
+
+                #[inline]
+                fn get_properties<'a>() -> ::std::collections::HashMap<
+                    &'static str, ::ext_php_rs::internal::property::PropertyInfo<'a, Self>
+                > {
+                    ::std::collections::HashMap::new()
+                }
+
+                #[inline]
+                fn method_builders() -> ::std::vec::Vec<
+                    (::ext_php_rs::builders::FunctionBuilder<'static>, ::ext_php_rs::flags::MethodFlags)
+                > {
+                    use ::ext_php_rs::internal::class::PhpClassImpl;
+                    ::ext_php_rs::internal::class::PhpClassImplCollector::<Self>::default().get_methods()
+                }
+
+                #[inline]
+                fn constructor() -> ::std::option::Option<::ext_php_rs::class::ConstructorMeta<Self>> {
+                    None
+                }
+
+                #[inline]
+                fn constants() -> &'static [(&'static str, &'static dyn ::ext_php_rs::convert::IntoZvalDyn, &'static [&'static str])] {
+                    use ::ext_php_rs::internal::class::PhpClassImpl;
+                    ::ext_php_rs::internal::class::PhpClassImplCollector::<Self>::default().get_constants()
+                }
+            }
+        };
+        let enum_impl = quote! {
+            impl ::ext_php_rs::enum_::PhpEnum for #ident {
+                const CASES: &'static [::ext_php_rs::enum_::EnumCase] = &[
+                    #(#cases,)*
+                ];
+            }
+        };
+
+        tokens.extend(quote! {
+            #class
+            #enum_impl
+        });
+    }
+}
+
+#[derive(Debug)]
+struct EnumCase<'a> {
+    ident: &'a Ident,
+    discriminant: Option<Discriminant>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+enum Discriminant {
+    String(String),
+    Integer(i64),
+}
+
+impl TryFrom<&Expr> for Discriminant {
+    type Error = syn::Error;
+
+    fn try_from(expr: &Expr) -> Result<Self> {
+        match expr {
+            Expr::Lit(expr) => match &expr.lit {
+                Lit::Str(s) => Ok(Discriminant::String(s.value())),
+                Lit::Int(i) => i.base10_parse::<i64>().map(Discriminant::Integer).map_err(
+                    |_| err!(expr => "Invalid integer literal for enum case: {:?}", expr.lit),
+                ),
+                _ => bail!(expr => "Unsupported discriminant type: {:?}", expr.lit),
+            },
+            _ => {
+                bail!(expr => "Unsupported discriminant type, expected a literal of type string or i64")
+            }
+        }
+    }
+}
+
+impl ToTokens for Discriminant {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        tokens.extend(match self {
+            Discriminant::String(s) => {
+                quote! { ::ext_php_rs::enum_::Discriminant::String(#s.to_string()) }
+            }
+            Discriminant::Integer(i) => {
+                quote! { ::ext_php_rs::enum_::Discriminant::Integer(#i) }
+            }
+        });
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+enum DiscriminantType {
+    None,
+    String,
+    Integer,
+}
+
+impl ToTokens for EnumCase<'_> {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        let ident = &self.ident.to_string();
+        let discriminant = self
+            .discriminant
+            .as_ref()
+            .map_or_else(|| quote! { None }, |v| quote! { Some(#v) });
+
+        tokens.extend(quote! {
+            ::ext_php_rs::enum_::EnumCase {
+                name: #ident,
+                discriminant: #discriminant,
+            }
+        });
+    }
+}