Split cairo-lang-macro crate into two (api <> abi)

commit-id:54582a03

Cargo.toml

@@ -6,8 +6,9 @@ members = [
     "extensions/scarb-cairo-run",
     "extensions/scarb-cairo-test",
     "extensions/scarb-snforge-test-collector",
-    "plugins/cairo-lang-macro-attributes",
     "plugins/cairo-lang-macro",
+    "plugins/cairo-lang-macro-attributes",
+    "plugins/cairo-lang-macro-stable",
     "utils/create-output-dir",
     "utils/scarb-build-metadata",
     "utils/scarb-test-support",

plugins/cairo-lang-macro-attributes/src/lib.rs

@@ -16,10 +16,10 @@ pub fn attribute_macro(_args: TokenStream, input: TokenStream) -> TokenStream {
         #item
 
         #[no_mangle]
-        pub unsafe extern "C" fn expand(token_stream: cairo_lang_macro::stable_abi::StableTokenStream) -> cairo_lang_macro::stable_abi::StableProcMacroResult {
-            let token_stream = token_stream.into_token_stream();
+        pub unsafe extern "C" fn expand(token_stream: cairo_lang_macro_stable::StableTokenStream) -> cairo_lang_macro_stable::StableProcMacroResult {
+            let token_stream = TokenStream::from_stable(token_stream);
             let result = #item_name(token_stream);
-            cairo_lang_macro::stable_abi::StableProcMacroResult::from_proc_macro_result(result)
+            result.into_stable()
         }
     };
     TokenStream::from(expanded)

plugins/cairo-lang-macro-stable/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "cairo-lang-macro-stable"
+version = "0.0.1"
+edition.workspace = true
+
+authors.workspace = true
+categories = ["development-tools"]
+description = "Cairo procedural macro stable ABI interface primitives."
+homepage.workspace = true
+keywords = ["scarb"]
+license.workspace = true
+readme = "README.md"
+repository.workspace = true
+
+[dependencies]
+anyhow.workspace = true
+serde.workspace = true
+serde_json.workspace = true

plugins/cairo-lang-macro-stable/README.md

@@ -0,0 +1,3 @@
+# cairo-lang-macro-stable
+
+Stable interface for Scarb procedural macros.

plugins/cairo-lang-macro-stable/src/lib.rs

@@ -0,0 +1,51 @@
+use std::ffi::CString;
+use std::os::raw::c_char;
+
+/// Token stream.
+///
+/// This struct implements FFI-safe stable ABI.
+#[repr(C)]
+#[derive(Debug)]
+pub struct StableTokenStream(pub *mut c_char);
+
+#[repr(C)]
+#[derive(Debug)]
+pub enum StableAuxData {
+    None,
+    Some(*mut c_char),
+}
+
+/// Procedural macro result.
+///
+/// This struct implements FFI-safe stable ABI.
+#[repr(C)]
+#[derive(Debug)]
+pub enum StableProcMacroResult {
+    /// Plugin has not taken any action.
+    Leave,
+    /// Plugin generated [`StableTokenStream`] replacement.
+    Replace {
+        token_stream: StableTokenStream,
+        aux_data: StableAuxData,
+    },
+    /// Plugin ordered item removal.
+    Remove,
+}
+
+impl StableTokenStream {
+    /// Convert to String.
+    ///
+    /// # Safety
+    pub unsafe fn to_string(&self) -> String {
+        raw_to_string(self.0)
+    }
+}
+
+unsafe fn raw_to_string(raw: *mut c_char) -> String {
+    if raw.is_null() {
+        String::default()
+    } else {
+        let cstr = CString::from_raw(raw);
+        cstr.to_string_lossy().to_string()
+    }
+}

plugins/cairo-lang-macro/Cargo.toml

@@ -15,5 +15,6 @@ repository.workspace = true
 [dependencies]
 anyhow.workspace = true
 cairo-lang-macro-attributes = { path = "../cairo-lang-macro-attributes" }
+cairo-lang-macro-stable = { path = "../cairo-lang-macro-stable" }
 serde.workspace = true
 serde_json.workspace = true

plugins/cairo-lang-macro/src/lib.rs

@@ -1,10 +1,9 @@
-use serde_json::Value;
+use serde_json::{Error, Value};
+use std::ffi::{c_char, CString};
 use std::fmt::Display;
 
 pub use cairo_lang_macro_attributes::*;
-
-#[doc(hidden)]
-pub mod stable_abi;
+use cairo_lang_macro_stable::{StableAuxData, StableProcMacroResult, StableTokenStream};
 
 #[derive(Debug)]
 pub enum ProcMacroResult {
@@ -48,3 +47,102 @@ impl AuxData {
         self.0
     }
 }
+
+impl ProcMacroResult {
+    /// Convert to FFI-safe representation.
+    ///
+    /// # Safety
+    #[doc(hidden)]
+    pub fn into_stable(self) -> StableProcMacroResult {
+        match self {
+            ProcMacroResult::Leave => StableProcMacroResult::Leave,
+            ProcMacroResult::Remove => StableProcMacroResult::Remove,
+            ProcMacroResult::Replace {
+                token_stream,
+                aux_data,
+            } => StableProcMacroResult::Replace {
+                token_stream: token_stream.into_stable(),
+                aux_data: AuxData::maybe_into_stable(aux_data),
+            },
+        }
+    }
+
+    /// Convert to native Rust representation.
+    ///
+    /// # Safety
+    #[doc(hidden)]
+    pub unsafe fn from_stable(result: StableProcMacroResult) -> Self {
+        match result {
+            StableProcMacroResult::Leave => ProcMacroResult::Leave,
+            StableProcMacroResult::Remove => ProcMacroResult::Remove,
+            StableProcMacroResult::Replace {
+                token_stream,
+                aux_data,
+            } => ProcMacroResult::Replace {
+                token_stream: TokenStream::from_stable(token_stream),
+                aux_data: AuxData::from_stable(aux_data).unwrap(),
+            },
+        }
+    }
+}
+
+impl TokenStream {
+    /// Convert to FFI-safe representation.
+    ///
+    /// # Safety
+    #[doc(hidden)]
+    pub fn into_stable(self) -> StableTokenStream {
+        let cstr = CString::new(self.0).unwrap();
+        StableTokenStream(cstr.into_raw())
+    }
+
+    /// Convert to native Rust representation.
+    ///
+    /// # Safety
+    #[doc(hidden)]
+    pub unsafe fn from_stable(token_stream: StableTokenStream) -> Self {
+        Self::new(token_stream.to_string())
+    }
+}
+
+impl AuxData {
+    /// Convert to FFI-safe representation.
+    ///
+    /// # Safety
+    pub fn maybe_into_stable(aux_data: Option<Self>) -> StableAuxData {
+        if let Some(aux_data) = aux_data {
+            aux_data.into_stable()
+        } else {
+            StableAuxData::None
+        }
+    }
+
+    /// Convert to FFI-safe representation.
+    ///
+    /// # Safety
+    #[doc(hidden)]
+    pub fn into_stable(self) -> StableAuxData {
+        let cstr = CString::new(self.0.to_string()).unwrap();
+        StableAuxData::Some(cstr.into_raw())
+    }
+
+    /// Convert to native Rust representation.
+    ///
+    /// # Safety
+    #[doc(hidden)]
+    pub unsafe fn from_stable(aux_data: StableAuxData) -> Result<Option<Self>, Error> {
+        match aux_data {
+            StableAuxData::None => Ok(None),
+            StableAuxData::Some(raw) => Some(Self::try_new(raw_to_string(raw))).transpose(),
+        }
+    }
+}
+
+unsafe fn raw_to_string(raw: *mut c_char) -> String {
+    if raw.is_null() {
+        String::default()
+    } else {
+        let cstr = CString::from_raw(raw);
+        cstr.to_string_lossy().to_string()
+    }
+}

scarb/Cargo.toml

@@ -54,6 +54,7 @@ redb.workspace = true
 reqwest.workspace = true
 scarb-build-metadata = { path = "../utils/scarb-build-metadata" }
 cairo-lang-macro = { path = "../plugins/cairo-lang-macro" }
+cairo-lang-macro-stable = { path = "../plugins/cairo-lang-macro-stable" }
 scarb-metadata = { path = "../scarb-metadata", default-features = false, features = ["builder"] }
 scarb-ui = { path = "../utils/scarb-ui" }
 semver.workspace = true