Implement procedural macro diagnostics

commit-id:f06e9653

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

@@ -16,6 +16,5 @@ repository.workspace = true
 proc-macro = true
 
 [dependencies]
-camino.workspace = true
 quote.workspace = true
 syn = { workspace = true, features = ["full", "extra-traits"] }

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

@@ -0,0 +1,45 @@
+/// This struct encapsulates a stable ABI representation of struct.
+///
+/// Please be aware that the memory management of values passing the FFI-barrier is tricky.
+/// The memory must be freed on the same side of the barrier, where the allocation was made.
+#[repr(C)]
+#[derive(Debug)]
+#[doc(hidden)]
+pub struct StableSlice<T> {
+    ptr: *mut T,
+    len: usize,
+}
+
+impl<T> Copy for StableSlice<T> {}
+
+impl<T> Clone for StableSlice<T> {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+impl<T> StableSlice<T> {
+    /// Create a new `StableSlice` from a Vector.
+    /// Note that the vector will not be deallocated automatically.
+    /// Please make sure to use `into_owned` afterward, to free the memory.
+    pub fn new(mut x: Vec<T>) -> Self {
+        x.shrink_to_fit();
+        assert_eq!(x.len(), x.capacity());
+        let ptr = x.as_mut_ptr();
+        let len = x.len();
+        std::mem::forget(x);
+        Self { ptr, len }
+    }
+
+    /// Convert to owned vector.
+    pub fn into_owned(self) -> Vec<T> {
+        unsafe { Vec::from_raw_parts(self.ptr, self.len, self.len) }
+    }
+
+    /// Returns raw pointer and length.
+    /// Can be used to construct a slice.
+    /// No ownership is transferred.
+    pub fn into_raw_parts(self) -> (*mut T, usize) {
+        (self.ptr, self.len)
+    }
+}

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

@@ -1,6 +1,9 @@
+use crate::ffi::StableSlice;
 use std::ffi::{CStr, CString};
 use std::os::raw::c_char;
 
+pub mod ffi;
+
 /// Token stream.
 ///
 /// This struct implements FFI-safe stable ABI.
@@ -15,21 +18,52 @@ pub enum StableAuxData {
     Some(*mut c_char),
 }
 
+/// Diagnostic returned by the procedural macro.
+///
+/// This struct implements FFI-safe stable ABI.
+#[repr(C)]
+#[derive(Debug)]
+pub struct StableDiagnostic {
+    pub message: *mut c_char,
+    pub severity: StableSeverity,
+}
+
+/// The severity of a diagnostic.
+///
+/// This struct implements FFI-safe stable ABI.
+#[repr(C)]
+#[derive(Debug)]
+pub enum StableSeverity {
+    Error,
+    Warning,
+}
+
 /// Procedural macro result.
 ///
 /// This struct implements FFI-safe stable ABI.
 #[repr(C)]
 #[derive(Debug, Clone)]
 pub enum StableProcMacroResult {
     /// Plugin has not taken any action.
-    Leave,
+    Leave {
+        diagnostics: StableSlice<StableDiagnostic>,
+        // diagnostics: *mut StableDiagnostic,
+        // diagnostics_n: usize,
+    },
     /// Plugin generated [`StableTokenStream`] replacement.
     Replace {
+        diagnostics: StableSlice<StableDiagnostic>,
         token_stream: StableTokenStream,
         aux_data: StableAuxData,
+        // diagnostics: *mut StableDiagnostic,
+        // diagnostics_n: usize,
     },
     /// Plugin ordered item removal.
-    Remove,
+    Remove {
+        diagnostics: StableSlice<StableDiagnostic>,
+        // diagnostics: *mut StableDiagnostic,
+        // diagnostics_n: usize,
+    },
 }
 
 impl StableTokenStream {