fix windows fileio

youknowone · Dec 28, 2025 · Dec 28, 2025 · Dec 28, 2025 · Dec 28, 2025 · Dec 28, 2025
commit 6ac1266dcd3ba1a68217cd7554f735482f5b52e4
diff --git a/crates/common/src/crt_fd.rs b/crates/common/src/crt_fd.rs
@@ -334,7 +334,21 @@ pub fn close(fd: Owned) -> io::Result<()> {
 }
 
 pub fn ftruncate(fd: Borrowed<'_>, len: Offset) -> io::Result<()> {
-    cvt(unsafe { suppress_iph!(c::ftruncate(fd.as_raw(), len)) })?;
+    let ret = unsafe { suppress_iph!(c::ftruncate(fd.as_raw(), len)) };
+    // On Windows, _chsize_s returns 0 on success, or a positive error code (errno value) on failure.
+    // On other platforms, ftruncate returns 0 on success, or -1 on failure with errno set.
+    #[cfg(windows)]
+    {
+        if ret != 0 {
+            // _chsize_s returns errno directly, convert to Windows error code
+            let winerror = crate::os::errno_to_winerror(ret);
+            return Err(io::Error::from_raw_os_error(winerror));
+        }
+    }
+    #[cfg(not(windows))]
+    {
+        cvt(ret)?;
+    }
     Ok(())
 }
 

diff --git a/crates/derive-impl/src/pystructseq.rs b/crates/derive-impl/src/pystructseq.rs
@@ -22,6 +22,8 @@ enum FieldKind {
 struct ParsedField {
     ident: Ident,
     kind: FieldKind,
+    /// Optional cfg attributes for conditional compilation
+    cfg_attrs: Vec<syn::Attribute>,
 }
 
 /// Parsed field info from struct
@@ -31,27 +33,24 @@ struct FieldInfo {
 }
 
 impl FieldInfo {
-    fn named_fields(&self) -> Vec<Ident> {
+    fn named_fields(&self) -> Vec<&ParsedField> {
         self.fields
             .iter()
             .filter(|f| f.kind == FieldKind::Named)
-            .map(|f| f.ident.clone())
             .collect()
     }
 
-    fn visible_fields(&self) -> Vec<Ident> {
+    fn visible_fields(&self) -> Vec<&ParsedField> {
         self.fields
             .iter()
             .filter(|f| f.kind != FieldKind::Skipped)
-            .map(|f| f.ident.clone())
             .collect()
     }
 
-    fn skipped_fields(&self) -> Vec<Ident> {
+    fn skipped_fields(&self) -> Vec<&ParsedField> {
         self.fields
             .iter()
             .filter(|f| f.kind == FieldKind::Skipped)
-            .map(|f| f.ident.clone())
             .collect()
     }
 
@@ -82,8 +81,15 @@ fn parse_fields(input: &mut DeriveInput) -> Result<FieldInfo> {
         let mut skip = false;
         let mut unnamed = false;
         let mut attrs_to_remove = Vec::new();
+        let mut cfg_attrs = Vec::new();
 
         for (i, attr) in field.attrs.iter().enumerate() {
+            // Collect cfg attributes for conditional compilation
+            if attr.path().is_ident("cfg") {
+                cfg_attrs.push(attr.clone());
+                continue;
+            }
+
             if !attr.path().is_ident("pystruct_sequence") {
                 continue;
             }
@@ -135,7 +141,11 @@ fn parse_fields(input: &mut DeriveInput) -> Result<FieldInfo> {
             FieldKind::Named
         };
 
-        parsed_fields.push(ParsedField { ident, kind });
+        parsed_fields.push(ParsedField {
+            ident,
+            kind,
+            cfg_attrs,
+        });
     }
 
     Ok(FieldInfo {
@@ -194,18 +204,91 @@ pub(crate) fn impl_pystruct_sequence_data(
     let skipped_fields = field_info.skipped_fields();
     let n_unnamed_fields = field_info.n_unnamed_fields();
 
-    // Generate field index constants for visible fields
+    // Generate field index constants for visible fields (with cfg guards)
     let field_indices: Vec<_> = visible_fields
         .iter()
         .enumerate()
         .map(|(i, field)| {
-            let const_name = format_ident!("{}_INDEX", field.to_string().to_uppercase());
+            let const_name = format_ident!("{}_INDEX", field.ident.to_string().to_uppercase());
+            let cfg_attrs = &field.cfg_attrs;
             quote! {
+                #(#cfg_attrs)*
                 pub const #const_name: usize = #i;
             }
         })
         .collect();
 
+    // Generate field name entries with cfg guards for named fields
+    let named_field_names: Vec<_> = named_fields
+        .iter()
+        .map(|f| {
+            let ident = &f.ident;
+            let cfg_attrs = &f.cfg_attrs;
+            if cfg_attrs.is_empty() {
+                quote! { stringify!(#ident), }
+            } else {
+                quote! {
+                    #(#cfg_attrs)*
+                    { stringify!(#ident) },
+                }
+            }
+        })
+        .collect();
+
+    // Generate field name entries with cfg guards for skipped fields
+    let skipped_field_names: Vec<_> = skipped_fields
+        .iter()
+        .map(|f| {
+            let ident = &f.ident;
+            let cfg_attrs = &f.cfg_attrs;
+            if cfg_attrs.is_empty() {
+                quote! { stringify!(#ident), }
+            } else {
+                quote! {
+                    #(#cfg_attrs)*
+                    { stringify!(#ident) },
+                }
+            }
+        })
+        .collect();
+
+    // Generate into_tuple items with cfg guards
+    let visible_tuple_items: Vec<_> = visible_fields
+        .iter()
+        .map(|f| {
+            let ident = &f.ident;
+            let cfg_attrs = &f.cfg_attrs;
+            if cfg_attrs.is_empty() {
+                quote! {
+                    ::rustpython_vm::convert::ToPyObject::to_pyobject(self.#ident, vm),
+                }
+            } else {
+                quote! {
+                    #(#cfg_attrs)*
+                    { ::rustpython_vm::convert::ToPyObject::to_pyobject(self.#ident, vm) },
+                }
+            }
+        })
+        .collect();
+
+    let skipped_tuple_items: Vec<_> = skipped_fields
+        .iter()
+        .map(|f| {
+            let ident = &f.ident;
+            let cfg_attrs = &f.cfg_attrs;
+            if cfg_attrs.is_empty() {
+                quote! {
+                    ::rustpython_vm::convert::ToPyObject::to_pyobject(self.#ident, vm),
+                }
+            } else {
+                quote! {
+                    #(#cfg_attrs)*
+                    { ::rustpython_vm::convert::ToPyObject::to_pyobject(self.#ident, vm) },
+                }
+            }
+        })
+        .collect();
+
     // Generate TryFromObject impl only when try_from_object=true
     let try_from_object_impl = if try_from_object {
         let n_required = visible_fields.len();
@@ -233,15 +316,17 @@ pub(crate) fn impl_pystruct_sequence_data(
 
     // Generate try_from_elements trait override only when try_from_object=true
     let try_from_elements_trait_override = if try_from_object {
+        let visible_field_idents: Vec<_> = visible_fields.iter().map(|f| &f.ident).collect();
+        let skipped_field_idents: Vec<_> = skipped_fields.iter().map(|f| &f.ident).collect();
         quote! {
             fn try_from_elements(
                 elements: Vec<::rustpython_vm::PyObjectRef>,
                 vm: &::rustpython_vm::VirtualMachine,
             ) -> ::rustpython_vm::PyResult<Self> {
                 let mut iter = elements.into_iter();
                 Ok(Self {
-                    #(#visible_fields: iter.next().unwrap().clone().try_into_value(vm)?,)*
-                    #(#skipped_fields: match iter.next() {
+                    #(#visible_field_idents: iter.next().unwrap().clone().try_into_value(vm)?,)*
+                    #(#skipped_field_idents: match iter.next() {
                         Some(v) => v.clone().try_into_value(vm)?,
                         None => vm.ctx.none(),
                     },)*
@@ -259,20 +344,14 @@ pub(crate) fn impl_pystruct_sequence_data(
 
         // PyStructSequenceData trait impl
         impl ::rustpython_vm::types::PyStructSequenceData for #data_ident {
-            const REQUIRED_FIELD_NAMES: &'static [&'static str] = &[#(stringify!(#named_fields),)*];
-            const OPTIONAL_FIELD_NAMES: &'static [&'static str] = &[#(stringify!(#skipped_fields),)*];
+            const REQUIRED_FIELD_NAMES: &'static [&'static str] = &[#(#named_field_names)*];
+            const OPTIONAL_FIELD_NAMES: &'static [&'static str] = &[#(#skipped_field_names)*];
             const UNNAMED_FIELDS_LEN: usize = #n_unnamed_fields;
 
             fn into_tuple(self, vm: &::rustpython_vm::VirtualMachine) -> ::rustpython_vm::builtins::PyTuple {
                 let items = vec![
-                    #(::rustpython_vm::convert::ToPyObject::to_pyobject(
-                        self.#visible_fields,
-                        vm,
-                    ),)*
-                    #(::rustpython_vm::convert::ToPyObject::to_pyobject(
-                        self.#skipped_fields,
-                        vm,
-                    ),)*
+                    #(#visible_tuple_items)*
+                    #(#skipped_tuple_items)*
                 ];
                 ::rustpython_vm::builtins::PyTuple::new_unchecked(items.into_boxed_slice())
             }

diff --git a/crates/vm/src/stdlib/io.rs b/crates/vm/src/stdlib/io.rs
@@ -4657,7 +4657,7 @@ mod fileio {
                 closefd: AtomicCell::new(true),
                 mode: AtomicCell::new(Mode::empty()),
                 seekable: AtomicCell::new(None),
-                blksize: AtomicCell::new(0),
+                blksize: AtomicCell::new(8 * 1024), // DEFAULT_BUFFER_SIZE
             }
         }
     }

diff --git a/crates/vm/src/stdlib/os.rs b/crates/vm/src/stdlib/os.rs
@@ -894,9 +894,11 @@ pub(super) mod _os {
         #[pystruct_sequence(skip)]
         pub st_ctime_ns: i128,
         // Unix-specific attributes
+        #[cfg(not(windows))]
         #[pyarg(any, default)]
         #[pystruct_sequence(skip)]
         pub st_blksize: i64,
+        #[cfg(not(windows))]
         #[pyarg(any, default)]
         #[pystruct_sequence(skip)]
         pub st_blocks: i64,
@@ -952,11 +954,12 @@ pub(super) mod _os {
             #[cfg(not(windows))]
             let st_ino = stat.st_ino;
 
-            #[cfg(any(unix, target_os = "wasi"))]
+            #[cfg(not(windows))]
             #[allow(clippy::useless_conversion)] // needed for 32-bit platforms
-            let (st_blksize, st_blocks) = (i64::from(stat.st_blksize), i64::from(stat.st_blocks));
-            #[cfg(windows)]
-            let (st_blksize, st_blocks) = (0i64, 0i64);
+            let st_blksize = i64::from(stat.st_blksize);
+            #[cfg(not(windows))]
+            #[allow(clippy::useless_conversion)] // needed for 32-bit platforms
+            let st_blocks = i64::from(stat.st_blocks);
 
             Self {
                 st_mode: vm.ctx.new_pyref(stat.st_mode),
@@ -975,7 +978,9 @@ pub(super) mod _os {
                 st_atime_ns: to_ns(atime),
                 st_mtime_ns: to_ns(mtime),
                 st_ctime_ns: to_ns(ctime),
+                #[cfg(not(windows))]
                 st_blksize,
+                #[cfg(not(windows))]
                 st_blocks,
                 st_reparse_tag,
                 st_file_attributes,