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Diffstat (limited to 'third_party/rust/bindgen/ir/comp.rs')
| -rw-r--r-- | third_party/rust/bindgen/ir/comp.rs | 1890 |
1 files changed, 1890 insertions, 0 deletions
diff --git a/third_party/rust/bindgen/ir/comp.rs b/third_party/rust/bindgen/ir/comp.rs new file mode 100644 index 0000000000..18a4291cf9 --- /dev/null +++ b/third_party/rust/bindgen/ir/comp.rs @@ -0,0 +1,1890 @@ +//! Compound types (unions and structs) in our intermediate representation. + +use super::analysis::Sizedness; +use super::annotations::Annotations; +use super::context::{BindgenContext, FunctionId, ItemId, TypeId, VarId}; +use super::dot::DotAttributes; +use super::item::{IsOpaque, Item}; +use super::layout::Layout; +use super::template::TemplateParameters; +use super::traversal::{EdgeKind, Trace, Tracer}; +use super::ty::RUST_DERIVE_IN_ARRAY_LIMIT; +use crate::clang; +use crate::codegen::struct_layout::{align_to, bytes_from_bits_pow2}; +use crate::ir::derive::CanDeriveCopy; +use crate::parse::ParseError; +use crate::HashMap; +use crate::NonCopyUnionStyle; +use peeking_take_while::PeekableExt; +use std::cmp; +use std::io; +use std::mem; + +/// The kind of compound type. +#[derive(Debug, Copy, Clone, PartialEq, Eq)] +pub enum CompKind { + /// A struct. + Struct, + /// A union. + Union, +} + +/// The kind of C++ method. +#[derive(Debug, Copy, Clone, PartialEq, Eq)] +pub enum MethodKind { + /// A constructor. We represent it as method for convenience, to avoid code + /// duplication. + Constructor, + /// A destructor. + Destructor, + /// A virtual destructor. + VirtualDestructor { + /// Whether it's pure virtual. + pure_virtual: bool, + }, + /// A static method. + Static, + /// A normal method. + Normal, + /// A virtual method. + Virtual { + /// Whether it's pure virtual. + pure_virtual: bool, + }, +} + +impl MethodKind { + /// Is this a destructor method? + pub fn is_destructor(&self) -> bool { + matches!( + *self, + MethodKind::Destructor | MethodKind::VirtualDestructor { .. } + ) + } + + /// Is this a pure virtual method? + pub fn is_pure_virtual(&self) -> bool { + match *self { + MethodKind::Virtual { pure_virtual } | + MethodKind::VirtualDestructor { pure_virtual } => pure_virtual, + _ => false, + } + } +} + +/// A struct representing a C++ method, either static, normal, or virtual. +#[derive(Debug)] +pub struct Method { + kind: MethodKind, + /// The signature of the method. Take into account this is not a `Type` + /// item, but a `Function` one. + /// + /// This is tricky and probably this field should be renamed. + signature: FunctionId, + is_const: bool, +} + +impl Method { + /// Construct a new `Method`. + pub fn new( + kind: MethodKind, + signature: FunctionId, + is_const: bool, + ) -> Self { + Method { + kind, + signature, + is_const, + } + } + + /// What kind of method is this? + pub fn kind(&self) -> MethodKind { + self.kind + } + + /// Is this a constructor? + pub fn is_constructor(&self) -> bool { + self.kind == MethodKind::Constructor + } + + /// Is this a virtual method? + pub fn is_virtual(&self) -> bool { + matches!( + self.kind, + MethodKind::Virtual { .. } | MethodKind::VirtualDestructor { .. } + ) + } + + /// Is this a static method? + pub fn is_static(&self) -> bool { + self.kind == MethodKind::Static + } + + /// Get the id for the `Function` signature for this method. + pub fn signature(&self) -> FunctionId { + self.signature + } + + /// Is this a const qualified method? + pub fn is_const(&self) -> bool { + self.is_const + } +} + +/// Methods common to the various field types. +pub trait FieldMethods { + /// Get the name of this field. + fn name(&self) -> Option<&str>; + + /// Get the type of this field. + fn ty(&self) -> TypeId; + + /// Get the comment for this field. + fn comment(&self) -> Option<&str>; + + /// If this is a bitfield, how many bits does it need? + fn bitfield_width(&self) -> Option<u32>; + + /// Is this feild declared public? + fn is_public(&self) -> bool; + + /// Get the annotations for this field. + fn annotations(&self) -> &Annotations; + + /// The offset of the field (in bits) + fn offset(&self) -> Option<usize>; +} + +/// A contiguous set of logical bitfields that live within the same physical +/// allocation unit. See 9.2.4 [class.bit] in the C++ standard and [section +/// 2.4.II.1 in the Itanium C++ +/// ABI](http://itanium-cxx-abi.github.io/cxx-abi/abi.html#class-types). +#[derive(Debug)] +pub struct BitfieldUnit { + nth: usize, + layout: Layout, + bitfields: Vec<Bitfield>, +} + +impl BitfieldUnit { + /// Get the 1-based index of this bitfield unit within its containing + /// struct. Useful for generating a Rust struct's field name for this unit + /// of bitfields. + pub fn nth(&self) -> usize { + self.nth + } + + /// Get the layout within which these bitfields reside. + pub fn layout(&self) -> Layout { + self.layout + } + + /// Get the bitfields within this unit. + pub fn bitfields(&self) -> &[Bitfield] { + &self.bitfields + } +} + +/// A struct representing a C++ field. +#[derive(Debug)] +pub enum Field { + /// A normal data member. + DataMember(FieldData), + + /// A physical allocation unit containing many logical bitfields. + Bitfields(BitfieldUnit), +} + +impl Field { + /// Get this field's layout. + pub fn layout(&self, ctx: &BindgenContext) -> Option<Layout> { + match *self { + Field::Bitfields(BitfieldUnit { layout, .. }) => Some(layout), + Field::DataMember(ref data) => { + ctx.resolve_type(data.ty).layout(ctx) + } + } + } +} + +impl Trace for Field { + type Extra = (); + + fn trace<T>(&self, _: &BindgenContext, tracer: &mut T, _: &()) + where + T: Tracer, + { + match *self { + Field::DataMember(ref data) => { + tracer.visit_kind(data.ty.into(), EdgeKind::Field); + } + Field::Bitfields(BitfieldUnit { ref bitfields, .. }) => { + for bf in bitfields { + tracer.visit_kind(bf.ty().into(), EdgeKind::Field); + } + } + } + } +} + +impl DotAttributes for Field { + fn dot_attributes<W>( + &self, + ctx: &BindgenContext, + out: &mut W, + ) -> io::Result<()> + where + W: io::Write, + { + match *self { + Field::DataMember(ref data) => data.dot_attributes(ctx, out), + Field::Bitfields(BitfieldUnit { + layout, + ref bitfields, + .. + }) => { + writeln!( + out, + r#"<tr> + <td>bitfield unit</td> + <td> + <table border="0"> + <tr> + <td>unit.size</td><td>{}</td> + </tr> + <tr> + <td>unit.align</td><td>{}</td> + </tr> + "#, + layout.size, layout.align + )?; + for bf in bitfields { + bf.dot_attributes(ctx, out)?; + } + writeln!(out, "</table></td></tr>") + } + } + } +} + +impl DotAttributes for FieldData { + fn dot_attributes<W>( + &self, + _ctx: &BindgenContext, + out: &mut W, + ) -> io::Result<()> + where + W: io::Write, + { + writeln!( + out, + "<tr><td>{}</td><td>{:?}</td></tr>", + self.name().unwrap_or("(anonymous)"), + self.ty() + ) + } +} + +impl DotAttributes for Bitfield { + fn dot_attributes<W>( + &self, + _ctx: &BindgenContext, + out: &mut W, + ) -> io::Result<()> + where + W: io::Write, + { + writeln!( + out, + "<tr><td>{} : {}</td><td>{:?}</td></tr>", + self.name().unwrap_or("(anonymous)"), + self.width(), + self.ty() + ) + } +} + +/// A logical bitfield within some physical bitfield allocation unit. +#[derive(Debug)] +pub struct Bitfield { + /// Index of the bit within this bitfield's allocation unit where this + /// bitfield's bits begin. + offset_into_unit: usize, + + /// The field data for this bitfield. + data: FieldData, + + /// Name of the generated Rust getter for this bitfield. + /// + /// Should be assigned before codegen. + getter_name: Option<String>, + + /// Name of the generated Rust setter for this bitfield. + /// + /// Should be assigned before codegen. + setter_name: Option<String>, +} + +impl Bitfield { + /// Construct a new bitfield. + fn new(offset_into_unit: usize, raw: RawField) -> Bitfield { + assert!(raw.bitfield_width().is_some()); + + Bitfield { + offset_into_unit, + data: raw.0, + getter_name: None, + setter_name: None, + } + } + + /// Get the index of the bit within this bitfield's allocation unit where + /// this bitfield begins. + pub fn offset_into_unit(&self) -> usize { + self.offset_into_unit + } + + /// Get the mask value that when &'ed with this bitfield's allocation unit + /// produces this bitfield's value. + pub fn mask(&self) -> u64 { + use std::u64; + + let unoffseted_mask = + if self.width() as u64 == mem::size_of::<u64>() as u64 * 8 { + u64::MAX + } else { + (1u64 << self.width()) - 1u64 + }; + + unoffseted_mask << self.offset_into_unit() + } + + /// Get the bit width of this bitfield. + pub fn width(&self) -> u32 { + self.data.bitfield_width().unwrap() + } + + /// Name of the generated Rust getter for this bitfield. + /// + /// Panics if called before assigning bitfield accessor names or if + /// this bitfield have no name. + pub fn getter_name(&self) -> &str { + assert!( + self.name().is_some(), + "`Bitfield::getter_name` called on anonymous field" + ); + self.getter_name.as_ref().expect( + "`Bitfield::getter_name` should only be called after\ + assigning bitfield accessor names", + ) + } + + /// Name of the generated Rust setter for this bitfield. + /// + /// Panics if called before assigning bitfield accessor names or if + /// this bitfield have no name. + pub fn setter_name(&self) -> &str { + assert!( + self.name().is_some(), + "`Bitfield::setter_name` called on anonymous field" + ); + self.setter_name.as_ref().expect( + "`Bitfield::setter_name` should only be called\ + after assigning bitfield accessor names", + ) + } +} + +impl FieldMethods for Bitfield { + fn name(&self) -> Option<&str> { + self.data.name() + } + + fn ty(&self) -> TypeId { + self.data.ty() + } + + fn comment(&self) -> Option<&str> { + self.data.comment() + } + + fn bitfield_width(&self) -> Option<u32> { + self.data.bitfield_width() + } + + fn is_public(&self) -> bool { + self.data.is_public() + } + + fn annotations(&self) -> &Annotations { + self.data.annotations() + } + + fn offset(&self) -> Option<usize> { + self.data.offset() + } +} + +/// A raw field might be either of a plain data member or a bitfield within a +/// bitfield allocation unit, but we haven't processed it and determined which +/// yet (which would involve allocating it into a bitfield unit if it is a +/// bitfield). +#[derive(Debug)] +struct RawField(FieldData); + +impl RawField { + /// Construct a new `RawField`. + fn new( + name: Option<String>, + ty: TypeId, + comment: Option<String>, + annotations: Option<Annotations>, + bitfield_width: Option<u32>, + public: bool, + offset: Option<usize>, + ) -> RawField { + RawField(FieldData { + name, + ty, + comment, + annotations: annotations.unwrap_or_default(), + bitfield_width, + public, + offset, + }) + } +} + +impl FieldMethods for RawField { + fn name(&self) -> Option<&str> { + self.0.name() + } + + fn ty(&self) -> TypeId { + self.0.ty() + } + + fn comment(&self) -> Option<&str> { + self.0.comment() + } + + fn bitfield_width(&self) -> Option<u32> { + self.0.bitfield_width() + } + + fn is_public(&self) -> bool { + self.0.is_public() + } + + fn annotations(&self) -> &Annotations { + self.0.annotations() + } + + fn offset(&self) -> Option<usize> { + self.0.offset() + } +} + +/// Convert the given ordered set of raw fields into a list of either plain data +/// members, and/or bitfield units containing multiple bitfields. +/// +/// If we do not have the layout for a bitfield's type, then we can't reliably +/// compute its allocation unit. In such cases, we return an error. +fn raw_fields_to_fields_and_bitfield_units<I>( + ctx: &BindgenContext, + raw_fields: I, + packed: bool, +) -> Result<(Vec<Field>, bool), ()> +where + I: IntoIterator<Item = RawField>, +{ + let mut raw_fields = raw_fields.into_iter().fuse().peekable(); + let mut fields = vec![]; + let mut bitfield_unit_count = 0; + + loop { + // While we have plain old data members, just keep adding them to our + // resulting fields. We introduce a scope here so that we can use + // `raw_fields` again after the `by_ref` iterator adaptor is dropped. + { + let non_bitfields = raw_fields + .by_ref() + .peeking_take_while(|f| f.bitfield_width().is_none()) + .map(|f| Field::DataMember(f.0)); + fields.extend(non_bitfields); + } + + // Now gather all the consecutive bitfields. Only consecutive bitfields + // may potentially share a bitfield allocation unit with each other in + // the Itanium C++ ABI. + let mut bitfields = raw_fields + .by_ref() + .peeking_take_while(|f| f.bitfield_width().is_some()) + .peekable(); + + if bitfields.peek().is_none() { + break; + } + + bitfields_to_allocation_units( + ctx, + &mut bitfield_unit_count, + &mut fields, + bitfields, + packed, + )?; + } + + assert!( + raw_fields.next().is_none(), + "The above loop should consume all items in `raw_fields`" + ); + + Ok((fields, bitfield_unit_count != 0)) +} + +/// Given a set of contiguous raw bitfields, group and allocate them into +/// (potentially multiple) bitfield units. +fn bitfields_to_allocation_units<E, I>( + ctx: &BindgenContext, + bitfield_unit_count: &mut usize, + fields: &mut E, + raw_bitfields: I, + packed: bool, +) -> Result<(), ()> +where + E: Extend<Field>, + I: IntoIterator<Item = RawField>, +{ + assert!(ctx.collected_typerefs()); + + // NOTE: What follows is reverse-engineered from LLVM's + // lib/AST/RecordLayoutBuilder.cpp + // + // FIXME(emilio): There are some differences between Microsoft and the + // Itanium ABI, but we'll ignore those and stick to Itanium for now. + // + // Also, we need to handle packed bitfields and stuff. + // + // TODO(emilio): Take into account C++'s wide bitfields, and + // packing, sigh. + + fn flush_allocation_unit<E>( + fields: &mut E, + bitfield_unit_count: &mut usize, + unit_size_in_bits: usize, + unit_align_in_bits: usize, + bitfields: Vec<Bitfield>, + packed: bool, + ) where + E: Extend<Field>, + { + *bitfield_unit_count += 1; + let align = if packed { + 1 + } else { + bytes_from_bits_pow2(unit_align_in_bits) + }; + let size = align_to(unit_size_in_bits, 8) / 8; + let layout = Layout::new(size, align); + fields.extend(Some(Field::Bitfields(BitfieldUnit { + nth: *bitfield_unit_count, + layout, + bitfields, + }))); + } + + let mut max_align = 0; + let mut unfilled_bits_in_unit = 0; + let mut unit_size_in_bits = 0; + let mut unit_align = 0; + let mut bitfields_in_unit = vec![]; + + // TODO(emilio): Determine this from attributes or pragma ms_struct + // directives. Also, perhaps we should check if the target is MSVC? + const is_ms_struct: bool = false; + + for bitfield in raw_bitfields { + let bitfield_width = bitfield.bitfield_width().unwrap() as usize; + let bitfield_layout = + ctx.resolve_type(bitfield.ty()).layout(ctx).ok_or(())?; + let bitfield_size = bitfield_layout.size; + let bitfield_align = bitfield_layout.align; + + let mut offset = unit_size_in_bits; + if !packed { + if is_ms_struct { + if unit_size_in_bits != 0 && + (bitfield_width == 0 || + bitfield_width > unfilled_bits_in_unit) + { + // We've reached the end of this allocation unit, so flush it + // and its bitfields. + unit_size_in_bits = + align_to(unit_size_in_bits, unit_align * 8); + flush_allocation_unit( + fields, + bitfield_unit_count, + unit_size_in_bits, + unit_align, + mem::take(&mut bitfields_in_unit), + packed, + ); + + // Now we're working on a fresh bitfield allocation unit, so reset + // the current unit size and alignment. + offset = 0; + unit_align = 0; + } + } else if offset != 0 && + (bitfield_width == 0 || + (offset & (bitfield_align * 8 - 1)) + bitfield_width > + bitfield_size * 8) + { + offset = align_to(offset, bitfield_align * 8); + } + } + + // According to the x86[-64] ABI spec: "Unnamed bit-fields’ types do not + // affect the alignment of a structure or union". This makes sense: such + // bit-fields are only used for padding, and we can't perform an + // un-aligned read of something we can't read because we can't even name + // it. + if bitfield.name().is_some() { + max_align = cmp::max(max_align, bitfield_align); + + // NB: The `bitfield_width` here is completely, absolutely + // intentional. Alignment of the allocation unit is based on the + // maximum bitfield width, not (directly) on the bitfields' types' + // alignment. + unit_align = cmp::max(unit_align, bitfield_width); + } + + // Always keep all bitfields around. While unnamed bitifields are used + // for padding (and usually not needed hereafter), large unnamed + // bitfields over their types size cause weird allocation size behavior from clang. + // Therefore, all bitfields needed to be kept around in order to check for this + // and make the struct opaque in this case + bitfields_in_unit.push(Bitfield::new(offset, bitfield)); + + unit_size_in_bits = offset + bitfield_width; + + // Compute what the physical unit's final size would be given what we + // have seen so far, and use that to compute how many bits are still + // available in the unit. + let data_size = align_to(unit_size_in_bits, bitfield_align * 8); + unfilled_bits_in_unit = data_size - unit_size_in_bits; + } + + if unit_size_in_bits != 0 { + // Flush the last allocation unit and its bitfields. + flush_allocation_unit( + fields, + bitfield_unit_count, + unit_size_in_bits, + unit_align, + bitfields_in_unit, + packed, + ); + } + + Ok(()) +} + +/// A compound structure's fields are initially raw, and have bitfields that +/// have not been grouped into allocation units. During this time, the fields +/// are mutable and we build them up during parsing. +/// +/// Then, once resolving typerefs is completed, we compute all structs' fields' +/// bitfield allocation units, and they remain frozen and immutable forever +/// after. +#[derive(Debug)] +enum CompFields { + Before(Vec<RawField>), + After { + fields: Vec<Field>, + has_bitfield_units: bool, + }, + Error, +} + +impl Default for CompFields { + fn default() -> CompFields { + CompFields::Before(vec![]) + } +} + +impl CompFields { + fn append_raw_field(&mut self, raw: RawField) { + match *self { + CompFields::Before(ref mut raws) => { + raws.push(raw); + } + _ => { + panic!( + "Must not append new fields after computing bitfield allocation units" + ); + } + } + } + + fn compute_bitfield_units(&mut self, ctx: &BindgenContext, packed: bool) { + let raws = match *self { + CompFields::Before(ref mut raws) => mem::take(raws), + _ => { + panic!("Already computed bitfield units"); + } + }; + + let result = raw_fields_to_fields_and_bitfield_units(ctx, raws, packed); + + match result { + Ok((fields, has_bitfield_units)) => { + *self = CompFields::After { + fields, + has_bitfield_units, + }; + } + Err(()) => { + *self = CompFields::Error; + } + } + } + + fn deanonymize_fields(&mut self, ctx: &BindgenContext, methods: &[Method]) { + let fields = match *self { + CompFields::After { ref mut fields, .. } => fields, + // Nothing to do here. + CompFields::Error => return, + CompFields::Before(_) => { + panic!("Not yet computed bitfield units."); + } + }; + + fn has_method( + methods: &[Method], + ctx: &BindgenContext, + name: &str, + ) -> bool { + methods.iter().any(|method| { + let method_name = ctx.resolve_func(method.signature()).name(); + method_name == name || ctx.rust_mangle(method_name) == name + }) + } + + struct AccessorNamesPair { + getter: String, + setter: String, + } + + let mut accessor_names: HashMap<String, AccessorNamesPair> = fields + .iter() + .flat_map(|field| match *field { + Field::Bitfields(ref bu) => &*bu.bitfields, + Field::DataMember(_) => &[], + }) + .filter_map(|bitfield| bitfield.name()) + .map(|bitfield_name| { + let bitfield_name = bitfield_name.to_string(); + let getter = { + let mut getter = + ctx.rust_mangle(&bitfield_name).to_string(); + if has_method(methods, ctx, &getter) { + getter.push_str("_bindgen_bitfield"); + } + getter + }; + let setter = { + let setter = format!("set_{}", bitfield_name); + let mut setter = ctx.rust_mangle(&setter).to_string(); + if has_method(methods, ctx, &setter) { + setter.push_str("_bindgen_bitfield"); + } + setter + }; + (bitfield_name, AccessorNamesPair { getter, setter }) + }) + .collect(); + + let mut anon_field_counter = 0; + for field in fields.iter_mut() { + match *field { + Field::DataMember(FieldData { ref mut name, .. }) => { + if name.is_some() { + continue; + } + + anon_field_counter += 1; + *name = Some(format!( + "{}{}", + ctx.options().anon_fields_prefix, + anon_field_counter + )); + } + Field::Bitfields(ref mut bu) => { + for bitfield in &mut bu.bitfields { + if bitfield.name().is_none() { + continue; + } + + if let Some(AccessorNamesPair { getter, setter }) = + accessor_names.remove(bitfield.name().unwrap()) + { + bitfield.getter_name = Some(getter); + bitfield.setter_name = Some(setter); + } + } + } + } + } + } +} + +impl Trace for CompFields { + type Extra = (); + + fn trace<T>(&self, context: &BindgenContext, tracer: &mut T, _: &()) + where + T: Tracer, + { + match *self { + CompFields::Error => {} + CompFields::Before(ref fields) => { + for f in fields { + tracer.visit_kind(f.ty().into(), EdgeKind::Field); + } + } + CompFields::After { ref fields, .. } => { + for f in fields { + f.trace(context, tracer, &()); + } + } + } + } +} + +/// Common data shared across different field types. +#[derive(Clone, Debug)] +pub struct FieldData { + /// The name of the field, empty if it's an unnamed bitfield width. + name: Option<String>, + + /// The inner type. + ty: TypeId, + + /// The doc comment on the field if any. + comment: Option<String>, + + /// Annotations for this field, or the default. + annotations: Annotations, + + /// If this field is a bitfield, and how many bits does it contain if it is. + bitfield_width: Option<u32>, + + /// If the C++ field is declared `public` + public: bool, + + /// The offset of the field (in bits) + offset: Option<usize>, +} + +impl FieldMethods for FieldData { + fn name(&self) -> Option<&str> { + self.name.as_deref() + } + + fn ty(&self) -> TypeId { + self.ty + } + + fn comment(&self) -> Option<&str> { + self.comment.as_deref() + } + + fn bitfield_width(&self) -> Option<u32> { + self.bitfield_width + } + + fn is_public(&self) -> bool { + self.public + } + + fn annotations(&self) -> &Annotations { + &self.annotations + } + + fn offset(&self) -> Option<usize> { + self.offset + } +} + +/// The kind of inheritance a base class is using. +#[derive(Clone, Debug, PartialEq, Eq)] +pub enum BaseKind { + /// Normal inheritance, like: + /// + /// ```cpp + /// class A : public B {}; + /// ``` + Normal, + /// Virtual inheritance, like: + /// + /// ```cpp + /// class A: public virtual B {}; + /// ``` + Virtual, +} + +/// A base class. +#[derive(Clone, Debug)] +pub struct Base { + /// The type of this base class. + pub ty: TypeId, + /// The kind of inheritance we're doing. + pub kind: BaseKind, + /// Name of the field in which this base should be stored. + pub field_name: String, + /// Whether this base is inherited from publically. + pub is_pub: bool, +} + +impl Base { + /// Whether this base class is inheriting virtually. + pub fn is_virtual(&self) -> bool { + self.kind == BaseKind::Virtual + } + + /// Whether this base class should have it's own field for storage. + pub fn requires_storage(&self, ctx: &BindgenContext) -> bool { + // Virtual bases are already taken into account by the vtable + // pointer. + // + // FIXME(emilio): Is this always right? + if self.is_virtual() { + return false; + } + + // NB: We won't include zero-sized types in our base chain because they + // would contribute to our size given the dummy field we insert for + // zero-sized types. + if self.ty.is_zero_sized(ctx) { + return false; + } + + true + } + + /// Whether this base is inherited from publically. + pub fn is_public(&self) -> bool { + self.is_pub + } +} + +/// A compound type. +/// +/// Either a struct or union, a compound type is built up from the combination +/// of fields which also are associated with their own (potentially compound) +/// type. +#[derive(Debug)] +pub struct CompInfo { + /// Whether this is a struct or a union. + kind: CompKind, + + /// The members of this struct or union. + fields: CompFields, + + /// The abstract template parameters of this class. Note that these are NOT + /// concrete template arguments, and should always be a + /// `Type(TypeKind::TypeParam(name))`. For concrete template arguments, see + /// `TypeKind::TemplateInstantiation`. + template_params: Vec<TypeId>, + + /// The method declarations inside this class, if in C++ mode. + methods: Vec<Method>, + + /// The different constructors this struct or class contains. + constructors: Vec<FunctionId>, + + /// The destructor of this type. The bool represents whether this destructor + /// is virtual. + destructor: Option<(MethodKind, FunctionId)>, + + /// Vector of classes this one inherits from. + base_members: Vec<Base>, + + /// The inner types that were declared inside this class, in something like: + /// + /// class Foo { + /// typedef int FooTy; + /// struct Bar { + /// int baz; + /// }; + /// } + /// + /// static Foo::Bar const = {3}; + inner_types: Vec<TypeId>, + + /// Set of static constants declared inside this class. + inner_vars: Vec<VarId>, + + /// Whether this type should generate an vtable (TODO: Should be able to + /// look at the virtual methods and ditch this field). + has_own_virtual_method: bool, + + /// Whether this type has destructor. + has_destructor: bool, + + /// Whether this type has a base type with more than one member. + /// + /// TODO: We should be able to compute this. + has_nonempty_base: bool, + + /// If this type has a template parameter which is not a type (e.g.: a + /// size_t) + has_non_type_template_params: bool, + + /// Whether this type has a bit field member whose width couldn't be + /// evaluated (e.g. if it depends on a template parameter). We generate an + /// opaque type in this case. + has_unevaluable_bit_field_width: bool, + + /// Whether we saw `__attribute__((packed))` on or within this type. + packed_attr: bool, + + /// Used to know if we've found an opaque attribute that could cause us to + /// generate a type with invalid layout. This is explicitly used to avoid us + /// generating bad alignments when parsing types like max_align_t. + /// + /// It's not clear what the behavior should be here, if generating the item + /// and pray, or behave as an opaque type. + found_unknown_attr: bool, + + /// Used to indicate when a struct has been forward declared. Usually used + /// in headers so that APIs can't modify them directly. + is_forward_declaration: bool, +} + +impl CompInfo { + /// Construct a new compound type. + pub fn new(kind: CompKind) -> Self { + CompInfo { + kind, + fields: CompFields::default(), + template_params: vec![], + methods: vec![], + constructors: vec![], + destructor: None, + base_members: vec![], + inner_types: vec![], + inner_vars: vec![], + has_own_virtual_method: false, + has_destructor: false, + has_nonempty_base: false, + has_non_type_template_params: false, + has_unevaluable_bit_field_width: false, + packed_attr: false, + found_unknown_attr: false, + is_forward_declaration: false, + } + } + + /// Compute the layout of this type. + /// + /// This is called as a fallback under some circumstances where LLVM doesn't + /// give us the correct layout. + /// + /// If we're a union without known layout, we try to compute it from our + /// members. This is not ideal, but clang fails to report the size for these + /// kind of unions, see test/headers/template_union.hpp + pub fn layout(&self, ctx: &BindgenContext) -> Option<Layout> { + // We can't do better than clang here, sorry. + if self.kind == CompKind::Struct { + return None; + } + + // By definition, we don't have the right layout information here if + // we're a forward declaration. + if self.is_forward_declaration() { + return None; + } + + // empty union case + if !self.has_fields() { + return None; + } + + let mut max_size = 0; + // Don't allow align(0) + let mut max_align = 1; + self.each_known_field_layout(ctx, |layout| { + max_size = cmp::max(max_size, layout.size); + max_align = cmp::max(max_align, layout.align); + }); + + Some(Layout::new(max_size, max_align)) + } + + /// Get this type's set of fields. + pub fn fields(&self) -> &[Field] { + match self.fields { + CompFields::Error => &[], + CompFields::After { ref fields, .. } => fields, + CompFields::Before(..) => { + panic!("Should always have computed bitfield units first"); + } + } + } + + fn has_fields(&self) -> bool { + match self.fields { + CompFields::Error => false, + CompFields::After { ref fields, .. } => !fields.is_empty(), + CompFields::Before(ref raw_fields) => !raw_fields.is_empty(), + } + } + + fn each_known_field_layout( + &self, + ctx: &BindgenContext, + mut callback: impl FnMut(Layout), + ) { + match self.fields { + CompFields::Error => {} + CompFields::After { ref fields, .. } => { + for field in fields.iter() { + if let Some(layout) = field.layout(ctx) { + callback(layout); + } + } + } + CompFields::Before(ref raw_fields) => { + for field in raw_fields.iter() { + let field_ty = ctx.resolve_type(field.0.ty); + if let Some(layout) = field_ty.layout(ctx) { + callback(layout); + } + } + } + } + } + + fn has_bitfields(&self) -> bool { + match self.fields { + CompFields::Error => false, + CompFields::After { + has_bitfield_units, .. + } => has_bitfield_units, + CompFields::Before(_) => { + panic!("Should always have computed bitfield units first"); + } + } + } + + /// Returns whether we have a too large bitfield unit, in which case we may + /// not be able to derive some of the things we should be able to normally + /// derive. + pub fn has_too_large_bitfield_unit(&self) -> bool { + if !self.has_bitfields() { + return false; + } + self.fields().iter().any(|field| match *field { + Field::DataMember(..) => false, + Field::Bitfields(ref unit) => { + unit.layout.size > RUST_DERIVE_IN_ARRAY_LIMIT + } + }) + } + + /// Does this type have any template parameters that aren't types + /// (e.g. int)? + pub fn has_non_type_template_params(&self) -> bool { + self.has_non_type_template_params + } + + /// Do we see a virtual function during parsing? + /// Get the has_own_virtual_method boolean. + pub fn has_own_virtual_method(&self) -> bool { + self.has_own_virtual_method + } + + /// Did we see a destructor when parsing this type? + pub fn has_own_destructor(&self) -> bool { + self.has_destructor + } + + /// Get this type's set of methods. + pub fn methods(&self) -> &[Method] { + &self.methods + } + + /// Get this type's set of constructors. + pub fn constructors(&self) -> &[FunctionId] { + &self.constructors + } + + /// Get this type's destructor. + pub fn destructor(&self) -> Option<(MethodKind, FunctionId)> { + self.destructor + } + + /// What kind of compound type is this? + pub fn kind(&self) -> CompKind { + self.kind + } + + /// Is this a union? + pub fn is_union(&self) -> bool { + self.kind() == CompKind::Union + } + + /// The set of types that this one inherits from. + pub fn base_members(&self) -> &[Base] { + &self.base_members + } + + /// Construct a new compound type from a Clang type. + pub fn from_ty( + potential_id: ItemId, + ty: &clang::Type, + location: Option<clang::Cursor>, + ctx: &mut BindgenContext, + ) -> Result<Self, ParseError> { + use clang_sys::*; + assert!( + ty.template_args().is_none(), + "We handle template instantiations elsewhere" + ); + + let mut cursor = ty.declaration(); + let mut kind = Self::kind_from_cursor(&cursor); + if kind.is_err() { + if let Some(location) = location { + kind = Self::kind_from_cursor(&location); + cursor = location; + } + } + + let kind = kind?; + + debug!("CompInfo::from_ty({:?}, {:?})", kind, cursor); + + let mut ci = CompInfo::new(kind); + ci.is_forward_declaration = + location.map_or(true, |cur| match cur.kind() { + CXCursor_ParmDecl => true, + CXCursor_StructDecl | CXCursor_UnionDecl | + CXCursor_ClassDecl => !cur.is_definition(), + _ => false, + }); + + let mut maybe_anonymous_struct_field = None; + cursor.visit(|cur| { + if cur.kind() != CXCursor_FieldDecl { + if let Some((ty, clang_ty, public, offset)) = + maybe_anonymous_struct_field.take() + { + if cur.kind() == CXCursor_TypedefDecl && + cur.typedef_type().unwrap().canonical_type() == + clang_ty + { + // Typedefs of anonymous structs appear later in the ast + // than the struct itself, that would otherwise be an + // anonymous field. Detect that case here, and do + // nothing. + } else { + let field = RawField::new( + None, ty, None, None, None, public, offset, + ); + ci.fields.append_raw_field(field); + } + } + } + + match cur.kind() { + CXCursor_FieldDecl => { + if let Some((ty, clang_ty, public, offset)) = + maybe_anonymous_struct_field.take() + { + let mut used = false; + cur.visit(|child| { + if child.cur_type() == clang_ty { + used = true; + } + CXChildVisit_Continue + }); + + if !used { + let field = RawField::new( + None, ty, None, None, None, public, offset, + ); + ci.fields.append_raw_field(field); + } + } + + let bit_width = if cur.is_bit_field() { + let width = cur.bit_width(); + + // Make opaque type if the bit width couldn't be + // evaluated. + if width.is_none() { + ci.has_unevaluable_bit_field_width = true; + return CXChildVisit_Break; + } + + width + } else { + None + }; + + let field_type = Item::from_ty_or_ref( + cur.cur_type(), + cur, + Some(potential_id), + ctx, + ); + + let comment = cur.raw_comment(); + let annotations = Annotations::new(&cur); + let name = cur.spelling(); + let is_public = cur.public_accessible(); + let offset = cur.offset_of_field().ok(); + + // Name can be empty if there are bitfields, for example, + // see tests/headers/struct_with_bitfields.h + assert!( + !name.is_empty() || bit_width.is_some(), + "Empty field name?" + ); + + let name = if name.is_empty() { None } else { Some(name) }; + + let field = RawField::new( + name, + field_type, + comment, + annotations, + bit_width, + is_public, + offset, + ); + ci.fields.append_raw_field(field); + + // No we look for things like attributes and stuff. + cur.visit(|cur| { + if cur.kind() == CXCursor_UnexposedAttr { + ci.found_unknown_attr = true; + } + CXChildVisit_Continue + }); + } + CXCursor_UnexposedAttr => { + ci.found_unknown_attr = true; + } + CXCursor_EnumDecl | + CXCursor_TypeAliasDecl | + CXCursor_TypeAliasTemplateDecl | + CXCursor_TypedefDecl | + CXCursor_StructDecl | + CXCursor_UnionDecl | + CXCursor_ClassTemplate | + CXCursor_ClassDecl => { + // We can find non-semantic children here, clang uses a + // StructDecl to note incomplete structs that haven't been + // forward-declared before, see [1]. + // + // Also, clang seems to scope struct definitions inside + // unions, and other named struct definitions inside other + // structs to the whole translation unit. + // + // Let's just assume that if the cursor we've found is a + // definition, it's a valid inner type. + // + // [1]: https://github.com/rust-lang/rust-bindgen/issues/482 + let is_inner_struct = + cur.semantic_parent() == cursor || cur.is_definition(); + if !is_inner_struct { + return CXChildVisit_Continue; + } + + // Even if this is a definition, we may not be the semantic + // parent, see #1281. + let inner = Item::parse(cur, Some(potential_id), ctx) + .expect("Inner ClassDecl"); + + // If we avoided recursion parsing this type (in + // `Item::from_ty_with_id()`), then this might not be a + // valid type ID, so check and gracefully handle this. + if ctx.resolve_item_fallible(inner).is_some() { + let inner = inner.expect_type_id(ctx); + + ci.inner_types.push(inner); + + // A declaration of an union or a struct without name + // could also be an unnamed field, unfortunately. + if cur.is_anonymous() && cur.kind() != CXCursor_EnumDecl + { + let ty = cur.cur_type(); + let public = cur.public_accessible(); + let offset = cur.offset_of_field().ok(); + + maybe_anonymous_struct_field = + Some((inner, ty, public, offset)); + } + } + } + CXCursor_PackedAttr => { + ci.packed_attr = true; + } + CXCursor_TemplateTypeParameter => { + let param = Item::type_param(None, cur, ctx).expect( + "Item::type_param should't fail when pointing \ + at a TemplateTypeParameter", + ); + ci.template_params.push(param); + } + CXCursor_CXXBaseSpecifier => { + let is_virtual_base = cur.is_virtual_base(); + ci.has_own_virtual_method |= is_virtual_base; + + let kind = if is_virtual_base { + BaseKind::Virtual + } else { + BaseKind::Normal + }; + + let field_name = match ci.base_members.len() { + 0 => "_base".into(), + n => format!("_base_{}", n), + }; + let type_id = + Item::from_ty_or_ref(cur.cur_type(), cur, None, ctx); + ci.base_members.push(Base { + ty: type_id, + kind, + field_name, + is_pub: cur.access_specifier() == + clang_sys::CX_CXXPublic, + }); + } + CXCursor_Constructor | CXCursor_Destructor | + CXCursor_CXXMethod => { + let is_virtual = cur.method_is_virtual(); + let is_static = cur.method_is_static(); + debug_assert!(!(is_static && is_virtual), "How?"); + + ci.has_destructor |= cur.kind() == CXCursor_Destructor; + ci.has_own_virtual_method |= is_virtual; + + // This used to not be here, but then I tried generating + // stylo bindings with this (without path filters), and + // cried a lot with a method in gfx/Point.h + // (ToUnknownPoint), that somehow was causing the same type + // to be inserted in the map two times. + // + // I couldn't make a reduced test case, but anyway... + // Methods of template functions not only used to be inlined, + // but also instantiated, and we wouldn't be able to call + // them, so just bail out. + if !ci.template_params.is_empty() { + return CXChildVisit_Continue; + } + + // NB: This gets us an owned `Function`, not a + // `FunctionSig`. + let signature = + match Item::parse(cur, Some(potential_id), ctx) { + Ok(item) + if ctx + .resolve_item(item) + .kind() + .is_function() => + { + item + } + _ => return CXChildVisit_Continue, + }; + + let signature = signature.expect_function_id(ctx); + + match cur.kind() { + CXCursor_Constructor => { + ci.constructors.push(signature); + } + CXCursor_Destructor => { + let kind = if is_virtual { + MethodKind::VirtualDestructor { + pure_virtual: cur.method_is_pure_virtual(), + } + } else { + MethodKind::Destructor + }; + ci.destructor = Some((kind, signature)); + } + CXCursor_CXXMethod => { + let is_const = cur.method_is_const(); + let method_kind = if is_static { + MethodKind::Static + } else if is_virtual { + MethodKind::Virtual { + pure_virtual: cur.method_is_pure_virtual(), + } + } else { + MethodKind::Normal + }; + + let method = + Method::new(method_kind, signature, is_const); + + ci.methods.push(method); + } + _ => unreachable!("How can we see this here?"), + } + } + CXCursor_NonTypeTemplateParameter => { + ci.has_non_type_template_params = true; + } + CXCursor_VarDecl => { + let linkage = cur.linkage(); + if linkage != CXLinkage_External && + linkage != CXLinkage_UniqueExternal + { + return CXChildVisit_Continue; + } + + let visibility = cur.visibility(); + if visibility != CXVisibility_Default { + return CXChildVisit_Continue; + } + + if let Ok(item) = Item::parse(cur, Some(potential_id), ctx) + { + ci.inner_vars.push(item.as_var_id_unchecked()); + } + } + // Intentionally not handled + CXCursor_CXXAccessSpecifier | + CXCursor_CXXFinalAttr | + CXCursor_FunctionTemplate | + CXCursor_ConversionFunction => {} + _ => { + warn!( + "unhandled comp member `{}` (kind {:?}) in `{}` ({})", + cur.spelling(), + clang::kind_to_str(cur.kind()), + cursor.spelling(), + cur.location() + ); + } + } + CXChildVisit_Continue + }); + + if let Some((ty, _, public, offset)) = maybe_anonymous_struct_field { + let field = + RawField::new(None, ty, None, None, None, public, offset); + ci.fields.append_raw_field(field); + } + + Ok(ci) + } + + fn kind_from_cursor( + cursor: &clang::Cursor, + ) -> Result<CompKind, ParseError> { + use clang_sys::*; + Ok(match cursor.kind() { + CXCursor_UnionDecl => CompKind::Union, + CXCursor_ClassDecl | CXCursor_StructDecl => CompKind::Struct, + CXCursor_CXXBaseSpecifier | + CXCursor_ClassTemplatePartialSpecialization | + CXCursor_ClassTemplate => match cursor.template_kind() { + CXCursor_UnionDecl => CompKind::Union, + _ => CompKind::Struct, + }, + _ => { + warn!("Unknown kind for comp type: {:?}", cursor); + return Err(ParseError::Continue); + } + }) + } + + /// Get the set of types that were declared within this compound type + /// (e.g. nested class definitions). + pub fn inner_types(&self) -> &[TypeId] { + &self.inner_types + } + + /// Get the set of static variables declared within this compound type. + pub fn inner_vars(&self) -> &[VarId] { + &self.inner_vars + } + + /// Have we found a field with an opaque type that could potentially mess up + /// the layout of this compound type? + pub fn found_unknown_attr(&self) -> bool { + self.found_unknown_attr + } + + /// Is this compound type packed? + pub fn is_packed( + &self, + ctx: &BindgenContext, + layout: Option<&Layout>, + ) -> bool { + if self.packed_attr { + return true; + } + + // Even though `libclang` doesn't expose `#pragma packed(...)`, we can + // detect it through its effects. + if let Some(parent_layout) = layout { + let mut packed = false; + self.each_known_field_layout(ctx, |layout| { + packed = packed || layout.align > parent_layout.align; + }); + if packed { + info!("Found a struct that was defined within `#pragma packed(...)`"); + return true; + } + + if self.has_own_virtual_method && parent_layout.align == 1 { + return true; + } + } + + false + } + + /// Returns true if compound type has been forward declared + pub fn is_forward_declaration(&self) -> bool { + self.is_forward_declaration + } + + /// Compute this compound structure's bitfield allocation units. + pub fn compute_bitfield_units( + &mut self, + ctx: &BindgenContext, + layout: Option<&Layout>, + ) { + let packed = self.is_packed(ctx, layout); + self.fields.compute_bitfield_units(ctx, packed) + } + + /// Assign for each anonymous field a generated name. + pub fn deanonymize_fields(&mut self, ctx: &BindgenContext) { + self.fields.deanonymize_fields(ctx, &self.methods); + } + + /// Returns whether the current union can be represented as a Rust `union` + /// + /// Requirements: + /// 1. Current RustTarget allows for `untagged_union` + /// 2. Each field can derive `Copy` or we use ManuallyDrop. + /// 3. It's not zero-sized. + /// + /// Second boolean returns whether all fields can be copied (and thus + /// ManuallyDrop is not needed). + pub fn is_rust_union( + &self, + ctx: &BindgenContext, + layout: Option<&Layout>, + name: &str, + ) -> (bool, bool) { + if !self.is_union() { + return (false, false); + } + + if !ctx.options().rust_features().untagged_union { + return (false, false); + } + + if self.is_forward_declaration() { + return (false, false); + } + + let union_style = if ctx.options().bindgen_wrapper_union.matches(name) { + NonCopyUnionStyle::BindgenWrapper + } else if ctx.options().manually_drop_union.matches(name) { + NonCopyUnionStyle::ManuallyDrop + } else { + ctx.options().default_non_copy_union_style + }; + + let all_can_copy = self.fields().iter().all(|f| match *f { + Field::DataMember(ref field_data) => { + field_data.ty().can_derive_copy(ctx) + } + Field::Bitfields(_) => true, + }); + + if !all_can_copy && union_style == NonCopyUnionStyle::BindgenWrapper { + return (false, false); + } + + if layout.map_or(false, |l| l.size == 0) { + return (false, false); + } + + (true, all_can_copy) + } +} + +impl DotAttributes for CompInfo { + fn dot_attributes<W>( + &self, + ctx: &BindgenContext, + out: &mut W, + ) -> io::Result<()> + where + W: io::Write, + { + writeln!(out, "<tr><td>CompKind</td><td>{:?}</td></tr>", self.kind)?; + + if self.has_own_virtual_method { + writeln!(out, "<tr><td>has_vtable</td><td>true</td></tr>")?; + } + + if self.has_destructor { + writeln!(out, "<tr><td>has_destructor</td><td>true</td></tr>")?; + } + + if self.has_nonempty_base { + writeln!(out, "<tr><td>has_nonempty_base</td><td>true</td></tr>")?; + } + + if self.has_non_type_template_params { + writeln!( + out, + "<tr><td>has_non_type_template_params</td><td>true</td></tr>" + )?; + } + + if self.packed_attr { + writeln!(out, "<tr><td>packed_attr</td><td>true</td></tr>")?; + } + + if self.is_forward_declaration { + writeln!( + out, + "<tr><td>is_forward_declaration</td><td>true</td></tr>" + )?; + } + + if !self.fields().is_empty() { + writeln!(out, r#"<tr><td>fields</td><td><table border="0">"#)?; + for field in self.fields() { + field.dot_attributes(ctx, out)?; + } + writeln!(out, "</table></td></tr>")?; + } + + Ok(()) + } +} + +impl IsOpaque for CompInfo { + type Extra = Option<Layout>; + + fn is_opaque(&self, ctx: &BindgenContext, layout: &Option<Layout>) -> bool { + if self.has_non_type_template_params || + self.has_unevaluable_bit_field_width + { + return true; + } + + // When we do not have the layout for a bitfield's type (for example, it + // is a type parameter), then we can't compute bitfield units. We are + // left with no choice but to make the whole struct opaque, or else we + // might generate structs with incorrect sizes and alignments. + if let CompFields::Error = self.fields { + return true; + } + + // Bitfields with a width that is larger than their unit's width have + // some strange things going on, and the best we can do is make the + // whole struct opaque. + if self.fields().iter().any(|f| match *f { + Field::DataMember(_) => false, + Field::Bitfields(ref unit) => unit.bitfields().iter().any(|bf| { + let bitfield_layout = ctx + .resolve_type(bf.ty()) + .layout(ctx) + .expect("Bitfield without layout? Gah!"); + bf.width() / 8 > bitfield_layout.size as u32 + }), + }) { + return true; + } + + if !ctx.options().rust_features().repr_packed_n { + // If we don't have `#[repr(packed(N)]`, the best we can + // do is make this struct opaque. + // + // See https://github.com/rust-lang/rust-bindgen/issues/537 and + // https://github.com/rust-lang/rust/issues/33158 + if self.is_packed(ctx, layout.as_ref()) && + layout.map_or(false, |l| l.align > 1) + { + warn!("Found a type that is both packed and aligned to greater than \ + 1; Rust before version 1.33 doesn't have `#[repr(packed(N))]`, so we \ + are treating it as opaque. You may wish to set bindgen's rust target \ + version to 1.33 or later to enable `#[repr(packed(N))]` support."); + return true; + } + } + + false + } +} + +impl TemplateParameters for CompInfo { + fn self_template_params(&self, _ctx: &BindgenContext) -> Vec<TypeId> { + self.template_params.clone() + } +} + +impl Trace for CompInfo { + type Extra = Item; + + fn trace<T>(&self, context: &BindgenContext, tracer: &mut T, item: &Item) + where + T: Tracer, + { + for p in item.all_template_params(context) { + tracer.visit_kind(p.into(), EdgeKind::TemplateParameterDefinition); + } + + for ty in self.inner_types() { + tracer.visit_kind(ty.into(), EdgeKind::InnerType); + } + + for &var in self.inner_vars() { + tracer.visit_kind(var.into(), EdgeKind::InnerVar); + } + + for method in self.methods() { + tracer.visit_kind(method.signature.into(), EdgeKind::Method); + } + + if let Some((_kind, signature)) = self.destructor() { + tracer.visit_kind(signature.into(), EdgeKind::Destructor); + } + + for ctor in self.constructors() { + tracer.visit_kind(ctor.into(), EdgeKind::Constructor); + } + + // Base members and fields are not generated for opaque types (but all + // of the above things are) so stop here. + if item.is_opaque(context, &()) { + return; + } + + for base in self.base_members() { + tracer.visit_kind(base.ty.into(), EdgeKind::BaseMember); + } + + self.fields.trace(context, tracer, &()); + } +} |