/build/cargo-vendor-dir/wasm-encoder-0.200.0/src/component/imports.rs

Source (jump to first uncovered line)
use crate::{
    encode_section, ComponentExportKind, ComponentSection, ComponentSectionId, ComponentValType,
    Encode,
};

/// Represents the possible type bounds for type references.
#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
pub enum TypeBounds {
    /// The type is bounded by equality to the type index specified.
    Eq(u32),
    /// This type is a fresh resource type,
    SubResource,
}

impl Encode for TypeBounds {
    fn encode(&self, sink: &mut Vec<u8>) {
        match self {
            Self::Eq(i) => {
                sink.push(0x00);
                i.encode(sink);
            }
            Self::SubResource => sink.push(0x01),
        }
    }
}

/// Represents a reference to a type.
#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
pub enum ComponentTypeRef {
    /// The reference is to a core module type.
    ///
    /// The index is expected to be core type index to a core module type.
    Module(u32),
    /// The reference is to a function type.
    ///
    /// The index is expected to be a type index to a function type.
    Func(u32),
    /// The reference is to a value type.
    Value(ComponentValType),
    /// The reference is to a bounded type.
    Type(TypeBounds),
    /// The reference is to an instance type.
    ///
    /// The index is expected to be a type index to an instance type.
    Instance(u32),
    /// The reference is to a component type.
    ///
    /// The index is expected to be a type index to a component type.
    Component(u32),
}

impl ComponentTypeRef {
    /// Gets the export kind of the reference.
    pub fn kind(&self) -> ComponentExportKind {
        match self {
            Self::Module(_) => ComponentExportKind::Module,
            Self::Func(_) => ComponentExportKind::Func,
            Self::Value(_) => ComponentExportKind::Value,
            Self::Type(..) => ComponentExportKind::Type,
            Self::Instance(_) => ComponentExportKind::Instance,
            Self::Component(_) => ComponentExportKind::Component,
        }
    }
}

impl Encode for ComponentTypeRef {
    fn encode(&self, sink: &mut Vec<u8>) {
        self.kind().encode(sink);

        match self {
            Self::Module(idx) | Self::Func(idx) | Self::Instance(idx) | Self::Component(idx) => {
                idx.encode(sink);
            }
            Self::Value(ty) => ty.encode(sink),
            Self::Type(bounds) => bounds.encode(sink),
        }
    }
}

/// An encoder for the import section of WebAssembly components.
///
/// # Example
///
/// ```rust
/// use wasm_encoder::{Component, ComponentTypeSection, PrimitiveValType, ComponentImportSection, ComponentTypeRef};
///
/// let mut types = ComponentTypeSection::new();
///
/// // Define a function type of `[string, string] -> string`.
/// types
///   .function()
///   .params(
///     [
///       ("a", PrimitiveValType::String),
///       ("b", PrimitiveValType::String)
///     ]
///   )
///   .result(PrimitiveValType::String);
///
/// // This imports a function named `f` with the type defined above
/// let mut imports = ComponentImportSection::new();
/// imports.import("f", ComponentTypeRef::Func(0));
///
/// let mut component = Component::new();
/// component.section(&types);
/// component.section(&imports);
///
/// let bytes = component.finish();
/// ```
#[derive(Clone, Debug, Default)]
pub struct ComponentImportSection {
    bytes: Vec<u8>,
    num_added: u32,
}

impl ComponentImportSection {
    /// Create a new component import section encoder.
    pub fn new() -> Self {
        Self::default()
    }

    /// The number of imports in the section.
    pub fn len(&self) -> u32 {
        self.num_added
    }

    /// Determines if the section is empty.
    pub fn is_empty(&self) -> bool {
        self.num_added == 0
    }

    /// Define an import in the component import section.
    pub fn import(&mut self, name: &str, ty: ComponentTypeRef) -> &mut Self {
        push_extern_name_byte(&mut self.bytes, name);
        name.encode(&mut self.bytes);
        ty.encode(&mut self.bytes);
        self.num_added += 1;
        self
    }
}

impl Encode for ComponentImportSection {
    fn encode(&self, sink: &mut Vec<u8>) {
        encode_section(sink, self.num_added, &self.bytes);
    }
}

impl ComponentSection for ComponentImportSection {
    fn id(&self) -> u8 {
        ComponentSectionId::Import.into()
    }
}

/// Prior to WebAssembly/component-model#263 import and export names were
/// discriminated with a leading byte indicating what kind of import they are.
/// After that PR though names are always prefixed with a 0x00 byte.
///
/// This function is a compatibility shim for the time being while this change
/// is being rolled out. That PR is technically a spec-breaking change relative
/// to prior but we want old tooling to continue to work with new modules. To
/// handle that names that look like IDs, `a:b/c`, get an 0x01 prefix instead of
/// the spec-defined 0x00 prefix. That makes components produced by current
/// versions of this crate compatible with older parsers.
///
/// Note that wasmparser has a similar case where it parses either 0x01 or 0x00.
/// That means that the selection of a byte here doesn't actually matter for
/// wasmparser's own validation. Eventually this will go away and an 0x00 byte
/// will always be emitted to align with the spec.
pub(crate) fn push_extern_name_byte(bytes: &mut Vec<u8>, name: &str) {
    if name.contains(':') {
        bytes.push(0x01);
    } else {
        bytes.push(0x00);
    }
}

Line	Count	Source (jump to first uncovered line)
1		use crate::{
2		encode_section, ComponentExportKind, ComponentSection, ComponentSectionId, ComponentValType,
3		Encode,
4		};
5
6		/// Represents the possible type bounds for type references.
7		#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
8		pub enum TypeBounds {
9		/// The type is bounded by equality to the type index specified.
10		Eq(u32),
11		/// This type is a fresh resource type,
12		SubResource,
13		}
14
15		impl Encode for TypeBounds {
16	0	fn encode(&self, sink: &mut Vec<u8>) {
17	0	match self {
18	0	Self::Eq(i) => {
19	0	sink.push(0x00);
20	0	i.encode(sink);
21	0	}
22	0	Self::SubResource => sink.push(0x01),
23		}
24	0	}
25		}
26
27		/// Represents a reference to a type.
28		#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
29		pub enum ComponentTypeRef {
30		/// The reference is to a core module type.
31		///
32		/// The index is expected to be core type index to a core module type.
33		Module(u32),
34		/// The reference is to a function type.
35		///
36		/// The index is expected to be a type index to a function type.
37		Func(u32),
38		/// The reference is to a value type.
39		Value(ComponentValType),
40		/// The reference is to a bounded type.
41		Type(TypeBounds),
42		/// The reference is to an instance type.
43		///
44		/// The index is expected to be a type index to an instance type.
45		Instance(u32),
46		/// The reference is to a component type.
47		///
48		/// The index is expected to be a type index to a component type.
49		Component(u32),
50		}
51
52		impl ComponentTypeRef {
53		/// Gets the export kind of the reference.
54	0	pub fn kind(&self) -> ComponentExportKind {
55	0	match self {
56	0	Self::Module(_) => ComponentExportKind::Module,
57	0	Self::Func(_) => ComponentExportKind::Func,
58	0	Self::Value(_) => ComponentExportKind::Value,
59	0	Self::Type(..) => ComponentExportKind::Type,
60	0	Self::Instance(_) => ComponentExportKind::Instance,
61	0	Self::Component(_) => ComponentExportKind::Component,
62		}
63	0	}
64		}
65
66		impl Encode for ComponentTypeRef {
67	0	fn encode(&self, sink: &mut Vec<u8>) {
68	0	self.kind().encode(sink);
69	0
70	0	match self {
71	0	Self::Module(idx) \| Self::Func(idx) \| Self::Instance(idx) \| Self::Component(idx) => {
72	0	idx.encode(sink);
73	0	}
74	0	Self::Value(ty) => ty.encode(sink),
75	0	Self::Type(bounds) => bounds.encode(sink),
76		}
77	0	}
78		}
79
80		/// An encoder for the import section of WebAssembly components.
81		///
82		/// # Example
83		///
84		/// ```rust
85		/// use wasm_encoder::{Component, ComponentTypeSection, PrimitiveValType, ComponentImportSection, ComponentTypeRef};
86		///
87		/// let mut types = ComponentTypeSection::new();
88		///
89		/// // Define a function type of `[string, string] -> string`.
90		/// types
91		/// .function()
92		/// .params(
93		/// [
94		/// ("a", PrimitiveValType::String),
95		/// ("b", PrimitiveValType::String)
96		/// ]
97		/// )
98		/// .result(PrimitiveValType::String);
99		///
100		/// // This imports a function named `f` with the type defined above
101		/// let mut imports = ComponentImportSection::new();
102		/// imports.import("f", ComponentTypeRef::Func(0));
103		///
104		/// let mut component = Component::new();
105		/// component.section(&types);
106		/// component.section(&imports);
107		///
108		/// let bytes = component.finish();
109		/// ```
110		#[derive(Clone, Debug, Default)]
111		pub struct ComponentImportSection {
112		bytes: Vec<u8>,
113		num_added: u32,
114		}
115
116		impl ComponentImportSection {
117		/// Create a new component import section encoder.
118	0	pub fn new() -> Self {
119	0	Self::default()
120	0	}
121
122		/// The number of imports in the section.
123	0	pub fn len(&self) -> u32 {
124	0	self.num_added
125	0	}
126
127		/// Determines if the section is empty.
128	0	pub fn is_empty(&self) -> bool {
129	0	self.num_added == 0
130	0	}
131
132		/// Define an import in the component import section.
133	0	pub fn import(&mut self, name: &str, ty: ComponentTypeRef) -> &mut Self {
134	0	push_extern_name_byte(&mut self.bytes, name);
135	0	name.encode(&mut self.bytes);
136	0	ty.encode(&mut self.bytes);
137	0	self.num_added += 1;
138	0	self
139	0	}
140		}
141
142		impl Encode for ComponentImportSection {
143	0	fn encode(&self, sink: &mut Vec<u8>) {
144	0	encode_section(sink, self.num_added, &self.bytes);
145	0	}
146		}
147
148		impl ComponentSection for ComponentImportSection {
149	0	fn id(&self) -> u8 {
150	0	ComponentSectionId::Import.into()
151	0	}
152		}
153
154		/// Prior to WebAssembly/component-model#263 import and export names were
155		/// discriminated with a leading byte indicating what kind of import they are.
156		/// After that PR though names are always prefixed with a 0x00 byte.
157		///
158		/// This function is a compatibility shim for the time being while this change
159		/// is being rolled out. That PR is technically a spec-breaking change relative
160		/// to prior but we want old tooling to continue to work with new modules. To
161		/// handle that names that look like IDs, `a:b/c`, get an 0x01 prefix instead of
162		/// the spec-defined 0x00 prefix. That makes components produced by current
163		/// versions of this crate compatible with older parsers.
164		///
165		/// Note that wasmparser has a similar case where it parses either 0x01 or 0x00.
166		/// That means that the selection of a byte here doesn't actually matter for
167		/// wasmparser's own validation. Eventually this will go away and an 0x00 byte
168		/// will always be emitted to align with the spec.
169	0	pub(crate) fn push_extern_name_byte(bytes: &mut Vec<u8>, name: &str) {
170	0	if name.contains(':') {
171	0	bytes.push(0x01);
172	0	} else {
173	0	bytes.push(0x00);
174	0	}
175	0	}

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Created: 2024-11-19 11:03