wasm/core/
error.rs

1use crate::validation_stack::ValidationStackEntry;
2use crate::RefType;
3use core::fmt::{Display, Formatter};
4use core::str::Utf8Error;
5
6use super::indices::FuncIdx;
7use crate::core::reader::section_header::SectionTy;
8use crate::core::reader::types::ValType;
9
10#[derive(Debug, PartialEq, Eq, Clone)]
11pub enum ValidationError {
12    /// The magic number at the start of the Wasm bytecode is invalid.
13    InvalidMagic,
14    /// The binary format version at the start of the Wasm bytecode is invalid.
15    InvalidBinaryFormatVersion,
16    /// The end of the binary file was reached unexpectedly.
17    Eof,
18
19    /// A UTF-8 string is malformed.
20    MalformedUtf8(Utf8Error),
21    /// The type of a section is malformed.
22    MalformedSectionTypeDiscriminator(u8),
23    /// The discriminator of a number type is malformed.
24    MalformedNumTypeDiscriminator(u8),
25    /// The discriminator of a vector type is malformed.
26    MalformedVecTypeDiscriminator(u8),
27    /// The discriminator of a function type is malformed.
28    MalformedFuncTypeDiscriminator(u8),
29    /// The discriminator of a reference type is malformed.
30    MalformedRefTypeDiscriminator(u8),
31    /// A valtype is malformed because it is neither a number, reference nor vector type.
32    MalformedValType,
33    /// The discriminator of an export description is malformed.
34    MalformedExportDescDiscriminator(u8),
35    /// The discriminator of an import description is malformed.
36    MalformedImportDescDiscriminator(u8),
37    /// The discriminator of a limits type is malformed.
38    MalformedLimitsDiscriminator(u8),
39    /// The min field of a limits type is larger than the max field.
40    MalformedLimitsMinLargerThanMax {
41        min: u32,
42        max: u32,
43    },
44    /// The discriminator of a mut type is malformed.
45    MalformedMutDiscriminator(u8),
46    /// Block types use a special 33-bit signed integer for encoding type indices.
47    MalformedBlockTypeTypeIdx(i64),
48    /// A variable-length integer was read but it overflowed.
49    MalformedVariableLengthInteger,
50    /// The discriminator of an element kind is malformed.
51    MalformedElemKindDiscriminator(u8),
52
53    /// An index for a type is invalid.
54    InvalidTypeIdx(u32),
55    /// An index for a function is invalid.
56    InvalidFuncIdx(u32),
57    /// An index for a table is invalid.
58    InvalidTableIdx(u32),
59    /// An index for a memory is invalid.
60    InvalidMemIdx(u32),
61    /// An index for a global is invalid.
62    InvalidGlobalIdx(u32),
63    /// An index for an element segment is invalid.
64    InvalidElemIdx(u32),
65    /// An index for a data segment is invalid.
66    InvalidDataIdx(u32),
67    /// An index for a local is invalid.
68    InvalidLocalIdx(u32),
69    /// An index for a label is invalid.
70    InvalidLabelIdx(u32),
71    /// An index for a lane of some vector type is invalid.
72    InvalidLaneIdx(u8),
73
74    /// A section with given type is out of order. All section types have a fixed order in which they must occur.
75    SectionOutOfOrder(SectionTy),
76    /// A custom section contains more bytes than its section header specifies.
77    InvalidCustomSectionLength,
78    ExprMissingEnd,
79    InvalidInstr(u8),
80    InvalidMultiByteInstr(u8, u32),
81    EndInvalidValueStack,
82    InvalidValidationStackValType(Option<ValType>),
83    InvalidValidationStackType(ValidationStackEntry),
84    ExpectedAnOperand,
85    /// The memory size specified by a mem type exceeds the maximum size.
86    MemoryTooLarge,
87    /// An attempt has been made to mutate a const global
88    MutationOfConstGlobal,
89    /// An alignment of some memory instruction is invalid
90    ErroneousAlignment {
91        alignment: u32,
92        minimum_required_alignment: u32,
93    },
94    /// The validation control stack is empty, even though an entry was expected.
95    // TODO Reconsider if we want to expose this error. It should probably never happen and thus also never bubble up to the user.
96    ValidationCtrlStackEmpty,
97    /// An `else` instruction was found while not inside an `if` block.
98    ElseWithoutMatchingIf,
99    /// An `end` for a matching `if` instruction was found, but there was no `else` instruction in between.
100    IfWithoutMatchingElse,
101    /// A `table.init` instruction specified a table and an element segment that store different reference types.
102    MismatchedRefTypesDuringTableInit {
103        table_ty: RefType,
104        elem_ty: RefType,
105    },
106    /// A `table.copy` instruction referenced two tables that store different reference types.
107    MismatchedRefTypesDuringTableCopy {
108        source_table_ty: RefType,
109        destination_table_ty: RefType,
110    },
111    /// An expected reference type did not match the actual reference type on the validation stack.
112    MismatchedRefTypesOnValidationStack {
113        expected: RefType,
114        actual: RefType,
115    },
116    /// An indirect call to a table with does not store function references was made.
117    IndirectCallToNonFuncRefTable(RefType),
118    /// A reference type was expected to be on the stack, but a value type was found.
119    ExpectedReferenceTypeOnStack(ValType),
120    /// When a is referenced in the code section it must be contained in `C.refs`, which was not the case
121    ReferencingAnUnreferencedFunction(FuncIdx),
122    /// The select instructions may work with multiple values in the future. However, as of now its vector may only have one element.
123    InvalidSelectTypeVectorLength(usize),
124    /// A function specifies too many locals, i.e. more than 2^32 - 1
125    TooManyLocals(u64),
126    /// Multiple exports share the same name
127    DuplicateExportName,
128    /// Multiple memories are not yet allowed without the proposal.
129    UnsupportedMultipleMemoriesProposal,
130    /// An expr in the code section has trailing instructions following its `end` instruction.
131    CodeExprHasTrailingInstructions,
132    /// The lengths of the function and code sections must match.
133    FunctionAndCodeSectionsHaveDifferentLengths,
134    /// The data count specified in the data count section and the length of the data section must match.
135    DataCountAndDataSectionsLengthAreDifferent,
136    InvalidImportType,
137    /// The function signature of the start function is invalid. It must not specify any parameters or return values.
138    InvalidStartFunctionSignature,
139    /// An active element segment's type and its table's type are different.
140    ActiveElementSegmentTypeMismatch,
141    /// 33-bit signed integers are sometimes used to encode unsigned 32-bit
142    /// integers to prevent collisions between bit patterns of different types.
143    /// Therefore, 33-bit signed integers may never be negative.
144    I33IsNegative,
145    /// The data count section is required, if there are instructions that use
146    /// data indices.
147    MissingDataCountSection,
148    /// The mode of a data segment was invalid. Only values in the range 0..=2
149    /// are allowed.
150    InvalidDataSegmentMode(u32),
151    /// The mode of an element was invalid. Only values in the range 0..=7 are
152    /// allowed.
153    InvalidElementMode(u32),
154    /// The module contains too many functions, i.e. imported or locally-defined
155    /// functions. The maximum number of functions is [`u32::MAX`].
156    TooManyFunctions,
157    /// The module contains too many tables, i.e. imported or locally-defined
158    /// tables. The maximum number of tables is [`u32::MAX`].
159    TooManyTables,
160    /// The module contains too many memories, i.e. imported or locally-defined
161    /// memories. The maximum number of memories is [`u32::MAX`].
162    TooManyMemories,
163    /// The module contains too many globals, i.e. imported or locally-defined
164    /// globals. The maximum number of memories is [`u32::MAX`].
165    TooManyGlobals,
166}
167
168impl core::error::Error for ValidationError {}
169
170impl Display for ValidationError {
171    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
172        match self {
173            ValidationError::InvalidMagic => write!(f, "The magic number is invalid"),
174            ValidationError::InvalidBinaryFormatVersion => write!(f, "The Wasm binary format version is invalid"),
175            ValidationError::Eof => write!(f, "The end of the Wasm bytecode was reached unexpectedly"),
176
177            ValidationError::MalformedUtf8(utf8_error) => write!(f, "Failed to parse a UTF-8 string: {utf8_error}"),
178            ValidationError::MalformedSectionTypeDiscriminator(byte) => write!(f, "Failed to parse {byte:#x} as a section type discriminator"),
179            ValidationError::MalformedNumTypeDiscriminator(byte) => write!(f, "Failed to parse {byte:#x} as a number type discriminator"),
180            ValidationError::MalformedVecTypeDiscriminator(byte) => write!(f, "Failed to parse {byte:#x} as a vector type discriminator"),
181            ValidationError::MalformedFuncTypeDiscriminator(byte) => write!(f, "Failed to parse {byte:#x} as a function type discriminator"),
182            ValidationError::MalformedRefTypeDiscriminator(byte) => write!(f, "Failed to parse {byte:#x} as a reference type discriminator"),
183            ValidationError::MalformedValType => write!(f, "Failed to read a value type because it is neither a number, reference or vector type"),
184            ValidationError::MalformedExportDescDiscriminator(byte) => write!(f, "Failed to parse {byte:#x} as an export description discriminator"),
185            ValidationError::MalformedImportDescDiscriminator(byte) => write!(f, "Failed to parse {byte:#x} as an import description discriminator"),
186            ValidationError::MalformedLimitsDiscriminator(byte) => write!(f, "Failed to parse {byte:#x} as a limits type discriminator"),
187            ValidationError::MalformedLimitsMinLargerThanMax { min, max } => write!(f, "Limits are malformed because min={min} is larger than max={max}"),
188            ValidationError::MalformedMutDiscriminator(byte) => write!(f, "Failed to parse {byte:#x} as a mute type discriminator"),
189            ValidationError::MalformedBlockTypeTypeIdx(idx) => write!(f, "The type index {idx} which is encoded as a singed 33-bit integer inside a block type is malformed"),
190            ValidationError::MalformedVariableLengthInteger => write!(f, "Reading a variable-length integer overflowed"),
191            ValidationError::MalformedElemKindDiscriminator(byte) => write!(f, "Failed to parse {byte:#x} as an element kind discriminator"),
192
193            ValidationError::InvalidTypeIdx(idx) => write!(f, "The type index {idx} is invalid"),
194            ValidationError::InvalidFuncIdx(idx) => write!(f, "The function index {idx} is invalid"),
195            ValidationError::InvalidTableIdx(idx) => write!(f, "The table index {idx} is invalid"),
196            ValidationError::InvalidMemIdx(idx) => write!(f, "The memory index {idx} is invalid"),
197            ValidationError::InvalidGlobalIdx(idx) => write!(f, "The global index {idx} is invalid"),
198            ValidationError::InvalidElemIdx(idx) => write!(f, "The element segment index {idx} is invalid"),
199            ValidationError::InvalidDataIdx(idx) => write!(f, "The data segment index {idx} is invalid"),
200            ValidationError::InvalidLocalIdx(idx) => write!(f, "The local index {idx} is invalid"),
201            ValidationError::InvalidLabelIdx(idx) => write!(f, "The label index {idx} is invalid"),
202            ValidationError::InvalidLaneIdx(idx) => write!(f, "The lane index {idx} is invalid"),
203
204            ValidationError::SectionOutOfOrder(ty) => write!(f, "A section of type `{ty:?}` is defined out of order"),
205            ValidationError::InvalidCustomSectionLength => write!(f, "A custom section contains more bytes than its section header specifies"),
206            ValidationError::ExprMissingEnd => write!(f, "An expr type is missing an end byte"),
207            ValidationError::InvalidInstr(byte) => write!(f, "The instruction opcode {byte:#x} is invalid"),
208            ValidationError::InvalidMultiByteInstr(first_byte, second_instr) => write!(f, "The multi-byte instruction opcode {first_byte:#x} {second_instr} is invalid"),
209            ValidationError::ActiveElementSegmentTypeMismatch => write!(f, "an element segment's type and its table's type are different"),
210            ValidationError::EndInvalidValueStack => write!(f, "Different value stack types were expected at the end of a block/function"),
211            ValidationError::InvalidValidationStackValType(ty) => write!(f, "An unexpected type `{ty:?}` was found on the stack when trying to pop another"),
212            ValidationError::InvalidValidationStackType(ty) => write!(f, "An unexpected type `{ty:?}` was found on the stack"),
213            ValidationError::ExpectedAnOperand => write!(f, "Expected a value type operand on the stack"),
214            ValidationError::MemoryTooLarge => write!(f, "The size specified by a memory type exceeds the maximum size"),
215            ValidationError::MutationOfConstGlobal => write!(f, "An attempt has been made to mutate a const global"),
216            ValidationError::ErroneousAlignment {alignment , minimum_required_alignment} => write!(f, "The alignment 2^{alignment} is not less or equal to the required alignment 2^{minimum_required_alignment}"),
217            ValidationError::ValidationCtrlStackEmpty => write!(f, "Failed to retrieve last ctrl block because validation ctrl stack is empty"),
218            ValidationError::ElseWithoutMatchingIf => write!(f, "Found `else` without a previous matching `if` instruction"),
219            ValidationError::IfWithoutMatchingElse => write!(f, "Found `end` without a previous matching `else` to an `if` instruction"),
220            ValidationError::MismatchedRefTypesDuringTableInit { table_ty, elem_ty } => write!(f, "Mismatch of table type `{table_ty:?}` and element segment type `{elem_ty:?}` for `table.init` instruction"),
221            ValidationError::MismatchedRefTypesDuringTableCopy { source_table_ty, destination_table_ty } => write!(f, "Mismatch of source table type `{source_table_ty:?}` and destination table type `{destination_table_ty:?}` for `table.copy` instruction"),
222            ValidationError::MismatchedRefTypesOnValidationStack { expected, actual } => write!(f, "Mismatch of reference types on the value stack: Expected `{expected:?}` but got `{actual:?}`"),
223            ValidationError::IndirectCallToNonFuncRefTable(table_ty) => write!(f, "An indirect call to a table which does not store function references but instead `{table_ty:?}` was made"),
224            ValidationError::ExpectedReferenceTypeOnStack(found_valtype) => write!(f, "Expected a reference type but instead found a `{found_valtype:?}` on the stack"),
225            ValidationError::ReferencingAnUnreferencedFunction(func_idx) => write!(f, "Referenced a function with index {func_idx} that was not referenced in prior validation"),
226            ValidationError::InvalidSelectTypeVectorLength(len) => write!(f, "The type vector of a `select` instruction must be of length 1 as of now but it is of length {len} instead"),
227            ValidationError::TooManyLocals(n) => write!(f,"There are {n} locals and this exceeds the maximum allowed number of 2^32-1"),
228            ValidationError::DuplicateExportName => write!(f,"Multiple exports share the same name"),
229            ValidationError::UnsupportedMultipleMemoriesProposal => write!(f,"A memory index other than 1 was used, but the proposal for multiple memories is not yet supported"),
230            ValidationError::CodeExprHasTrailingInstructions => write!(f,"A code expression has invalid trailing instructions following its `end` instruction"),
231            ValidationError::FunctionAndCodeSectionsHaveDifferentLengths => write!(f,"The function and code sections have different lengths"),
232            ValidationError::DataCountAndDataSectionsLengthAreDifferent => write!(f,"The data count section specifies a different length than there are data segments in the data section"),
233            ValidationError::InvalidImportType => f.write_str("Invalid import type"),
234            ValidationError::InvalidStartFunctionSignature => write!(f,"The start function has parameters or return types which it is not allowed to have"),
235            ValidationError::I33IsNegative => f.write_str("An i33 type is negative which is not allowed"),
236            ValidationError::MissingDataCountSection => f.write_str("Some instructions could not be validated because the data count section is missing"),
237            ValidationError::InvalidDataSegmentMode(mode) => write!(f, "The mode of a data segment was invalid (only 0..=2 is allowed): {mode}"),
238            ValidationError::InvalidElementMode(mode) => write!(f, "The mode of an element was invalid (only 0..=7 is allowed): {mode}"),
239            ValidationError::TooManyFunctions => f.write_str("The module contains too many functions. The maximum number of functions (either imported or locally-defined) is 2^32 - 1"),
240            ValidationError::TooManyTables => f.write_str("The module contains too many tables. The maximum number of tables (either imported or locally-defined) is 2^32 - 1"),
241            ValidationError::TooManyMemories => f.write_str("The module contains too many memories. The maximum number of memories (either imported or locally-defined) is 2^32 - 1"),
242            ValidationError::TooManyGlobals => f.write_str("The module contains too many globals. The maximum number of globals (either imported or locally-defined) is 2^32 - 1"),
243        }
244    }
245}
246
247impl ValidationError {
248    /// Convert this error to a message that is compatible with the error messages used by the official Wasm testsuite.
249    pub fn to_message(&self) -> &'static str {
250        todo!("convert validation error to testsuite message");
251    }
252}
253
254#[cfg(test)]
255mod test {
256    use alloc::string::ToString;
257
258    use crate::ValidationError;
259
260    #[test]
261    fn fmt_invalid_magic() {
262        assert!(ValidationError::InvalidMagic
263            .to_string()
264            .contains("magic number"));
265    }
266
267    #[test]
268    fn fmt_invalid_version() {
269        assert!(ValidationError::InvalidBinaryFormatVersion
270            .to_string()
271            .contains("version"));
272    }
273}
wasm/core/error.rs

wasm/core/
error.rs
