Ast.TypeDefinition Class

The is predicate identifies a syntax node that represents a complete type definition statement, such as a typedef declaration.

Example C++ code:

typedef const int MyInt;

Corresponding tree-sitter node (in snake_case):

(type_definition
  (type_qualifier) ; e.g. 'const'
  (type_identifier) ; e.g. 'int'
  (declarator)      ; e.g. 'MyInt'
)

The is predicate matches the entire type_definition node for the typedef statement. This allows queries to target the full typedef construct, including qualifiers, base type, and declarator.

This example demonstrates using the TypeDefinition.is predicate to match typedef/type-alias declarations. The C++ snippet below will trigger the rule because it contains typedefs and type aliases.

typedef int MyInt;
typedef const int MyConstInt;
using MyDouble = double;  // using-alias (may or may not be represented as TypeDefinition depending on parser)

rule CheckTypeDefinitionIs = { defectTypeDefIs }
defect defectTypeDefIs =
    when
        Cpp.TypeDefinition.is(&td)
        and td.declarator(&decl)
        and decl.nodeText(&name)
    raise "Found a TypeDefinition via TypeDefinition.is: '{name}'"
    on td

The is predicate identifies a syntax node that represents a complete type definition statement, such as a typedef declaration.

Example C++ code:

typedef const int MyInt;

Corresponding tree-sitter node (in snake_case):

(type_definition
  (type_qualifier) ; e.g. 'const'
  (type_identifier) ; e.g. 'int'
  (declarator)      ; e.g. 'MyInt'
)

The is predicate matches the entire type_definition node for the typedef statement. This allows queries to target the full typedef construct, including qualifiers, base type, and declarator.

This example demonstrates using the TypeDefinition.is predicate to match typedef/type-alias declarations. The C++ snippet below will trigger the rule because it contains typedefs and type aliases.

typedef int MyInt;
typedef const int MyConstInt;
using MyDouble = double;  // using-alias (may or may not be represented as TypeDefinition depending on parser)

rule CheckTypeDefinitionIs = { defectTypeDefIs }
defect defectTypeDefIs =
    when
        Cpp.TypeDefinition.is(&td)
        and td.declarator(&decl)
        and decl.nodeText(&name)
    raise "Found a TypeDefinition via TypeDefinition.is: '{name}'"
    on td

The declarator predicate identifies the declarator node within a TypeDefinition. It represents the name introduced by a typedef or type alias.

Example C++ code:

typedef int MyInt;

The equivalent tree-sitter node is type_definition. The declarator predicate matches the MyInt node inside the type_definition node, capturing the typedef's declared identifier.

This example demonstrates using the TypeDefinition.declarator predicate to find typedefs where the declared identifier name is captured. The C++ snippet below will trigger the rule:

rule CheckTypeDefinitionDeclarator = { defectTypeDefDeclarator }
defect defectTypeDefDeclarator =
    when
        Cpp.TypeDefinition.is(&td)
        and td.declarator(&decl)
        and decl.nodeText(&name)
    raise "TypeDefinition.declarator matched: '{name}'"
    on td

The type predicate retrieves the underlying type node defined by a typedef. This includes the type aliased by a typedef declaration.

Example C++ code:

typedef const int MyInt;

Equivalent tree-sitter node:

(type_definition
  type: (type_identifier) @type
  declarator: (identifier) @declarator)

The type predicate matches the node representing const int in the typedef. This allows queries to analyze the aliased type separately from the typedef name.

This example demonstrates using the TypeDefinition.type predicate to match a typedef's underlying type. The C++ snippet below defines a typedef for const int which will be matched by the rule.

typedef const int MyConstInt;

rule CheckTypePredicate = { defectTypePredicate }
defect defectTypePredicate =
    when
        Cpp.TypeDefinition.type(&underlyingType)
        and Cpp.ConstQualifier.isa(underlyingType)
        and underlyingType.nodeText(&txt)
    raise "Found a typedef with a const underlying type: '{txt}'"
    on underlyingType

The type predicate retrieves the underlying type node defined by a typedef. This includes the type aliased by a typedef declaration.

Example C++ code:

typedef const int MyInt;

Equivalent tree-sitter node:

(type_definition
  type: (type_identifier) @type
  declarator: (identifier) @declarator)

The type predicate matches the node representing const int in the typedef. This allows queries to analyze the aliased type separately from the typedef name.

This example demonstrates using the TypeDefinition.type predicate to match a typedef's underlying type. The C++ snippet below defines a typedef for const int which will be matched by the rule.

typedef const int MyConstInt;

rule CheckTypePredicate = { defectTypePredicate }
defect defectTypePredicate =
    when
        Cpp.TypeDefinition.type(&underlyingType)
        and Cpp.ConstQualifier.isa(underlyingType)
        and underlyingType.nodeText(&txt)
    raise "Found a typedef with a const underlying type: '{txt}'"
    on underlyingType

The attributeSpecifier predicate identifies attribute specifier nodes, such as [[nodiscard]], attached to a type definition in C++ code.

Example C++ code with the corresponding tree-sitter node:

typedef double MyDouble [[nodiscard]];

Tree-sitter node: type_definition.

The attributeSpecifier predicate matches the [[nodiscard]] attribute_specifier node within the type_definition node representing the typedef of MyDouble.

This example demonstrates using TypeDefinition.attributeSpecifier to detect typedefs that include a C++ attribute (e.g. [[nodiscard]]). The C++ snippet below will trigger the rule because the typedef for MyDouble has an attribute specifier.

rule CheckAttributeSpecifier = { defectAttributeSpecifier }
defect defectAttributeSpecifier =
    when
        Cpp.TypeDefinition.is(&td)
        and td.attributeSpecifier(&attr)
        and attr.nodeText(&txt)
    raise "TypeDefinition.attributeSpecifier matched: "{txt}""
    on td

// Example C++ that would trigger this rule:
// typedef double MyDouble [[nodiscard]];