Metadata Reading

The Metadata API gives developers low-level access to the information encoded in CLI modules: type and methods definitions encoded in metadata as well as access to the CIL code and embedded resources.

Managed developers access this information using either the System.Reflection API or a library like Cecil.

To start using the Metadata API it is necessary to open an assembly or a CIL image (a .dll or .exe file) using one of the CIL image opening API calls.

Metadata Heaps

ECMA CLI images contain four heaps that store different kinds of information, these are:

The ECMA file format also has an extra section called the "#~" stream, this stream is the one that holds the metadata tables. There is a high-level API to get access to the contents of this API, described in the section Metadata Tables.

mono_metadata_guid_heap
Syntax
const char * mono_metadata_guid_heap (MonoImage *meta, guint32 index)

Parameters
meta metadata context
index index into the guid heap.
Return value
an in-memory pointer to the index in the guid heap.
mono_metadata_string_heap
Syntax
const char * mono_metadata_string_heap (MonoImage *meta, guint32 index)

Parameters
meta metadata context
index index into the string heap.
Return value
an in-memory pointer to the index in the string heap.
mono_metadata_blob_heap
Syntax
const char * mono_metadata_blob_heap (MonoImage *meta, guint32 index)

Parameters
meta metadata context
index index into the blob.
Return value
an in-memory pointer to the index in the Blob heap.
mono_metadata_user_string
Syntax
const char * mono_metadata_user_string (MonoImage *meta, guint32 index)

Parameters
meta metadata context
index index into the user string heap.
Return value
an in-memory pointer to the index in the user string heap (US).
mono_metadata_decode_blob_size
Syntax
guint32 mono_metadata_decode_blob_size (const char *xptr, const char **rptr)

Parameters
ptr pointer to a blob object
rptr the new position of the pointer
Return value
the size of the blob object
Description

This decodes a compressed size as described by 24.2.4 (US and Blob a blob or user string object)

Metadata Tables

Metadata is encoded in a number of tables included on every CIL image. These tables contain type definitions, member definitions and so on, these constants are defined in the ECMA 335 specification Partition II section 22. The following table shows the C constants defined in the Mono runtime and how they map to the equivalent ECMA CLI metadata table:

ECMA CLI Table Name C Constant Name Table Schema (Array Size + Columns Constants)
AssemblyMONO_TABLE_ASSEMBLY Array size: MONO_ASSEMBLY_SIZE
  • MONO_ASSEMBLY_HASH_ALG
  • MONO_ASSEMBLY_MAJOR_VERSION
  • MONO_ASSEMBLY_MINOR_VERSION
  • MONO_ASSEMBLY_BUILD_NUMBER
  • MONO_ASSEMBLY_REV_NUMBER
  • MONO_ASSEMBLY_FLAGS
  • MONO_ASSEMBLY_PUBLIC_KEY
  • MONO_ASSEMBLY_NAME
  • MONO_ASSEMBLY_CULTURE
AssemblyOSMONO_TABLE_ASSEMBLYOS Array size: MONO_ASSEMBLYOS_SIZE
  • MONO_ASSEMBLYOS_PLATFORM
  • MONO_ASSEMBLYOS_MAJOR_VERSION
  • MONO_ASSEMBLYOS_MINOR_VERSION
AssemblyProcessorMONO_TABLE_ASSEMBLYPROCESSORArray size: MONO_ASSEMBLYPROCESSOR_SIZE
  • MONO_ASSEMBLY_PROCESSOR
AssemblyRefMONO_TABLE_ASSEMBLYREF Array size: MONO_ASSEMBLYREF_SIZE
  • MONO_ASSEMBLYREF_MAJOR_VERSION
  • MONO_ASSEMBLYREF_MINOR_VERSION
  • MONO_ASSEMBLYREF_BUILD_NUMBER
  • MONO_ASSEMBLYREF_REV_NUMBER
  • MONO_ASSEMBLYREF_FLAGS
  • MONO_ASSEMBLYREF_PUBLIC_KEY
  • MONO_ASSEMBLYREF_NAME
  • MONO_ASSEMBLYREF_CULTURE
  • MONO_ASSEMBLYREF_HASH_VALUE
AssemblyRefProcessorMONO_TABLE_ASSEMBLYREFPROCESSORArray size: MONO_ASSEMBLYREFPROC_SIZE
  • MONO_ASSEMBLYREFPROC_PROCESSOR
  • MONO_ASSEMBLYREFPROC_ASSEMBLYREF
AssemblyRefOSMONO_TABLE_ASSEMBLYREFOS Array size:
  • MONO_ASSEMBLYREFOS_SIZE
    • MONO_ASSEMBLYREFOS_PLATFORM
    • MONO_ASSEMBLYREFOS_MAJOR_VERSION
    • MONO_ASSEMBLYREFOS_MINOR_VERSION
    • MONO_ASSEMBLYREFOS_ASSEMBLYREF
    		• ClassLayoutMONO_TABLE_CLASSLAYOUT Array size: MONO_CLASSLAYOUT_SIZE
    • MONO_CLASS_LAYOUT_PACKING_SIZE
    • MONO_CLASS_LAYOUT_CLASS_SIZE
    • MONO_CLASS_LAYOUT_PARENT
    		ConstantMONO_TABLE_CONSTANT Array size: MONO_CONSTANT_SIZE
    • MONO_CONSTANT_TYPE
    • MONO_CONSTANT_PADDING
    • MONO_CONSTANT_PARENT
    • MONO_CONSTANT_VALUE
    		CustomAttributeMONO_TABLE_CUSTOMATTRIBUTE Array size: MONO_CUSTOM_ATTR_SIZE
    • MONO_CUSTOM_ATTR_PARENT
    • MONO_CUSTOM_ATTR_TYPE
    • MONO_CUSTOM_ATTR_VALUE
    		DeclSecurityMONO_TABLE_DECLSECURITY Array size: MONO_DECL_SECURITY_SIZE
    • MONO_DECL_SECURITY_ACTION
    • MONO_DECL_SECURITY_PARENT
    • MONO_DECL_SECURITY_PERMISSIONSET
    		EventMapMONO_TABLE_EVENTMAP Array size: MONO_EVENT_MAP_SIZE
    • MONO_EVENT_MAP_PARENT
    • MONO_EVENT_MAP_EVENTLIST
    		EventPtrMONO_TABLE_EVENT_POINTER Array size: MONO_EVENT_POINTER_SIZE
    • MONO_EVENT_POINTER_EVENT
    		EventMONO_TABLE_EVENT Array size: MONO_EVENT_SIZE
    • MONO_EVENT_FLAGS
    • MONO_EVENT_NAME
    • MONO_EVENT_TYPE
    		ExportedTypeMONO_TABLE_EXPORTEDTYPE Array size: MONO_EXPORTEDTYPE_SIZE
    • MONO_EXP_TYPE_FLAGS
    • MONO_EXP_TYPE_TYPEDEF
    • MONO_EXP_TYPE_NAME
    • MONO_EXP_TYPE_NAMESPACE
    • MONO_EXP_TYPE_IMPLEMENTATION
    		FieldMONO_TABLE_FIELD Array size: MONO_FIELD_SIZE
    • MONO_FIELD_FLAGS
    • MONO_FIELD_NAME
    • MONO_FIELD_SIGNATURE
    		FieldLayouttMONO_TABLE_FIELDLAYOUT Array size: MONO_FIELDLAYOUT_SIZE
    • MONO_FIELD_LAYOUT_OFFSET
    • MONO_FIELD_LAYOUT_FIELD
    		FieldMarshalMONO_TABLE_FIELDMARSHAL Array size: MONO_FIELD_MARSHAL_SIZE
    • MONO_FIELD_MARSHAL_PARENT
    • MONO_FIELD_MARSHAL_NATIVE_TYPE
    		FieldPtrMONO_TABLE_FIELD_POINTER Array size: MONO_FIELD_POINTER_SIZE
    • MONO_FIELD_POINTER_FIELD
    		FieldRVAMONO_TABLE_FIELDRVA Array size: MONO_FIELDRVA_SIZE
    • MONO_FIELD_RVA_RVA
    • MONO_FIELD_RVA_FIELD
    		FileMONO_TABLE_FILE Array size: MONO_FILE_SIZE
    • MONO_FILE_FLAGS
    • MONO_FILE_NAME
    • MONO_FILE_HASH_VALUE
    		GenericParamMONO_TABLE_GENERICPARAM Array size: MONO_GENERICPARAM_SIZE
    • MONO_GENERICPARAM_NUMBER
    • MONO_GENERICPARAM_FLAGS
    • MONO_GENERICPARAM_OWNER
    • MONO_GENERICPARAM_NAME
    		GenericParamConstraintMONO_TABLE_GENERICPARAMCONSTRAINTArray size: MONO_GENERICPARAMCONSTRAINT_SIZE
    • MONO_GENPARCONSTRAINT_GENERICPAR
    • MONO_GENPARCONSTRAINT_CONSTRAINT
    ImplMapMONO_TABLE_IMPLMAP Array size: MONO_IMPLMAP_SIZE
    • MONO_IMPLMAP_FLAGS
    • MONO_IMPLMAP_MEMBER
    • MONO_IMPLMAP_NAME
    • MONO_IMPLMAP_SCOPE
    InterfaceImplMONO_TABLE_INTERFACEIMPL Array size:
  • MONO_INTERFACEIMPL_SIZE
    • MONO_INTERFACEIMPL_CLASS
    • MONO_INTERFACEIMPL_INTERFACE
    		• ManifestResourceMONO_TABLE_MANIFESTRESOURCEArray size: MONO_MANIFESTRESOURCE_SIZE
    • MONO_MANIFEST_OFFSET
    • MONO_MANIFEST_FLAGS
    • MONO_MANIFEST_NAME
    • MONO_MANIFEST_IMPLEMENTATION
    MemberRefMONO_TABLE_MEMBERREF Array size: MONO_MEMBERREF_SIZE
    • MONO_MEMBERREF_CLASS
    • MONO_MEMBERREF_NAME
    • MONO_MEMBERREF_SIGNATURE
    MethodImplMONO_TABLE_METHODIMPL Array size: MONO_METHODIMPL_SIZE
    • MONO_METHODIMPL_CLASS
    • MONO_METHODIMPL_BODY
    • MONO_METHODIMPL_DECLARATION
    		MethodSpecMONO_TABLE_METHODSPEC Array size: MONO_METHODSPEC_SIZE
    • MONO_METHODSPEC_METHOD
    • MONO_METHODSPEC_SIGNATURE
    MethodSemanticsMONO_TABLE_METHODSEMANTICSArray size: MONO_METHOD_SEMA_SIZE
    • MONO_METHOD_SEMA_SEMANTICS
    • MONO_METHOD_SEMA_METHOD
    • MONO_METHOD_SEMA_ASSOCIATION
    ModulerefMONO_TABLE_MODULEREF Array size: MONO_MODULEREF_SIZE
    • MONO_MODULEREF_NAME
    ModuleMONO_TABLE_MODULE Array size: MONO_MODULE_SIZE
    Columns:
    • MONO_MODULE_GENERATION
    • MONO_MODULE_NAME
    • MONO_MODULE_MVID
    • MONO_MODULE_ENC
    • MONO_MODULE_ENCBASE
    TypeRefMONO_TABLE_TYPEREF Array size: MONO_TYPEREF_SIZE
    • MONO_TYPEREF_SCOPE
    • MONO_TYPEREF_NAME
    • MONO_TYPEREF_NAMESPACE
    MethodPtrMONO_TABLE_METHOD_POINTER Array size: MONO_METHOD_POINTER_SIZE
    • MONO_METHOD_POINTER_METHOD
    MethodMONO_TABLE_METHOD Array size: MONO_METHOD_SIZE
    • MONO_METHOD_RVA
    • MONO_METHOD_IMPLFLAGS
    • MONO_METHOD_FLAGS
    • MONO_METHOD_NAME
    • MONO_METHOD_SIGNATURE
    • MONO_METHOD_PARAMLIST
    NestedClassMONO_TABLE_NESTEDCLASS Array size: MONO_NESTEDCLASS_SIZE
    • MONO_NESTED_CLASS_NESTED
    • MONO_NESTED_CLASS_ENCLOSING
    ParamPtrMONO_TABLE_PARAM_POINTER Array size: MONO_PARAM_POINTER_SIZE
    • MONO_PARAM_POINTER_PARAM
    ParamMONO_TABLE_PARAM Array size: MONO_PARAM_SIZE
    • MONO_PARAM_FLAGS
    • MONO_PARAM_SEQUENCE
    • MONO_PARAM_NAME
    		PropertyMapMONO_TABLE_PROPERTYMAP Array size: MONO_PROPERTY_MAP_SIZE
    • MONO_PROPERTY_MAP_PARENT
    • MONO_PROPERTY_MAP_PROPERTY_LIST
    		PropertyPtrMONO_TABLE_PROPERTY_POINTERArray size: MONO_PROPERTY_POINTER_SIZE
    • MONO_PROPERTY_POINTER_PROPERTY
    		PropertyMONO_TABLE_PROPERTY Array size: MONO_PROPERTY_SIZE
    • MONO_PROPERTY_FLAGS
    • MONO_PROPERTY_NAME
    • MONO_PROPERTY_TYPE
    StandaloneSigMONO_TABLE_STANDALONESIG Array size:
  • MONO_STAND_ALONE_SIGNATURE_SIZE
    • MONO_STAND_ALONE_SIGNATURE
    • TypeDefMONO_TABLE_TYPEDEF Array size: MONO_TYPEDEF_SIZE
    • MONO_TYPEDEF_FLAGS
    • MONO_TYPEDEF_NAME
    • MONO_TYPEDEF_NAMESPACE
    • MONO_TYPEDEF_EXTENDS
    • MONO_TYPEDEF_FIELD_LIST
    • MONO_TYPEDEF_METHOD_LIST
    TypeSpecMONO_TABLE_TYPESPEC Array size: MONO_TYPESPEC_SIZE
    • MONO_TYPESPEC_SIGNATURE

    Each table can contain zero or more rows, you must call the mono_metadata_table_rows to obtain the number of rows in a table, and then you can extract individual row values by using the mono_metadata_decode_row or the mono_metadata_decode_row_col. When decoding rows you must provide an guint32 array large enough to hold as many columns as the table contains.

    The metadata tables are stored in the MonoImage, you obtain a pointer to the MonoTableInfo by calling the mono_image_get_table_info and then you can scan those tables, for example: 

    	/*
	 * Dumps a few fields from the AssemblyRef table
	 */
	void DumpAssemblyRefs (MonoImage *image)
	{
		/* Get a pointer to the AssemblyRef metadata table */
		MonoTableInfo *t = mono_image_get_table_info (image, MONO_TABLE_ASSEMBLYREF);

		/* Fetch the number of rows available in the table */
		int rows = mono_table_info_get_rows (t);
		int i;

		/* For each row, print some of its values */
		for (i = 0; i < rows; i++){
			/* Space where we extract one row from the metadata table */
			guint32 cols [MONO_ASSEMBLYREF_SIZE];

			/* Extract the row into the array cols */
			mono_metadata_decode_row (t, i, cols, MONO_ASSEMBLYREF_SIZE);

			fprintf (output, "%d: Version=%d.%d.%d.%d\n\tName=%s\n", i + 1,
                        	cols [MONO_ASSEMBLYREF_MAJOR_VERSION],
                        	cols [MONO_ASSEMBLYREF_MINOR_VERSION],
                        	cols [MONO_ASSEMBLYREF_BUILD_NUMBER],
                        	cols [MONO_ASSEMBLYREF_REV_NUMBER],
                        	mono_metadata_string_heap (image, cols [MONO_ASSEMBLYREF_NAME]));
		}
	}

    The above program shows the following output when ran on the C# compiler: 

    	1: Version=1.0.5000.0
		Name=mscorlib
	2: Version=1.0.5000.0
		Name=System
	3: Version=1.0.5000.0
		Name=System.Xml

    Metadata Tables API

    These are the APIs for dealing with tables:

    mono_image_get_table_info
    Syntax
    const MonoTableInfo* mono_image_get_table_info (MonoImage *image, int table_id)

    mono_image_get_table_rows
    Syntax
    int mono_image_get_table_rows (MonoImage *image, int table_id)

    mono_metadata_decode_row_col
    Syntax
    guint32 mono_metadata_decode_row_col (const MonoTableInfo *t, int idx, guint col)

    Parameters
    t table to extract information from.
    idx index for row in table.
    col column in the row.
    Description

    This function returns the value of column col from the idx row in the table t .

    mono_metadata_decode_row
    Syntax
    void mono_metadata_decode_row (const MonoTableInfo *t, int idx, guint32 *res, int res_size)

    Parameters
    t table to extract information from.
    idx index in table.
    res array of res_size cols to store the results in
    Description

    This decompresses the metadata element idx in table t into the guint32 res array that has res_size elements

    mono_metadata_compute_size
    Syntax
    int mono_metadata_compute_size (MonoImage *meta, int tableindex, guint32 *result_bitfield)

    Parameters
    meta metadata context
    tableindex metadata table number
    result_bitfield pointer to guint32 where to store additional info
    Description

    mono_metadata_compute_size computes the length in bytes of a single row in a metadata table. The size of each column is encoded in the result_bitfield return value along with the number of columns in the table. the resulting bitfield should be handed to the mono_metadata_table_size and mono_metadata_table_count macros. This is a Mono runtime internal only function.

    mono_metadata_custom_attrs_from_index
    Syntax
    guint32 mono_metadata_custom_attrs_from_index (MonoImage *meta, guint32 index)

    Parameters
    meta metadata context
    index token representing the parent
    returns the 1-based index into the CustomAttribute table of the first
    Description
    attribute which belongs to the metadata object described by index. Returns 0 if no such attribute is found.
    mono_metadata_decode_signed_value
    Syntax
    gint32 mono_metadata_decode_signed_value (const char *ptr, const char **rptr)

    Parameters
    ptr pointer to decode from
    rptr the new position of the pointer
    Return value
    the decoded value
    Description

    This routine decompresses 32-bit signed values (not specified in the spec)

    mono_metadata_decode_value
    Syntax
    guint32 mono_metadata_decode_value (const char *_ptr, const char **rptr)

    Parameters
    ptr pointer to decode from
    rptr the new position of the pointer
    Return value
    the decoded value
    Description

    This routine decompresses 32-bit values as specified in the "Blob and Signature" section (23.2)

    mono_metadata_encode_value
    Syntax
    mono_metadata_encode_value

    Metadata access API

    This is the low-level API for accessing the metadata images.

    mono_pe_file_open
    Syntax
    MonoImage* mono_pe_file_open (const char *fname, MonoImageOpenStatus *status)

    Parameters
    fname filename that points to the module we want to open
    status An error condition is returned in this field
    Return value
    An open image of type MonoImage or NULL on error. if NULL, then check the value of status for details on the error. This variant for mono_image_open DOES NOT SET UP CLI METADATA. It's just a PE file loader, used for FileVersionInfo. It also does not use the image cache.
    mono_metadata_events_from_typedef
    Syntax
    guint32 mono_metadata_events_from_typedef (MonoImage *meta, guint32 index, guint *end_idx)

    Parameters
    meta metadata context
    index 0-based index (in the TypeDef table) describing a type
    Return value
    the 0-based index in the Event table for the events in the type. The last event that belongs to the type (plus 1) is stored in the end_idx pointer.
    mono_metadata_decode_table_row
    Syntax
    void mono_metadata_decode_table_row (MonoImage *image, int table, int idx, guint32 *res, int res_size)

    Description

    Same as mono_metadata_decode_row, but takes an image + table ID pair, and takes uncompressed metadata into account, so it should be used to access the Method, Field, Param and Event tables when the access is made from metadata, i.e. idx is retrieved from a metadata table, like MONO_TYPEDEF_FIELD_LIST.

    mono_metadata_decode_table_row_col
    Syntax
    guint32 mono_metadata_decode_table_row_col (MonoImage *image, int table, int idx, guint col)

    Description

    Same as mono_metadata_decode_row_col, but takes an image + table ID pair, and takes uncompressed metadata into account, so it should be used to access the Method, Field, Param and Event tables.

    mono_metadata_field_info
    Syntax
    void mono_metadata_field_info (MonoImage *meta, guint32 index, guint32 *offset, guint32 *rva, MonoMarshalSpec **marshal_spec)

    Parameters
    meta the Image the field is defined in
    index the index in the field table representing the field
    offset a pointer to an integer where to store the offset that may have been specified for the field in a FieldLayout table
    rva a pointer to the RVA of the field data in the image that may have been defined in a FieldRVA table
    marshal_spec a pointer to the marshal spec that may have been defined for the field in a FieldMarshal table.
    Description

    Gather info for field index that may have been defined in the FieldLayout, FieldRVA and FieldMarshal tables. Either of offset, rva and marshal_spec can be NULL if you're not interested in the data.

    mono_metadata_free_array
    Syntax
    void mono_metadata_free_array (MonoArrayType *array)

    Parameters
    array array description
    Description

    Frees the array description returned from mono_metadata_parse_array.

    mono_metadata_free_marshal_spec
    Syntax
    void mono_metadata_free_marshal_spec (MonoMarshalSpec *spec)

    mono_metadata_free_mh
    Syntax
    void mono_metadata_free_mh (MonoMethodHeader *mh)

    Parameters
    mh a method header
    Description

    Free the memory allocated for the method header.

    mono_metadata_free_type
    Syntax
    void mono_metadata_free_type (MonoType *type)

    Parameters
    type type to free
    Description

    Free the memory allocated for type type which is allocated on the heap.

    mono_metadata_get_constant_index
    Syntax
    guint32 mono_metadata_get_constant_index (MonoImage *meta, guint32 token, guint32 hint)

    Parameters
    meta the Image the field is defined in
    index the token that may have a row defined in the constants table
    hint possible position for the row
    Return value
    the index into the Constants table or 0 if not found.
    Description

    token must be a FieldDef, ParamDef or PropertyDef token.

    mono_metadata_get_marshal_info
    Syntax
    const char* mono_metadata_get_marshal_info (MonoImage *meta, guint32 idx, gboolean is_field)

    mono_metadata_implmap_from_method
    Syntax
    guint32 mono_metadata_implmap_from_method (MonoImage *meta, guint32 method_idx)

    mono_metadata_interfaces_from_typedef
    Syntax
    MonoClass* mono_metadata_interfaces_from_typedef (MonoImage *meta, guint32 index, guint *count)

    Parameters
    meta metadata context
    index typedef token
    count Out parameter used to store the number of interfaces
    Return value
    the interface array on success, NULL on failure.
    Description

    The array of interfaces that the index typedef token implements is returned in interfaces. The number of elements in the array is returned in count. The returned array is allocated with g_malloc and the caller must free it.

    LOCKING: Acquires the loader lock .

    mono_metadata_locate
    Syntax
    const char * mono_metadata_locate (MonoImage *meta, int table, int idx)

    Parameters
    meta metadata context
    table table code.
    idx index of element to retrieve from table.
    Return value
    a pointer to the idx element in the metadata table whose code is table.
    Description

    mono_metadata_locate_token
    Syntax
    const char * mono_metadata_locate_token (MonoImage *meta, guint32 token)

    Parameters
    meta metadata context
    token metadata token
    Return value
    a pointer to the data in the metadata represented by the token token .
    Description

    mono_metadata_methods_from_event
    Syntax
    guint32 mono_metadata_methods_from_event (MonoImage *meta, guint32 index, guint *end_idx)

    Parameters
    meta metadata context
    index 0-based index (in the Event table) describing a event
    Return value
    the 0-based index in the MethodDef table for the methods in the event. The last method that belongs to the event (plus 1) is stored in the end_idx pointer.
    mono_metadata_methods_from_property
    Syntax
    guint32 mono_metadata_methods_from_property (MonoImage *meta, guint32 index, guint *end_idx)

    Parameters
    meta metadata context
    index 0-based index (in the PropertyDef table) describing a property
    Return value
    the 0-based index in the MethodDef table for the methods in the property. The last method that belongs to the property (plus 1) is stored in the end_idx pointer.
    mono_metadata_nested_in_typedef
    Syntax
    guint32 mono_metadata_nested_in_typedef (MonoImage *meta, guint32 index)

    Parameters
    meta metadata context
    index typedef token
    Return value
    the 1-based index into the TypeDef table of the type where the type described by index is nested. Returns 0 if index describes a non-nested type.
    mono_metadata_nesting_typedef
    Syntax
    guint32 mono_metadata_nesting_typedef (MonoImage *meta, guint32 index, guint32 start_index)

    Parameters
    meta metadata context
    index typedef token
    Return value
    the 1-based index into the TypeDef table of the first type that is nested inside the type described by index. The search starts at start_index. Returns 0 if no such type is found.
    mono_metadata_packing_from_typedef
    Syntax
    guint32 mono_metadata_packing_from_typedef (MonoImage *meta, guint32 index, guint32 *packing, guint32 *size)

    Parameters
    meta metadata context
    index token representing a type
    Return value
    the info stored in the ClassLayout table for the given typedef token into the packing and size pointers. Returns 0 if the info is not found.
    mono_metadata_properties_from_typedef
    Syntax
    guint32 mono_metadata_properties_from_typedef (MonoImage *meta, guint32 index, guint *end_idx)

    Parameters
    meta metadata context
    index 0-based index (in the TypeDef table) describing a type
    Return value
    the 0-based index in the Property table for the properties in the type. The last property that belongs to the type (plus 1) is stored in the end_idx pointer.
    mono_metadata_token_from_dor
    Syntax
    guint32 mono_metadata_token_from_dor (guint32 dor_index)

    Parameters
    dor_token A TypeDefOrRef coded index
    Return value
    an expanded token
    Description

    dor_token is a TypeDefOrRef coded index: it contains either a TypeDef, TypeRef or TypeSpec in the lower bits, and the upper bits contain an index into the table.

    mono_metadata_translate_token_index
    Syntax
    guint32 mono_metadata_translate_token_index (MonoImage *image, int table, guint32 idx)

    Description
    Translates the given 1-based index into the Method, Field, Event, or Param tables using the *Ptr tables in uncompressed metadata, if they are available.

    FIXME: The caller is not forced to call this function, which is error-prone, since forgetting to call it would only show up as a bug on uncompressed metadata.

    mono_metadata_typedef_from_field
    Syntax
    guint32 mono_metadata_typedef_from_field (MonoImage *meta, guint32 index)

    Parameters
    meta metadata context
    index FieldDef token
    Return value
    the 1-based index into the TypeDef table of the type that declared the field described by index, or 0 if not found.
    Description

    mono_metadata_typedef_from_method
    Syntax
    guint32 mono_metadata_typedef_from_method (MonoImage *meta, guint32 index)

    Parameters
    meta metadata context
    index MethodDef token
    Return value
    the 1-based index into the TypeDef table of the type that declared the method described by index. 0 if not found.
    mono_metadata_type_equal
    Syntax
    gboolean mono_metadata_type_equal (MonoType *t1, MonoType *t2)

    mono_metadata_type_hash
    Syntax
    guint mono_metadata_type_hash (MonoType *t1)

    Parameters
    t1 a type
    Description
    Computes a hash value for t1 to be used in GHashTable. The returned hash is guaranteed to be the same across executions.
    mono_metadata_declsec_from_index
    Syntax
    guint32 mono_metadata_declsec_from_index (MonoImage *meta, guint32 index)

    Parameters
    meta metadata context
    index token representing the parent
    Return value
    the 0-based index into the DeclarativeSecurity table of the first attribute which belongs to the metadata object described by index. Returns -1 if no such attribute is found.
    mono_metadata_free_method_signature
    Syntax
    void mono_metadata_free_method_signature (MonoMethodSignature *sig)

    Parameters
    sig signature to destroy
    Description

    Free the memory allocated in the signature sig. This method needs to be robust and work also on partially-built signatures, so it does extra checks.

    Retrieving Objects from Tokens

    mono_metadata_parse_array
    Syntax
    MonoArrayType* mono_metadata_parse_array (MonoImage *m, const char *ptr, const char **rptr)

    mono_metadata_parse_custom_mod
    Syntax
    int mono_metadata_parse_custom_mod (MonoImage *m, MonoCustomMod *dest, const char *ptr, const char **rptr)

    Parameters
    m a metadata context.
    dest storage where the info about the custom modifier is stored (may be NULL)
    ptr a pointer to (possibly) the start of a custom modifier list
    rptr pointer updated to match the end of the decoded stream
    Return value
    TRUE if a custom modifier was found, FALSE if not.
    Description

    Checks if ptr points to a type custom modifier compressed representation.

    mono_metadata_parse_field_type
    Syntax
    MonoType* mono_metadata_parse_field_type (MonoImage *m, short field_flags, const char *ptr, const char **rptr)

    Parameters
    m metadata context to extract information from
    ptr pointer to the field signature
    rptr pointer updated to match the end of the decoded stream
    Return value
    The MonoType that was extracted from ptr .
    Description

    Parses the field signature, and returns the type information for it.

    mono_metadata_parse_marshal_spec
    Syntax
    MonoMarshalSpec* mono_metadata_parse_marshal_spec (MonoImage *image, const char *ptr)

    mono_metadata_parse_method_signature
    Syntax
    MonoMethodSignature* mono_metadata_parse_method_signature (MonoImage *m, int def, const char *ptr, const char **rptr)

    Parameters
    m metadata context
    def the MethodDef index or 0 for Ref signatures.
    ptr pointer to the signature metadata representation
    rptr pointer updated to match the end of the decoded stream
    Return value
    a MonoMethodSignature describing the signature.
    Description

    Decode a method signature stored at ptr. This is a Mono runtime internal function.

    LOCKING: Assumes the loader lock is held.

    mono_metadata_parse_mh
    Syntax
    MonoMethodHeader* mono_metadata_parse_mh (MonoImage *m, const char *ptr)

    Parameters
    generic_context generics context
    ptr pointer to the method header.
    Return value
    a transient MonoMethodHeader allocated from the heap.
    Description

    Decode the method header at ptr, including pointer to the IL code, info about local variables and optional exception tables.

    mono_metadata_parse_param
    Syntax
    MonoType* mono_metadata_parse_param (MonoImage *m, const char *ptr, const char **rptr)

    Parameters
    m metadata context to extract information from
    ptr pointer to the param signature
    rptr pointer updated to match the end of the decoded stream
    Return value
    The MonoType that was extracted from ptr .
    Description

    Parses the param signature, and returns the type information for it.

    mono_metadata_parse_signature
    Syntax
    MonoMethodSignature* mono_metadata_parse_signature (MonoImage *image, guint32 token)

    Parameters
    image metadata context
    token metadata token
    Return value
    a MonoMethodSignature describing the signature.
    Description

    Decode a method signature stored in the StandAloneSig table

    mono_metadata_parse_typedef_or_ref
    Syntax
    guint32 mono_metadata_parse_typedef_or_ref (MonoImage *m, const char *ptr, const char **rptr)

    Parameters
    m a metadata context.
    ptr a pointer to an encoded TypedefOrRef in m
    rptr pointer updated to match the end of the decoded stream
    Return value
    a token valid in the m metadata decoded from the compressed representation.
    mono_metadata_parse_type
    Syntax
    static MonoType* mono_metadata_parse_type_internal (MonoImage *m, MonoGenericContainer *container, short opt_attrs, gboolean transient, const char *ptr, const char **rptr, MonoError *error)

    Parameters
    m metadata context
    mode kind of type that may be found at ptr
    opt_attrs optional attributes to store in the returned type
    ptr pointer to the type representation
    rptr pointer updated to match the end of the decoded stream
    transient whenever to allocate the result from the heap or from a mempool
    Return value
    a MonoType structure representing the decoded type.
    Description

    Decode a compressed type description found at ptr in m . mode can be one of MONO_PARSE_MOD_TYPE, MONO_PARSE_PARAM, MONO_PARSE_RET, MONO_PARSE_FIELD, MONO_PARSE_LOCAL, MONO_PARSE_TYPE. This function can be used to decode type descriptions in method signatures, field signatures, locals signatures etc.

    To parse a generic type, generic_container points to the current class'es (the generic_container field in the MonoClass) or the current generic method's (stored in image->property_hash) generic container. When we encounter a MONO_TYPE_VAR or MONO_TYPE_MVAR, it's looked up in this MonoGenericContainer.

    LOCKING: Acquires the loader lock.

    Generics Support

    mono_metadata_generic_class_is_valuetype
    Syntax
    gboolean mono_metadata_generic_class_is_valuetype (MonoGenericClass *gclass)

    Tokens

    mono_ldtoken
    Syntax
    gpointer mono_ldtoken (MonoImage *image, guint32 token, MonoClass **handle_class, MonoGenericContext *context)

    mono_ldstr
    Syntax
    MonoString* mono_ldstr (MonoDomain *domain, MonoImage *image, guint32 idx)

    Parameters
    domain the domain where the string will be used.
    image a metadata context
    idx index into the user string table.
    Return value
    a loaded string from the image / idx combination.
    Description
    Implementation for the ldstr opcode.
    mono_exception_from_token
    Syntax
    MonoException* mono_exception_from_token (MonoImage *image, guint32 token)

    Parameters
    image the Mono image where to look for the class
    token The type token of the class
    Return value
    the initialized exception instance.
    Description

    Creates an exception of the type given by token.

    OpCodes

    mono_opcode_name
    Syntax
    const char* mono_opcode_name (int opcode)