Common PE Types and Enumerations

#Philosophy The PE File format is expressed in terms of a number of common types. In code these are generally realized as an enumeration, typedef or type alias of some sort to help ensure both clarity of code and correctness of use. This additional clarity and type safety is preferred over use of raw primitive types directly as they convey no real meaning beyond their basic ranges making correct use of the code less obvious and more error prone.

##Table Index Many PE data structures store an index into a particular table index as a field. This table defines the type names used to store the index and which table it is an index into.

Name	underlying type	Description
StringTableIndex	unsigned 16 bit integer	Index into the string table (see: StringTables) for more details)
TypeDefTableIndex	unsigned 16 bit integer	Index into the type definition table
TypeRefTableIndex	unsigned 16 bit integer	Index into the type reference table
FieldDefTableIndex	unsigned 16 bit integer	Index into the field definition table
MethodDefTableIndex	unsigned 16 bit integer	Index into the method definition table
SigTableIndex	unsigned 16 bit integer	Index into the signature table (see: SignatureBlobs for more details)

##EmptyIndex Constant Since an index values are used to access members of a table and since (in C, C++, and many other languages) tables are indexed with the first element as index == 0 the value 0 is not useable as a constant to indicate "none" or "null". Thus a dedicated value is used for NETMF metadata tables. Any index with the value 0xFFFF is considered the EmptyIndex and this is normally defined as a manifest constant for the entire code base to test against.

##TableKind The TableKind enumeration identifies a specific table in the assembly metadata.

Name	Value	Description
AssemblyRef	0x0000	Assembly reference table
TypeRef	0x0001	Type Reference Table
FieldRef	0x0002	Field Reference table
MethodRef	0x0003	Method Reference Table
TypeDef	0x0004	Type Definition Table
FieldDef	0x0005	Field Definition Table
MethodDef	0x0006	Method Definition Table
Attributes	0x0007	Attribute Table
TypeSpec	0x0008	Type Specification Table
Resources	0x0009	Resources Table
ResourcesData	0x000A	Resource Data Blob Table
Strings	0x000B	String Blob table
Signatures	0x000C	Signature Blob table
ByteCode	0x000D	IL Byte Code Stream Blob Table
ResourcesFiles	0x000E	Resource Files Table
EndOfAssembly	0x000F	End of Assembly Table (Used to quickly find the end of the assembly when scanning assemblies)
Max	0x0010	End of enumeration valid enumeration values must be less than this value

##Miscellaneous Types

Name	underlying type	Description
MetadataOffset	unsigned 16 bit integer	Offset from the start of the IL instruction stream blob data
MetadataPtr	pointer to a const byte	Pointer to the interior of the IL instruction stream blob data

##Tokens Many instructions in IL and fields of data structures contain a token. Tokens in IL Metadata reference some other piece of metadata in the assembly. Tokens contain the table the token refers to along with an index into the table into a single primitive integral value. In NETMF PE files there are two kinds of tokens MetadataToken and a more compact BinaryToken.

###MetadataToken A metadata token is an unsigned 32 bit value where the Most significant byte is the table kind and the least significant 16 bits are the table index (In NETMF PE format a table index is 16bits only thus there are 8 bits of unused data in a MetadataToken)

###BinaryToken A Binary Token is a compact form of representing an index to one of two possible tables. Binary tokens are 16 but unsigned integers where the most significant bit is used to determine which of two possible tables the remaining 15 bits provide the index for. The following table provides the type name aliases for the various combinations of tables used in NETMF PE metadata.

Name	MSB==1 Table	MSB==0 Table
TypeRefOrAssemblyRef	TypeRef	AssemblyRef
TypeRefOrTypeDef	TypeRef	TypeDef
MethodRefOrMethodDef	MethodRef	MethodDef
FieldRefOrFieldDef	FieldRef	FieldDef

##VersionInfo Many NETMF PE data structures include a version. The versions, when presented for readability are typically represented as a quad of 4 integer values separated by a '.' (i.e. 1.2.3.4) the following table defines the Version info structure used in the PE file to represent a version.

Name	Type	Description
Major	unsigned 16 bit integer	Major component of the common version quad
Minor	unsigned 16 bit integer	Minor component of the common version quad
Build	unsigned 16 bit integer	Build component of the common version quad
Revision	unsigned 16 bit integer	Revision component of the common version quad