Portable PDB file format: debug tables

The eight tables

The tables use the same row format as the .NET metadata tables: columns one after another, little-endian, heap indexes of 2 or 4 bytes (by HeapSizes), table indexes of 2 or 4 bytes. A column that names a table of the assembly (MethodDef) takes its width from the row count in the #Pdb stream, because the PDB has no such table. The row counts of MethodDebugInformation normally equal the assembly’s MethodDef count: row n belongs to method n.

Table	Column	Size	Holds
0x30 Document	Name	#Blob	The document path: a separator character, then the parts as indexes into the #Blob heap.
	HashAlgorithm	#GUID	Which hash the Hash column holds (SHA-1, SHA-256 or MD5, each a well-known GUID), or none.
	Hash	#Blob	The hash of the source file.
	Language	#GUID	The language (C#, VB, F# have their own GUIDs).
0x31 MethodDebugInformation	Document	index	The document if the method has a single one, else 0.
0x31 MethodDebugInformation	SequencePoints	#Blob	The sequence points: IL offset deltas, line and column deltas, hidden points.
0x32 LocalScope	Method	index	The MethodDef the scope is in.
	ImportScope	index	The imports in effect.
	VariableList	index	The first LocalVariable of the scope.
	ConstantList	index	The first LocalConstant.
	StartOffset	4	The IL offset where the scope starts.
	Length	4	Its length in IL bytes.
0x33 LocalVariable	Attributes	2	0x1 DebuggerHidden.
	Index	2	The slot in the method’s local signature.
	Name	#Strings	The variable name.
0x34 LocalConstant	Name	#Strings	The constant’s name.
0x34 LocalConstant	Signature	#Blob	Its type and value.
0x35 ImportScope	Parent	index	The enclosing ImportScope, or 0.
0x35 ImportScope	Imports	#Blob	The imported namespaces, aliases and types.
0x36 StateMachineMethod	MoveNextMethod	index	The compiler-generated `MoveNext` of an async or iterator state machine.
0x36 StateMachineMethod	KickoffMethod	index	The method the programmer wrote, which starts the state machine.
0x37 CustomDebugInformation	Parent	coded	HasCustomDebugInformation: any row of the assembly’s tables or of the debug tables.
	Kind	#GUID	Which kind of information: SourceLink, embedded source, state machine hoisted locals, and others, each a GUID.
	Value	#Blob	The data.

Not described

Known, not yet covered

Reference: the encoding of the Name, SequencePoints, Imports and Value blobs and the GUIDs of the well-known kinds, hash algorithms and languages.
Viewer: those columns show as a byte count and the first bytes; the tables themselves are read and compared with Microsoft’s reader row by row.

.PDB File Format – Debug tables

The eight tables

Not described

Known, not yet covered

Links

Reference