• Module Streams
• Line Data (C13)
• Module Symbols
• Global Refs

Each module may have its own Module Stream. Modules are not required to have a Module Stream; a "stripped" (public) PDB is a PDB whose module streams have been removed. Different modules do not share a Module Stream; it is a 1:1 relationship (or 1:none).

The DBI Modules Substream describes the modules within an executable. For each module there is a ModuleInfo record which specifies the stream index of the Module Stream and the size of the substreams within the Module Stream. The ModuleInfo record is necessary to locate the Module Stream and its substreams.

Each Module Stream has this structure:

struct ModuleStream {
    uint8_t symbols[sym_byte_size];
    uint8_t c11_lines[c11_byte_size];
    uint8_t c13_lines[c13_byte_size];
    uint8_t global_refs[];
};

where sym_byte_size, c11_byte_size, and c13_byte_size are taken from ModuleInfo record.

Line Data (C13)

Module Streams may contain line number information, which describes the mapping between source locations and instruction streams.

c11_lines contains C11 Line Data. C11 Line Data is obsolete and will not be described in this document. c11_byte_size is expected to be zero in all modern PDBs.

c13_lines contains C13 Line Data. See C13 Line Data for the specification of the contents of this substream.

Module Symbols

sym_byte_size specifies the length of the symbols substream for this module. The symbols stream has a uint32_t (4-byte) prefix, followed by symbols records.

Global Refs

global_refs contains the locations of global symbols that are relevant to this module. Global Refs is an extension, and was added in such a way that older tools could safely ignore it. It is legal for global_refs to have a length of zero, meaning this Module Stream does not contain Global Refs.

If Global Refs is present, then it has this structure:

struct GlobalRefs {
    uint32_t size;                     // size in bytes of the global refs table
    uint32_t global_refs[size / 4];
};

Each value in global_refs is a byte offset into the Global Symbol Stream. Each entry identifies a global symbol that is relevant to this module.