i. Introduction

The TDF diagnostic information is intended to convey all that information, used by current source level debuggers, which would conventionally be part of an object file. Any particular installer will only use those parts of this information which its native object format can represent.

The version of the diagnostics described here is the first version. It has only been tested with TDF produced from C programs. There are known to be certain deficiencies relative to other languages (in particular to FORTRAN). A later version will correct these deficiencies. The changes already envisaged are detailed in §3, and would have minimal (if any) impact on C producers.

The diagnostic system introduces one new type of TDF linkable entities, and currently adds two new units to the bitstream representation of TDF.

Much of the actual annotation of procedure bodies is currently done by reserved TOKENs, which installers recognize specially. These TOKENs are described in §2.

There is a resemblance between the TDF diagnostic information and Unix International's DWARF format. DWARF has similar aims to the TDF diagnostics, and ensuring that complete DWARF information could be generated provided a useful check during the development of the TDF diagnostics. However the TDF diagnostics are intended to be architecture (and format) neutral. No inference should be made about any link (present or future) between DWARF and TDF diagnostics.