Source Code to Object Code Traceability Study

Approval of aviation software to the guidance of DO-178B/ED-12B and DO-178C/ED-12C [DO178C] requires an applicant to assess the correspondence between source code and object code in certain circumstances. In particular, for Level A software, source code to object code traceability must be established (see paragraph of DO-178C/ED-12C). When the compiler generates object code that is not directly traceable to the source code, additional verifications must be performed. As proposed in the position paper CAST-12 [CAST12], an acceptable approach is to identify that untraceable compiler-generated object code and verify it. This document analyzes the code generated by the GNAT Pro High-Integrity Edition 7.4.3 compiler hosted on Windows and targeting PowerPC e500v2 ELF identified by the string (issued when using the --version switch): powerpc-eabispe-gcc (GCC) 4.9.4 20151030 (for GNAT Pro 7.4.3 20161026)

Release 1.0 Document ID: TEC.PB04-045, Issue 1.0 December 16, 2016