Wei Ming, Beijing Shenzhou Aerospace Software Technology Co., Ltd., China

There are many critical systems containing complex software for which the implementation language of choice is C in many cases (DO 178 actually suggest Ada or C). Some current software-controlled embedded aerospace systems need to be qualified to DO 178C Level A or Level B.

At this level it is recommended that developer use certificated compilers. But due to business considerations, cost, and other factors, aerospace software development in China currently only use closed source/proprietary compilers, which are no longer being maintained.

We do not have access to the tools development process specification respectively the developer TOR, but we can do extensive tools testing according to DO330 section 6.14: "The objectives of tool testing are to execute the Tool Executable Object Code". While testing generally can not proof freedom from faults it is acknowledged that compilers can not be proven correct (IEC 61508-7 Ed2 C 4.4) states: "It is also known, presently, that no method exists to prove the correctness for all tool or translator parts." Thus systematic testing as well as "field-data" is an essential part of translator tools qualification.

This paper description different testing methods applicable to closed source COTS tool to provide acceptable assurance of compiler correctness for a well-defined and limited language/feature subset allowing to mitigate the risks posed by the use of a legacy compiler.