Issue: OPTIMIZE-DEBUG-INFO References: CLtL p. 160 Category: ADDITION Edit History: V1 9 Sep 1988, David Gray (initial version) V2 19 Sep 1988, David Gray (delete first alternative) Status: Proposal NEW-QUALITY passede Oct 88 Problem Description: The OPTIMIZE declaration provides a way to tell the compiler how important various qualities are in order to guide which optimizations are done. There is another quality, however, that is not mentioned, but is an important consideration for the compiler: how much information should be included in the object code to facilitate debugging. This includes both annotation added to enable a debugger to display more information to the user, and also suppression of optimizations that would confuse debugging by making it harder to connect the object code with the source code. Proposal OPTIMIZE-DEBUG-INFO:NEW-QUALITY: In the description of the OPTIMIZE declaration, add an additional quality named DEBUG, described as "ease of debugging". Rationale: Since ease of debugging is an issue that the user will be concerned with, and is an issue that the compiler needs to consider, this provides a clear way for the user to control the amount of debugging information placed in the object module, with DEBUG=0 meaning none and DEBUG=3 meaning "as much as possible". Current Practice: No current implementation of this is known. Cost to implementors: All would have to update their handling of OPTIMIZE declarations to accept the new quality. Cost to users: One more little feature to learn. Some problems may result from the addition of the symbol DEBUG to the LISP package. Benefits: Provides users a standard way to control the interaction between the compiler and debugger, and saves implementors from having to invent implementation-dependent solutions. Costs of Non-Adoption: Continued confusion about how debug information should be controlled. Discussion: Concern has been raised that there is already a problem with the non-orthogonality of SPEED, SAFETY, and SPACE that would be made even worse with DEBUG added, since users tend to be perplexed by the interactions of these qualities.