Merge pull request #6284 from TGWDB/FEATURES.md

Add FEATURE_IDEAS.md

Author: TGWDB

MINI-PROJECTS.md renamed to FEATURE_IDEAS.md

@@ -1,3 +1,97 @@
+This file contains various features and project ideas for CBMC. Below
+this are the larger feature ideas. Smaller mini project ideas are
+further down.
+
+# CBMC Feature and Project Ideas
+
+The following are features that would be good to add to CBMC. They are
+listed here to gather information on them and also as a starting point
+for contributors who are interested in undertaking a more comprehensive
+project.
+
+## Refinement-Based Slicing
+
+**Task**: Implement refinement-based slicing to improve the slicing
+of CBMC.
+
+**Background**:
+Some patches have been considered for this, but there is not yet
+evidence of performance improvement. See
+https://github.com/diffblue/cbmc/issues/28
+
+## Refinement-based reduction of partial order constraints
+
+**Task**: Implement refinement-based reduction of partial order
+constraints.
+
+**Background**:
+Some patches have been considered for this, but there needs to also be
+work on the performance. See
+https://github.com/diffblue/cbmc/issues/29
+
+
+## Advanced goto-diff
+
+**Task**: Improve the goto-diff utility to have both syntactic and
+semantic diff options for goto programs.
+
+**Background**: The current `goto-diff` program performs only syntatic
+diff of goto programs. Extensions to also consider semantic differences
+would be desirable. It would be nice to include:
+* deltacheck's change impact analysis
+* cemc equivalence checker
+
+See also https://github.com/diffblue/cbmc/issues/40
+
+## Function Summaries
+
+**Task**: Create function summaries that simplify analysis. The main
+goals of the function summaries are:
+* context insensitivity (there is one summary applicable in any
+context the function is called from)
+* transitive closure (effects of all callees are captured in summaries
+of the root caller function)
+* generalised interface (suitable for many different concrete
+summary-computing algorithms)
+* language independent (should work for Java, C, C++, ...)
+
+This also has links to other projects (albeit some may be out of date
+at this stage):
+* test_gen (our summaries should fit to needs of this tests generation
+task)
+* 2ls (their summaries should also be expressible in our summaries)
+* path-symex (summaries must also be usable for path-based symbolic
+execution)
+
+There are also complexities related to over/under-approximation
+for the function summaries. For more details see
+https://github.com/diffblue/cbmc/issues/218
+
+
+## --cover array
+
+**Task**: Extend the `--cover` option to add coverage goals for each
+possible entry of fixed size arrays. For more details see
+https://github.com/diffblue/cbmc/issues/265
+
+
+## Connecting Producers and Consumers of Knowledge about Termination
+
+There is very limited knowledge about loop termination conditions
+and this could be improved. For example, the slicing could be
+improved with knoweldge regarding loop termination so that
+irrelevant loops can be more effectively sliced. Similarly, in
+goto-analyze assertions can only be false if reachable, adding
+termination can give crude reachability analysis.
+
+The overall approach could be to have for each loop and/or
+function information: `TERMINATE`, `NON_TERMINATE`, or
+`UNKNOWN_TERMINATION`.
+
+Further details on possible implementations and discussion
+can be found here
+https://github.com/diffblue/cbmc/issues/618
+
 # CBMC Mini Project Ideas
 
 The following projects are short, focussed features that give new CBMC