* std::cout debugging statements
* comment out std::cout debugging as this is now a shared fork
* convert std::cout to TRACE statements for seq_rewriter and seq_regex
* add cases to min_length and max_length for regexes
* bug fix
* update min_length and max_length functions for REs
* initial pass on simplifying derivative normal forms by eliminating redundant predicates locally
* add seq_regex_brief trace statements
* working on debugging ref count issue
* fix ref count bug and convert trace statements to seq_regex_brief
* add compact tracing for cache hits/misses
* seq_regex fix cache hit/miss tracing and wrapper around is_nullable
* minor
* label and disable more experimental changes for testing
* minor documentation / tracing
* a few more @EXP annotations
* dead state elimination skeleton code
* progress on dead state elimination
* more progress on dead state elimination
* refactor dead state class to separate self-contained state_graph class
* finish factoring state_graph to only work with unsigned values, and implement separate functionality for expr* logic
* implement get_all_derivatives, add debug tracing
* trace statements for debugging is_nullable loop bug
* fix is_nullable loop bug
* comment out local nullable change and mark experimental
* pretty printing for state_graph
* rewrite state graph to remove the fragile assumption that all edges from a state are added at a time
* start of general cycle detection check + fix some comments
* implement full cycle detection procedure
* normalize derivative conditions to form 'ele <= a'
* order derivative conditions by character code
* fix confusing names m_to and m_from
* assign increasing state IDs from 1 instead of using get_id on AST node
* remove elim_condition call in get_dall_derivatives
* use u_map instead of uint_map to avoid memory leak
* remove unnecessary call to is_ground
* debugging
* small improvements to seq_regex_brief tracing
* fix bug on evil2 example
* save work
* new propagate code
* work in progress on using same seq sort for deriv calls
* avoid re-computing derivatives: use same head var for every derivative call
* use min_length on regexes to prune search
* simple implementation of can_be_in_cycle using rank function idea
* add a disabled experimental change
* minor cleanup comments, etc.
* seq_rewriter cleanup for PR
* typo noticed by Nikolaj
* move state graph to util/state_graph
* re-add accidentally removed line
* clean up seq_regex code removing obsolete functions and comments
* a few more cleanup items
* remove experimental functionality for integration
* fix compilation
* remove some tracing and TODOs
* remove old comment
* update copyright dates to 2020
* feedback from Nikolaj
* use [] for map access
* make state_graph methods constant
* avoid recursion in mark_dead_recursive and mark_live_recursive
* a possible bug fix in propagate_nonempty
* write down list of invariants in state_graph
* implement partial invariant check and insert CASSERT statements
* expand on invariant check and tracing
* finish state graph invariant check
* minor tweaks
* regex propagation: convert first two axioms to propagations
* remove obsolete regex solver functionality
Co-authored-by: calebstanford-msr <t-casta@microsoft.com>
* partial work on adding 'reverse' (broken code)
* new op codes for derivative and reverse + associated rewrite rules
* incorporate reverses and derivatives in rewriter + some fixes
* enable rewriting str.in_re constraints with right derivative
* z3str3: remove legacy fixed-length overlap testing
parameter smt.str.fixed_length_overlap_models has been deprecated
* z3str3: remove legacy length/value testing algorithm and binary search heuristic
the following parameters are deprecated:
smt.str.use_binary_search
smt.str.binary_search_start
smt.str.fixed_length_models (the fixed-length model construction is now always used)
* z3str3: remove legacy regex unroll methods
* z3str3: remove unused methods and member variables
