CREST is a concolic test generation tool for C.
Thanks for downloading and trying out CREST.
You can get the latest version of CREST, as well as news and announcements at CREST's homepage: https://burn.im/crest .
If you want to cite CREST, please refer to the (short) paper: Burnim, Sen, "Heuristics for Dynamic Test Generation", Proceedings of the 23rd IEEE/ACM International Conference on Automated Software Engineering (ASE), 2008.
You can find a list of papers using CREST at https://burn.im/crest/#publications .
NOTE: CREST is no longer being actively developed, but questions are still answered on the CREST-users mailing list -- firstname.lastname@example.org and https://groups.google.com/forum/#!forum/crest-users .
Preparing a Program for CREST
To use CREST on a C program, use functions CREST_int, CREST_char, etc., declared in "crest.h", to generate symbolic inputs for your program. For examples, see the programs in test/.
For simple, single-file programs, you can use the build script "bin/crestc" to instrument and compile your test program.
CREST can be used to instrument multi-file programs, too -- instructions may be added later. In the meantime, you can take a look at an example, instrumented form of grep-2.2, available at https://github.com/jburnim/crest/tree/master/benchmarks/grep-2.2 . For further information, please see this post on the CREST-users mailing list.
CREST is run on an instrumented program as:
bin/run_crest PROGRAM NUM_ITERATIONS -STRATEGY
Possibly strategies include: dfs, cfg, random, uniform_random, random_input. Some strategies take optional parameters.
Example commands to test the "test/uniform_test.c" program:
cd test ../bin/crestc uniform_test.c ../bin/run_crest ./uniform_test 10 -dfs
This should produce output roughly like:
... [GARBAGE] ... Read 8 branches. Read 13 nodes. Wrote 6 branch edges. Iteration 0 (0s): covered 0 branches [0 reach funs, 0 reach branches]. Iteration 1 (0s): covered 1 branches [1 reach funs, 8 reach branches]. Iteration 2 (0s): covered 3 branches [1 reach funs, 8 reach branches]. Iteration 3 (0s): covered 5 branches [1 reach funs, 8 reach branches]. Iteration 4 (0s): covered 7 branches [1 reach funs, 8 reach branches]. GOAL! Iteration 5 (0s): covered 8 branches [1 reach funs, 8 reach branches].
NOTE: run_crest and crestc currently leave a lot of files lying around, some of which are temporary and some of which must be kept. In particular, "cfg_branches" and "branches" are output by the instrumentation process and are needed to run run_crest, and run_crest produces "coverage", a list of the ID's of all covered branches.
CREST depends on Yices 1, an SMT solver tool and library available at http://yices.csl.sri.com/old/download-yices1.shtml. To build and run CREST, you must download and install Yices version 1 and change YICES_DIR in src/Makefile to point to Yices location.
CREST uses CIL to instrument C programs for testing. A modified distribution of CIL is included in directory cil/. To build CIL, simply run "configure" and "make" in the cil/ directory.
Finally, CREST can be built by running "make" in the src/ directory.
CREST is distributed under the revised BSD license. See LICENSE for details.
This distribution includes a modified version of CIL, a tool for parsing, analyzing, and transforming C programs. CIL is written by George Necula, Scott McPeak, Wes Weimer, Ben Liblit, and Matt Harren. It is also distributed under the revised BSD license. See cil/LICENSE for details.