      CIVL: The Concurrency Intermediate Verification Language
                               v1.22

------------------------------ Overview -------------------------------

CIVL is a framework encompassing... 

 * a programming language, CIVL-C, which adds to C a number of
   concurrency primitives, as well as the ability to define
   functions in any scope.  Together, these features make for
   a very expressive concurrent language that can faithfully
   represent programs using various APIs and parallel languages,
   such as MPI, OpenMP, Pthread, CUDA, and Chapel. CIVL-C also 
   provides a number of primitives supporting verification.
 * a model checker which uses symbolic execution to verify a
   number of safety properties of CIVL-C programs.   The model
   checker can also be used to verify that two CIVL-C programs
   are functionally equivalent.
 * a number of translators from various commonly-used languages
   and APIs to CIVL-C. (This part is still a work in progress.)

CIVL is developed by the Verified Software Laboratory at the
University of Delaware Department of Computer Science.
For more information, visit http://vsl.cis.udel.edu/civl

Active Developers:
Stephen F. Siegel
Wenhao Wu
Alexander Wilton

Inactive Developers:
John Edenhofner
Andre Marianiello
Michael Rogers
Timothy K. Zirkel
Manchun Zheng
Yihao Yan
Matthew B. Dwyer
Mitchell Gerrard
Ziqing Luo

------------------------------- License -------------------------------

CIVL is open source software distributed under the GNU
General Public License.  However, the libraries used by CIVL
(and incorporated into the complete distribution) use various
licenses.  See directory licenses for the license of each component.

-------------------------- Updates from v1.21 -------------------------

-- 1. Upgraded to Java 17
-- 2. Overhauled repository structure by moving ABC, SARL, and GMC
      repositories into this one.
-- 3. Core language changes
     3.1 Only the first statement in an $atomic block is allowed to block.
     3.2 $yield can be used to release the lock of the atomic block
     3.3 Removed $atom
-- 4. Total overhaul to OpenMP transformations. Now includes a robust data
      race detection feature as described in CAV 2023 paper 'Model Checking
      Race-freedom When “Sequential Consistency for Data-race-free Programs”
      is Guaranteed'
-- 5. A large number of bug fixes and small improvements.

-------------------------- Updates from v1.20 -------------------------
-- 1. refine the Fortran extension for paper submitted to TACAS 2022
     1.1 Complete Fortran Array Descriptor for tracking changes made on 
         index ranges by array section and reshape operations. 
         Any declared array type is transformed into a Fortran array 
         descriptor by Fortran to CIVL-C AST transformer.
     1.2 Introduce four basic CIVL verification primitives Fortran bindings
       1.2.1 Type qualifiers:
         - !$CVL $input:  indicates that all variables declared immediately
                          in the next line are symbolic and read-only.
         - !$CVL $output: indicates that all variables declared immediately
                          in the next line are write-only and used for 
                          verifying functional output equivalence.
         A type declaration statement is required to be used immediately 
         after any CIVL type qualifier and variables qualified shall follow
         read/write constraints mentioned above.
         CIVL assumption primitives can be used for limiting the value range 
         of variables qualified by '!$CVL $input'.
         e.g., 
         !$CVL $input
         integer :: n, a(n) 
         !! both 'n' and elements of 'a' are symbolic and read-only
         !$CVL $output
         integer :: sum
         !! sum is write-only and can be used for comparing with another
         !! program, which also has 'sum' with a same type and qualified 
         !! by '!$CVL $output'
         
       1.2.2 Verification
         - !$CVL $assume(logic_expr); 
             Make CIVL only explores paths, whose path conditions shall 
             make 'logic_expr' to be true.
             Set the value range for varialbes qualified by '!$CVL $input'
         - !$CVL $assert(logic_expr); 
             Checks predicates representing specific correctness properties 
             that users expect to verify.
             If any CIVL assertion primitive is evaluated as false, then 
             CIVL shall report an assertion violation. 
     1.3 Add supports for additional Fortran features include:
       1.3.1 'inout' and 'out' attributes declared by 'intent' statement
       1.3.2 compound types with fields having scalar types.
       1.3.3 pointer types to scalar types.
       1.3.4 logic expression evaluation without short-circuits
       1.3.5 line truncation for fixed and free forms 
       1.3.6 other features are shown here:
             https://vsl.cis.udel.edu/trac/civl/wiki/FortranTransformations
     1.4 Add test cases imported from SMACK verification suite 
             https://github.com/soarlab/gandalv/
   2. CUDA Support Improvement
     2.1 Fixed CUDA bug in which CUDA kernel declarations were not being 
         transformed properly
     2.2 Fixed source info bug (completeSources wasn’t being called 
         everywhere that it should)
     2.3 Fixed short circuit bug described in ticket #943
     2.4 Added small optimization to short circuit transformer to allow 
         for finer granularity of its transformation
   3. Other Improvement and Fixed Bugs
     3.1 MPI_Comm types can be compared by equality operator ('==').
     3.2 Java-Doc improvements


-------------------------- Updates from v1.19 -------------------------
-- 1. added new language primitives:
     1.1 $local_start() and $local_end()
       An execution of the statements in between of this pair, including this pair themselves,
       is NOT ONLY uninterruptable BUT ALSO purely local to the view of the verifier.
     1.2 $read_set_push() and $read_set_pop() (the correspondence for write set has already been supported)
       This pair of primitives can be used to turn on/off the capturing of read set during execution.
-- 2. added Fortran support for translating basic Fortran features into CIVL-AST
  (see: https://vsl.cis.udel.edu/trac/civl/wiki/FortranTransformations)
-- 3. added simple Fortran verification examples (edited)

   
------------------------- Binary Installation -------------------------

For most users, this will be the easiest way to install and
use CIVL.  Developers should instead follow the instructions for
"Source Installation" below.

1. Install at least one of the theorem provers below.
The more provers you install, the more precise CIVL analysis will
be.  Note that CIVL only requires the binary executable
version of each prover; you can ignore the libraries, various
API bindings, etc.   You just need to ensure that
each binary executable is in your PATH when you run
"civl config".   The currently supported provers are:
     
   - CVC4,  http://cvc4.cs.nyu.edu/downloads/
   
   - Z3, http://z3.codeplex.com/SourceControl/latest

2. Install a Java 17 SDK if you have not already.  Go to

  http://www.oracle.com/technetwork/java/javase/downloads/

for the latest from Oracle.  On linux, you can instead use
the package manager:

  sudo apt install openjdk-17-jdk

3. Download the CIVL distribution from http://vsl.cis.udel.edu/civl.

4. Unzip and untar the CIVL distribution file if this
does not happen automatically.  This should result in a
folder named CIVL-TAG, where TAG is some version ID string.
This folder contains the following:

 - README   : this file
 - bin      : containing one executable sh script called "civl"
 - lib      : containing civl-TAG.jar
 - doc      : containing the manual and the tutorial of CIVL
 - emacs    : CIVL-C emacs mode and its installation instructions
 - licenses : licenses for CIVL and included libraries
 - examples : some example CIVL programs

5.  You can move the CIVL folder wherever you want.
The JAR file in the lib directory is all you need to run CIVL.
You may also move this jar file wherever you want.   You 
run CIVL by typing a command that begins
"java -jar /path/to/civl-TAG.jar ...".  For convenience
you may instead use the shell script "civl" in bin,
which allows you to replace "java -jar /path/to/civl-TAG.jar"
with just "civl" on the command line.   Simply edit the civl script
to reflect the path to civl-TAG.jar and place the script 
somewhere in your PATH.   Alternatively, you can just define
an alias in your .profile, .bash_profile, or equivalent, such as

alias civl='java -jar /path/to/civl-TAG.jar'

In the following, we will assume that you have defined
a command "civl" in one these ways.

6. Type "civl config".  This should report that it found
the theorem provers you installed (and are in your PATH).
It should create a file called ".sarl" in your home directory
which you can also edit by hand.


------------------------- Source Installation -------------------------

Instructions found here:
https://vsl.cis.udel.edu/trac/civl/wiki/Be%20a%20CIVL%20developer
   
