Dafny 3.11.0

New features

• Go to definition now works reliably across all Dafny language constructs and across files. (#2734)

• Improve performance of Go code by using native byte/char arrays (#2818)

• Introduce the experimental measure-complexity command, whose output can be fed to the Dafny report generator. In a future update, we expect to merge the functionality of the report generator into this command. (#3061)

• Integrate the Dafny auditor plugin as a built-in dafny audit command. (#3175)

• Add the --solver-path option to allow customizing the SMT solver used when using the new Dafny CLI user interface. (#3184)

• Add the experimental --test-assumptions option to all execution commands: run, build, translate and test.
  When turned on, inserts runtime tests at locations where (implicit) assumptions occur, such as when calling or being called by external code and when using assume statements.
  Functionality is still being expanded. Currently only checks contracts on every call to a function or method marked with the {:extern} attribute.
  (#3185)

• For the command translate, renamed the option --target into language and turned it into a mandatory argument. (#3239)

• Havoc assignments now count as assignments for definite-assignment checks. (#3311)

• Unless --enforce-determinism is used, no errors are given for arrays that are allocated without being initialized.
  (#3311)

• Enable passing a percentage value to the --cores option, to use a percentage of the total number of logical cores on the machine for verification. (#3357)

• dafny build for Java now creates a library or executable jar file.

  • If there is a Main method, the jar is an executable jar. So a simple A.dfy can be built as dafny build -t:java A.dfy
    and then run as java -jar A.jar
  • If there is no Main entry point, all the generated class files are assembled into a library jar file that can be used on a
    classpath as a java library.
  • In both cases, the DafnyRuntime library is included in the generated jar.
  • In old and new CLIs, the default location and name of the jar file is the name of the first dfy file, with the extension changed
  • In old and new CLIs, the path and name of the output jar file can be given by the --output option, with .jar added if necessary
  • As before, the compilation artifacts (.java and .class files) are placed in a directory whose name is the same as the jar file
    but without the .jar extension and with '-java' appended
  • With the new CLI, the generated .java artifacts are deleted unless --spill-translation=true and the .class files are deleted in any case;
    both kinds of files are retained with the legacy CLI for backwards compatibility.
  • If any other jar files are needed to compile the dafny/java program, they must be on the CLASSPATH;
    the same CLASSPATH used to compile the program is needed to run the program

  Having a library or executable jar simplifies the user's task in figuring out how to use the built artifacts.
  (#3355)

Bug fixes

• Nonexistent files passed on the CLI now result in a graceful exit (#2719)

• Check loop invariants on entry, even when such are the only proof obligations in a method. (#3244)

• The :options attribute now accepts new style options --function-syntax and --quantifier-syntax (#3252)

• Improved error messages for dafny translate (#3274)

• The :test attribute is now compatible with dafny run and dafny build (#3275)

• Settings --cores=0 will cause Dafny to use half of the available cores. (#3276)

• Removed an infeasible assertion in the Dafny Runtime for Java (#3280)

• Language server displays more relevant information on hovering assertions (#3281)

• Any (==) inferred for a type parameter of an iterator is now also inferred for the corresponding non-null iterator type. (#3284)

• The otherwise ambiguous program fragment export least predicate is parsed such that least (or greatest) is the export identifier (#3291)

• The parser no longer generates bad tokens when invoked through /library (#3301)

• Match expressions no longer incorrectly convert between newtypes and their basetype (#3333)

• Warn that 'new' cannot be used in expressions, instead of throwing a parse error (#3366)

• The attributes :dllimport and :handle are now deprecated. They were undocumented, untested, and not maintained. (#3399)

• Fixed an axiom related to sequence comprehension extraction (#3411)