Introduction

nML Exception Analyzer (EA) analyzes a given nML program and estimates may-uncaught exceptions for each function in the program.

• Batch analyzer (nea)
  • Inputs are nML files and outputs are analysis results.
    eg. % nea file.n
  • In case of incremental analysis, two options should be provided. For nML type checker, every included directory should be mentioned by ``-I <dir>''. And for nML EA, all the previously analyzed file names should be listed by ``-F <file>''. The order of previously analyzed file names does not matter.
    eg. % nea -I kb -F kb/kb1.n kb/kb2.n
  • Options
    

    -I <dir>	Add <dir> to the list of include directories searched for
    	typechecked file ( .nty).
    -F <file>	Add <file> to the list of files searched for pre-analyzed
    	ea file ( .nea).
    -d	Print debugging information.
    -p	Print absyn.
    -t	Print time profile information.

• Toplevel analyzer (neatop)
  Input to the toplevel can span several lines. It terminates by ;; (a double-semicolon).
  

  eg.	% neatop
  	nML Exception Analyzer, Version 0.9, 08/06/2001, Sukyoung Ryu [ROPAS/KAIST]
  	#

• Analysis results
  For each function of the program, nML EA reports a set of pairs <exn, loc> of an exception exn and its birth (construction, not declaration) place loc. For example,
  • emitPar (type/e2m.n:862.14-121)
    <NotImplemented, type/e2m.n:58.40-54>
    tells that function emitPar defined at ``type/e2m.n:862.14-121'' may have an uncaught exception NotImplemented, which is constructed at ``type/e2m.n: 58.40-54.''
  • /unnamed ftn/ (type/e2m.n:962.21-40)
    
    tells that the unnamed function at ``type/e2m.n:962.21-40'' has no uncaught exception.
  • /emitBlock _ / (type/e2m.n:857.18-258)
    <NotSafe, type/e2m.n:58.40-54>
    tells that curried function emitBlock (of type t -> t' -> t''), given one argument, returns a function which may have an uncaught exception NotSafe when it is called.
  • /handler ftn/ (ppc/ppcEm2Ppc.n:3.9-112)
    
    tells that handler function at ``ppc/ppcEm2Ppc.n:3.9-112'' has no uncaught exception. Handler function is the match expression in handle expression: e handle match. If handler's match is not exhaustive, then the analysis says that the handler function (match) has uncaught exceptions.

There are two restrictions to use nML EA: (1) nML compiler 0.91 (n/nml-0.91) and nML Control Flow Analyzer (CFA) should be installed to use nML EA, and (2) every file should be type-checked.