Path: news.cs.au.dk!not-for-mail
From: Ole Lehrmann Madsen <olm@cs.au.dk>
Newsgroups: comp.lang.beta
Subject: Re: Sif crashes on this
Date: 14 Dec 1998 22:36:25 -0000
Organization: University of Aarhus, Department of Computer Science (DAIMI)
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Message-ID: <19981214223625.1880.qmail@noatun.mjolner.dk>
Reply-To: Ole Lehrmann Madsen <olm@cs.au.dk>
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Xref: news.cs.au.dk comp.lang.beta:11752

You have encountered an error in the BETA compiler.

Patterns like

	fun: (# exit 666 #)

are optimized as constants by the compiler. When used
as pattern variables as in your program, the compiler
gets confused.

You may get around the problem by making fun a non-constant
pattern as in

	fun: (# dummy: @integer exit 666 #)

	f2: (# dummy: @integer exit 2 #)

Note that f1 is a pattern with (666,2) as an exit value

This is not very nice, but should work. We will eventually
correct the error.

Don't hesitate to ask further questions or contacting us.

Sincerely

Ole Lehrmann Madsen

PS. I did not try the example with Sif, but the error should
    be Sif specific.
	
> I'm trying to figure out the BETA equivalent of calling a function through a pointer. I 
> don't have the BETA book yet, and the tutorials don't seem to address the question. 
> While playing around I discovered that attempting to compile:
> 
> ORIGIN '~beta/basiclib/v1.6/betaenv';
> -- program: Descriptor --
> (#
>    fun: (#  exit 666 #);
>    fptr: ##fun;
>    f1: fun (#  exit 1 #);
>    f2: (#  exit 2 #)
> do f1##->fptr##
> #)  
> 
> ..as the body of a new program crashes Sif with the following message:
> 
> <SIF>
> 
> Sif - Mjolner Browser and Editor version 5.2(0) nti
>       integrated with BETA Compiler version 5.3(4)
> Calling BETA compiler
> -------------------------------------------------------------------------------
> No qua-check warnings and .lst file
> Target machine type nti(ms)
> Building dependency graph for: 'k:\beta\start\fptr\fptr' ...
> Translating fragments ...
> Bind fragments in: 'k:\beta\start\fptr\fptr'Code generation
> DescRef is null! Fatal error
> f1
> 
> </SIF>
> 
> I compiled from the command line, and the compiler crashed as well. Here's the resulting 
> beta.dump file:
> 
> <DUMPFILE>
> 
> Beta execution aborted: Reference is none.
> 
> Call chain: (nti)
> 
>   item <putText#>putText# in ~beta/betaast/v5.2/private/indeximpl
>     -- outputStream#output# in ~beta/betaast/v5.2/private/indeximpl
>   item <*> in ~beta/pretty/v5.2/private/token
>     -- Output# in ~beta/pretty/v5.2/private/token
>   item <Output#> in ~beta/pretty/v5.2/private/token
>     -- Token# in ~beta/pretty/v5.2/private/token
>   item <PRINTER-~> in ~beta/pretty/v5.2/private/printer
>     -- Viewer# in ~beta/pretty/v5.2/astviewer
>   item <Advanceleft#> in ~beta/pretty/v5.2/private/scanner
>     -- SCANNER-~ in ~beta/pretty/v5.2/private/scanner
>   item <finish#> in ~beta/pretty/v5.2/private/scanner
>     -- SCANNER-~ in ~beta/pretty/v5.2/private/scanner
>   item <UNPARSER-~> in ~beta/pretty/v5.2/private/unparser
>     -- Viewer# in ~beta/pretty/v5.2/astviewer
>   item <DOPRESENT-~> in ~beta/pretty/v5.2/private/ppimpl
>     -- present# in ~beta/pretty/v5.2/astviewer
>   item <present#> in ~beta/pretty/v5.2/astviewer
>     -- Viewer# in ~beta/pretty/v5.2/astviewer
>   item <PRETTYPRINTERBODY-~> in ~beta/betaast/v5.2/private/indeximpl
>     -- prettyPrinter# in ~beta/betaast/v5.2/index
>   item <prettyPrinter#> in ~beta/betaast/v5.2/index
>     -- *astInterface# in ~beta/compiler/control/systembody
>   item <thePP#> in ~beta/compiler/control/systembody
>     -- compiler# in ~beta/compiler/control/system
>   item <Descrip#> in ~beta/compiler/checker/semattbody
>     -- SEMATT-~ in ~beta/compiler/checker/sematt
>   item strucRef#<StrucRef#> in ~beta/compiler/checker/sematt
>     -- *EvCase# in ~beta/compiler/synthesizer/evbody
>   item <EVCASE-~> in ~beta/compiler/checker/semattbody
>     -- *EvCase# in ~beta/compiler/synthesizer/evbody
>   item *<EvCase#> in ~beta/compiler/checker/sematt
>     -- SEMATT-~ in ~beta/compiler/checker/sematt
>   item <EXPEVAL-~> in ~beta/compiler/synthesizer/evbody
>     -- ExpEval# in ~beta/compiler/synthesizer/synthlib
>   item <ExpEval#> in ~beta/compiler/synthesizer/synthlib
>     -- EvalHandler# in ~beta/compiler/synthesizer/synthlib
>   item <assign#>binEv# in ~beta/compiler/synthesizer/evbody
>     -- *EvCase# in ~beta/compiler/synthesizer/evbody
>   item <EVCASE-~> in ~beta/compiler/checker/semattbody
>     -- *EvCase# in ~beta/compiler/synthesizer/evbody
>   item *<EvCase#> in ~beta/compiler/checker/sematt
>     -- SEMATT-~ in ~beta/compiler/checker/sematt
>   item <EVALBODY-~> in ~beta/compiler/synthesizer/evbody
>     -- GenEval# in ~beta/compiler/synthesizer/synthlib
>   item <GenEval#> in ~beta/compiler/synthesizer/synthlib
>     -- EvalHandler# in ~beta/compiler/synthesizer/synthlib
>   item <*> in ~beta/compiler/synthesizer/dobody
>     -- *scanList# in ~beta/compiler/synthesizer/dobody
>   item <*>scanList# in ~beta/compiler/synthesizer/dobody
>     -- Scan# in ~beta/compiler/synthesizer/dobody
>   item <Scan#> in ~beta/compiler/synthesizer/dobody
>     -- * in ~beta/compiler/synthesizer/dobody
>   item <*> in ~beta/compiler/synthesizer/dobody
>     -- GenDo# in ~beta/compiler/synthesizer/genlib
>   item <GenDo#> in ~beta/compiler/synthesizer/dobody
>     -- theGen# in ~beta/compiler/synthesizer/synthesizer
>   item <GenObj#> in ~beta/compiler/synthesizer/genlib
>     -- theGen# in ~beta/compiler/synthesizer/synthesizer
>   item <GENDESCBODY-~> in ~beta/compiler/synthesizer/gdbody
>     -- GenDesc# in ~beta/compiler/synthesizer/synthesizer
>   item <GenDesc#> in ~beta/compiler/synthesizer/synthesizer
>     -- theGen# in ~beta/compiler/synthesizer/synthesizer
>   item <body#> in ~beta/compiler/synthesizer/synthesizer
>     -- SYNTHESIZER-~ in ~beta/compiler/synthesizer/synthesizer
>   item <SYNTHESIZER-~> in ~beta/compiler/synthesizer/synthesizer
>     -- Synthesizer# in ~beta/compiler/control/system
>   item <Synthesizer#> in ~beta/compiler/control/system
>     -- compiler# in ~beta/compiler/control/system
>   item <DoTheCodeGen#> in ~beta/compiler/control/translate_controlbody
>     -- xcontroller#ScanNonCompiled#scanner# in ~beta/compiler/control/translate
>   item <*> in ~beta/compiler/control/translate_controlbody
>     -- Translate#translate# in ~beta/compiler/control/translate
>   item <Translate#>translate# in ~beta/compiler/control/translate_controlbody
>     -- xcontroller#ScanNonCompiled#scanner# in ~beta/compiler/control/translate
>   item <translate#>Translate# in ~beta/dependency/v1.3/private/scannoncompiledbody
>     -- *controller# in ~beta/dependency/v1.3/private/scannoncompiledbody
>   item <*>ScanAndClear# in ~beta/dependency/v1.3/private/controlbody
>     -- TransList#SimpleList# in ~beta/dependency/v1.3/private/dependencybody
>   item <CONTROLLERPRIVATE-~> in ~beta/dependency/v1.3/private/controlbody
>     -- *controller# in ~beta/dependency/v1.3/private/scannoncompiledbody
>   item *<controller#> in ~beta/dependency/v1.3/private/dependencybody
>     -- xcontroller#ScanNonCompiled#scanner# in ~beta/compiler/control/translate
>   item xcontroller#<ScanNonCompiled#>scanner# in 
> ~beta/dependency/v1.3/private/scannoncompiledbody
>     -- depGraph#DependencyGraph# in ~beta/compiler/control/translate
>   item <TRANSLATEDOBODY-~> in ~beta/compiler/control/translatebody
>     -- TRANSLATE-~ in ~beta/compiler/control/translate
>   item <TRANSLATE-~> in ~beta/compiler/control/translate
>     -- compiler# in ~beta/compiler/control/system
>   item <SYSTEMTRANSLATEBODY-~> in ~beta/compiler/control/systembody
>     -- *translate# in ~beta/compiler/control/interactive
>   item *<translate#> in ~beta/compiler/control/system
>     -- compiler# in ~beta/compiler/control/system
>   item <activateCompiler#> in ~beta/compiler/control/interactive
>     -- interactiveCompiler# in ~beta/compiler/control/interactive
>   item <interactiveCompiler#> in ~beta/compiler/control/interactive
>     -- PROGRAM-~SystemEnv#SysHead# in ~beta/compiler/beta
>   comp <PROGRAM-~>SystemEnv#SysHead# in ~beta/compiler/beta
>     -- BETAENV-~ in ~beta/basiclib/v1.6/betaenv
> 
> 
>   item <attNext#>realValue# in ~beta/basiclib/v1.6/private/basicsystemenvbody
>     -- BASICSYSTEMENVPRIVATE-~ in ~beta/basiclib/v1.6/private/basicsystemenvbody
>   item <*>cycle# in ~beta/basiclib/v1.6/private/systemenv_ntbody
>     -- BASICSCHEDULER-~ in ~beta/basiclib/v1.6/private/systemenv_ntbody
>   comp <BASICSCHEDULER-~> in ~beta/basiclib/v1.6/private/systemenv_ntbody
>     -- PROGRAM-~SystemEnv#SysHead# in ~beta/compiler/beta
> 
> 
>   basic component in ~beta/basiclib/v1.6/betaenv
> 
> 
> Legend:
>     <<snipped>>
>     
> </DUMPFILE>
> 
> BTW, what's the solution to my original problem?
> 
> Jean-Louis Leroy
> http://ourworld.compuserve.com/homepages/jl_leroy/
> 
>