On Wed, Aug 25, 2004 at 01:13:10PM -0700, John M McIntosh wrote:
> Let me turn that around and suggest code in Smalltalk versus in C  
> primitives, then anyone can participate. Not that one can't suggest VM  
> changes, it's
> just way easier for all parties if it's in the image...
> 
> englishErrorForSocketPrims: anErrorCode
> 	^EnglishErrorCodes for: anErrorCode hint: #SocketPrims
> 
> where hint tells me something about the primitive being used, thus I've  
> a handle on the fact it's from the SocketPrims
> 
> The just do something like
> 	platform _ Smalltalk platformName.
> 		platform = 'Mac OS' ifTrue:
>   		[Smalltalk osVersion asInteger >= 1000
> 			ifTrue: [stuff for osx ]
> 			ifFalse: [stuff for os 9 and earlier]].

Good point, but note also that strerror() and strerror_r() may already
do everything that is necessary. I'm not sure if they are available on
all platforms, but I think that Unix, Windows, and OS/X would be covered.

For example, a non-thread-safe implementation could look like this
(excerpted from some unreleased OSProcessPlugin code):

primitiveErrorMessageAt: errno
    "Answer a string describing an error message"
    | index errMessage p |
    self export: true.
    self var: 'p' declareC: 'char *p'.
    index _ interpreterProxy stackIntegerValue: 0.
    p _ self cCoerce: (self cCode: 'strerror(index)' inSmalltalk: ['']) to: 'char *'.
    errMessage _ self stringFromCString: p.
    interpreterProxy pop: 2; push: errMessage

stringFromCString: aCString
    "Answer a new String copied from a null-terminated C string.
    Caution: This may invoke the garbage collector."
    | len newString stringPtr |
    self var: 'aCString' declareC: 'char *aCString'.
    self var: 'stringPtr' declareC: 'char *stringPtr'.
    len _ self cCode: 'strlen(aCString)' inSmalltalk: [0].
    newString _ interpreterProxy
        instantiateClass: interpreterProxy classString
        indexableSize: len.
    stringPtr _ interpreterProxy arrayValueOf: newString.
    self cCode: '(char *)strncpy(stringPtr, aCString, len)'.
    ^ newString


Dave