namespace namespace

[Dave Korn]

Andrew Haley wrote:
> Dave Korn wrote:
>> Andrew Haley wrote:
>>
>>> This is an ABI change.  However, the ABI was almost completely broken
>>> anyway.
>>   Tangentially-related: Would it ever be possible to change the use of periods
>> as separators in java mangled names too, or is that too deeply entrenched or
>> part of a standard?
> 
> I suppose it could be done.  Is there some big problem with periods that
> I don't know about?
> 
> For example, java.lang.Object.class is mangled as _ZN4java4lang6Object6class$E.

  The kind of symbols I'm talking about are those with real actual periods in
them, things I've seen in libjava, such as these:

gnu/.libs/classpath.o:

00000030 r _java.io.IOException_ref.1567
00000034 r _java.io.IOException_ref.3036
0000002c r _java.lang.Exception_ref.1841

or these (from unidentified .o files):

000139c0 t
__ZN3gnu5javax3net3ssl8provider11CipherSuiteC1EPNS3_15CipherAlgorithmEPNS3_20KeyExchangeAlgorithmEPNS3_18SignatureAlgorithmEPNS3_12MacAlgorithmEiiiPN4java4lang6StringE.clone.1
0002a9b0 t
__ZN3gnu5javax3net3ssl8provider4Util11toHexStringEJPN4java4lang6StringEP6JArrayIcEw.clone.0
000139c0 t
__ZN3gnu5javax3net3ssl8provider11CipherSuiteC1EPNS3_15CipherAlgorithmEPNS3_20KeyExchangeAlgorithmEPNS3_18SignatureAlgorithmEPNS3_12MacAlgorithmEiiiPN4java4lang6StringE.clone.1
0002a9b0 t
__ZN3gnu5javax3net3ssl8provider4Util11toHexStringEJPN4java4lang6StringEP6JArrayIcEw.clone.0
00000d10 t __ZN3gnu5javax5swing4text4html6parser7support3low4nodeC1Eib.clone.0
00000f72 r __Utf106.2066
00000fe0 r __Utf117.2121
000002f4 r __Utf17.1621
00003b54 r __Utf1042.35506
0000c696 r __Utf1757.124553
000001d4 r _CSWTCH.18597
000001d4 r _CSWTCH.18597
00000000 d ___emutls_v._ZL12method_cache
00000020 t __Z17JvNewStringLatin1PKc.clone.0


> When do you see a problem with the use of periods as separators?

  Actually, there may not be a problem at all.  There is a /potential/ problem
relating to the export of symbols from DLLS, specified using DEF files.  The
syntax of DEF files uses periods as a separator in entries that forward an
export to another DLL, so having periods in the symbol names would cause
ambiguity in the grammar.

  Like I said I've seen these mysterious symbols with literal periods in them,
but I don't know what they actually are.  On closer inspection while writing
this mail, I suddenly notice that they all appear to be local symbols; if this
is always the case, then there's no problem at all because we'll never want to
export them from a DLL.  And noticing the '.clone.' in there makes me wonder
if this is in fact an entirely C++ issue and not Java at all?  (In which case
sorry for bothering you with something that's not your department!)

    cheers,
      DaveK