Re: gcj, libgcj, and GNU JVM for AIX

[Tom Tromey <tromey at redhat dot com>]

>>>>> "Dean" == Hill, Dean L <DHill4@LNC.com> writes:

Dean> /tmp//ccWqD8w2.s: line 1713: 1252-142 Syntax error.

Dean> To diagnose the problem, I had the compiler generate the
Dean> assembler source (prims.s).  Then I used the gcc assembler to
Dean> assemble prims.s.  I got the same syntax errors.  Inspecting the
Dean> offending lines, we noticed some dollar signs "$", e.g.:
Dean>         .tc _ZN4java4lang30ArrayIndexOutOfBoundsException6class$ETC],_ZN4java4lang30ArrayIndexOutOfBoundsException6class$E[RW]

Dean> I manually removed the dollar signs from each line and the file
Dean> assembled fine.  So, why does prims.cc generate prims.s with
Dean> dollar signs in symbol names?

The short answer is that this is the convention we picked.  It's sort
of an arbitrary choice, I think.

But, note that due to how inner classes are named, you're going to
wind up with "$" in identifiers even if you change gcj to avoid "$"
in this particular case.

I suppose it would be possible to change gcj to rewrite all these
dollar signs as well.  I haven't looked into it, since we never had a
problem with this before.

Note that you'd still need to accept "$" in C++ source files, since
they appear in gcjh-generated header files, and we want these headers
to remain platform-independent.

Dean> I tried changing the c++ option -fdollars-in-identifiers to
Dean> -fno-dollars-in-identifiers with no change in the generated
Dean> assembler code.

As I understand it, this flag changes the behavior of the front end,
but not the output.

Dean> How do I have the c++ compiler NOT generate dollar signs in the
Dean> assembler code?

One idea is to use gas instead:

   * Even if you specify `-fdollars-in-identifiers', you cannot
     successfully use `$' in identifiers on the RS/6000 due to a
     restriction in the IBM assembler.  GAS supports these identifiers.

Alternatively you could come up with a "$"-rewriting patch for gcj and
g++.

Tom