Patch: Improve demangling w.r.t. possible underscore prefix

Thu Feb 20 09:46:00 GMT 2003

Hi,
 If this patch looks OK, can we please commit it?
Thanks in advance.
Ranjit.
----- Original Message ----- 
From: "Ranjit Mathew" <rmathew@hotmail.com>
To: <java@gcc.gnu.org>
Sent: Tuesday, February 18, 2003 12:56 AM
Subject: Re: Patch: Improve demangling w.r.t. possible underscore prefix
> Andrew Haley wrote:
> > Ranjit Mathew writes:
> > > >Why can't you just cat __USER_LABEL_PREFIX__ to the start of the
name?
> > > >Surround the whole thing by #ifdef __USER_LABEL_PREFIX__.
> > >
> > > By "cat" if you mean the "##" preprocessor operator, it does not
work.
> >
> > No, I mean that you can stringify __USER_LABEL_PREFIX__ by using the #
> > token.
> ...
> > I haven't tested this, but you get the idea. It doesn't use gotos or
> > onstruct special symbols and it's won't break if ever
> > __USER_LABEL_PREFIX__ is "$" or somesuch.
>> Ok, the following is a patch based on your idea - tested on 3.3/MinGW,
> would request someone to test on some other platform.
>> Index: ChangeLog
> from Ranjit Mathew <rmathew@hotmail.com>
>> * gnu/gcj/runtime/NameFinder.java (usingAddr2name): New flag
> that is set if we are using addr2name.awk instead of addr2line.
> (NameFinder): Set usingAddr2name if using addr2name.awk.
> (getExternalLabel): New native method to convert a method
> name to an external label.
> (lookup): Convert name given by addr2line to an external label
> before demangling.
>> * gnu/gcj/runtime/natNameFinder.cc (LABEL_PREFIX): New string
> constant representing the prefix attached to method names to
> convert them to an external label.
> (gnu::gcj::runtime::NameFinder::getExternalLabel): Define
> using LABEL_PREFIX.
>> Index: gnu/gcj/runtime/NameFinder.java
> ===================================================================
> --- gnu/gcj/runtime/NameFinder.java 2003年02月13日 00:14:40.000000000 +0530
> +++ gnu/gcj/runtime/NameFinder.java 2003年02月18日 00:19:36.000000000 +0530
> @@ -104,4 +104,9 @@
>> /**
> + * Flag set if using addr2name.awk instead of addr2line from binutils.
> + */
> + private boolean usingAddr2name = false;
> +
> + /**
> * Creates a new NameFinder. Call close to get rid of any resources
> * created while using the <code>lookup</code> methods.
> @@ -143,4 +148,5 @@
> String[] exec = new String[] {"addr2name.awk", executable};
> addr2line = runtime.exec(exec);
> + usingAddr2name = true;
> }
> catch (IOException ioe2) { addr2line = null; }
> @@ -182,4 +188,9 @@
>> /**
> + * Returns the label that is exported for the given method name.
> + */
> + native private String getExternalLabel(String name);
> +
> + /**
> * If nth element of stack is an interpreted frame, return the
> * element representing the method being interpreted.
> @@ -213,4 +224,13 @@
> name = addr2lineIn.readLine();
> file = addr2lineIn.readLine();
> +
> + // addr2line uses symbolic debugging information instead
> + // of the actually exported labels as addr2name.awk does.
> + // This name might need some modification, depending on
> + // the system, to make it a label like that returned
> + // by addr2name.awk or dladdr.
> + if (! usingAddr2name)
> + if (name != null && ! "??".equals (name))
> + name = getExternalLabel (name);
> }
> catch (IOException ioe) { addr2line = null; }
> Index: gnu/gcj/runtime/natNameFinder.cc
> ===================================================================
> --- gnu/gcj/runtime/natNameFinder.cc 2003年02月16日 13:57:19.000000000 +0530
> +++ gnu/gcj/runtime/natNameFinder.cc 2003年02月18日 00:24:55.000000000 +0530
> @@ -16,4 +16,6 @@
> #include <config.h>
>> +#include <string.h>
> +
> #include <gcj/cni.h>
> #include <jvm.h>
> @@ -29,4 +31,35 @@
> #endif
>> +// On some systems, a prefix is attached to a method name before
> +// it is exported as a label. The GCC preprocessor predefines
> +// this prefix as the macro __USER_LABEL_PREFIX__ which expands to
> +// a string (not string constant) representing the prefix, if any.
> +#undef LABEL_PREFIX
> +#ifdef __USER_LABEL_PREFIX__
> +
> +#define USER_LABEL_PREFIX_STRING_0(s) #s
> +#define USER_LABEL_PREFIX_STRING(s) USER_LABEL_PREFIX_STRING_0(s)
> +
> +#define LABEL_PREFIX USER_LABEL_PREFIX_STRING(__USER_LABEL_PREFIX__)
> +
> +#else /* __USER_LABEL_PREFIX__ */
> +
> +#define LABEL_PREFIX ""
> +
> +#endif /* ! __USER_LABEL_PREFIX__ */
> +
> +java::lang::String*
> +gnu::gcj::runtime::NameFinder::getExternalLabel (java::lang::String*
name)
> +{
> + jsize nameLen = JvGetStringUTFLength (name);
> + jsize pfxLen = strlen (LABEL_PREFIX);
> + char *newName = (char *) JvMalloc (pfxLen + nameLen + 1);
> + *(newName + 0) = '0円';
> + strcpy (newName, LABEL_PREFIX);
> + JvGetStringUTFRegion (name, 0, nameLen, newName + pfxLen);
> + *(newName + pfxLen + nameLen) = '0円';
> + return JvNewStringLatin1 (newName);
> +}
> +
> java::lang::String*
> gnu::gcj::runtime::NameFinder::getExecutable (void)
>