SEGV compiling this class

Thu Jun 21 14:33:00 GMT 2001

I checked with GDB, it is exactly the same thing as you reported. I
also have a set of classes that reproduce this on x86 and PowerPC.
I'll include them. I also build a stock compiler (without my GC and
threads package) and it had the same problem.
I looked the the except.c code and I think I know what the problem is.
At least I see something kind of obvious :-). If you look at some of
the previous loops in duplicate_eh_regions, they look like:
 for (i = 1; i <= ifun_last_region_number; ++i)
 {
 cur = ifun->eh->region_array[i];
 if (!cur || cur->region_number != i)
	continue;
 n_array[i] = duplicate_eh_region_1 (cur, map);
 }
But the one where the exception happens is:
 for (i = 1; i <= ifun_last_region_number; ++i)
	if (n_array[i]->outer == NULL)
	 n_array[i]->outer = cur;
In the exeption-causing loop, there is no check for n_array[i] being
null, even though it seems that it is quite possible this is the case
from the previous loop. However, I don't even pretend to pretend I
know what this code is doing. Anyway, I have a small patch that seems
to fix the problem:

--- except.c.old	Thu Jun 21 16:30:31 2001
+++ except.c	Thu Jun 21 16:30:00 2001
@@ -1448,7 +1448,7 @@
 	cur->inner = root;
 
 for (i = 1; i <= ifun_last_region_number; ++i)
-	if (n_array[i]->outer == NULL)
+	if (n_array[i] && (n_array[i]->outer == NULL))
 	 n_array[i]->outer = cur;
 }
 else
-Corey
>minyard@acm.org writes:
>>> it works fine on PowerPC.
>>I couldn't reproduce the bug with the trunk and 3.0 on RHL7.1/x86, but
>it crashed on Linux/Alpha with -O, though it seems to be for different
>reasons.
>>./A

public class SymbolInvalidError extends Exception
{
 public final static String Revision = "$Revision: 1.1 $";
 public SymbolInvalidError(String info) {
 super(info);
 }
}
public class SymbolTableValueEntry
{
 public static final String Revision = "$Revision: 1.10 $";
 /* The entry in the name tree for this value. */
 private String name;
 public byte infoByte;
 public Object infoObject;
 public String getName() throws SymbolInvalidError
 {
	return this.name;
 }
}
import java.util.Vector;
import SymbolTableValueEntry;
import SymbolInvalidError;
class tester
{
 private Vector ignorePacks = new Vector();
 private byte ignorePackCurrInfoByte = 1;
 private synchronized final boolean inIgnoredPackages(String name)
 {
	int i;
	int length = ignorePacks.size();
	String val;
	for (i=0; i<length; i++) {
	 val = (String) ignorePacks.elementAt(i);
	 if (name.indexOf(val) != -1) {
		return true;
	 }
	}
	return false;
 }
 private final void testBranchTrace(SymbolTableValueEntry v)
 {
	try {
	 String name = v.getName();
	 if (((name.charAt(0) == '_') && (! name.startsWith("__Q")))
		|| name.startsWith("pthread")
		|| name.startsWith("egc")
		|| inIgnoredPackages(name))
	 {
		v.infoByte = (byte) -ignorePackCurrInfoByte;
	 } else {
		v.infoByte = ignorePackCurrInfoByte;
	 }
	} catch (SymbolInvalidError e) {
	 v.infoByte = ignorePackCurrInfoByte;
	}
 }
}
