<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Can you not set a HW watchpoint to check for the location being overwritten with the bogus pointer?<div>Also, better to run with @M3paranoidgc so you catch it in the heap sanity checks (which check to make sure that pointers really look like pointers) rather than some arbitrary place.<br><div><br class="webkit-block-placeholder"></div><div> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div style="word-wrap: break-word; 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text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div><font class="Apple-style-span" color="#0000FF"><font class="Apple-style-span" face="Gill Sans"><span class="Apple-style-span" style="color: rgb(0, 0, 255); font-family: 'Gill Sans'; "><span class="Apple-style-span" style="color: rgb(0, 0, 255); font-family: 'Gill Sans'; ">Antony Hosking</span></span></font></font><font class="Apple-style-span" face="Gill Sans"><span class="Apple-style-span" style="font-family: 'Gill Sans'; "><span class="Apple-style-span" style="font-family: 'Gill Sans'; "><span class="Apple-converted-space"> </span>|<span class="Apple-converted-space"> </span></span></span><span class="Apple-style-span" style="font-family: 'Gill Sans'; "><span class="Apple-style-span" style="font-family: 'Gill Sans'; ">Associate Professor</span></span><span class="Apple-style-span" style="font-family: 'Gill Sans'; "><span class="Apple-style-span" style="font-family: 'Gill Sans'; "> | Computer Science | Purdue University</span></span></font></div><div><font class="Apple-style-span" face="GillSans-Light"><span class="Apple-style-span" style="font-family: GillSans-Light; ">305 N. University Street | West Lafayette | IN 47907 | USA</span></font></div><div><font class="Apple-style-span" color="#0000FF" face="Gill Sans"><span class="Apple-style-span" style="color: rgb(0, 0, 255); font-family: 'Gill Sans'; "><span class="Apple-style-span" style="color: rgb(0, 0, 255); font-family: 'Gill Sans'; ">Office</span></span></font><font class="Apple-style-span" face="GillSans-Light"><span class="Apple-style-span" style="font-family: GillSans-Light; "><span class="Apple-style-span" style="font-family: GillSans-Light; "> +1 765 494 6001 |<span class="Apple-converted-space"> </span></span></span></font><font class="Apple-style-span" color="#0000FF" face="Gill Sans"><span class="Apple-style-span" style="color: rgb(0, 0, 255); font-family: 'Gill Sans'; "><span class="Apple-style-span" style="color: rgb(0, 0, 255); font-family: 'Gill Sans'; ">Mobile</span></span></font><font class="Apple-style-span" face="GillSans-Light"><span class="Apple-style-span" style="font-family: GillSans-Light; "><span class="Apple-style-span" style="font-family: GillSans-Light; "><span class="Apple-converted-space"> </span>+1 765 427 5484</span></span></font></div><div><font class="Apple-style-span" face="GillSans-Light"><br class="khtml-block-placeholder"></font></div></span></span></span></span></span></span></span><br class="Apple-interchange-newline"></span></div></span></div></span><br class="Apple-interchange-newline"> </div><br><div><div>On 21 Oct 2009, at 06:21, Jay K wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div class="hmmessage" style="font-size: 10pt; font-family: Verdana; ">I thought this was gone, but now I'm still seeing occasional heap corruption in Juno on Win32.<br>It has the same signature of accessing 001ffffc.<br> <br> <br>(adc.f8): Access violation - code c0000005 (first chance)<br>First chance exceptions are reported before any exception handling.<br>This exception may be expected and handled.<br>eax=00000001 ebx=00200000 ecx=00000000 edx=005cf3f8 esi=001ffffc edi=02040018<br>eip=005cf449 esp=0012f89c ebp=0012f8d4 iopl=0 nv up ei pl nz ac pe nc<br>cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010216<br>*** WARNING: Unable to verify checksum for C:\cm3\bin\m3core.dll<br>m3core!RTCollector__Move+0x51:<br>005cf449 8b5e00 mov ebx,dword ptr [esi] ds:0023:001ffffc=????????<br>0:000> r esi<br>esi=001ffffc<br>0:000> k<br>ChildEBP RetAddr<br>0012f8d4 005cb121 m3core!RTCollector__Move+0x51 [..\src\runtime\common\RTCollector.m3 @ 409]<br>0012f918 005ca9fa m3core!RTHeapMap__Walk+0x467 [..\src\runtime\common\RTHeapMap.m3 @ 202]<br>0012f93c 005ca990 m3core!RTHeapMap__DoWalkRef+0x62 [..\src\runtime\common\RTHeapMap.m3 @ 62]<br>0012f968 005d0fae m3core!RTHeapMap__WalkRef+0x100 [..\src\runtime\common\RTHeapMap.m3 @ 47]<br>0012f990 005d0df6 m3core!RTCollector__CleanBetween+0xec [..\src\runtime\common\RTCollector.m3 @ 1090]<br>0012f9b8 005d076f m3core!RTCollector__CleanPage+0x55 [..\src\runtime\common\RTCollector.m3 @ 1063]<br>0012fa0c 005d01ef m3core!RTCollector__CollectSomeInStateZero+0x544 [..\src\runtime\common\RTCollector.m3 @ 884]<br>0012fa20 005cfe86 m3core!RTCollector__CollectSome+0x6e [..\src\runtime\common\RTCollector.m3 @ 719]<br>0012fa64 005c802c m3core!RTHeapRep__CollectEnough+0x9b [..\src\runtime\common\RTCollector.m3 @ 654]<br>0012faa4 005c7466 m3core!RTAllocator__AllocTraced+0xd7 [..\src\runtime\common\RTAllocator.m3 @ 366]<br>0012fad8 005c7100 m3core!RTAllocator__GetTracedRef+0x8c [..\src\runtime\common\RTAllocator.m3 @ 202]<br>0012fafc 0051d1ae m3core!RTHooks__AllocateTracedRef+0x15 [..\src\runtime\common\RTAllocator.m3 @ 113]<br>0012fb44 1002c564 m3!AtomRefTbl__Put+0x250 [..\NT386\AtomRefTbl.m3 @ 127]<br>0012fb74 0041fcf5 juno_compiler!JunoScope__Bind+0x79 [..\src\JunoScope.m3 @ 114]<br>0012fbc8 00420b88 Juno!Editor__Pass1+0xe3b [..\src\Editor.m3 @ 711]<br>0012fc84 00420a30 Juno!Editor__Compile2+0x148 [..\src\Editor.m3 @ 812]<br>0012fcb8 004447f1 Juno!Editor__Compile+0x53 [..\src\Editor.m3 @ 793]<br>0012fcf8 00452244 Juno!Juno__CompileEditor+0x2c [..\src\Juno.m3 @ 140]<br>0012fd58 004532b6 Juno!Juno__CompileFile+0xb8 [..\src\Juno.m3 @ 1897]<br>0012fed4 005d8d64 Juno!Juno_M3+0x9d8 [..\src\Juno.m3 @ 2068]<br><br><br><br><br><br><br></div></span></blockquote></div><br></div></body></html>