Re: Crash using TMemberInspector

Hi,

The 2nd parameter to ShowMembers __must__ be modifiable. So use something like:

char cbuf[1000]; *cbuf=0;
Insp insp;
obj->ShowMembers(insp,cbuf);

Cheers,
Philippe.

Christopher Backhouse wrote:
> Hi,
>
> I want to compare two objects (of the same class, inheriting from
> TObject) field by field.
> I thought I could use TMemeberInspector to accomplish this, but my
> test program crashes:
>
> #include "TMemberInspector.h"
> #include "TH1F.h"
>
> #include <iostream>
> using namespace std;
>
> class Insp: public TMemberInspector
> {
> public:
> virtual void Inspect(TClass *cl, const char *parent, const char
> *name, const void *addr)
> {
> cout << cl << " " << parent << name << " " << addr << endl;
> }
> };
>
> void show_members()
> {
> TObject* obj = new TH1F("bar", "baz", 100, 0, 100);
> Insp insp;
> obj->ShowMembers(insp, "TH1F.");
> }
>
>
> > loon show_members.C+
> loon [0]
> Processing show_members.C+...
> Info in <TUnixSystem::ACLiC>: creating shared library
> /data/minos/bckhouse/tests/./show_members_C.so
> 0xa077468 TH1F.fNcells 0x9ffb0f4
> 0xa077468 TH1F.fXaxis 0x9ffb0f8
> Segmentation fault
>
>
> Running under gdb, I see the segfault is in strcat()
>
> If I substitute a class from our framework instead of TH1F then I can
> see the line that crashes:
>
>
> #1 0x03ea67a2 in ANtpHeaderInfo::ShowMembers (this=0x92ce0f0,
> R__insp=@0xbff45e10, R__parent=0x503300 "TH1F.")
> at
> /data/minos/minos/software/OO/minossoft/releases/dev_2/tmp/Linux2.6-GCC_3_4/AnalysisNtuples/libAnalysisNtuples-shared/AnalysisNtuplesCint.cc:1362
>
> 1362 softVersion.ShowMembers(R__insp,
> strcat(R__parent,"softVersion.")); R__parent[R__ncp] = 0;
> Current language: auto; currently c++
> (gdb) list
> 1357 R__insp.Inspect(R__cl, R__parent, "isGoodFDData",
> &isGoodFDData);
> 1358 R__insp.Inspect(R__cl, R__parent, "snarlPE", &snarlPE);
> 1359 R__insp.Inspect(R__cl, R__parent, "sntpRow", &sntpRow);
> 1360 R__insp.Inspect(R__cl, R__parent, "isLI", &isLI);
> 1361 R__insp.Inspect(R__cl, R__parent, "softVersion",
> &softVersion);
> 1362 softVersion.ShowMembers(R__insp,
> strcat(R__parent,"softVersion.")); R__parent[R__ncp] = 0;
> 1363 TObject::ShowMembers(R__insp, R__parent);
> 1364 }
> 1365
>
>
> I am using root trunk.
> Any ideas? Am I using TMemberInspector right?
>
> Thanks - Chris
>
Received on Fri Dec 05 2008 - 22:11:39 CET