c++ char memory leakage with valgrind analysis - c++

Question

I have around 350 lines code where I am parsing xml file and creating another 2 sheets out of it using C++.
After adding the last 2 or 3 functions I started having memory error,
Signal: SIGSEGV (Segmentation fault)
Removing them didn't solve the error so definitely I edited something else. I searched online and found about valgrind which showed me errors that I can't translate.
As per the valgrind manual, I have to check from below to up so as per the last one,
==7276== 4,064 bytes in 1 blocks are definitely lost in loss record 52 of 54
==7276== at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==7276== by 0x456BDD: ??? (in /usr/bin/g++-5)
==7276== by 0x4EC260D: _obstack_begin (obstack.c:176)
==7276== by 0x456FCE: ??? (in /usr/bin/g++-5)
==7276== by 0x43BA49: ??? (in /usr/bin/g++-5)
==7276== by 0x43BAC0: ??? (in /usr/bin/g++-5)
==7276== by 0x4E5A82F: (below main) (libc-start.c:291)
For line 291 is the append line in the below code,
if (vlan_ether)
sprintf(cConfStr, "**.Switch%ld.eth[%d].queue.VlanClassifier = true\n", srcindex + 1, portno);
else if (!vlan_ether)
sprintf(cConfStr, "**.Switch%ld.eth[%d].queue.etherType = false\n", srcindex + 1, portno);
else
cout << "Switch" << srcindex + 1 << "port# " << portno << " Classifier is not specified." << endl;
confStr.append(string(cConfStr));
Removing the above lines didn't do any change, while line 176 is a comment so am hesitating that valgrind is not showing the lines of error.
So I am not sure what to show you in my question from the code. Still I am definite that it should be related to string and char usage In which I used them several times.
char cNedStr[600];
char cConfStr[600];
sprintf(cConfStr, "%d ", intervalvector[q]);
confStr.append(string(cConfStr));
The Valgrind result as per below,
amr#amr-PC:~$ valgrind --leak-check=yes g++ main.cpp pugixml.cpp headers.h -Wall -std=c++11
EDIT:
amr#amr-PC:~/ClionProjects/converter$ valgrind ./a.out
==7624== Memcheck, a memory error detector
==7624== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==7624== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==7624== Command: ./a.out
==7624== Invalid free() / delete / delete[] / realloc()
==7624== at 0x4C2F24B: operator delete(void*) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==7624== by 0x5714FF7: __run_exit_handlers (exit.c:82)
==7624== by 0x5715044: exit (exit.c:104)
==7624== by 0x56FB836: (below main) (libc-start.c:325)
==7624== Address 0x35663a37323a6536 is not stack'd, malloc'd or (recently) free'd
==7624==
==7624==
==7624== HEAP SUMMARY:
==7624== in use at exit: 72,704 bytes in 1 blocks
==7624== total heap usage: 525 allocs, 525 frees, 214,887 bytes allocated
==7624==
==7624== LEAK SUMMARY:
==7624== definitely lost: 0 bytes in 0 blocks
==7624== indirectly lost: 0 bytes in 0 blocks
==7624== possibly lost: 0 bytes in 0 blocks
==7624== still reachable: 72,704 bytes in 1 blocks
==7624== suppressed: 0 bytes in 0 blocks
==7624== Rerun with --leak-check=full to see details of leaked memory
==7624==
==7624== For counts of detected and suppressed errors, rerun with: -v
==7624== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)

Answer 1

First compile, without the header file, (default output is a.out):
g++ main.cpp pugixml.cpp -Wall -std=c++11
Then check using valgrind:
valgrind --leak-check=yes ./a.out
Other comments:
You could consider adding the following flags to g++:
-Wextra (more warnings)
-pedantic (turns off extensions and generates more warnings)
-g (debug symbols)
-O3 (maximum optimization, not recommended for debugging!)