Question's pretty self-explanatory. I want to implement a function which creates a structure with dynamic array of initial capacity of.. initial_capacity and some properties inside.
Here's the code:
#include <malloc.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
typedef struct IntVector {
int *vector;
unsigned int capacity;
unsigned int size;
} IntVector;
IntVector *int_vector_new(size_t initial_capacity) {
struct IntVector v = {calloc(initial_capacity, sizeof(int)),
initial_capacity, 0};
IntVector* v_ptr = &v;
return v_ptr;
}
And here's what valgrind --leak-check=full --show-leak-kinds=all --track-origins=yes -v ./debug says:
==1713== Memcheck, a memory error detector
==1713== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==1713== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==1713== Command: ./debug
==1713==
--1713-- Valgrind options:
--1713-- --leak-check=full
--1713-- --show-leak-kinds=all
--1713-- --track-origins=yes
--1713-- -v
--1713-- Contents of /proc/version:
--1713-- Linux version 4.4.0-18362-Microsoft ([email protected]) (gcc version 5.4.0 (GCC) ) #476-Microsoft Fri Nov 01 16:53:00 PST 2019
--1713--
--1713-- Arch and hwcaps: AMD64, LittleEndian, amd64-cx16-lzcnt-rdtscp-sse3-avx-avx2-bmi
--1713-- Page sizes: currently 4096, max supported 4096
--1713-- Valgrind library directory: /usr/lib/valgrind
--1713-- Reading syms from /home/altbrace/IntVector/debug
--1713-- Reading syms from /lib/x86_64-linux-gnu/ld-2.27.so
--1713-- Considering /lib/x86_64-linux-gnu/ld-2.27.so ..
--1713-- .. CRC mismatch (computed 1b7c895e wanted 2943108a)
--1713-- Considering /usr/lib/debug/lib/x86_64-linux-gnu/ld-2.27.so ..
--1713-- .. CRC is valid
--1713-- Reading syms from /usr/lib/valgrind/memcheck-amd64-linux
--1713-- Considering /usr/lib/valgrind/memcheck-amd64-linux ..
--1713-- .. CRC mismatch (computed 41ddb025 wanted 9972f546)
--1713-- object doesn't have a symbol table
--1713-- object doesn't have a dynamic symbol table
--1713-- Scheduler: using generic scheduler lock implementation.
--1713-- Reading suppressions file: /usr/lib/valgrind/default.supp
==1713== embedded gdbserver: reading from /tmp/vgdb-pipe-from-vgdb-to-1713-by-altbrace-on-???
==1713== embedded gdbserver: writing to /tmp/vgdb-pipe-to-vgdb-from-1713-by-altbrace-on-???
==1713== embedded gdbserver: shared mem /tmp/vgdb-pipe-shared-mem-vgdb-1713-by-altbrace-on-???
==1713==
==1713== TO CONTROL THIS PROCESS USING vgdb (which you probably
==1713== don't want to do, unless you know exactly what you're doing,
==1713== or are doing some strange experiment):
==1713== /usr/lib/valgrind/../../bin/vgdb --pid=1713 ...command...
==1713==
==1713== TO DEBUG THIS PROCESS USING GDB: start GDB like this
==1713== /path/to/gdb ./debug
==1713== and then give GDB the following command
==1713== target remote | /usr/lib/valgrind/../../bin/vgdb --pid=1713
==1713== --pid is optional if only one valgrind process is running
==1713==
==1713== error calling PR_SET_PTRACER, vgdb might block
--1713-- REDIR: 0x401f2f0 (ld-linux-x86-64.so.2:strlen) redirected to 0x580608c1 (???)
--1713-- REDIR: 0x401f0d0 (ld-linux-x86-64.so.2:index) redirected to 0x580608db (???)
--1713-- Reading syms from /usr/lib/valgrind/vgpreload_core-amd64-linux.so
--1713-- Considering /usr/lib/valgrind/vgpreload_core-amd64-linux.so ..
--1713-- .. CRC mismatch (computed 50df1b30 wanted 4800a4cf)
--1713-- object doesn't have a symbol table
--1713-- Reading syms from /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so
--1713-- Considering /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so ..
--1713-- .. CRC mismatch (computed f893b962 wanted 95ee359e)
--1713-- object doesn't have a symbol table
==1713== WARNING: new redirection conflicts with existing -- ignoring it
--1713-- old: 0x0401f2f0 (strlen ) R-> (0000.0) 0x580608c1 ???
--1713-- new: 0x0401f2f0 (strlen ) R-> (2007.0) 0x04c32db0 strlen
--1713-- REDIR: 0x401d360 (ld-linux-x86-64.so.2:strcmp) redirected to 0x4c33ee0 (strcmp)
--1713-- REDIR: 0x401f830 (ld-linux-x86-64.so.2:mempcpy) redirected to 0x4c374f0 (mempcpy)
--1713-- Reading syms from /lib/x86_64-linux-gnu/libc-2.27.so
--1713-- Considering /lib/x86_64-linux-gnu/libc-2.27.so ..
--1713-- .. CRC mismatch (computed b1c74187 wanted 042cc048)
--1713-- Considering /usr/lib/debug/lib/x86_64-linux-gnu/libc-2.27.so ..
--1713-- .. CRC is valid
--1713-- REDIR: 0x4edac70 (libc.so.6:memmove) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ed9d40 (libc.so.6:strncpy) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4edaf50 (libc.so.6:strcasecmp) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ed9790 (libc.so.6:strcat) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ed9d70 (libc.so.6:rindex) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4edc7c0 (libc.so.6:rawmemchr) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4edade0 (libc.so.6:mempcpy) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4edac10 (libc.so.6:bcmp) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ed9d00 (libc.so.6:strncmp) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ed9800 (libc.so.6:strcmp) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4edad40 (libc.so.6:memset) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ef80f0 (libc.so.6:wcschr) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ed9ca0 (libc.so.6:strnlen) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ed9870 (libc.so.6:strcspn) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4edafa0 (libc.so.6:strncasecmp) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ed9840 (libc.so.6:strcpy) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4edb0e0 (libc.so.6:memcpy@@GLIBC_2.14) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ed9da0 (libc.so.6:strpbrk) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ed97c0 (libc.so.6:index) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ed9c70 (libc.so.6:strlen) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ee46c0 (libc.so.6:memrchr) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4edaff0 (libc.so.6:strcasecmp_l) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4edabe0 (libc.so.6:memchr) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4ef8eb0 (libc.so.6:wcslen) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4eda050 (libc.so.6:strspn) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4edaf20 (libc.so.6:stpncpy) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4edaef0 (libc.so.6:stpcpy) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4edc7f0 (libc.so.6:strchrnul) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4edb040 (libc.so.6:strncasecmp_l) redirected to 0x4a2a6e0 (_vgnU_ifunc_wrapper)
--1713-- REDIR: 0x4fca3c0 (libc.so.6:__strrchr_avx2) redirected to 0x4c32730 (rindex)
--1713-- REDIR: 0x4ed6030 (libc.so.6:calloc) redirected to 0x4c31a70 (calloc)
--1713-- REDIR: 0x4ed3950 (libc.so.6:free) redirected to 0x4c30cd0 (free)
==1713==
==1713== HEAP SUMMARY:
==1713== in use at exit: 20 bytes in 1 blocks
==1713== total heap usage: 1 allocs, 0 frees, 20 bytes allocated
==1713==
==1713== Searching for pointers to 1 not-freed blocks
==1713== Checked 69,336 bytes
==1713==
==1713== 20 bytes in 1 blocks are definitely lost in loss record 1 of 1
==1713== at 0x4C31B25: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==1713== by 0x1086F2: int_vector_new (IntVector.c:13)
==1713== by 0x1086BB: main (main.c:8)
==1713==
==1713== LEAK SUMMARY:
==1713== definitely lost: 20 bytes in 1 blocks
==1713== indirectly lost: 0 bytes in 0 blocks
==1713== possibly lost: 0 bytes in 0 blocks
==1713== still reachable: 0 bytes in 0 blocks
==1713== suppressed: 0 bytes in 0 blocks
==1713==
==1713== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
==1713== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
I've been trying to fix this for three hours straight with no progress, as you can see.
Hope on your help.
I don't know everything that may be going on because at the moment you don't have any code showing where this is called, but I see a big issue. You are returning a pointer to a value created in int_vector_new, so once that function returns the local variable pointed to (v) will be gone.
You could do allocate memory for v, like this: IntVector* v = malloc(sizeof(IntVector));.
Then set each field using the -> syntax. Like this:
IntVector* v = malloc(sizeof(IntVector));
v->vector = calloc(initial_capacity, sizeof(int));
v->capacity = initial_capacity;
v->size = 0;
return v;
Since valgrind complains about leaks, I'd guess you are not freeing vector later on in your code. Freeing that will fix the complaint about the leaked memory. And once you use malloc to allocate v, you will need to free any values that int_vector_new returns.