Segmentation Fault with Array of Structs

[celest token]

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[peak sedge]

And i don't know why i need to use lines[count].str instead of lines[count]->str

[hushed beacon]

You have not given str any pointer value.

[foggy mural]

!asan

[celest token]

@peak sedge

Address Sanitizer

Memory errors in C and C++ are easy to make and they can be very hard to debug because they can manifest far from their source. Address sanitizer is a runtime checker that identifies memory errors at their source and makes debugging much simpler. Address sanitizer is available for gcc/clang on linux and msvc on windows. To use it simply pass -fsanitize=address to the compiler.

Note: Make sure to turn on debug symbols with -g for gcc/clang and -Zi for msvc.

Example

How to read sanitizer output

The first few lines tell you the problem, heap-use-after-free, due to performing a READ of size 4, at example.c line 7 (from the first line of the stack trace).

==1==ERROR: AddressSanitizer: heap-use-after-free on address ....
READ of size 4 at 0x602000000010 thread T0
    #0 0x40120f in main /app/example.c:7
    #1 0x7fda58629d8f  (...)
    #2 0x7fda58629e3f in __libc_start_main (...)
    #3 0x4010b4 in _start (...)

Additional information is also included such as where the allocation was performed and where the allocation was freed.

See Also

• Other sanitizers exist and can be similarly helpful, including ubsan, threadsan, and memorysan.

[hushed beacon]

-> is used to access a member of an object pointed to by a pointer; p->m is the same as (*p).m.

[peak sedge]

Ok, now is "working", i don't get a segfault, but now i have other problem

while (sup != NULL) {
    lines[count].str = (char *)malloc(sizeof(char) * sup->value->len);
    memcpy(lines[count].str, sup->value->str, sup->value->len);
    count += 1;
    sup = sup->next;
}

i'm just looping and printing the values

for (int i; i < lista->len; i++)
    printf("%s\n", lines[i].str);

[hushed beacon]

Try debugging.

[peak sedge]

well, i'm having problems with this too

ok, i find the problem, the debugger is compiling only the main file, not the headers, and i cant find then to edit this