Following the question here: Writing a Python script to print out an array of recs in lldb
I would like to be able to create a type summary for an array of a given struct in lldb. Problem is that I am not able to access array correctly through python-lldb. Some data is incorrect.
I have the following test code in C:
#include <stdio.h>
#include <stdlib.h>
struct Buffer
{
struct Buffer* next;
struct Buffer* prev;
};
struct Base
{
struct Buffer* buffers;
int count;
};
void fill(struct Buffer* buf, int count)
{
for (int i = 0; i < count; ++i)
{
struct Buffer t = {(void*)0xdeadbeef,(void*)i};
buf[i] = t;
}
}
void foo(struct Base* base)
{
printf("break here\n");
}
int main(int argc, char** argv)
{
int c = 20;
void* buf = malloc(sizeof (struct Buffer) * c);
struct Base base = {.buffers = buf, .count = c};
fill(base.buffers, base.count);
foo(&base);
return 0;
}
In lldb:
(lldb) b foo
(lldb) r
(lldb) script
>>> debugger=lldb.debugger
>>> target=debugger.GetSelectedTarget()
>>> frame=lldb.frame
>>> base=frame.FindVariable('base')
>>> buffers=base.GetChildMemberWithName('buffers')
Now, buffers should point to array of struct Buffer and I should be able to access each and every Buffer via the buffers.GetChildAtIndex function, but the data is corrupted in the first 2 items.
>>> print buffers.GetChildAtIndex(0,0,1)
(Buffer *) next = 0x00000000deadbeef
>>> print buffers.GetChildAtIndex(1,0,1)
(Buffer *) prev = 0x0000000000000000
>>> print buffers.GetChildAtIndex(2,0,1)
(Buffer) [2] = {
next = 0x00000000deadbeef
prev = 0x0000000000000002
}
Only the buffers[2] and up items are ok.
Why does print buffers.GetChildAtIndex(1,0,1) points to buffers[0].count item instead of buffers[1]?
What am I doing wrong?
