How to avoid entering library's source files while debugging in Qt Creator with gdb?

You need to turn off auto-solib-add. From a normal gdb prompt you would type:

(gdb) set auto-solib-add off

In Qt Creator, under Options->Debugger->Gdb you can specify a Gdb startup script. Create a file with the "set auto-solib-add off" command in it and then set your Gdb startup script to that file.

The feature you want (as described by rpg) is not available from GDB, and IMHO would be difficult to use if it were implemented.

A similar, but simpler to use fstep feature is proposed for GDB. Given:

foo((string("Hello") + string(" World!)).c_str());

the fstep would skip all calls on the current line, except the last one (thus skipping string constructors, operator+(), and c_str(), and stepping only into foo).

This hasn't been implemented either, but likely will be in a couple of month (it's very useful for C++ debugging).

In the mean time, you can approximate the feature by setting a temporary breakpoint:

(gdb) list
1       #include <string>
2       #include <iostream>
3       using namespace std;
4
5       void foo(const char *s)
6       {
7         cout << s << endl;
8       }
9
10      int main()
11      {
12        foo((string("Hello") + string(" World!")).c_str());
13        return 0;
14      }
(gdb) b main
Breakpoint 2 at 0x8048901: file t.cc, line 12.
(gdb) run

Breakpoint 1, main () at t.cc:12
12        foo((string("Hello") + string(" World!")).c_str());
(gdb) tb foo
Breakpoint 3 at 0x80488ca: file t.cc, line 7.
(gdb) c
foo (s=0x804a1f4 "Hello World!") at t.cc:7
7         cout << s << endl;
(gdb) q