how to create conditional breakpoint with std::string

Question

Suppose I have this function:

std::string Func1(std::string myString)
{
   //do some string processing 
   std::string newString = Func2(myString)
   return          


        

Answer 1

In VS2015 you can do

newstring[0]=='x' && newString[1]=='y' && newString[2]=='z'

Answer 2

In VS2017 you can do

strcmp(newString._Mypair._Myval2._Bx._Buf,"myvalue")==0

Answer 3

Tried to use strcmp in gdb8.1 under ubuntu18.04, but it doesn't work:

(ins)(gdb) p strcmp("a", "b")
$20 = (int (*)(const char *, const char *)) 0x7ffff5179d60 <__strcmp_ssse3>

According to this answer, strcmp, is a special IFUNC, one can setup condition like this:

condition 1 __strcmp_ssse3(camera->_name.c_str(), "ping")==0

It's pretty ugly, don't want to do it the second time.

This answer gives a much better solution, it use std::string::compare :

condition 1 camera->_name.compare("ping") == 0

Answer 4

In VS2017, I was able to set the condition as:

strcmp(&newString[0], "my value") == 0

Answer 5

Comparing string works better than comparing characters

strcmp(name._Mypair._Myval2._Bx._Buf, "foo")==0

This works, but is very inconvenient to use and error prone.

name._Mypair._Myval2._Bx._Buf[0] == 'f' && 
name._Mypair._Myval2._Bx._Buf[1] == '0' && 
name._Mypair._Myval2._Bx._Buf[2] == '0'

Answer 6

@OBWANDO (almost) has the solution, but as multiple comments rightly point out, the actual buffer depends on the string size; I see 16 to be the threshold. Prepending a size check to the strcmp on the appropriate buffer works.

newString._Mysize < 16 && strcmp(newString._Bx._Buf, "test value") == 0

or

newString._Mysize >= 16 && strcmp(newString._Bx._Ptr, "ultra super long test value") == 0