If user specifies some tool chain for the C/C++ dynamic library and then adds this library to C/C++ application, then after he'll run clean & build command the wrong tool chain will be used to build dynamic library.
 
Say you have 2 tool cains GNU_1 and GNU_2.
1) Create C/C++ Dynamic Library project
2) Select GNU_1 toolchain
3) Create newfile.c and newfile.h files
4) Clean&Build project
5) Create C/C++ Application project with main.c
6) Select GNU_2 toolchain
7) Add CppDynamicLibrary_1 project into Linker|Libraries|Add Project
8) Add ../CppDynamicLibrary_1 into Build|C Compiler|Include Directories field
9) Modify main.c file. In my case it contains:
#include <newfile.h>
int main(int argc, char** argv) {
    foo();
    return (0);
}
10) Clean&Build project

Result -> IDE won't use GNU_1 tool chain to build dynamic library