What is __gxx_personality_v0 and why does it cause linker errors in C ?

Understanding the Purpose of __gxx_personality_v0

In the realm of C programming, especially when dealing with free-standing applications, you may encounter a linker error referencing an undefined symbol named '__gxx_personality_v0'. While a simple workaround exists, it's essential to delve deeper into its purpose.

__gxx_personality_v0 is intimately connected to exception handling in C . Within the stack unwinding tables, which define how the program should unwind the stack in case of exceptions, this symbol represents the Personality Routine as defined by the Itanium C ABI.

In a nutshell, __gxx_personality_v0 assists in unwinding the stack when an exception is thrown. When nothing is throwing an exception, merely defining it as a global NULL void pointer may suffice to prevent the error, but this approach could lead to unexpected behavior if exceptions are later used.

To avoid such issues, it's crucial to acknowledge that exception handling requires the compiler and linker to be aware of the necessary libraries. Instead of using gcc, which does not implicitly link to libstdc , it's advisable to compile using g . This automatically includes -lstdc and ensures that __gxx_personality_v0 and the associated functionality are present.

Alternatively, if exceptions and RTTI are not utilized, it's possible to disable them explicitly using compiler flags like -fno-exceptions and -fno-rtti. By understanding the purpose of __gxx_personality_v0 and its role in exception handling, you can effectively address this linker error and ensure the smooth functioning of your free-standing C applications.

The above is the detailed content of What is __gxx_personality_v0 and why does it cause linker errors in C ?. For more information, please follow other related articles on the PHP Chinese website!