GDB relies on
libcc1‘s GCC and GDB plugins to implement the “
compile code” feature, now extended to support the C++ language.
Compile and Execute machinery enables GDB users to compile and execute code snippets within the context of an existing process. This allows users to perform inspection and modification of the program state using the target language well beyond the feature set historically exposed by symbolic debuggers. Almost anything that can be expressed in C, and now also in C++, can be compiled, loaded into the running program, and executed on the spot! It is envisioned that this machinery may also be used in the future to speed up conditional breakpoints, and as a foundation for more advanced features such as “Edit and Continue”.
libcc1 module offers plugins for GDB and GCC that allow GDB to start GCC to compile a user-supplied code snippet. The plugins combine GDB and GCC into a single multi-process program. Through the plugins, GCC can query GDB about the meaning, in the target program, of names encountered in the snippet, and GDB can incrementally inform GCC about variables, functions, types and other constructs present in the program.
Continue reading “C++ support in libcc1: A comprehensive update”