Additional GCC args/test

[jwbensley]

Are these of any benefit?

From: https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html

-fsanitize=alignment - Enable ThreadSanitizer, a fast data race detector. Memory access instructions will be instrumented to detect data race bugs...The option cannot be combined with -fsanitize=address, -fsanitize=leak and/or -fcheck-pointer-bounds.

-fsanitize=thread - Enable ThreadSanitizer, a fast data race detector. Memory access instructions are instrumented to detect data race bugs...The option cannot be combined with -fsanitize=address, -fsanitize=leak and/or -fcheck-pointer-bounds.

-fsanitize=pointer-compare - Instrument comparison operation (<, <=, >, >=) with pointer operands. The option must be combined with either -fsanitize=kernel-address or -fsanitize=address. The option cannot be combined with -fsanitize=thread and/or -fcheck-pointer-bounds. Note: By default the check is disabled at run time. To enable it, add detect_invalid_pointer_pairs=2 to the environment variable ASAN_OPTIONS. Using detect_invalid_pointer_pairs=1 detects invalid operation only when both pointers are non-null.

-fsanitize=pointer-subtract - Instrument subtraction with pointer operands. The option must be combined with either -fsanitize=kernel-address or -fsanitize=address. The option cannot be combined with -fsanitize=thread and/or -fcheck-pointer-bounds. Note: By default the check is disabled at run time. To enable it, add detect_invalid_pointer_pairs=2 to the environment variable ASAN_OPTIONS. Using detect_invalid_pointer_pairs=1 detects invalid operation only when both pointers are non-null.

-fsanitize-address-use-after-scope - Enable sanitization of local variables to detect use-after-scope bugs. The option sets -fstack-reuse to ‘none’.

Investigate the many sub-options available for -fsanitize=undefined - Enable UndefinedBehaviorSanitizer, a fast undefined behavior detector. Various computations are instrumented to detect undefined behavior at runtime.

-fstack-clash-protection - Generate code to prevent stack clash style attacks. When this option is enabled, the compiler will only allocate one page of stack space at a time and each page is accessed immediately after allocation. Thus, it prevents allocations from jumping over any stack guard page provided by the operating system.

This is already in use:
-fsanitize=address - Enable AddressSanitizer, a fast memory error detector. Memory access instructions are instrumented to detect out-of-bounds and use-after-free bugs. The option enables -fsanitize-address-use-after-scope...The option cannot be combined with -fsanitize=thread and/or -fcheck-pointer-bounds.

[jwbensley]

-fanalyzer
https://developers.redhat.com/blog/2020/03/26/static-analysis-in-gcc-10/