Remove O1 from sanitizer feature flag defaults

[chiragramani]

This PR removes -O1 from the current set of sanitizer related feature flags defaults.

Context and Repro

1. Heap buffer overflow in the following code block is not caught by asan.

example.cc

#include <cstdlib>

int main(int argc, char **argv) {
  int *array = new int[100];
  array[0] = 0;
  int res = array[argc + 100];  // BOOM
  delete [] array;
  return res;
}

BUILD

cc_binary(
  name = 'example',
  srcs = ['example.cc'],
  features = ['asan'],
)

execute:

bazel run :example

Expectation:
Address sanitizer should detect and report heap buffer overflow.

But this doesn't happen in the above case. It is because of O1 being applied by default and since this is added at the last, it also overrides explicit copts passed(O0). It would be nice if the optimization level is a bit de-coupled from the default group here.

[chiragramani]

cc: @brentleyjones

[fmeum]

@chiragramani I can't reproduce this on Linux with clang 14. What is your setup?

Given that -O0 tends to lead to much slower code, ideally we would find less invasive flags that allow you to reproduce the ASan finding in this case. This is especially relevant when combining sanitizers with fuzzing, where execution speed is key.

[brentleyjones]

But can't you add -O1 if you need it? The main issue for us is that it forces this change on us, especially in the rules_xcodeproj case.

[fmeum]

@brentleyjones Sorry, I somehow thought this would add -O0 instead of -O1 - yes, I agree that the sanitizer features shouldn't affect the optimization level by themselves.

If the C++ toolchain framework supports it, we could add flags we know work well depending on the build mode, but that's a separate effort.

[fmeum]

@oquenchil Could you review?

[fmeum]

@bazel-io flag

[fmeum]

@chiragramani Could you also remove the -O1 flag added in #17083 for consistency?

[chiragramani]

@chiragramani Could you also remove the -O1 flag added in #17083 for consistency?

Thanks for reviewing it, updated the PR.

[ShreeM01]

@bazel-io fork 6.1.0