tree fe89d37daddefef3f3634e70cbd1c9ddf5677d6e
parent f2ae8f8c04b68e12545c9a6d402a42ac9f1c7dcb
author Googler <noreply@google.com> 1676291956 -0800
committer Copybara-Service <copybara-worker@google.com> 1676292042 -0800

Introduce flag --@bazel_tools//tools/cpp:link_extra_libs

Numerous tools override --custom_malloc to add debugging or monitoring runtimes
(see e.g. sanitizers). While this is fine for cases where the tool must also
override malloc to function, in other cases it's simply misuse of
--custom_malloc where no other mechanism exists to link an extra library.

This becomes especially problematic where a runtime library is supposed to be
added in certain configurations that should run in production or other
performance sensitive builds. In these cases, we should _not_ override malloc,
which may also be specified by a cc_binary target. Doing so would introduce
unwanted changes, potentially affecting performance negatively.

To fix abuse of --custom_malloc, add --@bazel_tools//tools/cpp:link_extra_libs,
which is similar, but otherwise does not override other runtime libraries.

Finally, extra libraries are collected in //tools/cpp:link_extra_lib, which can
be used to also introduce libraries based on global configuration rather than
via the command line option.

PiperOrigin-RevId: 509191255
Change-Id: I932afafed574b0cf5f37a8358f6e12c43f59ba1c