Previously, we linked LibCrypt against LibCrypto. This creates a
circular symbol dependency between LibCore, LibCrypto and LibCrypt.
LibCrypto uses Core::DateTime, LibCrypt uses Crypto::SHA2, and LibCore
uses crypt in Core::Account. The GNU toolchain massages the DT_NEEDED
lines of each library and applications that use each library such that
the Loader finds all the symbols as necessary. However, when using the
Clang toolchain, the circular library dependency is not as tolerated.
We get a symbol not found error in the Loader at runtime, and the app in
question crashes.
Now, we build the SHA2.cpp implementation file into LibCrypt using an
object library and `-fvisibility=hidden -fvisibility-hidden-inlines`.
This adds the implementation in a way that only creates STB_LOCAL
symbols and should avoid nasty ODR problems in the future.
An alternative approach to resolving this dependency would be to move
Core::DateTime to AK, or to make Crypto::ASN1::parse_utc_date return a
struct tm instead of a Core::DateTime. One of those approaches to
remove the LibCore dependency from LibCrypto should probabably be
investigated further in the future.
The net effect of removing this circular library dependency is that one
can now build and run the python3 port with the Clang toolchain :^)
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
