Fix compilation on macOS with GCC.

[Jhuighuy]

Description

This PR fixes compilation on macOS with GCC (broken in 2022.0, worked fine in 2021.13). What's changed:

• GCC toolchain code assumed that the assembler is always GAS. This may not always be the case, for example, on macOS GCC uses LLVM assembler.
• Changed __TBB_WAITPKG_INTRINSICS_PRESENT: it is now always defined to true on macOS and GCC (always fresh LLVM assembler, so the intrinsic is always present).
• Changed a workaround for -Wdeprecated-declarations in co_context.h: the warning was disabled with a Clang-specific pragma, replaced with Clang-compatible GCC version.

With this changes it is possible to compile and run all tests:

$ mkdir build
$ cd build
$ CXX=g++-14 cmake .. -DBUILD_SHARED_LIBS=NO
$ make
$ make test

Compilation with BUILD_SHARED_LIBS=YES still fails: the linker cannot find a vtable for detail::r1::unsafe_wait. This should be fixed separately.

Fixes #1556

Type of change

• bug fix - change that fixes an issue
• new feature - change that adds functionality
• tests - change in tests
• infrastructure - change in infrastructure and CI
• documentation - documentation update

Tests

• added - required for new features and some bug fixes
• not needed

Documentation

• updated in # - add PR number
• needs to be updated
• not needed

Breaks backward compatibility

• Yes
• No
• Unknown

Notify the following users

Other information

[Jhuighuy]

Updated copyright years.

[saschasc]

What is the status? Currently, I am blocked updating to 2022.0 on macOS.

[dnmokhov]

I am blocked updating to 2022.0 on macOS.

@saschasc, feel free to use -DTBB_STRICT=OFF (cmake/README.md).

[dnmokhov]

Sorry. I realized there is more to this than disabling the warnings. We will review this pull request,

[isaevil]

Is __GNUC__ macro really predefined when using Apple Clang? Shouldn't we still have "elif __clang__"?

[Jhuighuy]

Yes, __GNUC__ is defined.

$ /usr/bin/clang --version
Apple clang version 16.0.0 (clang-1600.0.26.6)
Target: arm64-apple-darwin24.3.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
$ cat ./a.cpp
#ifdef __GNUC__
#error __GNUC__ is defined.
#endif
$ /usr/bin/clang ./a.cpp
./a.cpp:2:2: error: __GNUC__ is defined.
    2 | #error __GNUC__ is defined.
      |  ^
1 error generated.

[Jhuighuy]

I've checked the CI, it is using Apple Clang.

[saschasc]

I am blocked updating to 2022.0 on macOS.

@saschasc, feel free to use -DTBB_STRICT=OFF (cmake/README.md).

I am using the Conan version and right now switching back to the older one. Happy if this gets fixed for the next version. Thank you!

[isaevil]

LGTM