Opt out install set

[SchrodingerZhu]

When using snmalloc as a header-only library, one may not want the default installation targets. We should provide a way to opt out the installation.

[mjp41]

Do you have in mind what would be the right approach

• A new flag to remove install targets.
• Some other CMake magic I don't understand ;)

[nickdesaulniers]

Would it be possible to have two distinct targets? A build target which is distinct from an install target (which depends on the build target)? That way, users who want to build, but not install can be more specific.

[mjp41]

@nickdesaulniers I am not sure I follow

The main target for snmalloc is snmalloc, which is just the settings to build it in a header only way:

snmalloc/CMakeLists.txt

Line 222 in e3e5584

add_library(snmalloc INTERFACE)

I would have thought you could just consume this build target, and as long as you EXCLUDE_FROM_ALL on the add_subdirectory cmake call, then the install targets wouldn't be added to the parent project.

@SchrodingerZhu can you confirm the install trick is actually required in the libc work?

[SchrodingerZhu]

I remember the problem was that LLVM was doing sth with export sets and that messed up with snmalloc even when EXCLUDE_FROM_ALL is used.

I will be retrying it to get the error log.