Re: [gentoo-dev] Packaging changes in LLVM 10

2020-03-16 Thread Michał Górny
On Mon, 2020-03-16 at 13:37 +0100, Gerion Entrup wrote:
> Am Montag, 16. März 2020, 09:23:49 CET schrieb Michał Górny:
> > Hi,
> > 
> > Since 10.0.0 final is around the corner, I'd like to take a minute to
> > inform developers of packaging changes in Gentoo that affect its
> > revdeps.  Following frequently repeated requests from Gentoo developers
> > and users, LLVM 10 is stopping to use BUILD_SHARED_LIBS=ON, i.e. split
> > shared libraries.  Instead, we'll be using the 'dylib' model recommended
> > upstream.
> > 
> > This means that sys-devel/{llvm,clang} no longer install those small
> > libLLVM*.so and libclang*.so files.  Instead, one big libLLVM-${ver}.so
> > and libclang-cpp.so.${sover} are installed (yes, I know this historical
> > inconsistency sucks).  Also note that Clang continues installing
> > libclang.so which is a *C* (not C++) library.
> > 
> > Most of LLVM revdeps should not have problem with LLVM dylib, as it was
> > the de-facto standard on other distros.  llvm-config handles it
> > transparently.  If you're dealing with a custom build system that
> > doesn't handle it, it's as simple as trying '-lLLVM' first (note that
> > you will '-L' due to slotting).
> > 
> > Clang revdeps may have trouble with clang-cpp library since it's
> > a fairly recent addition.  Again, the solution is simple: '-lclang-cpp'
> > (repeating: do not confuse it with -lclang which is a different library
> > for historical reasons).
> > 
> > sys-devel/lld does not install any libraries anymore.  If you ever need
> > them, please ping me and we'll try to come up with something upstream.
> > 
> > dev-util/lldb installs liblldb.so.  However, I'm not familiar with that
> > library and I don't know if it has any consumers.
> > 
> > If you need any help, please don't hesitate to ping me.
> 
> Hi,
> 
> when I compile LLVM for myself, I also always choose SHARED_LIBS simply
> because of RAM usage when linking the libraries. In the past, I was not
> able to link the single library on my 16 GB machine (I have not tested
> it now and this could be dependent on other circumstances). What is the
> current expected RAM usage for LLVM 10?
> 

To be honest, I don't know.  I have 8G here, and it's entirely
sufficient for -j3 build.  I don't experience major linking problems
as I used to, so things might have improved on binutils end.

-- 
Best regards,
Michał Górny



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Re: [gentoo-dev] Packaging changes in LLVM 10

2020-03-16 Thread Gerion Entrup
Am Montag, 16. März 2020, 09:23:49 CET schrieb Michał Górny:
> Hi,
> 
> Since 10.0.0 final is around the corner, I'd like to take a minute to
> inform developers of packaging changes in Gentoo that affect its
> revdeps.  Following frequently repeated requests from Gentoo developers
> and users, LLVM 10 is stopping to use BUILD_SHARED_LIBS=ON, i.e. split
> shared libraries.  Instead, we'll be using the 'dylib' model recommended
> upstream.
> 
> This means that sys-devel/{llvm,clang} no longer install those small
> libLLVM*.so and libclang*.so files.  Instead, one big libLLVM-${ver}.so
> and libclang-cpp.so.${sover} are installed (yes, I know this historical
> inconsistency sucks).  Also note that Clang continues installing
> libclang.so which is a *C* (not C++) library.
> 
> Most of LLVM revdeps should not have problem with LLVM dylib, as it was
> the de-facto standard on other distros.  llvm-config handles it
> transparently.  If you're dealing with a custom build system that
> doesn't handle it, it's as simple as trying '-lLLVM' first (note that
> you will '-L' due to slotting).
> 
> Clang revdeps may have trouble with clang-cpp library since it's
> a fairly recent addition.  Again, the solution is simple: '-lclang-cpp'
> (repeating: do not confuse it with -lclang which is a different library
> for historical reasons).
> 
> sys-devel/lld does not install any libraries anymore.  If you ever need
> them, please ping me and we'll try to come up with something upstream.
> 
> dev-util/lldb installs liblldb.so.  However, I'm not familiar with that
> library and I don't know if it has any consumers.
> 
> If you need any help, please don't hesitate to ping me.

Hi,

when I compile LLVM for myself, I also always choose SHARED_LIBS simply
because of RAM usage when linking the libraries. In the past, I was not
able to link the single library on my 16 GB machine (I have not tested
it now and this could be dependent on other circumstances). What is the
current expected RAM usage for LLVM 10?

Best,
Gerion


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