[cfe-dev] [llvm-dev] Disk space and RAM requirements in docs
David Chisnall via cfe-dev
cfe-dev at lists.llvm.org
Tue Apr 30 06:23:49 PDT 2019
On 30/04/2019 04:29, Petr Penzin via llvm-dev wrote:
> Have anybody recently built LLVM in Debug mode /within/ space
> requirements from the Getting Started doc?
> > An LLVM-only build will need about 1-3 GB of space. A full build of
> LLVM and Clang will need around 15-20 GB of disk space.
> From my experience this numbers looks drastically low. On FreeBSD my
> recent builds consumed more than 70 GB and on Linux - more than 60. I am
> building LLVM, Clang, and LLD with all default targets and default
> settings. On FreeBSD I am also building Polly. Also, building
> `clang-check` target adds around to 20 GB to the build directory size.
It looks as if running the tests is adding a lot of space to your
builds. I have three LLVM trunk build directories on this machine
Release, building clang, clang-tools-extras, and lld: 1.2GB
Debug, building clang, clang-tools-extras, and lld: 36GB
Debug + ASan, building clang, lldb, and lld: 40GB
1-3GB is still enough to do a release build and not run the tests. I
don't think I've ever done a 'ninja check' in any of these (I have other
build directories for things I'm actively working on), so you can get
down to under 40GB without running the tests for a Debug build.
I'd definitely recommend following Chandler's advice though and not
bothering with a debug-without-asan build. Debug builds are
sufficiently slow that the overhead of Asan on top is not very big -
working on a release build for fast testing and then switching to Asan +
Debug for debugging is a nice way of working.
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