692c77f2af
This commit does a few things, with the intent to make it more straightforward
to potential future users how to get started with llvm-libc. Answers to "What's
the status and how do I use it?" are front and center, "above the fold."
This commit does a few things:
* reorganize the landing page's toctree: start with implementation status, arch
* support, platform support, and
compiler support.
* Then a (new) simple getting started page using full host builds. Then more
* Advanced topics such as host vs cross builds, overlay mode,
gpu builds and additional configuration options.
* Remove c23 status, the old fullbuild_mode landing page, and
usage_modes landing pages. c23 status isn't as interesting as I originally
thought it might.
We should point people at full host builds to start, then link to more info on
cross compilation, or overlay mode as more advanced topics. I assert most users
starting out won't care about those.
59 lines
1.6 KiB
ReStructuredText
59 lines
1.6 KiB
ReStructuredText
Getting Started
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===============
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Let's fetch the llvm-libc sources and build them.
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Install dependencies first:
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.. code-block:: sh
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$ sudo apt update
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$ sudo apt install git cmake ninja-build clang gcc-multilib
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.. code-block:: sh
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$ git clone --depth=1 git@github.com:llvm/llvm-project.git /tmp/llvm-project
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$ mkdir /tmp/llvm-project/build
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$ cd /tmp/llvm-project/build
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$ cmake ../runtimes -GNinja \
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-DLLVM_ENABLE_RUNTIMES="libc;compiler-rt" \
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-DCMAKE_BUILD_TYPE=Debug \
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-DCMAKE_CXX_COMPILER=clang++ \
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-DCMAKE_C_COMPILER=clang \
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-DLLVM_LIBC_FULL_BUILD=ON \
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-DLLVM_LIBC_INCLUDE_SCUDO=ON \
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-DCOMPILER_RT_BUILD_SCUDO_STANDALONE_WITH_LLVM_LIBC=ON \
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-DCOMPILER_RT_BUILD_GWP_ASAN=OFF \
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-DCOMPILER_RT_SCUDO_STANDALONE_BUILD_SHARED=OFF
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$ ninja libc libm
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This will produce the following artifacts:
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.. code-block::
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llvm-project/build/libc/lib/libc.a
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llvm-project/build/libc/lib/libm.a
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llvm-project/build/libc/startup/linux/crt1.o
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llvm-project/build/libc/include/**.h
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We can then compile and run hello world via:
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.. code-block:: c++
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// hello.c
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#include <stdio.h>
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int main () { puts("hello world"); }
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.. code-block:: sh
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$ clang -nostdinc -nostdlib hello.c -I libc/include \
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-I $(clang -print-resource-dir)/include libc/startup/linux/crt1.o \
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libc/lib/libc.a
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$ ./a.out
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hello world
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This was what we call a "full build" of llvm-libc. From here, you can visit
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:ref:`full_host_build` for more info, :ref:`full_cross_build` for cross
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compiling, :ref:`overlay_mode` for mixing llvm-libc with another libc, or
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:ref:`libc_gpu` for targeting GPUs.
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