// file      : INSTALL.cli
// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
// license   : MIT; see accompanying LICENSE file

"
One of the primary goals of the \c{build2} toolchain is to provide a uniform
build interface across all the platforms and compilers. If you already have
the toolchain installed and would like to upgrade to a newer version, then
there is a single set of \l{#UPGRADE upgrade instructions} for all the
platforms.

If, however, you need to install the toolchain for the first time, then it has
to be bootstrapped and that process is platform-specific. The rest of this
section discusses a few general bootstrap considerations and then directs
you to appropriate platform-specific instructions.

The \c{build2} toolchain requires a C++14 compiler. From the commonly-used
options, GCC 4.8, Clang 3.4, and MSVC 2015/14 Update 2 or later
versions are known to work. Note also that the C++ compiler that you use to
build the \c{build2} toolchain and the one that you will use to build your
projects need not be the same. For example, if you are using MSVC 2013/12
(which cannot build \c{build2}), it is perfectly fine to get a minimal
MinGW toolchain and use that to build \c{build2}; you will still be able
to use MSVC to build your own projects.

At the high level, the bootstrap process involves the following 5 steps.

\dl|

\li|1. Bootstrap, Phase 1\n

First, a minimal build system executable is built using provided shell
scripts/batch files. The result is only guaranteed to be able to rebuild the
build system itself.|

\li|\n2. Bootstrap, Phase 2\n

Then, the build system is rebuilt with static libraries. The result is only
guaranteed to be able to build the toolchain.|

\li|\n3. Stage\n

On this step the entire toolchain is built and staged.|

\li|\n4. Install\n

Next, the staged toolchain is used to build and install the toolchain from
the package repository and using the \c{bpkg} package manager.|

\li|\n5. Clean\n

Finally, the staged toolchain is uninstalled.||

The end result of the bootstrap process is the installed toolchain as well as
the \c{bpkg} configuration (created on step 4) that can be used to upgrade to
newer versions. You can also skip step 4 and instead install on step 3 if
you would prefer not to use the package manager (for example, because the
machine is offline).


For Windows, if using either MSVC or MinGW, continue with
\l{#BOOTSTRAP-WINDOWS Bootstrapping on Windows}. If using MSYS or Cygwin,
then instead refer to \l{#BOOTSTRAP-UNIX Bootstrapping on UNIX}.

For Mac OS X, continue with \l{#BOOTSTRAP-MACOSX Bootstrapping on Mac OS X}.

For other UNIX-like operating systems (GNU/Linux, FreeBSD, etc; this also
includes MSYS/Cygwin), continue with \l{#BOOTSTRAP-UNIX Bootstrapping on
UNIX}.
"