doc: Improve install guide (#1121)

diff --git a/doc/INSTALL.md b/doc/INSTALL.md
index 641d0169738cca44116e50d6f9fd1c9c4e9e06b3..5c10109b431c6ecd800508f86fc08f1b4063837b 100644 (file)
--- a/doc/INSTALL.md
+++ b/doc/INSTALL.md
@@ -11,31 +11,28 @@ To build ccache you need:
   languages](https://ccache.dev/platform-compiler-language-support.html) for
   details.
 - A C99 compiler.
-- [libzstd](http://www.zstd.net). If you don't have libzstd installed and
-  can't or don't want to install it in a standard system location, there are
-  two options:
+- [libzstd](http://www.zstd.net). If you don't have libzstd installed and can't
+  or don't want to install it in a standard system location, it will be
+  automatically downloaded, built and linked statically as part of the build
+  process. To disable this, pass `-DZSTD_FROM_INTERNET=OFF` to `cmake`. You can
+  also install zstd in a custom path and pass
+  `-DCMAKE_PREFIX_PATH=/some/custom/path` to `cmake`.
 
-    1. Install zstd in a custom path and set `CMAKE_PREFIX_PATH` to it, e.g.
-       by passing `-DCMAKE_PREFIX_PATH=/some/custom/path` to `cmake`, or
-    2. Pass `-DZSTD_FROM_INTERNET=ON` to `cmake` to make it download libzstd
-       from the Internet and unpack it in the local binary tree. Ccache will
-       then be linked statically to the locally built libzstd.
-
-  To link libzstd statically you can use `-DZSTD_LIBRARY=/path/to/libzstd.a`.
+  To link libzstd statically, if you have a static libzstd available pass
+  `-DSTATIC_LINK=ON` to cmake, this is the default on Windows. Or use
+  `-DZSTD_LIBRARY=/path/to/libzstd.a`.
 
 Optional:
 
 - [hiredis](https://github.com/redis/hiredis) for the Redis storage backend. If
   you don't have libhiredis installed and can't or don't want to install it in a
-  standard system location, there are two options:
-
-    1. Install hiredis in a custom path and set `CMAKE_PREFIX_PATH` to it, e.g.
-       by passing `-DCMAKE_PREFIX_PATH=/some/custom/path` to `cmake`, or
-    2. Pass `-DHIREDIS_FROM_INTERNET=ON` to `cmake` to make it download hiredis
-       from the Internet and unpack it in the local binary tree. Ccache will
-       then be linked statically to the locally built libhiredis.
+  standard system location, it will be automatically downloaded, built and
+  linked statically as part of the build process. To disable this, pass
+  `-DHIREDIS_FROM_INTERNET=OFF` to cmake. You can also install hiredis in a
+  custom path and pass `-DCMAKE_PREFIX_PATH=/some/custom/path` to `cmake`.
 
-  To link libhiredis statically you can use
+  To link libhiredis statically, if you have a static libhiredis available pass
+  `-DSTATIC_LINK=ON` to cmake, this is the default on Windows. Or use
   `-DHIREDIS_LIBRARY=/path/to/libhiredis.a`.
 - GNU Bourne Again SHell (bash) for tests.
 - [Asciidoctor](https://asciidoctor.org) to build the HTML documentation.
@@ -52,11 +49,13 @@ Installation
 
 Here is the typical way to build and install ccache:
 
-    mkdir build
-    cd build
-    cmake -DCMAKE_BUILD_TYPE=Release ..
-    make
-    make install
+```bash
+mkdir build
+cd build
+cmake -DCMAKE_BUILD_TYPE=Release ..
+make
+make install
+```
 
 You can set the installation directory to e.g. `/usr` by adding
 `-DCMAKE_INSTALL_PREFIX=/usr` to the `cmake` command. You can set the directory
@@ -72,21 +71,21 @@ There are two different ways to use ccache to cache a compilation:
    wish to use ccache for all your compilations. To do this, create a symbolic
    link to ccache named as the compiler. For example, here is set up ccache to
    masquerade as `gcc` and `g++`:
-+
--------------------------------------------------------------------------------
+
+```bash
 cp ccache /usr/local/bin/
 ln -s ccache /usr/local/bin/gcc
 ln -s ccache /usr/local/bin/g++
--------------------------------------------------------------------------------
-+
-On platforms that don't support symbolic links you can simply copy ccache to the
+```
+
+. On platforms that don't support symbolic links you can simply copy ccache to the
 compiler name instead for a similar effect:
-+
--------------------------------------------------------------------------------
+
+```bash
 cp ccache /usr/local/bin/gcc
 cp ccache /usr/local/bin/g++
--------------------------------------------------------------------------------
-+
-And so forth. This will work as long as the directory with symbolic links or
+```
+
+. And so forth. This will work as long as the directory with symbolic links or
 ccache copies comes before the directory with the compiler (typically
 `/usr/bin`) in `PATH`.