Merge branch 'mainstream'

[sliver-openvswitch.git] / INSTALL

diff --git a/INSTALL b/INSTALL
index 0ff237c..c8b1aa7 100644 (file)
--- a/INSTALL
+++ b/INSTALL
@@ -18,8 +18,13 @@ you will need the following software:
 
     - GNU make.
 
-    - The GNU C compiler.  We generally test with version 4.1, 4.2, or
-      4.3.
+    - A C compiler, such as:
+
+        * GCC 4.x.
+
+        * Clang.  Clang 3.4 and later provide useful static semantic
+          analysis and thread-safety checks.  For Ubuntu, there are
+          nightly built packages available on clang's website.
 
     - libssl, from OpenSSL, is optional but recommended if you plan to
       connect the Open vSwitch to an OpenFlow controller.  libssl is
@@ -88,9 +93,8 @@ To run the unit tests, you also need:
     - Perl.  Version 5.10.1 is known to work.  Earlier versions should
       also work.
 
-If you modify the vswitchd database schema, then the E-R diagram in
-the ovs-vswitchd.conf.db(5) manpage will be updated properly only if
-you have the following:
+The ovs-vswitchd.conf.db(5) manpage will include an E-R diagram, in
+formats other than plain text, only if you have the following:
 
     - "dot" from graphviz (http://www.graphviz.org/).
 
@@ -107,6 +111,10 @@ installing the following to obtain better warnings:
 
     - GNU make.
 
+    - clang, version 3.4 or later
+
+Also, you may find the ovs-dev script found in utilities/ovs-dev.py useful.
+
 Installation Requirements
 -------------------------
 
@@ -171,6 +179,10 @@ Prerequisites section, follow the procedure below to build.
 
       % ./configure CC=gcc-4.2
 
+   To use 'clang' compiler:
+
+      % ./configure CC=clang
+
    To build the Linux kernel module, so that you can run the
    kernel-based switch, pass the location of the kernel build
    directory on --with-linux.  For example, to build for a running