Update documentation for pkg_config().

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41229 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 14 insertions, 4 deletions

diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index 672b97b7ec..f6637b493d 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -1717,11 +1717,21 @@ SRC
 
   # :stopdoc:
 
-  # Handles meta information about installed libraries. Uses your platform's
-  # pkg-config program if it has one.
+  # Returns compile/link information about an installed library in a
+  # tuple of <code>[cflags, ldflags, libs]</code>, by using the
+  # command found first in the following commands:
   #
-  # The actual command name can be overridden by
-  # <code>--with-pkg-config</code> command line option.
+  # 1. If <code>--with-{pkg}-config={command}</code> is given via
+  #    command line option: <code>{command} {option}</code>
+  #
+  # 2. <code>{pkg}-config {option}</code>
+  #
+  # 3. <code>pkg-config {option} {pkg}</code>
+  #
+  # Where {option} is, for instance, <code>--cflags</code>.
+  #
+  # If an <code>option</code> argument is given, the config command is
+  # invoked with the option and a stripped output string is returned.
   def pkg_config(pkg, option=nil)
     if pkgconfig = with_config("#{pkg}-config") and find_executable0(pkgconfig)
       # iff package specific config command is given