Detect inotify.v5.32.0-rc1v5.32.0

Summary:
On Linux, inotify always exists; all you need is the header file.
On the BSDs, inotify is provided through a shim to kqueue, which
must be installed separately. Add a FindInotify to help sort
that out.

Based on RB 129316 and RB 129549.

Test Plan:
 - On FreeBSD, reliably detects presence of libinotify in $LOCALBASE,
 - Needs testing on Linux that it does find the header file.

Reviewers: apol, arrowdodger, #build_system, #frameworks, tcberner, ervin, skelly, dfaure, kfunk

Reviewed By: tcberner, kfunk

Subscribers: kfunk, #freebsd

Tags: #frameworks, #build_system

Differential Revision: https://phabricator.kde.org/D3826

1 files changed, 79 insertions, 0 deletions

diff --git a/find-modules/FindInotify.cmake b/find-modules/FindInotify.cmake
new file mode 100644
index 00000000..281d6c8b
--- /dev/null
+++ b/find-modules/FindInotify.cmake
@@ -0,0 +1,79 @@
+#.rest:
+# FindInotify
+# --------------
+#
+# Try to find inotify on this system. This finds:
+#  - libinotiy on Unix like systems, or 
+#  - the kernel's inotify on Linux systems.
+#
+# This will define the following variables:
+#
+# ``Inotify_FOUND``
+#    True if inotify is available
+# ``Inotify_LIBRARIES``
+#    This has to be passed to target_link_libraries()
+# ``Inotify_INCLUDE_DIRS``
+#    This has to be passed to target_include_directories()
+#
+# On Linux, the libraries and include directories are empty,
+# even though Inotify_FOUND may be set to TRUE. This is because
+# no special includes or libraries are needed. On other systems
+# these may be needed to use inotify.
+
+#=============================================================================
+# Copyright 2016 Tobias C. Berner <tcberner@FreeBSD.org>
+# Copyright 2017 Adriaan de Groot <groot@kde.org>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#=============================================================================
+
+find_path(Inotify_INCLUDE_DIRS sys/inotify.h)
+
+if(Inotify_INCLUDE_DIRS)
+# On Linux there is no library to link against, on the BSDs there is.
+# On the BSD's, inotify is implemented through a library, libinotify.
+    if( CMAKE_SYSTEM_NAME MATCHES "Linux")
+        set(Inotify_FOUND TRUE)
+        set(Inotify_LIBRARIES "")
+        set(Inotify_INCLUDE_DIRS "")
+    else()
+        find_library(Inotify_LIBRARIES NAMES inotify)
+        include(FindPackageHandleStandardArgs)
+        find_package_handle_standard_args(Inotify
+            FOUND_VAR
+                Inotify_FOUND
+            REQUIRED_VARS
+                Inotify_LIBRARIES
+                Inotify_INCLUDE_DIRS
+        )
+        mark_as_advanced(Inotify_LIBRARIES Inotify_INCLUDE_DIRS)
+        include(FeatureSummary)
+        set_package_properties(Inotify PROPERTIES
+            URL "https://github.com/libinotify-kqueue/"
+            DESCRIPTION "inotify API on the *BSD family of operating systems."
+        )
+    endif()
+else()
+   set(Inotify_FOUND FALSE)
+endif()
+
+mark_as_advanced(Inotify_LIBRARIES Inotify_INCLUDE_DIRS)