From 73f6f8ebff678a0847e6b197b574082cc285b528 Mon Sep 17 00:00:00 2001
From: Thomas Klausner <tk@giga.or.at>
Date: Sat, 25 Jul 2020 12:03:29 +0200
Subject: [PATCH] Add FindGnuTLS.cmake from 3.17.3.

Addresses #199

[Retrieved from:
https://github.com/nih-at/libzip/commit/73f6f8ebff678a0847e6b197b574082cc285b528]
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
---
 cmake-compat/FindGnuTLS.cmake | 82 +++++++++++++++++++++++++++++++++++
 1 file changed, 82 insertions(+)
 create mode 100644 cmake-compat/FindGnuTLS.cmake

diff --git a/cmake-compat/FindGnuTLS.cmake b/cmake-compat/FindGnuTLS.cmake
new file mode 100644
index 00000000..819f0001
--- /dev/null
+++ b/cmake-compat/FindGnuTLS.cmake
@@ -0,0 +1,82 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+#[=======================================================================[.rst:
+FindGnuTLS
+----------
+
+Find the GNU Transport Layer Security library (gnutls)
+
+IMPORTED Targets
+^^^^^^^^^^^^^^^^
+
+This module defines :prop_tgt:`IMPORTED` target ``GnuTLS::GnuTLS``, if
+gnutls has been found.
+
+Result Variables
+^^^^^^^^^^^^^^^^
+
+``GNUTLS_FOUND``
+  System has gnutls
+``GNUTLS_INCLUDE_DIR``
+  The gnutls include directory
+``GNUTLS_LIBRARIES``
+  The libraries needed to use gnutls
+``GNUTLS_DEFINITIONS``
+  Compiler switches required for using gnutls
+``GNUTLS_VERSION``
+  version of gnutls.
+#]=======================================================================]
+
+# Note that this doesn't try to find the gnutls-extra package.
+
+
+if (GNUTLS_INCLUDE_DIR AND GNUTLS_LIBRARY)
+  # in cache already
+  set(gnutls_FIND_QUIETLY TRUE)
+endif ()
+
+if (NOT WIN32)
+  # try using pkg-config to get the directories and then use these values
+  # in the find_path() and find_library() calls
+  # also fills in GNUTLS_DEFINITIONS, although that isn't normally useful
+  find_package(PkgConfig QUIET)
+  PKG_CHECK_MODULES(PC_GNUTLS QUIET gnutls)
+  set(GNUTLS_DEFINITIONS ${PC_GNUTLS_CFLAGS_OTHER})
+  set(GNUTLS_VERSION ${PC_GNUTLS_VERSION})
+  # keep for backward compatibility
+  set(GNUTLS_VERSION_STRING ${PC_GNUTLS_VERSION})
+endif ()
+
+find_path(GNUTLS_INCLUDE_DIR gnutls/gnutls.h
+  HINTS
+    ${PC_GNUTLS_INCLUDEDIR}
+    ${PC_GNUTLS_INCLUDE_DIRS}
+  )
+
+find_library(GNUTLS_LIBRARY NAMES gnutls libgnutls
+  HINTS
+    ${PC_GNUTLS_LIBDIR}
+    ${PC_GNUTLS_LIBRARY_DIRS}
+  )
+
+mark_as_advanced(GNUTLS_INCLUDE_DIR GNUTLS_LIBRARY)
+
+include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(GnuTLS
+                                  REQUIRED_VARS GNUTLS_LIBRARY GNUTLS_INCLUDE_DIR
+                                  VERSION_VAR GNUTLS_VERSION_STRING)
+
+if(GNUTLS_FOUND)
+  set(GNUTLS_LIBRARIES    ${GNUTLS_LIBRARY})
+  set(GNUTLS_INCLUDE_DIRS ${GNUTLS_INCLUDE_DIR})
+
+  if(NOT TARGET GnuTLS::GnuTLS)
+    add_library(GnuTLS::GnuTLS UNKNOWN IMPORTED)
+    set_target_properties(GnuTLS::GnuTLS PROPERTIES
+      INTERFACE_INCLUDE_DIRECTORIES "${GNUTLS_INCLUDE_DIRS}"
+      INTERFACE_COMPILE_DEFINITIONS "${GNUTLS_DEFINITIONS}"
+      IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+      IMPORTED_LOCATION "${GNUTLS_LIBRARIES}")
+  endif()
+endif()