From 217985adf0785779799b8b6f9b39d89f811d56f9 Mon Sep 17 00:00:00 2001
From: Axel Huebl <axel.huebl@plasma.ninja>
Date: Fri, 14 Jul 2017 16:03:06 +0200
Subject: [PATCH 1/3] CMake: pkg-config Fallback

Try to find installs of `libzmq` that were performed with
autotools with a `pkg-config` fallback.
---
 CMakeLists.txt        | 30 +++++++++++++++++++++++++++++-
 cppzmqConfig.cmake.in | 30 +++++++++++++++++++++++++++++-
 2 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c0d0d29..08fb7a6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,7 +1,35 @@
 cmake_minimum_required(VERSION 2.8.12)
 project(cppzmq)
 
-find_package(ZeroMQ REQUIRED)
+find_package(ZeroMQ)
+
+# libzmq autotools install: fallback to pkg-config
+if(NOT ZeroMQ_FOUND)
+    find_package(PkgConfig)
+    pkg_check_modules(PC_LIBZMQ QUIET libzmq)
+
+    set(ZeroMQ_VERSION ${PC_LIBZMQ_VERSION})
+    find_library(ZeroMQ_LIBRARY NAMES libzmq.so
+                 PATHS ${PC_LIBZMQ_LIBDIR} ${PC_LIBZMQ_LIBRARY_DIRS})
+    find_library(ZeroMQ_STATIC_LIBRARY NAMES libzmq.a
+                 PATHS ${PC_LIBZMQ_LIBDIR} ${PC_LIBZMQ_LIBRARY_DIRS})
+
+    add_library(libzmq SHARED IMPORTED)
+    set_property(TARGET libzmq PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${PC_LIBZMQ_INCLUDE_DIRS})
+    set_property(TARGET libzmq PROPERTY IMPORTED_LOCATION ${ZeroMQ_LIBRARY})
+
+    add_library(libzmq-static STATIC IMPORTED ${PC_LIBZMQ_INCLUDE_DIRS})
+    set_property(TARGET libzmq-static PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${PC_LIBZMQ_INCLUDE_DIRS})
+    set_property(TARGET libzmq-static PROPERTY IMPORTED_LOCATION ${ZeroMQ_STATIC_LIBRARY})
+
+    if(ZeroMQ_LIBRARY AND ZeroMQ_STATIC_LIBRARY)
+        set(ZeroMQ_FOUND ON)
+    endif()
+endif()
+
+if(NOT ZeroMQ_FOUND)
+    message(FATAL_ERROR "ZeroMQ was NOT found!")
+endif()
 
 if (ZeroMQ_FOUND AND (NOT TARGET libzmq OR NOT TARGET libzmq-static))
   message(FATAL_ERROR "ZeroMQ version not supported!")
diff --git a/cppzmqConfig.cmake.in b/cppzmqConfig.cmake.in
index 24b217c..2dd990b 100644
--- a/cppzmqConfig.cmake.in
+++ b/cppzmqConfig.cmake.in
@@ -17,7 +17,35 @@
 @PACKAGE_INIT@
 
 include(CMakeFindDependencyMacro)
-find_dependency(ZeroMQ)
+find_package(ZeroMQ)
+
+# libzmq autotools install: fallback to pkg-config
+if(NOT ZeroMQ_FOUND)
+    find_package(PkgConfig)
+    pkg_check_modules(PC_LIBZMQ QUIET libzmq)
+
+    set(ZeroMQ_VERSION ${PC_LIBZMQ_VERSION})
+    find_library(ZeroMQ_LIBRARY NAMES libzmq.so
+                 PATHS ${PC_LIBZMQ_LIBDIR} ${PC_LIBZMQ_LIBRARY_DIRS})
+    find_library(ZeroMQ_STATIC_LIBRARY NAMES libzmq.a
+                 PATHS ${PC_LIBZMQ_LIBDIR} ${PC_LIBZMQ_LIBRARY_DIRS})
+
+    add_library(libzmq SHARED IMPORTED)
+    set_property(TARGET libzmq PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${PC_LIBZMQ_INCLUDE_DIRS})
+    set_property(TARGET libzmq PROPERTY IMPORTED_LOCATION ${ZeroMQ_LIBRARY})
+
+    add_library(libzmq-static STATIC IMPORTED ${PC_LIBZMQ_INCLUDE_DIRS})
+    set_property(TARGET libzmq-static PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${PC_LIBZMQ_INCLUDE_DIRS})
+    set_property(TARGET libzmq-static PROPERTY IMPORTED_LOCATION ${ZeroMQ_STATIC_LIBRARY})
+
+    if(ZeroMQ_LIBRARY AND ZeroMQ_STATIC_LIBRARY)
+        set(ZeroMQ_FOUND ON)
+    endif()
+endif()
+
+if(NOT ZeroMQ_FOUND)
+    message(FATAL_ERROR "ZeroMQ was NOT found!")
+endif()
 
 if(NOT TARGET @PROJECT_NAME@)
   include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Targets.cmake")

From 2008da35e6b7e2fcd441e0e4eb3314c88d2d39b1 Mon Sep 17 00:00:00 2001
From: Axel Huebl <axel.huebl@plasma.ninja>
Date: Tue, 18 Jul 2017 20:15:41 +0200
Subject: [PATCH 2/3] Pkg-Config Fallback: File

move the new logic to a simple file so we
do not add code duplication
---
 CMakeLists.txt                | 22 ++--------------------
 cppzmqConfig.cmake.in         | 21 +--------------------
 libzmqPkgConfigFallback.cmake | 20 ++++++++++++++++++++
 3 files changed, 23 insertions(+), 40 deletions(-)
 create mode 100644 libzmqPkgConfigFallback.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 08fb7a6..f0b8f89 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,26 +5,7 @@ find_package(ZeroMQ)
 
 # libzmq autotools install: fallback to pkg-config
 if(NOT ZeroMQ_FOUND)
-    find_package(PkgConfig)
-    pkg_check_modules(PC_LIBZMQ QUIET libzmq)
-
-    set(ZeroMQ_VERSION ${PC_LIBZMQ_VERSION})
-    find_library(ZeroMQ_LIBRARY NAMES libzmq.so
-                 PATHS ${PC_LIBZMQ_LIBDIR} ${PC_LIBZMQ_LIBRARY_DIRS})
-    find_library(ZeroMQ_STATIC_LIBRARY NAMES libzmq.a
-                 PATHS ${PC_LIBZMQ_LIBDIR} ${PC_LIBZMQ_LIBRARY_DIRS})
-
-    add_library(libzmq SHARED IMPORTED)
-    set_property(TARGET libzmq PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${PC_LIBZMQ_INCLUDE_DIRS})
-    set_property(TARGET libzmq PROPERTY IMPORTED_LOCATION ${ZeroMQ_LIBRARY})
-
-    add_library(libzmq-static STATIC IMPORTED ${PC_LIBZMQ_INCLUDE_DIRS})
-    set_property(TARGET libzmq-static PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${PC_LIBZMQ_INCLUDE_DIRS})
-    set_property(TARGET libzmq-static PROPERTY IMPORTED_LOCATION ${ZeroMQ_STATIC_LIBRARY})
-
-    if(ZeroMQ_LIBRARY AND ZeroMQ_STATIC_LIBRARY)
-        set(ZeroMQ_FOUND ON)
-    endif()
+    include(${CMAKE_CURRENT_LIST_DIR}/libzmqPkgConfigFallback.cmake)
 endif()
 
 if(NOT ZeroMQ_FOUND)
@@ -79,4 +60,5 @@ install(EXPORT ${PROJECT_NAME}-targets
         DESTINATION ${CPPZMQ_CMAKECONFIG_INSTALL_DIR})
 install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake
               ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
+              ${CMAKE_SOURCE_DIR}/libzmqPkgConfigFallback.cmake
               DESTINATION ${CPPZMQ_CMAKECONFIG_INSTALL_DIR})
diff --git a/cppzmqConfig.cmake.in b/cppzmqConfig.cmake.in
index 2dd990b..6fe6f5f 100644
--- a/cppzmqConfig.cmake.in
+++ b/cppzmqConfig.cmake.in
@@ -21,26 +21,7 @@ find_package(ZeroMQ)
 
 # libzmq autotools install: fallback to pkg-config
 if(NOT ZeroMQ_FOUND)
-    find_package(PkgConfig)
-    pkg_check_modules(PC_LIBZMQ QUIET libzmq)
-
-    set(ZeroMQ_VERSION ${PC_LIBZMQ_VERSION})
-    find_library(ZeroMQ_LIBRARY NAMES libzmq.so
-                 PATHS ${PC_LIBZMQ_LIBDIR} ${PC_LIBZMQ_LIBRARY_DIRS})
-    find_library(ZeroMQ_STATIC_LIBRARY NAMES libzmq.a
-                 PATHS ${PC_LIBZMQ_LIBDIR} ${PC_LIBZMQ_LIBRARY_DIRS})
-
-    add_library(libzmq SHARED IMPORTED)
-    set_property(TARGET libzmq PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${PC_LIBZMQ_INCLUDE_DIRS})
-    set_property(TARGET libzmq PROPERTY IMPORTED_LOCATION ${ZeroMQ_LIBRARY})
-
-    add_library(libzmq-static STATIC IMPORTED ${PC_LIBZMQ_INCLUDE_DIRS})
-    set_property(TARGET libzmq-static PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${PC_LIBZMQ_INCLUDE_DIRS})
-    set_property(TARGET libzmq-static PROPERTY IMPORTED_LOCATION ${ZeroMQ_STATIC_LIBRARY})
-
-    if(ZeroMQ_LIBRARY AND ZeroMQ_STATIC_LIBRARY)
-        set(ZeroMQ_FOUND ON)
-    endif()
+    include(${CMAKE_CURRENT_LIST_DIR}/libzmqPkgConfigFallback.cmake)
 endif()
 
 if(NOT ZeroMQ_FOUND)
diff --git a/libzmqPkgConfigFallback.cmake b/libzmqPkgConfigFallback.cmake
new file mode 100644
index 0000000..bb57aaf
--- /dev/null
+++ b/libzmqPkgConfigFallback.cmake
@@ -0,0 +1,20 @@
+find_package(PkgConfig)
+pkg_check_modules(PC_LIBZMQ QUIET libzmq)
+
+set(ZeroMQ_VERSION ${PC_LIBZMQ_VERSION})
+find_library(ZeroMQ_LIBRARY NAMES libzmq.so
+             PATHS ${PC_LIBZMQ_LIBDIR} ${PC_LIBZMQ_LIBRARY_DIRS})
+find_library(ZeroMQ_STATIC_LIBRARY NAMES libzmq.a
+             PATHS ${PC_LIBZMQ_LIBDIR} ${PC_LIBZMQ_LIBRARY_DIRS})
+
+add_library(libzmq SHARED IMPORTED)
+set_property(TARGET libzmq PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${PC_LIBZMQ_INCLUDE_DIRS})
+set_property(TARGET libzmq PROPERTY IMPORTED_LOCATION ${ZeroMQ_LIBRARY})
+
+add_library(libzmq-static STATIC IMPORTED ${PC_LIBZMQ_INCLUDE_DIRS})
+set_property(TARGET libzmq-static PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${PC_LIBZMQ_INCLUDE_DIRS})
+set_property(TARGET libzmq-static PROPERTY IMPORTED_LOCATION ${ZeroMQ_STATIC_LIBRARY})
+
+if(ZeroMQ_LIBRARY AND ZeroMQ_STATIC_LIBRARY)
+    set(ZeroMQ_FOUND ON)
+endif()

From d1568bf1e95b699693655a5d9994861534752f07 Mon Sep 17 00:00:00 2001
From: Axel Huebl <axel.huebl@plasma.ninja>
Date: Wed, 19 Jul 2017 10:43:07 +0200
Subject: [PATCH 3/3] Fix #121 CMake Min Version

CMake targets / interfaces need at least CMake 3.0
---
 CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f0b8f89..44c0835 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8.12)
+cmake_minimum_required(VERSION 3.0.0)
 project(cppzmq)
 
 find_package(ZeroMQ)