cmake: Added ENABLE_STATIC_LIBS option

- Allows building static libraries
- For users calling find_package(UHD), provides extra options
  for building apps statically linking UHD.
- Updated the init_usrp example to link UHD statically.

4 files changed, 95 insertions, 6 deletions

diff --git a/host/CMakeLists.txt b/host/CMakeLists.txt
index 67a824c8f..c90c5de14 100644
--- a/host/CMakeLists.txt
+++ b/host/CMakeLists.txt
@@ -66,6 +66,14 @@ INCLUDE_DIRECTORIES(${CMAKE_BINARY_DIR}/include)
 INCLUDE_DIRECTORIES(${CMAKE_SOURCE_DIR}/include)
 
 ########################################################################
+# Static Lib Configuration
+########################################################################
+OPTION(ENABLE_STATIC_LIBS "Enable building of static libraries" OFF)
+IF(ENABLE_STATIC_LIBS)
+    MESSAGE(STATUS "Building Static Libraries: ${ENABLE_STATIC_LIBS}")
+ENDIF(ENABLE_STATIC_LIBS)
+
+########################################################################
 # On Apple only, set install name and use rpath correctly, if not already set
 ########################################################################
 IF(APPLE)
@@ -315,14 +323,35 @@ IF(NOT CMAKE_MODULES_DIR)
    SET(CMAKE_MODULES_DIR lib${LIB_SUFFIX}/cmake)
 ENDIF(NOT CMAKE_MODULES_DIR)
 
+# UHDConfig.cmake needs UHD_LINK_LIST_STATIC set:
+LIST(APPEND UHD_LINK_LIST_STATIC "dl")
+LIST(APPEND UHD_LINK_LIST_STATIC "pthread")
+FOREACH(Boost_Comp ${BOOST_REQUIRED_COMPONENTS})
+    IF(NOT ${Boost_Comp} STREQUAL "unit_test_framework")
+        LIST(APPEND UHD_LINK_LIST_STATIC "boost_${Boost_Comp}")
+    ENDIF(NOT ${Boost_Comp} STREQUAL "unit_test_framework")
+ENDFOREACH(Boost_Comp)
+IF(ENABLE_USB)
+    LIST(APPEND UHD_LINK_LIST_STATIC "usb-1.0")
+ENDIF(ENABLE_USB)
+IF(ENABLE_ORC)
+    LIST(APPEND UHD_LINK_LIST_STATIC "orc-0.4")
+ENDIF(ENABLE_ORC)
+message(STATUS "libs: ${UHD_LINK_LIST_STATIC}")
+
 CONFIGURE_FILE(
     ${CMAKE_SOURCE_DIR}/cmake/Modules/UHDConfigVersion.cmake.in
     ${CMAKE_BINARY_DIR}/cmake/Modules/UHDConfigVersion.cmake
     @ONLY
 )
+CONFIGURE_FILE(
+    ${CMAKE_SOURCE_DIR}/cmake/Modules/UHDConfig.cmake.in
+    ${CMAKE_BINARY_DIR}/cmake/Modules/UHDConfig.cmake
+    @ONLY
+)
 
 SET(cmake_configs
-    ${CMAKE_SOURCE_DIR}/cmake/Modules/UHDConfig.cmake
+    ${CMAKE_BINARY_DIR}/cmake/Modules/UHDConfig.cmake
     ${CMAKE_BINARY_DIR}/cmake/Modules/UHDConfigVersion.cmake
 )
 
diff --git a/host/cmake/Modules/UHDConfig.cmake b/host/cmake/Modules/UHDConfig.cmake.in
index cf841cc85..78f01706f 100644
--- a/host/cmake/Modules/UHDConfig.cmake
+++ b/host/cmake/Modules/UHDConfig.cmake.in
@@ -60,6 +60,19 @@ ENDIF()
 LIST(APPEND UHD_INCLUDE_HINTS ${CMAKE_INSTALL_PREFIX}/include)
 LIST(APPEND UHD_LIBDIR_HINTS ${CMAKE_INSTALL_PREFIX}/lib)
 
+
+# Search for static libs if so required
+IF( UHD_USE_STATIC_LIBS )
+    SET( _UHD_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES ${CMAKE_FIND_LIBRARY_SUFFIXES})
+    IF(WIN32)
+        SET(CMAKE_FIND_LIBRARY_SUFFIXES .lib .a ${CMAKE_FIND_LIBRARY_SUFFIXES})
+    ELSE()
+        SET(CMAKE_FIND_LIBRARY_SUFFIXES .a )
+    ENDIF()
+    # This is set during build of UHD to match the installed version:
+    SET(UHD_STATIC_LIB_DEPS "@UHD_LINK_LIST_STATIC@")
+ENDIF()
+
 # Verify that <uhd/config.hpp> and libuhd are available, and, if a
 # version is provided, that UHD meets the version requirements -- no
 # matter what pkg-config might think.
@@ -80,6 +93,18 @@ FIND_LIBRARY(
           /usr/lib
 )
 
+# Set up linker flags for static linking:
+IF(UHD_USE_STATIC_LIBS)
+    IF(WIN32)
+        MESSAGE(FATAL_ERROR "Static linking not available on Windows")
+    ELSE(WIN32)
+        # This works for gcc and Clang:
+        SET(UHD_STATIC_LIB_LINK_FLAG "-Wl,-whole-archive ${UHD_LIBRARIES} -Wl,-no-whole-archive")
+    ENDIF(WIN32)
+    # Restore the library suffixes, if we changed them:
+    SET(CMAKE_FIND_LIBRARY_SUFFIXES ${_UHD_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES})
+ENDIF(UHD_USE_STATIC_LIBS)
+
 IF(UHD_LIBRARIES AND UHD_INCLUDE_DIRS)
 
   INCLUDE(FindPackageHandleStandardArgs)
diff --git a/host/examples/init_usrp/CMakeLists.txt b/host/examples/init_usrp/CMakeLists.txt
index 420e79993..3560dbd45 100644
--- a/host/examples/init_usrp/CMakeLists.txt
+++ b/host/examples/init_usrp/CMakeLists.txt
@@ -1,5 +1,5 @@
 #
-# Copyright 2014 Ettus Research LLC
+# Copyright 2014-2015 Ettus Research LLC
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -18,6 +18,11 @@
 cmake_minimum_required(VERSION 2.8)
 
 ### Set up build environment ##################################################
+# Choose a static or shared-library build (shared is default, and static will
+# probably need some special care!)
+# Set this to ON in order to link a static build of UHD:
+option(UHD_USE_STATIC_LIBS OFF)
+
 # This example also requires Boost:
 set(BOOST_REQUIRED_COMPONENTS
     program_options
@@ -35,10 +40,10 @@ endif(MSVC)
 find_package(Boost "1.46" REQUIRED ${BOOST_REQUIRED_COMPONENTS})
 
 # To add UHD as a dependency to this project, add a line such as this:
-find_package(UHD "3.7.1" REQUIRED)
+find_package(UHD "3.8.0" REQUIRED)
 # The version in  ^^^^^  here is a minimum version.
 # To specify an exact version:
-#find_package(UHD 3.7.1 EXACT REQUIRED)
+#find_package(UHD 3.8.1 EXACT REQUIRED)
 
 ### Configure Compiler ########################################################
 include_directories(
@@ -49,7 +54,26 @@ link_directories(${Boost_LIBRARY_DIRS})
 
 ### Make the executable #######################################################
 add_executable(init_usrp init_usrp.cpp)
-target_link_libraries(init_usrp ${UHD_LIBRARIES} ${Boost_LIBRARIES})
 
+# Shared library case: All we need to do is link against the library, and
+# anything else we need (in this case, some Boost libraries):
+if(NOT UHD_USE_STATIC_LIBS)
+    message(STATUS "Linking against shared UHD library.")
+    target_link_libraries(init_usrp ${UHD_LIBRARIES} ${Boost_LIBRARIES})
+# Shared library case: All we need to do is link against the library, and
+# anything else we need (in this case, some Boost libraries):
+else(NOT UHD_USE_STATIC_LIBS)
+    message(STATUS "Linking against static UHD library.")
+    target_link_libraries(init_usrp
+        # We could use ${UHD_LIBRARIES}, but linking requires some extra flags,
+        # so we use this convenience variable provided to us
+        ${UHD_STATIC_LIB_LINK_FLAG}
+        # Also, when linking statically, we need to pull in all the deps for
+        # UHD as well, because the dependencies don't get resolved automatically
+        ${UHD_STATIC_LIB_DEPS}
+    )
+endif(NOT UHD_USE_STATIC_LIBS)
+
+### Once it's built... ########################################################
 # Here, you would have commands to install your program.
 # We will skip these in this example.
diff --git a/host/lib/CMakeLists.txt b/host/lib/CMakeLists.txt
index eed8b642c..5755a6c4c 100644
--- a/host/lib/CMakeLists.txt
+++ b/host/lib/CMakeLists.txt
@@ -1,5 +1,5 @@
 #
-# Copyright 2010-2014 Ettus Research LLC
+# Copyright 2010-2015 Ettus Research LLC
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -128,3 +128,14 @@ IF(NOT UHDHOST_PKG) #Syntax makes it unusable by UHD_INSTALL
         RUNTIME DESTINATION ${RUNTIME_DIR} COMPONENT libraries # .dll file
     )
 ENDIF(NOT UHDHOST_PKG)
+
+#######################################################
+# Setup libuhd library (static)
+#######################################################
+IF(ENABLE_STATIC_LIBS)
+    ADD_LIBRARY(uhd_static STATIC ${libuhd_sources})
+    SET_TARGET_PROPERTIES(uhd_static PROPERTIES OUTPUT_NAME uhd)
+    INSTALL(TARGETS uhd_static
+        ARCHIVE DESTINATION lib${LIB_SUFFIX} # .lib or .a file
+    )
+ENDIF(ENABLE_STATIC_LIBS)