ENH: add optional support for c-ares

CMake/FindCARES.cmake

@@ -0,0 +1,42 @@
+# - Find c-ares
+# Find the c-ares includes and library
+# This module defines
+#  CARES_INCLUDE_DIR, where to find ares.h, etc.
+#  CARES_LIBRARIES, the libraries needed to use c-ares.
+#  CARES_FOUND, If false, do not try to use c-ares.
+# also defined, but not for general use are
+# CARES_LIBRARY, where to find the c-ares library.
+
+FIND_PATH(CARES_INCLUDE_DIR ares.h
+  /usr/local/include
+  /usr/include
+  )
+
+SET(CARES_NAMES ${CARES_NAMES} cares)
+FIND_LIBRARY(CARES_LIBRARY
+  NAMES ${CARES_NAMES}
+  PATHS /usr/lib /usr/local/lib
+  )
+
+IF (CARES_LIBRARY AND CARES_INCLUDE_DIR)
+  SET(CARES_LIBRARIES ${CARES_LIBRARY})
+  SET(CARES_FOUND "YES")
+ELSE (CARES_LIBRARY AND CARES_INCLUDE_DIR)
+  SET(CARES_FOUND "NO")
+ENDIF (CARES_LIBRARY AND CARES_INCLUDE_DIR)
+
+
+IF (CARES_FOUND)
+  IF (NOT CARES_FIND_QUIETLY)
+    MESSAGE(STATUS "Found c-ares: ${CARES_LIBRARIES}")
+  ENDIF (NOT CARES_FIND_QUIETLY)
+ELSE (CARES_FOUND)
+  IF (CARES_FIND_REQUIRED)
+    MESSAGE(FATAL_ERROR "Could not find c-ares library")
+  ENDIF (CARES_FIND_REQUIRED)
+ENDIF (CARES_FOUND)
+
+MARK_AS_ADVANCED(
+  CARES_LIBRARY
+  CARES_INCLUDE_DIR
+  )

CMakeLists.txt

@@ -68,6 +68,17 @@ endif()
 option(BUILD_CURL_EXE "Set to ON to build cURL executable." ON)
 option(BUILD_CURL_TESTS "Set to ON to build cURL tests." ON)
 option(CURL_STATICLIB "Set to ON to build libcurl with static linking." OFF)
+option(CURL_USE_ARES "Set to ON to enable c-ares support" OFF)
+# initialize CURL_LIBS
+set(CURL_LIBS "")
+
+if(CURL_USE_ARES)
+  set(USE_ARES ${CURL_USE_ARES})
+  find_package(CARES REQUIRED) 
+  list(APPEND CURL_LIBS ${CARES_LIBRARY} )
+  message("CURL_LIBS = ${CURL_LIBS}")
+  set(CURL_LIBS ${CURL_LIBS} ${CARES_LIBRARY})
+endif()
 
 option(BUILD_DASHBOARD_REPORTS "Set to ON to activate reporting of cURL builds here http://www.cdash.org/CDashPublic/index.php?project=CURL" OFF)
 if(BUILD_DASHBOARD_REPORTS)
@@ -188,7 +199,6 @@ endif(WIN32)
 
 # This macro checks if the symbol exists in the library and if it
 # does, it appends library to the list.
-set(CURL_LIBS "")
 macro(CHECK_LIBRARY_EXISTS_CONCAT LIBRARY SYMBOL VARIABLE)
   check_library_exists("${LIBRARY};${CURL_LIBS}" ${SYMBOL} "" 
     ${VARIABLE})

lib/CMakeLists.txt

@@ -5,7 +5,6 @@ configure_file(${CURL_SOURCE_DIR}/include/curl/curlbuild.h.cmake
 configure_file(curl_config.h.cmake
   ${CMAKE_CURRENT_BINARY_DIR}/curl_config.h)
 
-
 transform_makefile_inc("Makefile.inc" "${CMAKE_CURRENT_BINARY_DIR}/Makefile.inc.cmake")
 include(${CMAKE_CURRENT_BINARY_DIR}/Makefile.inc.cmake)
 
@@ -77,6 +76,9 @@ include_directories(${CMAKE_CURRENT_SOURCE_DIR}/../include)
 include_directories(${CMAKE_CURRENT_BINARY_DIR}/..)
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 include_directories(${CMAKE_CURRENT_BINARY_DIR})
+if(CURL_USE_ARES)
+  include_directories(${CARES_INCLUDE_DIR})
+endif()
 
 if(CURL_STATICLIB)
   # Static lib

tests/libtest/CMakeLists.txt

@@ -9,7 +9,9 @@ function(SETUP_TEST TEST_NAME)          # ARGN are the files in the test
     ${CURL_BINARY_DIR}/lib          # To be able to reach "curl_config.h"
     ${CURL_BINARY_DIR}/include      # To be able to reach "curl/curlbuild.h"
     )
-
+  if(CURL_USE_ARES)
+    include_directories(${CARES_INCLUDE_DIR})
+  endif()
   setup_curl_dependencies(${TEST_NAME})
   target_link_libraries( ${TEST_NAME} libcurl )
 

tests/server/CMakeLists.txt

@@ -9,7 +9,10 @@ function(SETUP_EXECUTABLE TEST_NAME)    # ARGN are the files in the test
     ${CURL_BINARY_DIR}/lib              # To be able to reach "curl_config.h"
     ${CURL_BINARY_DIR}/include  # To be able to reach "curl/curlbuild.h"
     )
-
+  if(CURL_USE_ARES)
+    include_directories(${CARES_INCLUDE_DIR})
+  endif()  
+  # resolve test needs this 
   setup_curl_dependencies(${TEST_NAME})
   #TARGET_LINK_LIBRARIES( ${TEST_NAME} libcurl )