cmake: find folly using its CMake package configuration file

Summary:
Update thrift's CMakeLists.txt to find folly using its installed CMake package
configuration file, and depend on it via the `Folly::folly` target.

By using the `Folly::folly` target all include directories required to use
folly are automatically included in the include paths, and all libraries that
folly depends on are automatically added to the link line.  Since wangle only
requires double-conversion indirectly via folly I also deleted the explicit
checks for double-conversion.

Note that this change does require that folly was built and installed with
CMake, rather than with its older autoconf build system.

Reviewed By: wez

Differential Revision: D7479054

fbshipit-source-id: 093a69d83e9f1c62718d22cec8d6b180d84e4325

CMakeLists.txt

@@ -74,8 +74,7 @@ endif(compiler_only OR build_all)
 
 # Find required dependencies for thrift/lib
 if(lib_only OR build_all)
-  find_package(DoubleConversion REQUIRED)
-  find_package(Folly REQUIRED)
+  find_package(folly CONFIG REQUIRED)
   find_package(GFlags REQUIRED)
   find_package(Glog REQUIRED)
   find_package(Krb5 REQUIRED gssapi)
@@ -87,8 +86,6 @@ if(lib_only OR build_all)
   set(THREADS_PREFER_PTHREAD_FLAG ON)
   find_package(Threads)
   include_directories(
-    ${DOUBLE_CONVERSION_INCLUDE_DIR}
-    ${FOLLY_INCLUDE_DIR}
     ${GFLAGS_INCLUDE_DIRS}
     ${GLOG_INCLUDE_DIRS}
     ${KRB5_INCLUDE_DIRS}

thrift/lib/cpp/CMakeLists.txt

@@ -13,7 +13,7 @@ target_include_directories(
 target_link_libraries(
   thrift-core
   PUBLIC
-    ${FOLLY_LIBRARY}
+    Folly::folly
 )
 
 add_library(
@@ -29,7 +29,7 @@ add_library(
 target_link_libraries(
   concurrency
   PUBLIC
-    ${FOLLY_LIBRARY}
+    Folly::folly
     ${GFLAGS_LIBRARIES}
     ${GLOG_LIBRARIES}
 )
@@ -49,8 +49,7 @@ add_dependencies(protocol reflection-cpp2-target)
 target_link_libraries(
   protocol
   PUBLIC
-    ${DOUBLE_CONVERSION_LIBRARY}
-    ${FOLLY_LIBRARY}
+    Folly::folly
     ${GLOG_LIBRARIES}
 )
 
@@ -85,7 +84,7 @@ target_link_libraries(
   PUBLIC
     concurrency
     thrift-core
-    ${FOLLY_LIBRARY}
+    Folly::folly
     ${OPENSSL_LIBRARIES}
     ${ZLIB_LIBRARIES}
     ${ZSTD_LIBRARIES}
@@ -110,7 +109,7 @@ target_link_libraries(
     concurrency
     transport
     ${Boost_LIBRARIES}
-    ${FOLLY_LIBRARY}
+    Folly::folly
     ${GLOG_LIBRARIES}
     ${OPENSSL_LIBRARIES}
 )
@@ -135,7 +134,7 @@ target_link_libraries(
   PUBLIC
     ${KRB5_LIBRARIES}
     ${Boost_LIBRARIES}
-    ${FOLLY_LIBRARY}
+    Folly::folly
     ${GFLAGS_LIBRARIES}
     ${GLOG_LIBRARIES}
 )
@@ -148,7 +147,7 @@ add_library(
 target_link_libraries(
   server
   PUBLIC
-    ${FOLLY_LIBRARY}
+    Folly::folly
 )
 
 add_library(
@@ -163,7 +162,7 @@ target_link_libraries(
     concurrency
     protocol
     transport
-    ${FOLLY_LIBRARY}
+    Folly::folly
     ${GLOG_LIBRARIES}
 )
 

thrift/lib/cpp2/CMakeLists.txt

@@ -28,8 +28,7 @@ add_dependencies(thriftfrozen2 frozen-cpp2-target)
 target_link_libraries(
   thriftfrozen2
   PUBLIC
-    ${DOUBLE_CONVERSION_LIBRARY}
-    ${FOLLY_LIBRARY}
+    Folly::folly
     ${GLOG_LIBRARIES}
     ${GFLAGS_LIBRARIES}
 )
@@ -51,9 +50,8 @@ target_link_libraries(
   thriftprotocol
   PUBLIC
     thrift
-    ${FOLLY_LIBRARY}
+    Folly::folly
     ${WANGLE_LIBRARIES}
-    ${DOUBLE_CONVERSION_LIBRARY}
 )
 
 thrift_generate(