Adjust linking flags to not embed some libs

Summary:
Feature: Basic Build Fixes

Adjust mysql linking flags to not embed openssl and zlib in static libs.

By default, libmysqlclient.a includes a copy of the openssl and
zlib it was linked against, thanks to a MERGE_LIBRARY call.  This isn't
ideal in fbcode's third-party environment where we want targets to have
to link in openssl on their own.

This change removes the ssl and zlib libraries from the merge and
instead sets them as a dependency for the build, so that other built
targets, such as the command line tools, still end up properly linked
but libmysqlclient.a doesn't include embedded copies.  It also removes
the munging of the library names when doing a static build so that they
are not called "imported_crypto" and "imported_openssl" and instead are
called by their normal names.

Test Plan:
mtr; also builting in third-party, confirming the .a file
does not contain openssl symbols and that building a third-party library
that depends on libmysqlclient works as expected

Reviewers: flamingcow, pivanof, jeremycole, andrew-ford, inaam-rana

Reviewed By: pivanof

CC: jtolmer, MarkCallaghan

Differential Revision: https://reviews.facebook.net/D15657

Author: Chip Turner

cmake/build_configurations/mysql_release.cmake

@@ -34,8 +34,6 @@ ENDIF()
 IF(UNIX)
   SET(WITH_EXTRA_CHARSETS all CACHE STRING "")
 
-  OPTION(WITH_PIC "" ON) # Why?
-
   IF(CMAKE_SYSTEM_NAME STREQUAL "Linux")
     IF(NOT IGNORE_AIO_CHECK)
       # Ensure aio is available on Linux (required by InnoDB)

cmake/ssl.cmake

@@ -189,22 +189,6 @@ MACRO (MYSQL_CHECK_SSL)
     # to get LOCATION and do correct dependency analysis.
     SET(MY_CRYPTO_LIBRARY "${CRYPTO_LIBRARY}")
     SET(MY_OPENSSL_LIBRARY "${OPENSSL_LIBRARY}")
-    IF (WITH_SSL_PATH)
-      GET_FILENAME_COMPONENT(CRYPTO_EXT "${CRYPTO_LIBRARY}" EXT)
-      GET_FILENAME_COMPONENT(OPENSSL_EXT "${OPENSSL_LIBRARY}" EXT)
-      IF (CRYPTO_EXT STREQUAL ".a")
-        SET(MY_CRYPTO_LIBRARY imported_crypto)
-        ADD_LIBRARY(imported_crypto STATIC IMPORTED)
-        SET_TARGET_PROPERTIES(imported_crypto
-          PROPERTIES IMPORTED_LOCATION "${CRYPTO_LIBRARY}")
-      ENDIF()
-      IF (OPENSSL_EXT STREQUAL ".a")
-        SET(MY_OPENSSL_LIBRARY imported_openssl)
-        ADD_LIBRARY(imported_openssl STATIC IMPORTED)
-        SET_TARGET_PROPERTIES(imported_openssl
-          PROPERTIES IMPORTED_LOCATION "${OPENSSL_LIBRARY}")
-      ENDIF()
-    ENDIF()
 
     MESSAGE(STATUS "OPENSSL_INCLUDE_DIR = ${OPENSSL_INCLUDE_DIR}")
     MESSAGE(STATUS "OPENSSL_LIBRARY = ${OPENSSL_LIBRARY}")

libmysql/CMakeLists.txt

@@ -167,7 +167,10 @@ ADD_CONVENIENCE_LIBRARY(clientlib ${CLIENT_SOURCES})
 DTRACE_INSTRUMENT(clientlib)
 ADD_DEPENDENCIES(clientlib GenError)
 
-SET(LIBS clientlib dbug strings vio mysys mysys_ssl ${ZLIB_LIBRARY} ${SSL_LIBRARIES} ${LIBDL})
+# Don't merge zlib, ssl, etc when building static libraries.
+SET(STATIC_MERGE_LIBS clientlib dbug strings vio mysys mysys_ssl ${LIBDL})
+
+SET(LIBS ${STATIC_MERGE_LIBS} ${ZLIB_LIBRARY} ${SSL_LIBRARIES})
 
 #
 # On Windows platform client library includes the client-side 
@@ -180,7 +183,8 @@ IF(WIN32)
 ENDIF()
 
 # Merge several convenience libraries into one big mysqlclient
-MERGE_LIBRARIES(mysqlclient STATIC ${LIBS} COMPONENT Development)
+MERGE_LIBRARIES(mysqlclient STATIC ${STATIC_MERGE_LIBS} COMPONENT Development)
+TARGET_LINK_LIBRARIES(mysqlclient ${ZLIB_LIBRARY} ${SSL_LIBRARIES})
 
 # Visual Studio users need debug  static library for debug projects
 INSTALL_DEBUG_SYMBOLS(clientlib)