CMake: Add option to link leveldb statically

Use -DLEVELDB_USE_STATIC_LIBS=ON to request this.

Author: chfast

circle.yml

@@ -132,7 +132,7 @@ jobs:
       - GENERATOR: Ninja
       - BUILD_PARALLEL_JOBS: 8
       - TEST_PARALLEL_JOBS: 8
-      - CMAKE_OPTIONS: -DALETH_INTERPRETER_SHARED=ON -DSTATIC_LIBSTDCPP=ON
+      - CMAKE_OPTIONS: -DALETH_INTERPRETER_SHARED=ON -DSTATIC_LIBSTDCPP=ON -DLEVELDB_USE_STATIC_LIBS=ON
     docker:
       - image: ethereum/cpp-build-env:2
     steps:

cmake/FindLevelDB.cmake

@@ -16,22 +16,25 @@ find_path(
 	DOC "leveldb include dir"
 )
 
+if(LEVELDB_USE_STATIC_LIBS)
+	set(names ${CMAKE_STATIC_LIBRARY_PREFIX}leveldb${CMAKE_STATIC_LIBRARY_SUFFIX})
+else()
+	set(names leveldb)
+endif()
+
 find_library(
 	LEVELDB_LIBRARY
-	NAMES leveldb
+	NAMES ${names}
 	DOC "leveldb library"
 )
 
 set(LEVELDB_INCLUDE_DIRS ${LEVELDB_INCLUDE_DIR})
 set(LEVELDB_LIBRARIES ${LEVELDB_LIBRARY})
 
-# When we're static linking (at least on OS X), leveldb also drags in snappy.
-# This might be due to some dependency within leveldb which would be dead-code
-# stripped if we were using a static lib for leveldb.   We aren't (yet), because
-# we only have partial static-linkage on OS X so far.
-if (NOT BUILD_SHARED_LIBS AND APPLE)
+# When linking statically we should include also the snappy static lib.
+if(LEVELDB_LIBRARY MATCHES ${CMAKE_STATIC_LIBRARY_SUFFIX})
 	find_path(SNAPPY_INCLUDE_DIR snappy.h PATH_SUFFIXES snappy)
-	find_library(SNAPPY_LIBRARY snappy)
+	find_library(SNAPPY_LIBRARY ${CMAKE_STATIC_LIBRARY_PREFIX}snappy${CMAKE_STATIC_LIBRARY_SUFFIX})
 	set(LEVELDB_INCLUDE_DIRS ${LEVELDB_INCLUDE_DIR} ${SNAPPY_INCLUDE_DIR})
 	set(LEVELDB_LIBRARIES ${LEVELDB_LIBRARY} ${SNAPPY_LIBRARY})
 endif()
@@ -58,4 +61,3 @@ include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(leveldb DEFAULT_MSG
 	LEVELDB_LIBRARY LEVELDB_INCLUDE_DIR)
 mark_as_advanced (LEVELDB_INCLUDE_DIR LEVELDB_LIBRARY)
-