cmake: Some fixes and optional targets (dashpay#14)

* cmake: Only include GMP_INCLUDES if gmp has been found

Otherwise it fails with the following if gmp wasn't found:

CMake Error in src/CMakeLists.txt:
  Found relative path while evaluating include directories of <target>:  "GMP_INCLUDES-NOTFOUND"

* cmake: Drop broken gmp include

This seems to be broken because `GMP_INCLUDE_DIR` isn't set at all by `Findgmp.cmake`, it sets `GMP_INCLUDES` instead. It's however set by relic's script which isn't configured at this point though. If you want to keep this include it should be `include_directories(${GMP_INCLUDES})` rather i guess?

* cmake: Install relic headers into chiabls

I think this should be done because chiabls depends on how relic was
configure.

* cmake: Make blspy optional

* cmake: Make runbench/runtest optional

CMakeLists.txt

@@ -8,6 +8,14 @@ ENDIF()
 
 project(BLS)
 
+set(BUILD_BLS_PYTHON_BINDINGS 1 CACHE INTEGER "")
+set(BUILD_BLS_TESTS 1 CACHE INTEGER "")
+set(BUILD_BLS_BENCHMARKS 1 CACHE INTEGER "")
+
+message(STATUS "Build python bindings: ${BUILD_BLS_PYTHON_BINDINGS}")
+message(STATUS "Build tests: ${BUILD_BLS_TESTS}")
+message(STATUS "Build benchmarks: ${BUILD_BLS_BENCHMARKS}")
+
 # Add path for custom modules
 set(CMAKE_MODULE_PATH
 	${CMAKE_MODULE_PATH}
@@ -32,7 +40,6 @@ set(STBIN TRUE)
 find_package(gmp)
 if (GMP_FOUND)
   message(STATUS "Found libgmp")
-  include_directories(${GMP_INCLUDE_DIR})
   set(ARITH "gmp" CACHE STRING "")
 else()
   set(ARITH "easy" CACHE STRING "")
@@ -90,5 +97,7 @@ if (EMSCRIPTEN)
 else()
   # emscripten can't build python bindings, it produces only javascript
   # add_subdirectory(contrib/pybind11)
-  add_subdirectory(python-bindings)
+  if (BUILD_BLS_PYTHON_BINDINGS)
+    add_subdirectory(python-bindings)
+  endif()
 endif()

python-bindings/CMakeLists.txt

@@ -17,9 +17,12 @@ include_directories(
   ${relic_SOURCE_DIR}/include
   ${relic_BINARY_DIR}/include
   ${CMAKE_CURRENT_SOURCE_DIR}/../contrib/catch
-  ${GMP_INCLUDES}
   )
 
+if (GMP_FOUND)
+  include_directories(${GMP_INCLUDES})
+endif(GMP_FOUND)
+
 pybind11_add_module(blspy ${CMAKE_CURRENT_SOURCE_DIR}/pythonbindings.cpp)
 
 if (SODIUM_FOUND)

src/CMakeLists.txt

@@ -26,10 +26,12 @@ include_directories(
   ${INCLUDE_DIRECTORIES}
   ${relic_SOURCE_DIR}/include
   ${relic_BINARY_DIR}/include
-  ${CMAKE_CURRENT_SOURCE_DIR}/../contrib/catch
-  ${GMP_INCLUDES}
   )
 
+if (GMP_FOUND)
+  include_directories(${GMP_INCLUDES})
+endif(GMP_FOUND)
+
 set(C_LIB ${CMAKE_BINARY_DIR}/libbls.a)
 
 add_library(bls ${CMAKE_CURRENT_SOURCE_DIR}/privatekey.cpp)
@@ -78,16 +80,26 @@ set_target_properties(combined
         )
 
 file(GLOB includes "${CMAKE_CURRENT_SOURCE_DIR}/*.hpp")
+install(DIRECTORY ${relic_SOURCE_DIR}/include/ DESTINATION include/chiabls)
+install(DIRECTORY ${relic_BINARY_DIR}/include/ DESTINATION include/chiabls)
 install(FILES ${includes} DESTINATION include/chiabls)
 install(FILES ${C_LIB} DESTINATION lib)
 
-add_executable(runtest test.cpp)
-add_executable(runbench test-bench.cpp)
+if (BUILD_BLS_TESTS)
+  include_directories(${CMAKE_CURRENT_SOURCE_DIR}/../contrib/catch)
+  add_executable(runtest test.cpp)
+  if (SODIUM_FOUND)
+    target_link_libraries(runtest blstmp relic_s sodium)
+  else()
+    target_link_libraries(runtest blstmp relic_s)
+  endif()
+endif()
 
-if (SODIUM_FOUND)
-  target_link_libraries(runtest blstmp relic_s sodium)
-  target_link_libraries(runbench blstmp relic_s sodium)
-else()
-  target_link_libraries(runtest blstmp relic_s)
-  target_link_libraries(runbench blstmp relic_s)
+if (BUILD_BLS_BENCHMARKS)
+  add_executable(runbench test-bench.cpp)
+  if (SODIUM_FOUND)
+    target_link_libraries(runbench blstmp relic_s sodium)
+  else()
+    target_link_libraries(runbench blstmp relic_s)
+  endif()
 endif()