cmake: remove BUILD_TOOLS option

autotools build does not have this option.
Capnp tools are built when CAPNP_LITE == OFF

c++/CMakeLists.txt

@@ -25,30 +25,15 @@ set(INSTALL_TARGETS_DEFAULT_ARGS
 
 # Options ======================================================================
 
-option(BUILD_TOOLS "Build command-line tools and compiler." ON)
 option(BUILD_TESTING "Build unit tests and enable CTest 'check' target." ON)
 option(EXTERNAL_CAPNP "Use the system capnp binary, or the one specified in $CAPNP, instead of using the compiled one." OFF)
-option(CAPNP_LITE "Compile Cap'n Proto in 'lite mode', in which all reflection APIs (schema.h, dynamic.h, etc.) are not included. Produces a smaller library at the cost of features. All programs built against the library must be compiled with -DCAPNP_LITE. Requires EXTERNAL_CAPNP to build the tests." OFF)
+option(CAPNP_LITE "Compile Cap'n Proto in 'lite mode', in which all reflection APIs (schema.h, dynamic.h, etc.) are not included. Produces a smaller library at the cost of features. All programs built against the library must be compiled with -DCAPNP_LITE. Requires EXTERNAL_CAPNP." OFF)
 
 # Check for invalid combinations of build options
-if(NOT BUILD_TOOLS AND BUILD_TESTING AND NOT EXTERNAL_CAPNP)
-  # Not *all* of the tests require the capnp compiler, and those that do could be excluded
-  # when not building the tools, but it's easier to just have a blanket rule.
-  message(SEND_ERROR "Tests (BUILD_TESTING) cannot be build without either BUILD_TOOLS or EXTERNAL_CAPNP.")
+if(CAPNP_LITE AND NOT EXTERNAL_CAPNP)
+  message(SEND_ERROR "You must set EXTERNAL_CAPNP when using CAPNP_LITE.")
 endif()
 
-if(CAPNP_LITE AND BUILD_TESTING AND NOT EXTERNAL_CAPNP)
-  # As above, we could exclude only the tests that depend on the compiler.
-  message(SEND_ERROR "CAPNP_LITE with BUILD_TESTING requires EXTERNAL_CAPNP.")
-endif()
-
-if(CAPNP_LITE AND BUILD_TOOLS)
-  message(WARNING "Command-line tools will not be built with CAPNP_LITE.")
-endif()
-
-if(BUILD_TOOLS AND EXTERNAL_CAPNP)
-  message(SEND_ERROR "EXTERNAL_CAPNP cannot be set with BUILD_TOOLS.")
-endif()
 
 if(MSVC AND NOT CAPNP_LITE)
   message(SEND_ERROR "Building with MSVC is only supported with CAPNP_LITE.")

c++/src/capnp/CMakeLists.txt

@@ -142,7 +142,7 @@ if(NOT CAPNP_LITE)
   install(FILES ${capnpc_headers} DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/capnp")
 endif()
 
-if(BUILD_TOOLS AND NOT CAPNP_LITE)
+if(NOT CAPNP_LITE)
   add_executable(capnp_tool
     compiler/module-loader.c++
     compiler/capnp.c++
@@ -174,7 +174,7 @@ if(BUILD_TOOLS AND NOT CAPNP_LITE)
 
   # Symlink capnpc -> capnp
   install(CODE "execute_process(COMMAND \"${CMAKE_COMMAND}\" -E create_symlink capnp \"\$ENV{DESTDIR}${CMAKE_INSTALL_FULL_BINDIR}/capnpc\")")
-endif()  # BUILD_TOOLS AND NOT CAPNP_LITE
+endif()  # NOT CAPNP_LITE
 
 # Tests ========================================================================