Make it possible to disable building chcache

Author: antaljanosbenjamin

CMakeLists.txt

@@ -624,6 +624,9 @@ if (COMPILER_CACHE STREQUAL "chcache" AND CHCACHE_EXECUTABLE_PATH STREQUAL "")
     message(STATUS "Adding chcache as dependency to all other targets")
     get_all_targets(all_targets)
     set(chcache_targets _cargo-build_chcache cargo-build_chcache cargo-prebuild_chcache)
+    if(NOT TARGET cargo-build_chcache)
+        message(FATAL_ERROR "Building chcache is disabled and CHCACHE_EXECUTABLE_PATH is not set, cannot use chcache as compiler cache.")
+    endif()
     foreach(target ${all_targets})
         if (target IN_LIST chcache_targets)
             continue()

cmake/ccache.cmake

@@ -24,16 +24,16 @@ set(COMPILER_CACHE "auto" CACHE STRING "Speedup re-compilations using the cachin
 
 if(COMPILER_CACHE STREQUAL "auto")
     find_program (CCACHE_EXECUTABLE NAMES sccache ccache)
-elseif (COMPILER_CACHE STREQUAL "ccache")
+elseif(COMPILER_CACHE STREQUAL "ccache")
     find_program (CCACHE_EXECUTABLE ccache)
 elseif(COMPILER_CACHE STREQUAL "sccache")
     find_program (CCACHE_EXECUTABLE sccache)
 elseif(COMPILER_CACHE STREQUAL "chcache")
-    if (CHCACHE_EXECUTABLE_PATH STREQUAL "")
-        message(STATUS "Using built chcache")
+    if(CHCACHE_EXECUTABLE_PATH STREQUAL "")
+        message(STATUS "Using self-built chcache")
         set(CCACHE_EXECUTABLE ${CMAKE_CURRENT_BINARY_DIR}/rust/chcache/chcache)
     else()
-        message(STATUS "Using chcache from ${CHCACHE_EXECUTABLE_PATH}")
+        message(STATUS "Using already built chcache from ${CHCACHE_EXECUTABLE_PATH}")
         set(CCACHE_EXECUTABLE ${CHCACHE_EXECUTABLE_PATH})
     endif()
 elseif(COMPILER_CACHE STREQUAL "disabled")

rust/CMakeLists.txt

@@ -1,2 +1,7 @@
 add_subdirectory (workspace)
-add_subdirectory (chcache)
+
+option(ENABLE_CHCACHE "Enable chcache" ${ENABLE_RUST})
+
+if (ENABLE_CHCACHE)
+    add_subdirectory (chcache)
+endif()