cmake: Introduce a key version to invalidate corrupted caches

When a bug in the caching mechanism is detected the cache format must be bumped to ensure that we no longer get a cache hit on old corrupted keys. This fixes zephyrproject-rtos#7246 when the cache is corrupted. Signed-off-by: Sebastian Bøe <[email protected]>
mgsb · May 2, 2018 · aa90d72 · aa90d72
1 parent 5f08b10
commit aa90d72
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/cmake/extensions.cmake b/cmake/extensions.cmake
@@ -622,8 +622,15 @@ function(zephyr_check_compiler_flag lang option check)
   # We need to create a unique key wrt. testing the toolchain
   # capability. This key must be a valid C identifier that includes
   # everything that can affect the toolchain test.
+
+  # The 'cacheformat' must be bumped if a bug in the caching mechanism
+  # is detected and all old keys must be invalidated.
+  set(cacheformat 2)
+
   set(key_string "")
   set(key_string "${key_string}ZEPHYR_TOOLCHAIN_CAPABILITY_CACHE_")
+  set(key_string "${key_string}cacheformat_")
+  set(key_string "${key_string}${cacheformat}_")
   set(key_string "${key_string}${TOOLCHAIN_SIGNATURE}_")
   set(key_string "${key_string}${lang}_")
   set(key_string "${key_string}${option}_")