build system: Enable static analysis in the CI

For a select set of boards, enable static analysis. The cost of static
analysis in terms of CPU time is quite significant, so we try to get
the most out of as little extra CPU time as possible by having it
enabled only a small set of popular boards.

Author: maribu

Makefile.include

@@ -520,6 +520,22 @@ ifeq ($(RIOT_CI_BUILD),1)
     endif
     # be more quiet when building for CI
     QUIETER=1
+
+    # Enable static analysis only for some boards to not spent to much CPU time.
+    # This list is intentionally a subset of the `QUICKBUILD_BOARDS` from
+    # `.murdock`
+    BOARDS_CI_STATIC_ANALYSIS := \
+      esp32-wroom-32 \
+      native64 \
+      nrf52840dk \
+      samr21-xpro \
+      stm32f429i-disc1 \
+      #
+    ifneq (,$(filter $(BOARD),$(BOARDS_CI_STATIC_ANALYSIS)))
+      export STATIC_ANALYSIS := 1
+    else
+      export STATIC_ANALYSIS := 0
+    endif
 endif
 
 ifeq ($(QUIETER),1)