diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
index 7d4b6f2948..c087032293 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -19,6 +19,7 @@ Constant expressions and unreachable branches of if and switch statements are ex
 
 -doc_begin="Unreachability inside an ASSERT_UNREACHABLE() and analogous macro calls is deliberate and safe."
 -config=MC3A2.R2.1,reports+={deliberate, "any_area(any_loc(any_exp(macro(name(ASSERT_UNREACHABLE||PARSE_ERR_RET||PARSE_ERR||FAIL_MSR||FAIL_CPUID)))))"}
+-config=MC3A2.R2.1,reports+={deliberate, "any_area(any_loc(any_exp(macro(^BUILD_ERROR(|_IF(|_NOT))$))))"}
 -doc_end
 
 -doc_begin="The asm-offset files are not linked deliberately, since they are used to generate definitions for asm modules."
@@ -667,6 +668,7 @@ deliberate."
 to the # or ## operators within the following macros are deliberate, to provide
 useful diagnostic messages to the user."
 -config=MC3A2.R20.12,macros+={deliberate, "name(ASSERT||BUILD_BUG_ON||BUILD_BUG_ON_ZERO||RUNTIME_CHECK)"}
+-config=MC3A2.R20.12,macros+={deliberate, "^BUILD_ERROR(|_IF(|_NOT))$"}
 -doc_end
 
 -doc_begin="The helper macro GENERATE_CASE may use a macro parameter for ordinary
diff --git a/xen/include/xen/macros.h b/xen/include/xen/macros.h
index e29cff791e..b07bd5f530 100644
--- a/xen/include/xen/macros.h
+++ b/xen/include/xen/macros.h
@@ -64,6 +64,21 @@
  */
 #define BUILD_ERROR(msg) asm ( ".error \"" msg "\"" )
 
+/*
+ * Like above, but conditional upon @cfg (not) being enabled.  @cfg must be
+ * suitable to pass to IS_ENABLED().
+ */
+#define BUILD_ERROR_IF(cfg)                               \
+    (IS_ENABLED(cfg)                                      \
+     ? ({ BUILD_ERROR( #cfg " unexpectedly enabled"); })  \
+     : (void)0)
+
+#define BUILD_ERROR_IF_NOT(cfg)                           \
+    (!IS_ENABLED(cfg)                                     \
+     ? ({ BUILD_ERROR( #cfg " unexpectedly disabled"); }) \
+     : (void)0)
+
+
 /* Hide a value from the optimiser. */
 #define HIDE(x)                                 \
     ({                                          \