Bug 855850: Use MOZ_STATIC_ASSERT instead of #if, to verify that "break type" values are representable in 4 bits. r=mats

layout/generic/nsLineBox.cpp

@@ -16,6 +16,7 @@
 #include "nsBidiPresUtils.h"
 #endif
 #include "nsStyleStructInlines.h"
+#include "mozilla/Assertions.h"
 #include "mozilla/Likely.h"
 
 #ifdef DEBUG
@@ -43,6 +44,9 @@ nsLineBox::nsLineBox(nsIFrame* aFrame, int32_t aCount, bool aIsBlock)
   }
 #endif
 
+  MOZ_STATIC_ASSERT(NS_STYLE_CLEAR_LAST_VALUE <= 15,
+                    "FlagBits needs more bits to store the full range of "
+                    "break type ('clear') values");
 #if NS_STYLE_CLEAR_NONE > 0
   mFlags.mBreakType = NS_STYLE_CLEAR_NONE;
 #endif

layout/generic/nsLineBox.h

@@ -146,10 +146,6 @@ protected:
 #define LINE_MAX_BREAK_TYPE  ((1 << 4) - 1)
 #define LINE_MAX_CHILD_COUNT INT32_MAX
 
-#if NS_STYLE_CLEAR_LAST_VALUE > 15
-need to rearrange the mBits bitfield;
-#endif
-
 /**
  * Function to create a line box and initialize it with a single frame.
  * The allocation is infallible.