Add HB_FALLTHROUGH
Borrowed from https://bugzilla.mozilla.org/show_bug.cgi?id=1215411
diff --git a/src/hb-ot-shape-complex-indic.cc b/src/hb-ot-shape-complex-indic.cc
index 00526f3..0a0257d 100644
--- a/src/hb-ot-shape-complex-indic.cc
+++ b/src/hb-ot-shape-complex-indic.cc
@@ -756,7 +756,7 @@
{
default:
assert (false);
- /* fallthrough */
+ HB_FALLTHROUGH;
case BASE_POS_LAST:
{
diff --git a/src/hb-ot-shape-complex-thai.cc b/src/hb-ot-shape-complex-thai.cc
index d4ede20..8a8f2f7 100644
--- a/src/hb-ot-shape-complex-thai.cc
+++ b/src/hb-ot-shape-complex-thai.cc
@@ -139,7 +139,7 @@
};
switch (action) {
- default: assert (false); /* Fallthrough */
+ default: assert (false); HB_FALLTHROUGH;
case NOP: return u;
case SD: pua_mappings = SD_mappings; break;
case SDL: pua_mappings = SDL_mappings; break;
diff --git a/src/hb-ot-shape-fallback.cc b/src/hb-ot-shape-fallback.cc
index 748372d..3cb3456 100644
--- a/src/hb-ot-shape-fallback.cc
+++ b/src/hb-ot-shape-fallback.cc
@@ -224,7 +224,7 @@
pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width / 2 - mark_extents.x_bearing;
break;
}
- /* Fall through */
+ HB_FALLTHROUGH;
default:
case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
@@ -259,6 +259,7 @@
case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT:
/* Add gap, fall-through. */
base_extents.height -= y_gap;
+ HB_FALLTHROUGH;
case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT:
case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
@@ -279,6 +280,7 @@
/* Add gap, fall-through. */
base_extents.y_bearing += y_gap;
base_extents.height -= y_gap;
+ HB_FALLTHROUGH;
case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT:
diff --git a/src/hb-private.hh b/src/hb-private.hh
index be29391..9db19eb 100644
--- a/src/hb-private.hh
+++ b/src/hb-private.hh
@@ -119,6 +119,36 @@
#define HB_FUNC __func__
#endif
+/*
+ * Borrowed from https://bugzilla.mozilla.org/show_bug.cgi?id=1215411
+ * HB_FALLTHROUGH is an annotation to suppress compiler warnings about switch
+ * cases that fall through without a break or return statement. HB_FALLTHROUGH
+ * is only needed on cases that have code:
+ *
+ * switch (foo) {
+ * case 1: // These cases have no code. No fallthrough annotations are needed.
+ * case 2:
+ * case 3:
+ * foo = 4; // This case has code, so a fallthrough annotation is needed:
+ * HB_FALLTHROUGH;
+ * default:
+ * return foo;
+ * }
+ */
+#if defined(__clang__) && __cplusplus >= 201103L
+ /* clang's fallthrough annotations are only available starting in C++11. */
+# define HB_FALLTHROUGH [[clang::fallthrough]]
+#elif defined(_MSC_VER)
+ /*
+ * MSVC's __fallthrough annotations are checked by /analyze (Code Analysis):
+ * https://msdn.microsoft.com/en-us/library/ms235402%28VS.80%29.aspx
+ */
+# include <sal.h>
+# define HB_FALLTHROUGH __fallthrough
+#else
+# define HB_FALLTHROUGH /* FALLTHROUGH */
+#endif
+
#if defined(_WIN32) || defined(__CYGWIN__)
/* We need Windows Vista for both Uniscribe backend and for
* MemoryBarrier. We don't support compiling on Windows XP,
