Merge pull request #2156 from svaarala/gcc-noreturn-workaround

Disable noreturn attributes for GCC 5+

RELEASES.rst

@@ -3532,6 +3532,12 @@ Planned
 * Use GCC (>= 5.0) and Clang builtin bswap macros, add internal DUK_BSWAP64()
   macro (GH-2122)
 
+* Short term workaround for a noreturn-related issue with GCC 5+ (GH-2155)
+  where some internal duk_require_constructor_call() calls are entirely
+  missing in compiler output in certain circumstances (GCC 5+, noreturn
+  attributes enabled, debugger support enabled); the workaround is to
+  disable noreturn macros for GCC 5+ for now (GH-2156)
+
 * Improve assertion coverage for internal structures during mark-and-sweep
   (GH-2092)
 

config/compilers/compiler_gcc.h.in

@@ -6,13 +6,17 @@
 #define DUK_VA_COPY(dest,src) __va_copy(dest,src)
 #endif
 
-#if defined(DUK_F_GCC_VERSION) && (DUK_F_GCC_VERSION >= 20500L)
+#if defined(DUK_F_GCC_VERSION) && (DUK_F_GCC_VERSION >= 20500L) && (DUK_F_GCC_VERSION < 50000L)
-/* since gcc-2.5 */
+/* Since gcc-2.5.
+ *
+ * Disabled temporarily in GCC 5+ because of an unresolved noreturn-related
+ * issue: https://github.com/svaarala/duktape/issues/2155.
+ */
 #define DUK_NORETURN(decl)  decl __attribute__((noreturn))
 #endif
 
 #if defined(DUK_F_GCC_VERSION) && (DUK_F_GCC_VERSION >= 40500L)
-/* since gcc-4.5 */
+/* Since gcc-4.5. */
 #define DUK_UNREACHABLE()  do { __builtin_unreachable(); } while (0)
 #endif