build: use -fno-strict-aliasing for GCC <= 4.4

Julien Gilli · Julien Gilli · commit a541b9257eab · 2015-01-28T10:40:21.000-08:00
Revert the previous change to the queue implementation, and instead
disable aliasing optimizations for toolchains using GCC &lt;= 4.4.
diff --git a/deps/debugger-agent/debugger-agent.gyp b/deps/debugger-agent/debugger-agent.gyp
@@ -17,6 +17,14 @@
         "include",
       ],
     },
+    'conditions': [
+      [ 'gcc_version<=44', {
+        # GCC versions <= 4.4 do not handle the aliasing in the queue
+        # implementation, so disable aliasing on these platforms
+        # to avoid subtle bugs
+        'cflags': [ '-fno-strict-aliasing' ],
+      }],
+    ],
     "sources": [
       "src/agent.cc",
     ],
diff --git a/deps/uv/uv.gyp b/deps/uv/uv.gyp
@@ -84,6 +84,12 @@
         'src/version.c'
       ],
       'conditions': [
+        [ 'gcc_version<=44', {
+          # GCC versions <= 4.4 do not handle the aliasing in the queue
+          # implementation, so disable aliasing on these platforms
+          # to avoid subtle bugs
+          'cflags': [ '-fno-strict-aliasing' ],
+        }],
         [ 'OS=="win"', {
           'defines': [
             '_WIN32_WINNT=0x0600',
diff --git a/node.gyp b/node.gyp
@@ -168,6 +168,12 @@
       ],
 
       'conditions': [
+        [ 'gcc_version<=44', {
+          # GCC versions <= 4.4 do not handle the aliasing in the queue
+          # implementation, so disable aliasing on these platforms
+          # to avoid subtle bugs
+          'cflags': [ '-fno-strict-aliasing' ],
+        }],
         [ 'v8_enable_i18n_support==1', {
           'defines': [ 'NODE_HAVE_I18N_SUPPORT=1' ],
           'dependencies': [
diff --git a/src/queue.h b/src/queue.h
@@ -19,23 +19,23 @@
 typedef void *QUEUE[2];
 
 /* Private macros. */
-#define QUEUE_NEXT(q)       ((*(q))[0])
-#define QUEUE_PREV(q)       ((*(q))[1])
-#define QUEUE_PREV_NEXT(q)  (QUEUE_NEXT((QUEUE *)QUEUE_PREV(q)))
-#define QUEUE_NEXT_PREV(q)  (QUEUE_PREV((QUEUE *)QUEUE_NEXT(q)))
+#define QUEUE_NEXT(q)       (*(QUEUE **) &((*(q))[0]))
+#define QUEUE_PREV(q)       (*(QUEUE **) &((*(q))[1]))
+#define QUEUE_PREV_NEXT(q)  (QUEUE_NEXT(QUEUE_PREV(q)))
+#define QUEUE_NEXT_PREV(q)  (QUEUE_PREV(QUEUE_NEXT(q)))
 
 /* Public macros. */
 #define QUEUE_DATA(ptr, type, field)                                          \
   ((type *) ((char *) (ptr) - ((char *) &((type *) 0)->field)))
 
 #define QUEUE_FOREACH(q, h)                                                   \
-  for ((q) = (QUEUE *) QUEUE_NEXT(h); (q) != (h); (q) = (QUEUE *) QUEUE_NEXT(q))
+  for ((q) = QUEUE_NEXT(h); (q) != (h); (q) = QUEUE_NEXT(q))
 
 #define QUEUE_EMPTY(q)                                                        \
-  ((q) == QUEUE_NEXT(q))
+  ((const QUEUE *) (q) == (const QUEUE *) QUEUE_NEXT(q))
 
 #define QUEUE_HEAD(q)                                                         \
-  ((QUEUE*)QUEUE_NEXT(q))
+  (QUEUE_NEXT(q))
 
 #define QUEUE_INIT(q)                                                         \
   do {                                                                        \
