src/hotspot/share/gc/shared/gcConfig.cpp

@@ -61,10 +61,13 @@
   SupportedGC(UseConcMarkSweepGC, CollectedHeap::CMS,      cmsArguments,      "cmsgc"     ),
   SupportedGC(UseG1GC,            CollectedHeap::G1,       g1Arguments,       "g1gc"      ),
 #endif // INCLUDE_ALL_GCS
 };
 
+#define FOR_EACH_SUPPORTED_GC(var) \
+  for (const SupportedGC* var = &SupportedGCs[0]; var < &SupportedGCs[ARRAY_SIZE(SupportedGCs)]; var++)
+
 GCArguments* GCConfig::_arguments = NULL;
 bool GCConfig::_gc_selected_ergonomically = false;
 
 void GCConfig::select_gc_ergonomically() {
 #if INCLUDE_ALL_GCS

@@ -81,27 +84,27 @@
   FLAG_SET_ERGO_IF_DEFAULT(bool, UseSerialGC, true);
 #endif // INCLUDE_ALL_GCS
 }
 
 bool GCConfig::is_no_gc_selected() {
-  for (size_t i = 0; i < ARRAY_SIZE(SupportedGCs); i++) {
-    if (SupportedGCs[i]._flag) {
+  FOR_EACH_SUPPORTED_GC(gc) {
+    if (gc->_flag) {
       return false;
     }
   }
 
   return true;
 }
 
 bool GCConfig::is_exactly_one_gc_selected() {
   CollectedHeap::Name selected = CollectedHeap::None;
 
-  for (size_t i = 0; i < ARRAY_SIZE(SupportedGCs); i++) {
-    if (SupportedGCs[i]._flag) {
-      if (SupportedGCs[i]._name == selected || selected == CollectedHeap::None) {
+  FOR_EACH_SUPPORTED_GC(gc) {
+    if (gc->_flag) {
+      if (gc->_name == selected || selected == CollectedHeap::None) {
         // Selected
-        selected = SupportedGCs[i]._name;
+        selected = gc->_name;
       } else {
         // More than one selected
         return false;
       }
     }

@@ -125,13 +128,13 @@
     _gc_selected_ergonomically = true;
   }
 
   if (is_exactly_one_gc_selected()) {
     // Exacly one GC selected
-    for (size_t i = 0; i < ARRAY_SIZE(SupportedGCs); i++) {
-      if (SupportedGCs[i]._flag) {
-        return &SupportedGCs[i]._arguments;
+    FOR_EACH_SUPPORTED_GC(gc) {
+      if (gc->_flag) {
+        return &gc->_arguments;
       }
     }
   }
 
   // More than one GC selected

@@ -144,24 +147,24 @@
   assert(_arguments == NULL, "Already initialized");
   _arguments = select_gc();
 }
 
 bool GCConfig::is_gc_supported(CollectedHeap::Name name) {
-  for (size_t i = 0; i < ARRAY_SIZE(SupportedGCs); i++) {
-    if (SupportedGCs[i]._name == name) {
+  FOR_EACH_SUPPORTED_GC(gc) {
+    if (gc->_name == name) {
       // Supported
       return true;
     }
   }
 
   // Not supported
   return false;
 }
 
 bool GCConfig::is_gc_selected(CollectedHeap::Name name) {
-  for (size_t i = 0; i < ARRAY_SIZE(SupportedGCs); i++) {
-    if (SupportedGCs[i]._name == name && SupportedGCs[i]._flag) {
+  FOR_EACH_SUPPORTED_GC(gc) {
+    if (gc->_name == name && gc->_flag) {
       // Selected
       return true;
     }
   }
 

@@ -174,13 +177,13 @@
 }
 
 const char* GCConfig::hs_err_name() {
   if (is_exactly_one_gc_selected()) {
     // Exacly one GC selected
-    for (size_t i = 0; i < ARRAY_SIZE(SupportedGCs); i++) {
-      if (SupportedGCs[i]._flag) {
-        return SupportedGCs[i]._hs_err_name;
+    FOR_EACH_SUPPORTED_GC(gc) {
+      if (gc->_flag) {
+        return gc->_hs_err_name;
       }
     }
   }
 
   // Zero or more than one GC selected