8062808: Turn on the -Wreturn-type warning

Reviewed-by: mgerdin, tschatzl, coleenp, jrose, kbarrett

hotspot/make/linux/makefiles/gcc.make

@@ -214,7 +214,7 @@ ifeq ($(USE_CLANG), true)
   WARNINGS_ARE_ERRORS += -Wno-return-type -Wno-empty-body
 endif
 
-WARNING_FLAGS = -Wpointer-arith -Wsign-compare -Wundef -Wunused-function -Wunused-value -Wformat=2
+WARNING_FLAGS = -Wpointer-arith -Wsign-compare -Wundef -Wunused-function -Wunused-value -Wformat=2 -Wreturn-type
 
 ifeq ($(USE_CLANG),)
   # Since GCC 4.3, -Wconversion has changed its meanings to warn these implicit

hotspot/src/cpu/x86/vm/x86_32.ad

@@ -1210,6 +1210,7 @@ uint MachSpillCopyNode::implementation( CodeBuffer *cbuf, PhaseRegAlloc *ra_, bo
 
 
   Unimplemented();
+  return 0; // Mute compiler
 }
 
 #ifndef PRODUCT

hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp

@@ -542,6 +542,7 @@ JVM_handle_linux_signal(int sig,
   err.report_and_die();
 
   ShouldNotReachHere();
+  return true; // Mute compiler
 }
 
 void os::Linux::init_thread_fpu_state(void) {

hotspot/src/share/vm/classfile/defaultMethods.cpp

@@ -506,7 +506,7 @@ Symbol* MethodFamily::generate_method_message(Symbol *klass_name, Method* method
   ss.write((const char*)name->bytes(), name->utf8_length());
   ss.write((const char*)signature->bytes(), signature->utf8_length());
   ss.print(" is abstract");
-  return SymbolTable::new_symbol(ss.base(), (int)ss.size(), CHECK_NULL);
+  return SymbolTable::new_symbol(ss.base(), (int)ss.size(), THREAD);
 }
 
 Symbol* MethodFamily::generate_conflicts_message(GrowableArray<Method*>* methods, TRAPS) const {
@@ -521,7 +521,7 @@ Symbol* MethodFamily::generate_conflicts_message(GrowableArray<Method*>* methods
     ss.print(".");
     ss.write((const char*)name->bytes(), name->utf8_length());
   }
-  return SymbolTable::new_symbol(ss.base(), (int)ss.size(), CHECK_NULL);
+  return SymbolTable::new_symbol(ss.base(), (int)ss.size(), THREAD);
 }
 
 

hotspot/src/share/vm/classfile/symbolTable.cpp

@@ -235,7 +235,7 @@ Symbol* SymbolTable::lookup(const char* name, int len, TRAPS) {
   MutexLocker ml(SymbolTable_lock, THREAD);
 
   // Otherwise, add to symbol to table
-  return the_table()->basic_add(index, (u1*)name, len, hashValue, true, CHECK_NULL);
+  return the_table()->basic_add(index, (u1*)name, len, hashValue, true, THREAD);
 }
 
 Symbol* SymbolTable::lookup(const Symbol* sym, int begin, int end, TRAPS) {
@@ -274,7 +274,7 @@ Symbol* SymbolTable::lookup(const Symbol* sym, int begin, int end, TRAPS) {
   // Grab SymbolTable_lock first.
   MutexLocker ml(SymbolTable_lock, THREAD);
 
-  return the_table()->basic_add(index, (u1*)buffer, len, hashValue, true, CHECK_NULL);
+  return the_table()->basic_add(index, (u1*)buffer, len, hashValue, true, THREAD);
 }
 
 Symbol* SymbolTable::lookup_only(const char* name, int len,

hotspot/src/share/vm/classfile/systemDictionary.cpp

@@ -233,15 +233,15 @@ Klass* SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader
                  class_name->as_C_string(),
                  class_loader.is_null() ? "null" : class_loader->klass()->name()->as_C_string()));
   if (FieldType::is_array(class_name)) {
-    return resolve_array_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL);
+    return resolve_array_class_or_null(class_name, class_loader, protection_domain, THREAD);
   } else if (FieldType::is_obj(class_name)) {
     ResourceMark rm(THREAD);
     // Ignore wrapping L and ;.
     TempNewSymbol name = SymbolTable::new_symbol(class_name->as_C_string() + 1,
                                    class_name->utf8_length() - 2, CHECK_NULL);
-    return resolve_instance_class_or_null(name, class_loader, protection_domain, CHECK_NULL);
+    return resolve_instance_class_or_null(name, class_loader, protection_domain, THREAD);
   } else {
-    return resolve_instance_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL);
+    return resolve_instance_class_or_null(class_name, class_loader, protection_domain, THREAD);
   }
 }
 

hotspot/src/share/vm/memory/heapInspection.hpp

@@ -367,7 +367,7 @@ class HeapInspection : public StackObj {
       _csv_format(csv_format), _print_help(print_help),
       _print_class_stats(print_class_stats), _columns(columns) {}
   void heap_inspection(outputStream* st) NOT_SERVICES_RETURN;
-  size_t populate_table(KlassInfoTable* cit, BoolObjectClosure* filter = NULL) NOT_SERVICES_RETURN;
+  size_t populate_table(KlassInfoTable* cit, BoolObjectClosure* filter = NULL) NOT_SERVICES_RETURN_(0);
   static void find_instances_at_safepoint(Klass* k, GrowableArray<oop>* result) NOT_SERVICES_RETURN;
  private:
   void iterate_over_heap(KlassInfoTable* cit, BoolObjectClosure* filter = NULL);

hotspot/src/share/vm/memory/metaspaceShared.hpp

@@ -92,7 +92,7 @@ class MetaspaceShared : AllStatic {
   static void preload_and_dump(TRAPS) NOT_CDS_RETURN;
   static int preload_and_dump(const char * class_list_path,
                               GrowableArray<Klass*>* class_promote_order,
-                              TRAPS) NOT_CDS_RETURN;
+                              TRAPS) NOT_CDS_RETURN_(0);
 
   static ReservedSpace* shared_rs() {
     CDS_ONLY(return _shared_rs);

hotspot/src/share/vm/oops/constantPool.hpp

@@ -336,13 +336,13 @@ class ConstantPool : public Metadata {
 
   Klass* klass_at(int which, TRAPS) {
     constantPoolHandle h_this(THREAD, this);
-    return klass_at_impl(h_this, which, true, CHECK_NULL);
+    return klass_at_impl(h_this, which, true, THREAD);
   }
 
   // Version of klass_at that doesn't save the resolution error, called during deopt
   Klass* klass_at_ignore_error(int which, TRAPS) {
     constantPoolHandle h_this(THREAD, this);
-    return klass_at_impl(h_this, which, false, CHECK_NULL);
+    return klass_at_impl(h_this, which, false, THREAD);
   }
 
   Symbol* klass_name_at(int which);  // Returns the name, w/o resolving.

hotspot/src/share/vm/prims/jvm.cpp

@@ -3537,7 +3537,7 @@ JVM_ENTRY(jlong,JVM_DTraceActivate(
     JVM_DTraceProvider* providers))
   JVMWrapper("JVM_DTraceActivate");
   return DTraceJSDT::activate(
-    version, module_name, providers_count, providers, CHECK_0);
+    version, module_name, providers_count, providers, THREAD);
 JVM_END
 
 JVM_ENTRY(jboolean,JVM_DTraceIsProbeEnabled(JNIEnv* env, jmethodID method))

hotspot/src/share/vm/runtime/reflection.cpp

@@ -1004,7 +1004,7 @@ oop Reflection::invoke(instanceKlassHandle klass, methodHandle reflected_method,
   } else {
     if (rtype == T_BOOLEAN || rtype == T_BYTE || rtype == T_CHAR || rtype == T_SHORT)
       narrow((jvalue*) result.get_value_addr(), rtype, CHECK_NULL);
-    return box((jvalue*) result.get_value_addr(), rtype, CHECK_NULL);
+    return box((jvalue*) result.get_value_addr(), rtype, THREAD);
   }
 }
 

hotspot/src/share/vm/runtime/sharedRuntime.cpp

@@ -986,7 +986,7 @@ Handle SharedRuntime::find_callee_info(JavaThread* thread, Bytecodes::Code& bc,
   // last java frame on stack (which includes native call frames)
   vframeStream vfst(thread, true);  // Do not skip and javaCalls
 
-  return find_callee_info_helper(thread, vfst, bc, callinfo, CHECK_(Handle()));
+  return find_callee_info_helper(thread, vfst, bc, callinfo, THREAD);
 }
 
 

hotspot/src/share/vm/services/memTracker.hpp

@@ -64,7 +64,7 @@ class MemTracker : AllStatic {
     const NativeCallStack& stack, MEMFLAGS flag = mtNone) { }
   static inline void record_virtual_memory_commit(void* addr, size_t size, const NativeCallStack& stack) { }
   static inline Tracker get_virtual_memory_uncommit_tracker() { return Tracker(); }
-  static inline Tracker get_virtual_memory_release_tracker() { }
+  static inline Tracker get_virtual_memory_release_tracker() { return Tracker(); }
   static inline void record_virtual_memory_type(void* addr, MEMFLAGS flag) { }
   static inline void record_thread_stack(void* addr, size_t size) { }
   static inline void release_thread_stack(void* addr, size_t size) { }