Re: some warnings (from Gentoos build process)

[Keith Seitz <keiths at redhat dot com>]

Andrew Haley wrote:
> Keith, most of these warnings are yours.  Please fix them.

As a matter of fact, they aren't mine. They're all API specification 
silliness. Only one of them occurs in code that I touched.

The attach patch removes the all the warnings I could find in 
natVMVirtualMachine.cc and jvmti.cc. I will commit it when it is approved.

Thank you for looking,
Keith

>  >  * /mnt/data/tmp/portage/dev-java/gcj-4.3.0_alpha20070216/work/gcc-4.3-20070216/libjava/jvmti.cc:1002: warning: dereferencing type-punned pointer will break strict-aliasing rules
>  > /mnt/data/tmp/portage/dev-java/gcj-4.3.0_alpha20070216/work/gcc-4.3-20070216/libjava/jvmti.cc:1009: warning: dereferencing type-punned pointer will break strict-aliasing rules
>  > /mnt/data/tmp/portage/dev-java/gcj-4.3.0_alpha20070216/work/gcc-4.3-20070216/libjava/jvmti.cc:1016: warning: dereferencing type-punned pointer will break strict-aliasing rules
>  > /mnt/data/tmp/portage/dev-java/gcj-4.3.0_alpha20070216/work/gcc-4.3-20070216/libjava/gnu/classpath/jdwp/natVMVirtualMachine.cc:105: warning: dereferencing type-punned pointer will break strict-aliasing rules

Index: jvmti.cc
===================================================================
--- jvmti.cc	(revision 122057)
+++ jvmti.cc	(working copy)
@@ -997,23 +997,23 @@
                                  table_slot) 
             >= 0)
     {
+      char **charp = &((*locals)[table_slot].name);
       jerr = env->Allocate (static_cast<jlong> (strlen (name) + 1),
-                             reinterpret_cast<unsigned char **>
-                               (&(*locals)[table_slot].name));
+			    reinterpret_cast<unsigned char **> (charp));
       if (jerr != JVMTI_ERROR_NONE)
         return jerr;
       strcpy ((*locals)[table_slot].name, name);
 
+      charp = &((*locals)[table_slot].signature);
       jerr = env->Allocate (static_cast<jlong> (strlen (name) + 1),
-                               reinterpret_cast<unsigned char **>
-                                 (&(*locals)[table_slot].signature));
+			    reinterpret_cast<unsigned char **> (charp));
       if (jerr != JVMTI_ERROR_NONE)
         return jerr;
       strcpy ((*locals)[table_slot].signature, sig);
   
+      charp = &((*locals)[table_slot].generic_signature);
       jerr = env->Allocate (static_cast<jlong> (strlen (name) + 1),
-                               reinterpret_cast<unsigned char **>
-                               (&(*locals)[table_slot].generic_signature));
+			    reinterpret_cast<unsigned char **> (charp));
       if (jerr != JVMTI_ERROR_NONE)
         return jerr;
       strcpy ((*locals)[table_slot].generic_signature, generic_sig);
Index: gnu/classpath/jdwp/natVMVirtualMachine.cc
===================================================================
--- gnu/classpath/jdwp/natVMVirtualMachine.cc	(revision 122065)
+++ gnu/classpath/jdwp/natVMVirtualMachine.cc	(working copy)
@@ -111,7 +111,13 @@
   _stepping_threads = new ::java::util::Hashtable ();
 
   JavaVM *vm = _Jv_GetJavaVM ();
-  vm->GetEnv (reinterpret_cast<void **> (&_jdwp_jvmtiEnv), JVMTI_VERSION_1_0);
+  union
+  {
+    void *ptr;
+    jvmtiEnv *env;
+  } foo;
+  vm->GetEnv (&(foo.ptr), JVMTI_VERSION_1_0);
+  _jdwp_jvmtiEnv = foo.env;
 
   // Wait for VM_INIT to do more initialization
   jvmtiEventCallbacks callbacks;
 }
 
 static void JNICALL
-jdwpSingleStepCB (jvmtiEnv *env, JNIEnv *jni_env, jthread thread,
+jdwpSingleStepCB (jvmtiEnv *env, MAYBE_UNUSED JNIEnv *jni_env, jthread thread,
 		  jmethodID method, jlocation location)
 {
   jobject si =