7188168: 7071904 broke the DEBUG_BINARIES option on Linux

Change DEBUG_BINARIES option logic to be more clear.

Reviewed-by: fparain, andrew

hotspot/make/linux/makefiles/adlc.make

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 1999, 2012, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -133,8 +133,10 @@ $(GENERATEDFILES): refresh_adfiles
 # Note that product files are updated via "mv", which is atomic.
 TEMPDIR := $(OUTDIR)/mktmp$(shell echo $$$$)
 
-# Debuggable by default
+ifneq ($(DEBUG_BINARIES), true)
+  # Debuggable by default (unless already done by DEBUG_BINARIES)
   CFLAGS += -g
+endif
 
 # Pass -D flags into ADLC.
 ADLCFLAGS += $(SYSDEFS)

hotspot/make/linux/makefiles/gcc.make

@@ -215,6 +215,10 @@ AOUT_FLAGS += -Xlinker -export-dynamic
 #------------------------------------------------------------------------
 # Debug flags
 
+# DEBUG_BINARIES uses full -g debug information for all configs
+ifeq ($(DEBUG_BINARIES), true)
+  CFLAGS += -g
+else
   # Use the stabs format for debugging information (this is the default
   # on gcc-2.91). It's good enough, has all the information about line
   # numbers and local variables, and libjvm_g.so is only about 16M.
@@ -249,11 +253,6 @@ ifeq ($(ENABLE_FULL_DEBUG_SYMBOLS),1)
       OPT_CFLAGS += -gstabs
     endif
   endif
-
-# DEBUG_BINARIES overrides everything, use full -g debug information
-ifeq ($(DEBUG_BINARIES), true)
-  DEBUG_CFLAGS = -g
-  CFLAGS += $(DEBUG_CFLAGS)
 endif
 
 # If we are building HEADLESS, pass on to VM