Status of building problem with GCC 6

[Yasumasa Suenaga]

Hi all,

I want to share task list for building OpenJDK with GCC 6.


* jdk:
   - JDK-8160294: reviewing

* hotspot
     Subtasks of JDK-8160310:
       - JDK-8160353: reviewing (includes patch for JDK-8156980)
       - JDK-8160354: reviewing (a part of fix depends on JDK-8156980)
       - JDK-8160356: waiting to push
       - JDK-8160357: might be discarded if JDK-8156980 will be resolved.
       - JDK-8160361: waiting to push
       - JDK-8160363: might be discarded if JDK-8156980 will be resolved.


For HotSpot, I think JDK-8156980 should be fixed at first.
I've proposed changes as below:

-----------
diff -r ba08710f3b6c make/lib/CompileJvm.gmk
--- a/make/lib/CompileJvm.gmk   Mon Jun 27 09:35:18 2016 +0200
+++ b/make/lib/CompileJvm.gmk   Tue Jun 28 12:10:09 2016 +0900
@@ -187,6 +187,11 @@

   JVM_OPTIMIZATION ?= HIGHEST_JVM

+JVM_CXXFLAGS := $(JVM_CFLAGS)
+ifeq ($(TOOLCHAIN_TYPE), gcc)
+  JVM_CXXFLAGS += -std=gnu++98 -fno-delete-null-pointer-checks -fno-lifetime-dse
+endif
+
   ################################################################################
   # Now set up the actual compilation of the main hotspot native library

@@ -202,6 +207,7 @@
       CFLAGS := $(JVM_CFLAGS), \
       CFLAGS_DEBUG_SYMBOLS := $(JVM_CFLAGS_SYMBOLS), \
       CXXFLAGS_DEBUG_SYMBOLS := $(JVM_CFLAGS_SYMBOLS), \
+    CXXFLAGS := $(JVM_CXXFLAGS), \
       vm_version.cpp_CXXFLAGS := $(CFLAGS_VM_VERSION), \
       DISABLED_WARNINGS_clang := delete-non-virtual-dtor dynamic-class-memaccess \
           empty-body format logical-op-parentheses parentheses \
-----------


I guess GCC 6 (or later) will be provided from several Linux Distros in near future.
In fact, Fedora 24 already provides it.

I'm sure this work helps many developers who use Linux.


Thanks,

Yasumasa