openjdk-8: gcc-8 fix #4: undefined behaviour (hotspot)

Using gcc-8, Hotspot is being miscompiled, resulting in non-
working binaries.

The reason is undefined behaviour, which gcc-8 even warns about
and errors out. We have so far have taped over those warnings,
but it turns out that we simply cannot do that.

Add patches to address undefined behaviour causing miscompilation
of hotsport.

This also means we can remove the -Wno-error=return-type C compiler
flag again which was recently added in error in
commit 52fb41cec7d5 ("openjdk-8: fix build for gcc8.x") only hiding
the compiler warnings/errors that were flagging the incorrect code
in the first place.

With these patches applied, the openjdk-8 ARM port works again:
| RESULTS:
| RESULTS - ping.PingTest.test_ping - Testcase 964: PASSED (0.04s)
| RESULTS - ssh.SSHTest.test_ssh - Testcase 224: PASSED (0.68s)
| RESULTS - java.JavaTest.test_java_exists - Testcase -1: PASSED (0.14s)
| RESULTS - java.JavaTest.test_java_jar_comp_mode - Testcase -1: FAILED (5.13s)
| RESULTS - java.JavaTest.test_java_jar_int_mode - Testcase -1: PASSED (4.48s)
| RESULTS - java.JavaTest.test_java_jar_works - Testcase -1: PASSED (4.44s)
| RESULTS - java.JavaTest.test_java_version - Testcase -1: PASSED (3.66s)
| RESULTS - javac.JavacTest.test_javac_exists - Testcase -1: PASSED (0.13s)
| RESULTS - javac.JavacTest.test_javac_works - Testcase -1: PASSED (30.87s)
| SUMMARY:
| openjdk-8-test-image () - Ran 9 tests in 50.263s

The java.JavaTest.test_java_jar_comp_mode failure can be ignored for now,
as that test verifies compiled mode which is not available on arm. The
testcase must be fixed instead.

(We need to refresh one unrelated existing patch to avoid patch fuzz warnings)

Signed-off-by: André Draszik <andre.draszik@jci.com>
Signed-off-by: Richard Leitner <richard.leitner@skidata.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/recipes-core/openjdk/patches-openjdk-8/0012-hotspot-aarch64-fix-undefined-behaviour-gcc-v8-fix.patch b/recipes-core/openjdk/patches-openjdk-8/0012-hotspot-aarch64-fix-undefined-behaviour-gcc-v8-fix.patch
new file mode 100644
index 0000000..e11c19c
--- /dev/null
+++ b/recipes-core/openjdk/patches-openjdk-8/0012-hotspot-aarch64-fix-undefined-behaviour-gcc-v8-fix.patch
@@ -0,0 +1,41 @@
+From 1fa1097d45afa2fe2bfd989fbd90578f5c5fc540 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Andr=C3=A9=20Draszik?= <andre.draszik@jci.com>
+Date: Mon, 13 Aug 2018 12:14:21 +0100
+Subject: [PATCH] hotspot/aarch64: fix undefined behaviour (gcc v8 fix)
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Backport patch from
+  http://hg.openjdk.java.net/aarch64-port/jdk8u/hotspot/rev/253b0c304db6
+to address segfaults due to undefined behaviour.
+
+|# HG changeset patch
+|# User shade
+|# Date 1526068247 -7200
+|# Node ID 253b0c304db6d31be3d3d7cf7cf1b3561a16dc3a
+|# Parent  1ced2ae00e35e6f855175fc44500b37fbac9e314
+UB in os_linux_aarch64.cpp SpinPause
+Reviewed-by: aph, shade, adinn
+
+Signed-off-by: André Draszik <andre.draszik@jci.com>
+Upstream-Status: Backport [http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/rev/ca4663e58916]
+---
+ hotspot/src/os_cpu/linux_aarch64/vm/os_linux_aarch64.cpp | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/hotspot/src/os_cpu/linux_aarch64/vm/os_linux_aarch64.cpp b/hotspot/src/os_cpu/linux_aarch64/vm/os_linux_aarch64.cpp
+index 8b985693..f536817e 100644
+--- a/hotspot/src/os_cpu/linux_aarch64/vm/os_linux_aarch64.cpp
++++ b/hotspot/src/os_cpu/linux_aarch64/vm/os_linux_aarch64.cpp
+@@ -699,6 +699,7 @@ void os::verify_stack_alignment() {
+ 
+ extern "C" {
+   int SpinPause() {
++    return 0;
+   }
+ 
+   void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
+-- 
+2.18.0
+