build clang

clang_stack.patch

@@ -0,0 +1,12 @@
+diff -urN openjdk/src/hotspot/os_cpu/linux_x86/os_linux_x86.cpp openjdk-diff/src/hotspot/os_cpu/linux_x86/os_linux_x86.cpp
+--- openjdk/src/hotspot/os_cpu/linux_x86/os_linux_x86.cpp	2020-06-10 19:44:52.000000000 +0000
++++ openjdk-diff/src/hotspot/os_cpu/linux_x86/os_linux_x86.cpp	2020-07-12 21:26:42.912877532 +0000
+@@ -825,7 +825,7 @@
+ 
+ #ifndef PRODUCT
+ void os::verify_stack_alignment() {
+-#ifdef AMD64
++#if defined(AMD64) && ! defined(__clang__)
+   assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
+ #endif
+ }

java-11-openjdk.spec

@@ -1156,13 +1156,13 @@ Patch8: s390-8214206_fix.patch
 #############################################
 # JDK-8247874: Replacement in VersionProps.java.template not working when --with-vendor-bug-url contains '&'
 Patch9: jdk8247874-fix_ampersand_in_vm_bug_url.patch
-
+Patch10: clang_stack.patch
 #############################################
 #
 # JDK 9+ only patches
 #
 #############################################
-
+BuildRequires: clang
 BuildRequires: autoconf
 BuildRequires: automake
 BuildRequires: binutils
@@ -1430,6 +1430,7 @@ pushd %{top_level_dir_name}
 %patch7 -p1
 %patch8 -p1
 %patch9 -p1
+%patch10 -p1
 popd # openjdk
 
 %patch1000
@@ -1482,6 +1483,8 @@ sed -e "s:@NSS_LIBDIR@:%{NSS_LIBDIR}:g" %{SOURCE11} > nss.cfg
 
 
 %build
+export CC="clang"
+export CXX="clang++"
 # How many CPU's do we have?
 export NUM_PROC=%(/usr/bin/getconf _NPROCESSORS_ONLN 2> /dev/null || :)
 export NUM_PROC=${NUM_PROC:-1}
@@ -1563,7 +1566,8 @@ bash ../configure \
 %ifarch x86_64
     --with-jvm-features=zgc \
 %endif
-    --disable-warnings-as-errors
+    --disable-warnings-as-errors \
+    --with-toolchain-type="clang"
 
 # Debug builds don't need same targets as release for
 # build speed-up