The FreeBSD folks did an in-depth analysis of why jdk 1.8 and 11 fail to build with llvm13. You can read about it here:
https://github.com/freebsd/freebsd-ports/commit/3822416493c In llvm13 the 'this' pointer was annotated with alignment: https://github.com/llvm/llvm-project/commit/0aa0458f142 It was reverted and then put back in: https://github.com/llvm/llvm-project/commit/16d03818412 In jdk/1.8 and jdk/11 code bases there's a class markOopDesc that bit twiddles the 'this' pointer and the alignment change is presumably optimizing it away. I don't have an llvm13 system setup yet so I'm taking a shot in the dark that annotating the value() method as no-inline will correct the llvm13 build. The idea being that value() is getting optimized away and the compiler is seeing 'this' as aligned and further optimizing away the bit twiddling. https://github.com/openjdk/jdk11u/blob/master/src/hotspot/share/oops/markOop.hpp#L107 For jdk/17 markOopDesc was rewritten and it fails to build due to -Werror. Adding -Wno-unused-but-set-parameter should fix that. Index: 1.8/Makefile =================================================================== RCS file: /cvs/ports/devel/jdk/1.8/Makefile,v retrieving revision 1.64 diff -u -p -u -r1.64 Makefile --- 1.8/Makefile 5 Aug 2021 15:40:20 -0000 1.64 +++ 1.8/Makefile 30 Oct 2021 12:56:25 -0000 @@ -13,7 +13,7 @@ V= ${BASE_VER}.${UPDATE_VER}.${BUILD_VE PKGNAME= jdk-${V} PKGSTEM= jdk-${BASE_VER} EPOCH= 0 -REVISION= 0 +REVISION= 1 DIST_SUBDIR= jdk DISTNAME= jdk8u${UPDATE_VER}-${BUILD_VER}.${BSD_PORT_REL} Index: 1.8/patches/patch-hotspot_src_share_vm_oops_markOop_hpp =================================================================== RCS file: 1.8/patches/patch-hotspot_src_share_vm_oops_markOop_hpp diff -N 1.8/patches/patch-hotspot_src_share_vm_oops_markOop_hpp --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ 1.8/patches/patch-hotspot_src_share_vm_oops_markOop_hpp 30 Oct 2021 12:56:25 -0000 @@ -0,0 +1,16 @@ +$OpenBSD$ + +Fix build with llvm 13 + +Index: hotspot/src/share/vm/oops/markOop.hpp +--- hotspot/src/share/vm/oops/markOop.hpp.orig ++++ hotspot/src/share/vm/oops/markOop.hpp +@@ -104,7 +104,7 @@ class JavaThread; + class markOopDesc: public oopDesc { + private: + // Conversion +- uintptr_t value() const { return (uintptr_t) this; } ++ NOINLINE uintptr_t value() const { return (uintptr_t) this; } + + public: + // Constants Index: 11/Makefile =================================================================== RCS file: /cvs/ports/devel/jdk/11/Makefile,v retrieving revision 1.25 diff -u -p -u -r1.25 Makefile --- 11/Makefile 5 Aug 2021 02:21:41 -0000 1.25 +++ 11/Makefile 30 Oct 2021 12:56:25 -0000 @@ -13,6 +13,7 @@ PACKAGE_VER= ${BASE_VER}.${PATCH_VER}.${ PKGNAME= jdk-${PACKAGE_VER} PKGSTEM= jdk-11 EPOCH= 0 +REVISION= 0 DIST_SUBDIR= jdk DISTNAME= jdk-${VERSION_STR} Index: 11/patches/patch-src_hotspot_share_oops_markOop_hpp =================================================================== RCS file: 11/patches/patch-src_hotspot_share_oops_markOop_hpp diff -N 11/patches/patch-src_hotspot_share_oops_markOop_hpp --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ 11/patches/patch-src_hotspot_share_oops_markOop_hpp 30 Oct 2021 12:56:25 -0000 @@ -0,0 +1,16 @@ +$OpenBSD$ + +Fix build for llvm13 + +Index: src/hotspot/share/oops/markOop.hpp +--- src/hotspot/share/oops/markOop.hpp.orig ++++ src/hotspot/share/oops/markOop.hpp +@@ -104,7 +104,7 @@ class JavaThread; + class markOopDesc: public oopDesc { + private: + // Conversion +- uintptr_t value() const { return (uintptr_t) this; } ++ NOINLINE uintptr_t value() const { return (uintptr_t) this; } + + public: + // Constants Index: 17/Makefile =================================================================== RCS file: /cvs/ports/devel/jdk/17/Makefile,v retrieving revision 1.2 diff -u -p -u -r1.2 Makefile --- 17/Makefile 30 Oct 2021 00:31:15 -0000 1.2 +++ 17/Makefile 30 Oct 2021 12:56:25 -0000 @@ -13,7 +13,7 @@ PACKAGE_VER= ${BASE_VER}.${PATCH_VER}.${ PKGNAME= jdk-${PACKAGE_VER} PKGSTEM= jdk-17 EPOCH= 0 -REVISION= 0 +REVISION= 1 DIST_SUBDIR= jdk DISTNAME= jdk-${VERSION_STR} Index: 17/patches/patch-make_hotspot_lib_CompileJvm_gmk =================================================================== RCS file: /cvs/ports/devel/jdk/17/patches/patch-make_hotspot_lib_CompileJvm_gmk,v retrieving revision 1.1.1.1 diff -u -p -u -r1.1.1.1 patch-make_hotspot_lib_CompileJvm_gmk --- 17/patches/patch-make_hotspot_lib_CompileJvm_gmk 29 Oct 2021 18:15:16 -0000 1.1.1.1 +++ 17/patches/patch-make_hotspot_lib_CompileJvm_gmk 30 Oct 2021 12:56:25 -0000 @@ -1,11 +1,22 @@ $OpenBSD: patch-make_hotspot_lib_CompileJvm_gmk,v 1.1.1.1 2021/10/29 18:15:16 kurt Exp $ -This file name changed in 17 and needs to be excluded +threadLS_bsd_aarch64.S name changed in 17 and needs to be excluded. +Disable unused-but-set-parameter for llvm13. Index: make/hotspot/lib/CompileJvm.gmk --- make/hotspot/lib/CompileJvm.gmk.orig +++ make/hotspot/lib/CompileJvm.gmk -@@ -128,7 +128,7 @@ else ifeq ($(call And, $(call isTargetOs, linux) $(cal +@@ -95,7 +95,8 @@ DISABLED_WARNINGS_clang := tautological-compare \ + undefined-var-template sometimes-uninitialized unknown-pragmas \ + delete-non-virtual-dtor missing-braces char-subscripts \ + ignored-qualifiers missing-field-initializers mismatched-tags \ +- unnamed-type-template-args shift-negative-value format-nonliteral ++ unnamed-type-template-args shift-negative-value format-nonliteral \ ++ unused-but-set-parameter + + ifneq (,$(filter 1%,$(CC_VERSION_NUMBER))) + DISABLED_WARNINGS_clang += misleading-indentation +@@ -128,7 +129,7 @@ else ifeq ($(call And, $(call isTargetOs, linux) $(cal endif ifeq ($(OPENJDK_TARGET_OS_ENV)-$(OPENJDK_TARGET_CPU), bsd.openbsd-aarch64)
