Merge pull request SAP#2193 from SAP/pr-jdk-27+11

Merge to tag jdk-27+11

Author: RealCLanger

make/autoconf/flags-cflags.m4

@@ -214,6 +214,7 @@ AC_DEFUN([FLAGS_SETUP_WARNINGS],
       WARNINGS_ENABLE_ADDITIONAL_CXX=""
       WARNINGS_ENABLE_ADDITIONAL_JVM=""
       DISABLED_WARNINGS="4800 5105"
+      CFLAGS_CONVERSION_WARNINGS=
       ;;
 
     gcc)
@@ -239,6 +240,7 @@ AC_DEFUN([FLAGS_SETUP_WARNINGS],
       if test "x$OPENJDK_TARGET_CPU_ARCH" = "xppc"; then
         DISABLED_WARNINGS="$DISABLED_WARNINGS psabi"
       fi
+      CFLAGS_CONVERSION_WARNINGS="-Wconversion -Wno-float-conversion"
       ;;
 
     clang)
@@ -258,6 +260,7 @@ AC_DEFUN([FLAGS_SETUP_WARNINGS],
       # These warnings will never be turned on, since they generate too many
       # false positives.
       DISABLED_WARNINGS="unknown-warning-option unused-parameter"
+      CFLAGS_CONVERSION_WARNINGS="-Wimplicit-int-conversion"
       ;;
   esac
   WARNINGS_ENABLE_ALL="$WARNINGS_ENABLE_ALL_NORMAL $WARNINGS_ENABLE_ADDITIONAL"
@@ -270,6 +273,7 @@ AC_DEFUN([FLAGS_SETUP_WARNINGS],
   AC_SUBST(DISABLED_WARNINGS)
   AC_SUBST(DISABLED_WARNINGS_C)
   AC_SUBST(DISABLED_WARNINGS_CXX)
+  AC_SUBST(CFLAGS_CONVERSION_WARNINGS)
 ])
 
 AC_DEFUN([FLAGS_SETUP_QUALITY_CHECKS],

make/autoconf/platform.m4

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2025, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2026, 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
@@ -311,6 +311,12 @@ AC_DEFUN([PLATFORM_EXTRACT_TARGET_AND_BUILD],
   else
     OPENJDK_BUILD_OS_ENV="$VAR_OS"
   fi
+  # Special handling for MSYS2 that reports a Cygwin triplet as the default host triplet.
+  case `uname` in
+    MSYS*)
+      OPENJDK_BUILD_OS_ENV=windows.msys2
+      ;;
+  esac
   OPENJDK_BUILD_CPU="$VAR_CPU"
   OPENJDK_BUILD_CPU_ARCH="$VAR_CPU_ARCH"
   OPENJDK_BUILD_CPU_BITS="$VAR_CPU_BITS"

make/autoconf/spec.gmk.template

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2025, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2026, 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
@@ -538,6 +538,7 @@ CFLAGS_WARNINGS_ARE_ERRORS := @CFLAGS_WARNINGS_ARE_ERRORS@
 DISABLED_WARNINGS := @DISABLED_WARNINGS@
 DISABLED_WARNINGS_C := @DISABLED_WARNINGS_C@
 DISABLED_WARNINGS_CXX := @DISABLED_WARNINGS_CXX@
+CFLAGS_CONVERSION_WARNINGS := @CFLAGS_CONVERSION_WARNINGS@
 
 # A global flag (true or false) determining if native warnings are considered errors.
 WARNINGS_AS_ERRORS := @WARNINGS_AS_ERRORS@

make/common/MakeBase.gmk

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2025, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2026, 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
@@ -141,6 +141,66 @@ endef
 # Make sure logging is setup for everyone that includes MakeBase.gmk.
 $(eval $(call SetupLogging))
 
+################################################################################
+# Make does not have support for VARARGS, you can send variable amount
+# of arguments, but you can for example not append a list at the end.
+# It is therefore not easy to send the elements of a list of unknown
+# length as argument to a function. This can somewhat be worked around
+# by sending a list as an argument, and then interpreting each element
+# of the list as an argument to the function. However, Make is
+# limited, and using this method you can not easily send spaces.
+#
+# We need to quote strings for two reasons when sending them as
+# "variable append packs":
+#
+# 1) variable appends can include spaces, and those must be preserved
+# 2) variable appends can include assignment strings ":=", and those
+# must be quoted to a form so that we can recognise the "append pack".
+# We recognise an "append pack" by its lack of strict assignment ":="
+
+Q       := $(HASH)
+SpaceQ  := $(Q)s
+AppendQ := $(Q)+
+AssignQ := $(Q)a
+QQ      := $(Q)$(Q)
+
+# $(call Quote,echo "#trala:=") -> echo#s"##trala#a"
+Quote = $(subst :=,$(AssignQ),$(subst $(SPACE),$(SpaceQ),$(subst $(Q),$(QQ),$1)))
+
+# $(call Unquote,echo#s"##trala#a") -> echo "#trala:="
+Unquote = $(subst $(QQ),$(Q),$(subst $(SpaceQ),$(SPACE),$(subst $(AssignQ),:=,$1)))
+
+# $(call QuoteAppend,name,some value) -> name#+some#svalue
+# $(call QuoteAppend,bad+=name,some value) -> error
+QuoteAppend = $(if $(findstring +=,$1),$(error you can not have += in a variable name: "$1"),$(call Quote,$1)$(AppendQ)$(call Quote,$2))
+
+# $(call UnquoteAppendIndex,name#+some#svalue,1) -> name
+# $(call UnquoteAppendIndex,name#+some#svalue,2) -> some value
+UnquoteAppendIndex = $(call Unquote,$(word $2,$(subst $(AppendQ),$(SPACE),$1)))
+
+# $(call FilterFiles,dir,%.cpp) -> file1.cpp file2.cpp (without path)
+FilterFiles = $(filter $2,$(notdir $(call FindFiles,$1)))
+
+# $(call Unpack module_,file1.cpp_CXXFLAGS#+-Wconversion file2.cpp_CXXFLAGS#+-Wconversion) -> module_file1.cpp_CXXFLAGS += -Wconversion
+#                                                                                             module_file2.cpp_CXXFLAGS += -Wconversion
+Unpack = $(foreach pair,$2,$1$(call UnquoteAppendIndex,$(pair),1) += $(call UnquoteAppendIndex,$(pair),2)$(NEWLINE))
+
+# This macro takes four arguments:
+# $1: directory where to find files (striped), example: $(TOPDIR)/src/hotspot/share/gc/g1
+# $2: filter to match what to keep (striped), example: g1Concurrent%.cpp
+# $3: what flags to override (striped), example: _CXXFLAGS
+# $4: what value to append to the flag (striped), example: $(CFLAGS_CONVERSION_WARNINGS)
+#
+# The result will be a quoted string that can be unpacked to a list of
+# variable appendings (see macro Unpack above). You do not need to take
+# care of unpacking, it is done in NamedParamsMacroTemplate.
+#
+# This feature should only be used for warnings that we want to
+# incrementally add to the rest of the code base.
+#
+# $(call ExtendFlags,dir,%.cpp,_CXXFLAGS,-Wconversion) -> file1.cpp_CXXFLAGS#+-Wconversion file2.cpp_CXXFLAGS#+-Wconversion
+ExtendFlags = $(foreach file,$(call FilterFiles,$(strip $1),$(strip $2)),$(call QuoteAppend,$(file)$(strip $3),$(strip $4)))
+
 ################################################################################
 
 MAX_PARAMS := 96
@@ -166,7 +226,10 @@ define NamedParamsMacroTemplate
       Too many named arguments to macro, please update MAX_PARAMS in MakeBase.gmk))
   # Iterate over 2 3 4... and evaluate the named parameters with $1_ as prefix
   $(foreach i, $(PARAM_SEQUENCE), $(if $(strip $($i)), \
-    $(strip $1)_$(strip $(call EscapeHash, $(call DoubleDollar, $($i))))$(NEWLINE)))
+    $(if $(findstring :=,$($i)), \
+      $(strip $1)_$(strip $(call EscapeHash, $(call DoubleDollar, $($i))))$(NEWLINE), \
+      $(call Unpack,$(strip $1)_,$($i)))))
+
   # Debug print all named parameter names and values
   $(if $(findstring $(LOG_LEVEL), trace), \
     $(info $0 $(strip $1) $(foreach i, $(PARAM_SEQUENCE), \

make/hotspot/lib/CompileJvm.gmk

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2013, 2025, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2013, 2026, 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
@@ -105,7 +105,7 @@ DISABLED_WARNINGS_gcc := array-bounds comment delete-non-virtual-dtor \
 DISABLED_WARNINGS_clang := delete-non-abstract-non-virtual-dtor \
     invalid-offsetof missing-braces \
     sometimes-uninitialized unknown-pragmas unused-but-set-variable \
-    unused-function unused-local-typedef unused-private-field unused-variable
+    unused-local-typedef unused-private-field unused-variable
 
 ifneq ($(DEBUG_LEVEL), release)
   # Assert macro gives warning
@@ -190,6 +190,8 @@ $(eval $(call SetupJdkLibrary, BUILD_LIBJVM, \
     abstract_vm_version.cpp_CXXFLAGS := $(CFLAGS_VM_VERSION), \
     arguments.cpp_CXXFLAGS := $(CFLAGS_VM_VERSION), \
     whitebox.cpp_CXXFLAGS := $(CFLAGS_SHIP_DEBUGINFO), \
+    $(call ExtendFlags, $(TOPDIR)/src/hotspot/share/gc/g1, \
+        g1Numa.cpp, _CXXFLAGS, $(CFLAGS_CONVERSION_WARNINGS)), \
     DISABLED_WARNINGS_gcc := $(DISABLED_WARNINGS_gcc), \
     DISABLED_WARNINGS_gcc_ad_$(HOTSPOT_TARGET_CPU_ARCH).cpp := nonnull, \
     DISABLED_WARNINGS_gcc_bytecodeInterpreter.cpp := unused-label, \

make/modules/java.base/Copy.gmk

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2014, 2025, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2014, 2026, 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
@@ -172,6 +172,10 @@ ifeq ($(USE_EXTERNAL_LIBZ), true)
   LEGAL_EXCLUDES += zlib.md
 endif
 
+ifneq ($(TOOLCHAIN_TYPE), gcc)
+  LEGAL_EXCLUDES += gcc.md
+endif
+
 $(eval $(call SetupCopyLegalFiles, COPY_LEGAL, \
     EXCLUDES := $(LEGAL_EXCLUDES), \
 ))

src/hotspot/cpu/aarch64/c2_MacroAssembler_aarch64.cpp

@@ -30,7 +30,9 @@
 #include "opto/matcher.hpp"
 #include "opto/output.hpp"
 #include "opto/subnode.hpp"
+#include "runtime/objectMonitorTable.hpp"
 #include "runtime/stubRoutines.hpp"
+#include "runtime/synchronizer.hpp"
 #include "utilities/globalDefinitions.hpp"
 #include "utilities/powerOfTwo.hpp"
 
@@ -221,37 +223,52 @@ void C2_MacroAssembler::fast_lock(Register obj, Register box, Register t1,
     if (!UseObjectMonitorTable) {
       assert(t1_monitor == t1_mark, "should be the same here");
     } else {
+      const Register t1_hash = t1;
       Label monitor_found;
 
-      // Load cache address
-      lea(t3_t, Address(rthread, JavaThread::om_cache_oops_offset()));
+      // Save the mark, we might need it to extract the hash.
+      mov(t3, t1_mark);
 
-      const int num_unrolled = 2;
+      // Look for the monitor in the om_cache.
+
+      ByteSize cache_offset   = JavaThread::om_cache_oops_offset();
+      ByteSize monitor_offset = OMCache::oop_to_monitor_difference();
+      const int num_unrolled  = OMCache::CAPACITY;
       for (int i = 0; i < num_unrolled; i++) {
-        ldr(t1, Address(t3_t));
-        cmp(obj, t1);
+        ldr(t1_monitor, Address(rthread, cache_offset + monitor_offset));
+        ldr(t2, Address(rthread, cache_offset));
+        cmp(obj, t2);
         br(Assembler::EQ, monitor_found);
-        increment(t3_t, in_bytes(OMCache::oop_to_oop_difference()));
+        cache_offset = cache_offset + OMCache::oop_to_oop_difference();
       }
 
-      Label loop;
+      // Look for the monitor in the table.
+
+      // Get the hash code.
+      ubfx(t1_hash, t3, markWord::hash_shift, markWord::hash_bits);
 
-      // Search for obj in cache.
-      bind(loop);
+      // Get the table and calculate the bucket's address
+      lea(t3, ExternalAddress(ObjectMonitorTable::current_table_address()));
+      ldr(t3, Address(t3));
+      ldr(t2, Address(t3, ObjectMonitorTable::table_capacity_mask_offset()));
+      ands(t1_hash, t1_hash, t2);
+      ldr(t3, Address(t3, ObjectMonitorTable::table_buckets_offset()));
 
-      // Check for match.
-      ldr(t1, Address(t3_t));
-      cmp(obj, t1);
-      br(Assembler::EQ, monitor_found);
+      // Read the monitor from the bucket.
+      ldr(t1_monitor, Address(t3, t1_hash, Address::lsl(LogBytesPerWord)));
+
+      // Check if the monitor in the bucket is special (empty, tombstone or removed).
+      cmp(t1_monitor, (unsigned char)ObjectMonitorTable::SpecialPointerValues::below_is_special);
+      br(Assembler::LO, slow_path);
 
-      // Search until null encountered, guaranteed _null_sentinel at end.
-      increment(t3_t, in_bytes(OMCache::oop_to_oop_difference()));
-      cbnz(t1, loop);
-      // Cache Miss, NE set from cmp above, cbnz does not set flags
-      b(slow_path);
+      // Check if object matches.
+      ldr(t3, Address(t1_monitor, ObjectMonitor::object_offset()));
+      BarrierSetAssembler* bs_asm = BarrierSet::barrier_set()->barrier_set_assembler();
+      bs_asm->try_resolve_weak_handle_in_c2(this, t3, t2, slow_path);
+      cmp(t3, obj);
+      br(Assembler::NE, slow_path);
 
       bind(monitor_found);
-      ldr(t1_monitor, Address(t3_t, OMCache::oop_to_monitor_difference()));
     }
 
     const Register t2_owner_addr = t2;

src/hotspot/cpu/aarch64/gc/shared/barrierSetAssembler_aarch64.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2026, 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
@@ -441,6 +441,11 @@ OptoReg::Name BarrierSetAssembler::refine_register(const Node* node, OptoReg::Na
   return opto_reg;
 }
 
+void BarrierSetAssembler::try_resolve_weak_handle_in_c2(MacroAssembler* masm, Register obj, Register tmp, Label& slow_path) {
+  // Load the oop from the weak handle.
+  __ ldr(obj, Address(obj));
+}
+
 #undef __
 #define __ _masm->
 

src/hotspot/cpu/aarch64/gc/shared/barrierSetAssembler_aarch64.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2026, 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
@@ -135,6 +135,7 @@ class BarrierSetAssembler: public CHeapObj<mtGC> {
                                                   OptoReg::Name opto_reg);
   OptoReg::Name refine_register(const Node* node,
                                 OptoReg::Name opto_reg);
+  virtual void try_resolve_weak_handle_in_c2(MacroAssembler* masm, Register obj, Register tmp, Label& slow_path);
 #endif // COMPILER2
 };
 

src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp

@@ -1,4 +1,5 @@
 /*
+ * Copyright (c) 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2018, 2022, Red Hat, Inc. All rights reserved.
  * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
@@ -442,6 +443,30 @@ void ShenandoahBarrierSetAssembler::try_resolve_jobject_in_native(MacroAssembler
   __ bind(done);
 }
 
+#ifdef COMPILER2
+void ShenandoahBarrierSetAssembler::try_resolve_weak_handle_in_c2(MacroAssembler* masm, Register obj,
+                                                                  Register tmp, Label& slow_path) {
+  assert_different_registers(obj, tmp);
+
+  Label done;
+
+  // Resolve weak handle using the standard implementation.
+  BarrierSetAssembler::try_resolve_weak_handle_in_c2(masm, obj, tmp, slow_path);
+
+  // Check if the reference is null, and if it is, take the fast path.
+  __ cbz(obj, done);
+
+  Address gc_state(rthread, ShenandoahThreadLocalData::gc_state_offset());
+  __ lea(tmp, gc_state);
+  __ ldrb(tmp, __ legitimize_address(gc_state, 1, tmp));
+
+  // Check if the heap is under weak-reference/roots processing, in
+  // which case we need to take the slow path.
+  __ tbnz(tmp, ShenandoahHeap::WEAK_ROOTS_BITPOS, slow_path);
+  __ bind(done);
+}
+#endif
+
 // Special Shenandoah CAS implementation that handles false negatives due
 // to concurrent evacuation.  The service is more complex than a
 // traditional CAS operation because the CAS operation is intended to