Merge branch 'master' of https://github.com/openjdk/jdk into docs/cf-overall

Author: liach

make/InitSupport.gmk

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2024, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2025, 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
@@ -211,13 +211,15 @@ ifeq ($(HAS_SPEC), )
                 $$(if $$(findstring $$(CONF), $$(var)), $$(var))))
           endif
           ifneq ($$(filter $$(CONF), $$(matching_confs)), )
+            ifneq ($$(word 2, $$(matching_confs)), )
+              # Don't repeat this output on make restarts caused by including
+              # generated files.
+              ifeq ($$(MAKE_RESTARTS), )
+                $$(info Using exact match for CONF=$$(CONF) (other matches are possible))
+              endif
+            endif
             # If we found an exact match, use that
             matching_confs := $$(CONF)
-            # Don't repeat this output on make restarts caused by including
-            # generated files.
-            ifeq ($$(MAKE_RESTARTS), )
-              $$(info Using exact match for CONF=$$(CONF) (other matches are possible))
-            endif
           endif
         endif
         ifeq ($$(matching_confs), )

make/autoconf/basic.m4

@@ -84,9 +84,15 @@ AC_DEFUN_ONCE([BASIC_SETUP_PATHS],
 
   # We get the top-level directory from the supporting wrappers.
   BASIC_WINDOWS_VERIFY_DIR($TOPDIR, source)
+  orig_topdir="$TOPDIR"
   UTIL_FIXUP_PATH(TOPDIR)
   AC_MSG_CHECKING([for top-level directory])
   AC_MSG_RESULT([$TOPDIR])
+  if test "x$TOPDIR" != "x$orig_topdir"; then
+    AC_MSG_WARN([Your top dir was originally represented as $orig_topdir,])
+    AC_MSG_WARN([but after rewriting it became $TOPDIR.])
+    AC_MSG_WARN([This typically means you have characters like space in the path, which can cause all kind of trouble.])
+  fi
   AC_SUBST(TOPDIR)
 
   if test "x$CUSTOM_ROOT" != x; then

make/autoconf/util_paths.m4

@@ -77,7 +77,10 @@ AC_DEFUN([UTIL_FIXUP_PATH],
           imported_path=""
         fi
       fi
-      if test "x$imported_path" != "x$path"; then
+      [ imported_path_lower=`$ECHO $imported_path | $TR '[:upper:]' '[:lower:]'` ]
+      [ orig_path_lower=`$ECHO $path | $TR '[:upper:]' '[:lower:]'` ]
+      # If only case differs, keep original path
+      if test "x$imported_path_lower" != "x$orig_path_lower"; then
         $1="$imported_path"
       fi
     else
@@ -357,6 +360,8 @@ AC_DEFUN([UTIL_SETUP_TOOL],
           fi
           $1="$tool_command"
         fi
+        # Make sure we add fixpath if needed
+        UTIL_FIXUP_EXECUTABLE($1)
         if test "x$tool_args" != x; then
           # If we got arguments, re-append them to the command after the fixup.
           $1="[$]$1 $tool_args"

src/hotspot/share/nmt/mallocHeader.hpp

@@ -36,7 +36,7 @@ class outputStream;
 /*
  * Malloc tracking header.
  *
- * If NMT is active (state >= minimal), we need to track allocations. A simple and cheap way to
+ * If NMT is active (state >= summary), we need to track allocations. A simple and cheap way to
  * do this is by using malloc headers.
  *
  * The user allocation is preceded by a header and is immediately followed by a (possibly unaligned)

src/hotspot/share/opto/stringopts.cpp

@@ -173,6 +173,9 @@ class StringConcat : public ResourceObj {
     assert(!_control.contains(ctrl), "only push once");
     _control.push(ctrl);
   }
+  bool has_control(Node* ctrl) {
+    return _control.contains(ctrl);
+  }
   void add_constructor(Node* init) {
     assert(!_constructors.contains(init), "only push once");
     _constructors.push(init);
@@ -407,7 +410,66 @@ Node_List PhaseStringOpts::collect_toString_calls() {
   return string_calls;
 }
 
-// Recognize a fluent-chain of StringBuilder/Buffer. They are either explicit usages
+PhaseStringOpts::ProcessAppendResult PhaseStringOpts::process_append_candidate(CallStaticJavaNode* cnode,
+                                                                               StringConcat* sc,
+                                                                               ciMethod* m,
+                                                                               ciSymbol* string_sig,
+                                                                               ciSymbol* int_sig,
+                                                                               ciSymbol* char_sig) {
+  if (cnode->method() != nullptr && !cnode->method()->is_static() &&
+      cnode->method()->holder() == m->holder() &&
+      cnode->method()->name() == ciSymbols::append_name() &&
+      (cnode->method()->signature()->as_symbol() == string_sig ||
+       cnode->method()->signature()->as_symbol() == char_sig ||
+       cnode->method()->signature()->as_symbol() == int_sig)) {
+    if (sc->has_control(cnode)) {
+      return ProcessAppendResult::AppendWasAdded;
+    }
+    sc->add_control(cnode);
+    Node* arg = cnode->in(TypeFunc::Parms + 1);
+    if (arg == nullptr || arg->is_top()) {
+#ifndef PRODUCT
+      if (PrintOptimizeStringConcat) {
+        tty->print("giving up because the call is effectively dead");
+        cnode->jvms()->dump_spec(tty);
+        tty->cr();
+      }
+#endif
+      return ProcessAppendResult::AbortOptimization;
+    }
+
+    if (cnode->method()->signature()->as_symbol() == int_sig) {
+      sc->push_int(arg);
+    } else if (cnode->method()->signature()->as_symbol() == char_sig) {
+      sc->push_char(arg);
+    } else if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
+      CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
+      if (csj->method() != nullptr &&
+          csj->method()->intrinsic_id() == vmIntrinsics::_Integer_toString &&
+          arg->outcnt() == 1) {
+        // _control is the list of StringBuilder calls nodes which
+        // will be replaced by new String code after this optimization.
+        // Integer::toString() call is not part of StringBuilder calls
+        // chain. It could be eliminated only if its result is used
+        // only by this SB calls chain.
+        // Another limitation: it should be used only once because
+        // it is unknown that it is used only by this SB calls chain
+        // until all related SB calls nodes are collected.
+        assert(arg->unique_out() == cnode, "sanity");
+        sc->add_control(csj);
+        sc->push_int(csj->in(TypeFunc::Parms));
+      } else {
+        sc->push_string(arg);
+      }
+    } else {
+      sc->push_string(arg);
+    }
+    return ProcessAppendResult::AppendWasAdded;
+  }
+  return ProcessAppendResult::CandidateIsNotAppend;
+}
+
+// Recognize fluent-chain and non-fluent uses of StringBuilder/Buffer. They are either explicit usages
 // of them or the legacy bytecodes of string concatenation prior to JEP-280. eg.
 //
 // String result = new StringBuilder()
@@ -416,18 +478,17 @@ Node_List PhaseStringOpts::collect_toString_calls() {
 //   .append(123)
 //   .toString(); // "foobar123"
 //
-// PS: Only a certain subset of constructor and append methods are acceptable.
-// The criterion is that the length of argument is easy to work out in this phrase.
-// It will drop complex cases such as Object.
+// Fluent-chains are recognized by walking upwards along the receivers, starting from toString().
+// Once the allocation of the StringBuilder has been reached, DU pairs are examined to find the
+// constructor and non-fluent uses of the StringBuilder such as in this example:
 //
-// Since it walks along the receivers of fluent-chain, it will give up if the codeshape is
-// not "fluent" enough. eg.
 //   StringBuilder sb = new StringBuilder();
 //   sb.append("foo");
 //   sb.toString();
 //
-// The receiver of toString method is the result of Allocation Node(CheckCastPP).
-// The append method is overlooked. It will fail at validate_control_flow() test.
+// PS: Only a certain subset of constructor and append methods are acceptable.
+// The criterion is that the length of argument is easy to work out in this phrase.
+// It will drop complex cases such as Object.
 //
 StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
   ciMethod* m = call->method();
@@ -466,7 +527,7 @@ StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
     if (cnode == nullptr) {
       alloc = recv->isa_Allocate();
       if (alloc == nullptr) {
-        break;
+        return nullptr;
       }
       // Find the constructor call
       Node* result = alloc->result_cast();
@@ -478,7 +539,7 @@ StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
           alloc->jvms()->dump_spec(tty); tty->cr();
         }
 #endif
-        break;
+        return nullptr;
       }
       Node* constructor = nullptr;
       for (SimpleDUIterator i(result); i.has_next(); i.next()) {
@@ -489,6 +550,10 @@ StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
             use->method()->name() == ciSymbols::object_initializer_name() &&
             use->method()->holder() == m->holder()) {
           // Matched the constructor.
+          if (constructor != nullptr) {
+            // The constructor again. We must only process it once.
+            continue;
+          }
           ciSymbol* sig = use->method()->signature()->as_symbol();
           if (sig == ciSymbols::void_method_signature() ||
               sig == ciSymbols::int_void_signature() ||
@@ -542,7 +607,16 @@ StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
             }
 #endif
           }
-          break;
+        } else if (use != nullptr) {
+          if (process_append_candidate(use, sc, m, string_sig, int_sig, char_sig) == ProcessAppendResult::AbortOptimization) {
+            // We must abort if process_append_candidate tells us to...
+            return nullptr;
+          }
+          // ...but we do not care if we really found an append or not:
+          // - If we found an append, that's perfect. Nothing further to do.
+          // - If this is a call to an unrelated method, validate_mem_flow() (and validate_control_flow())
+          //   will later check if this call prevents the optimization. So nothing to do here.
+          // We will continue to look for the constructor (if not found already) and appends.
         }
       }
       if (constructor == nullptr) {
@@ -553,7 +627,7 @@ StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
           alloc->jvms()->dump_spec(tty); tty->cr();
         }
 #endif
-        break;
+        return nullptr;
       }
 
       // Walked all the way back and found the constructor call so see
@@ -568,62 +642,23 @@ StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
       } else {
         return nullptr;
       }
-    } else if (cnode->method() == nullptr) {
-      break;
-    } else if (!cnode->method()->is_static() &&
-               cnode->method()->holder() == m->holder() &&
-               cnode->method()->name() == ciSymbols::append_name() &&
-               (cnode->method()->signature()->as_symbol() == string_sig ||
-                cnode->method()->signature()->as_symbol() == char_sig ||
-                cnode->method()->signature()->as_symbol() == int_sig)) {
-      sc->add_control(cnode);
-      Node* arg = cnode->in(TypeFunc::Parms + 1);
-      if (arg == nullptr || arg->is_top()) {
+    } else {
+      ProcessAppendResult result = process_append_candidate(cnode, sc, m, string_sig, int_sig, char_sig);
+
+      if (result == ProcessAppendResult::AbortOptimization) {
+        return nullptr;
+      } else if (result == ProcessAppendResult::CandidateIsNotAppend) {
+        // some unhandled signature
 #ifndef PRODUCT
         if (PrintOptimizeStringConcat) {
-          tty->print("giving up because the call is effectively dead");
-          cnode->jvms()->dump_spec(tty); tty->cr();
+          tty->print("giving up because encountered unexpected signature ");
+          cnode->tf()->dump();
+          tty->cr();
+          cnode->in(TypeFunc::Parms + 1)->dump();
         }
 #endif
-        break;
-      }
-      if (cnode->method()->signature()->as_symbol() == int_sig) {
-        sc->push_int(arg);
-      } else if (cnode->method()->signature()->as_symbol() == char_sig) {
-        sc->push_char(arg);
-      } else {
-        if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
-          CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
-          if (csj->method() != nullptr &&
-              csj->method()->intrinsic_id() == vmIntrinsics::_Integer_toString &&
-              arg->outcnt() == 1) {
-            // _control is the list of StringBuilder calls nodes which
-            // will be replaced by new String code after this optimization.
-            // Integer::toString() call is not part of StringBuilder calls
-            // chain. It could be eliminated only if its result is used
-            // only by this SB calls chain.
-            // Another limitation: it should be used only once because
-            // it is unknown that it is used only by this SB calls chain
-            // until all related SB calls nodes are collected.
-            assert(arg->unique_out() == cnode, "sanity");
-            sc->add_control(csj);
-            sc->push_int(csj->in(TypeFunc::Parms));
-            continue;
-          }
-        }
-        sc->push_string(arg);
-      }
-      continue;
-    } else {
-      // some unhandled signature
-#ifndef PRODUCT
-      if (PrintOptimizeStringConcat) {
-        tty->print("giving up because encountered unexpected signature ");
-        cnode->tf()->dump(); tty->cr();
-        cnode->in(TypeFunc::Parms + 1)->dump();
+        return nullptr;
       }
-#endif
-      break;
     }
   }
   return nullptr;

src/hotspot/share/opto/stringopts.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2009, 2025, 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
@@ -34,7 +34,7 @@ class IdealVariable;
 class PhaseStringOpts : public Phase {
   friend class StringConcat;
 
- private:
+private:
   PhaseGVN* _gvn;
 
   // List of dead nodes to clean up aggressively at the end
@@ -53,6 +53,23 @@ class PhaseStringOpts : public Phase {
   // a single string construction.
   StringConcat* build_candidate(CallStaticJavaNode* call);
 
+  enum class ProcessAppendResult {
+    // Indicates that the candidate was indeed an append and process_append_candidate processed it
+    // accordingly (added it to the StringConcat etc.)
+    AppendWasAdded,
+    // The candidate turned out not to be an append call. process_append_candidate did not do anything.
+    CandidateIsNotAppend,
+    // The candidate is an append call, but circumstances completely preventing string concat
+    // optimization were detected and the optimization must abort.
+    AbortOptimization
+  };
+
+  // Called from build_candidate. Looks at an "append candidate", a call that might be a call
+  // to StringBuilder::append. If so, adds it to the StringConcat.
+  ProcessAppendResult process_append_candidate(CallStaticJavaNode* cnode, StringConcat* sc,
+                                               ciMethod* m, ciSymbol* string_sig, ciSymbol* int_sig,
+                                               ciSymbol* char_sig);
+
   // Replace all the SB calls in concat with an optimization String allocation
   void replace_string_concat(StringConcat* concat);
 
@@ -105,12 +122,13 @@ class PhaseStringOpts : public Phase {
     unroll_string_copy_length = 6
   };
 
- public:
+public:
   PhaseStringOpts(PhaseGVN* gvn);
 
 #ifndef PRODUCT
   static void print_statistics();
- private:
+
+private:
   static uint _stropts_replaced;
   static uint _stropts_merged;
   static uint _stropts_total;

src/java.base/share/data/tzdata/VERSION

@@ -21,4 +21,4 @@
 # or visit www.oracle.com if you need additional information or have any
 # questions.
 #
-tzdata2024b
+tzdata2025a

src/java.base/share/data/tzdata/antarctica

@@ -197,6 +197,8 @@ Zone Antarctica/Mawson	0	-	-00	1954 Feb 13
 
 # France & Italy - year-round base
 # Concordia, -750600+1232000, since 2005
+# https://en.wikipedia.org/wiki/Concordia_Station
+# Can use Asia/Singapore, which it has agreed with since inception.
 
 # Germany - year-round base
 # Neumayer III, -704080-0081602, since 2009