Improve and complete implementation of new/delete

cores/arduino/abi.cpp

@@ -21,15 +21,16 @@
 extern "C" void __cxa_pure_virtual(void) __attribute__ ((__noreturn__));
 extern "C" void __cxa_deleted_virtual(void) __attribute__ ((__noreturn__));
 
+namespace std {
+  [[gnu::weak, noreturn]] void terminate() {
+    abort();
+  }
+}
+
 void __cxa_pure_virtual(void) {
-  // We might want to write some diagnostics to uart in this case
-  //std::terminate();
-  abort();
+  std::terminate();
 }
 
 void __cxa_deleted_virtual(void) {
-  // We might want to write some diagnostics to uart in this case
-  //std::terminate();
-  abort();
+  std::terminate();
 }
-

cores/arduino/new

@@ -1,5 +1,66 @@
 /*
-this header is for compatibility with standard c++ header names
-so that #include<new> works as expected
+  Copyright (c) 2014 Arduino.  All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+  See the GNU Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
-#include "new.h"
+
+#ifndef NEW_H
+#define NEW_H
+
+#include <stdlib.h>
+
+namespace std {
+  struct nothrow_t {};
+  extern const nothrow_t nothrow;
+
+  // These are not actually implemented, to prevent overhead and
+  // complexity. They are still declared to allow implementing
+  // them in user code if needed.
+  typedef void (*new_handler)();
+  new_handler set_new_handler(new_handler new_p) noexcept;
+  new_handler get_new_handler() noexcept;
+
+  // This is normally declared in various headers that we do not have
+  // available, so just define it here. We could also use ::size_t
+  // below, but then anyone including <new> can no longer assume
+  // std::size_t is available.
+  using size_t = ::size_t;
+} // namespace std
+
+[[gnu::weak]] void * operator new(std::size_t size);
+[[gnu::weak]] void * operator new[](std::size_t size);
+
+[[gnu::weak]] void * operator new(std::size_t size, const std::nothrow_t tag) noexcept;
+[[gnu::weak]] void * operator new[](std::size_t size, const std::nothrow_t& tag) noexcept;
+
+void * operator new(std::size_t size, void *place) noexcept;
+void * operator new[](std::size_t size, void *place) noexcept;
+
+[[gnu::weak]] void operator delete(void * ptr) noexcept;
+[[gnu::weak]] void operator delete[](void * ptr) noexcept;
+
+#if __cplusplus >= 201402L
+[[gnu::weak]] void operator delete(void* ptr, std::size_t size) noexcept;
+[[gnu::weak]] void operator delete[](void * ptr, std::size_t size) noexcept;
+#endif // __cplusplus >= 201402L
+
+[[gnu::weak]] void operator delete(void* ptr, const std::nothrow_t& tag) noexcept;
+[[gnu::weak]] void operator delete[](void* ptr, const std::nothrow_t& tag) noexcept;
+
+void operator delete(void* ptr, void* place) noexcept;
+void operator delete[](void* ptr, void* place) noexcept;
+
+#endif
+

cores/arduino/new.cpp

@@ -16,26 +16,102 @@
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
-#include <stdlib.h>
+#include "new.h"
 
-void *operator new(size_t size) {
-  return malloc(size);
+// The C++ spec dicates that allocation failure should cause the
+// (non-nothrow version of the) operator new to throw an exception.
+// Since we expect to have exceptions disabled, it would be more
+// appropriate (and probably standards-compliant) to terminate instead.
+// Historically failure causes null to be returned, but this define
+// allows switching to more robust terminating behaviour (that might
+// become the default at some point in the future). Note that any code
+// that wants null to be returned can (and should) use the nothrow
+// versions of the new statement anyway and is unaffected by this.
+// #define NEW_TERMINATES_ON_FAILURE
+
+namespace std {
+  // Defined in abi.cpp
+  void terminate();
+
+  const nothrow_t nothrow;
 }
 
-void *operator new[](size_t size) {
+static void * new_helper(std::size_t size) {
+  // Even zero-sized allocations should return a unique pointer, but
+  // malloc does not guarantee this
+  if (size == 0)
+    size = 1;
   return malloc(size);
 }
 
-void * operator new(size_t size, void * ptr) noexcept {
-  (void)size;
-  return ptr;
+void * operator new(std::size_t size) {
+  void *res = new_helper(size);
+#if defined(NEW_TERMINATES_ON_FAILURE)
+  if (!res)
+    std::terminate();
+#endif
+  return res;
+}
+void * operator new[](std::size_t size) {
+  return operator new(size);
 }
 
-void operator delete(void * ptr) {
-  free(ptr);
+void * operator new(std::size_t size, const std::nothrow_t tag) noexcept {
+#if defined(NEW_TERMINATES_ON_FAILURE)
+  // Cannot call throwing operator new as standard suggests, so call
+  // new_helper directly then
+  return new_helper(size);
+#else
+  return operator new(size);
+#endif
+}
+void * operator new[](std::size_t size, const std::nothrow_t& tag) noexcept {
+#if defined(NEW_TERMINATES_ON_FAILURE)
+  // Cannot call throwing operator new[] as standard suggests, so call
+  // malloc directly then
+  return new_helper(size);
+#else
+  return operator new[](size);
+#endif
+}
+
+void * operator new(std::size_t size, void *place) noexcept {
+  // Nothing to do
+  (void)size; // unused
+  return place;
+}
+void * operator new[](std::size_t size, void *place) noexcept {
+  return operator new(size, place);
 }
 
-void operator delete[](void * ptr) {
+void operator delete(void * ptr) noexcept {
   free(ptr);
 }
+void operator delete[](void * ptr) noexcept {
+  operator delete(ptr);
+}
 
+#if __cplusplus >= 201402L
+void operator delete(void* ptr, std::size_t size) noexcept {
+  operator delete(ptr);
+}
+void operator delete[](void * ptr, std::size_t size) noexcept {
+  operator delete[](ptr);
+}
+#endif // __cplusplus >= 201402L
+
+void operator delete(void* ptr, const std::nothrow_t& tag) noexcept {
+  operator delete(ptr);
+}
+void operator delete[](void* ptr, const std::nothrow_t& tag) noexcept {
+  operator delete[](ptr);
+}
+
+void operator delete(void* ptr, void* place) noexcept {
+  (void)ptr; (void)place; // unused
+  // Nothing to do
+}
+void operator delete[](void* ptr, void* place) noexcept {
+  (void)ptr; (void)place; // unused
+  // Nothing to do
+}

cores/arduino/new.h

@@ -1,31 +1,3 @@
-/*
-  Copyright (c) 2014 Arduino.  All right reserved.
-
-  This library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Lesser General Public
-  License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
-
-  This library is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-  See the GNU Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public
-  License along with this library; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
-*/
-
-#ifndef NEW_H
-#define NEW_H
-
-#include <stdlib.h>
-
-void * operator new(size_t size);
-void * operator new[](size_t size);
-void * operator new(size_t size, void * ptr) noexcept;
-void operator delete(void * ptr);
-void operator delete[](void * ptr);
-
-#endif
-
+// This file originally used a non-standard name for this Arduino core
+// only, so still expose the old new.h name for compatibility.
+#include "new"