Merge pull request #361 from matthijskooijman/improve-new

Improve and complete implementation of new/delete

1 files changed, 86 insertions, 10 deletions

diff --git a/cores/arduino/new.cpp b/cores/arduino/new.cpp
index fc30cf8..9047b2d 100644
--- a/cores/arduino/new.cpp
+++ b/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
+}