Provide global non-throwing operator new/delete in gccpp library

Note: this might require define GC_INCLUDE_NEW by client before
include gc_cpp.h on Windows hosts (to have nothrow_t declared before
the global inline operator new and delete are defined).

* gc_cpp.cc [(!_MSC_VER && !__DMC__ || GC_NO_INLINE_STD_NEW)
&& !GC_INLINE_STD_NEW && GC_OPERATOR_NEW_NOTHROW] (operator new,
operator delete): Define with nothrow_t argument.
* gc_cpp.cc [(!_MSC_VER && !__DMC__ || GC_NO_INLINE_STD_NEW)
&& !GC_INLINE_STD_NEW && GC_OPERATOR_NEW_ARRAY && !CPPCHECK
&& GC_OPERATOR_NEW_NOTHROW] (operator new[], operator delete[]):
Likewise.
* include/gc/gc_cpp.h [GC_INLINE_STD_NEW && GC_OPERATOR_NEW_ARRAY
&& GC_OPERATOR_NEW_NOTHROW] (operator new[], operator delete[]):
Likewise.
* include/gc/gc_cpp.h [GC_INLINE_STD_NEW && GC_OPERATOR_NEW_NOTHROW]
(operator new, operator delete): Likewise.
* include/gc/gc_cpp.h [!GC_OPERATOR_NEW_NOTHROW
&& !GC_NO_OPERATOR_NEW_NOTHROW && (GC_INCLUDE_NEW
&& (__cplusplus>=201103L || _MSVC_LANG>=201103L)
|| __NOTHROW_T_DEFINED)] (GC_OPERATOR_NEW_NOTHROW): Define macro;
add comment.
* include/gc/gc_cpp.h [!GC_INLINE_STD_NEW && GC_NO_INLINE_STD_NEW
&& _MSC_VER && GC_OPERATOR_NEW_ARRAY && GC_OPERATOR_NEW_NOTHROW]
(operator new[], operator delete[]): Add prototype with nothrow_t
argument (with commented out GC_ATTR_MALLOC).
* include/gc/gc_cpp.h [!GC_INLINE_STD_NEW && GC_NO_INLINE_STD_NEW
&& _MSC_VER && GC_OPERATOR_NEW_NOTHROW] (operator new,
operator delete): Likewise.

2 files changed, 71 insertions, 0 deletions

diff --git a/gc_cpp.cc b/gc_cpp.cc
index bcc049f5..d55c4a76 100644
--- a/gc_cpp.cc
+++ b/gc_cpp.cc
@@ -78,6 +78,18 @@ built-in "new" and "delete".
     GC_FREE(obj);
   }
 
+# ifdef GC_OPERATOR_NEW_NOTHROW
+    void* operator new(GC_SIZE_T size, const std::nothrow_t&) GC_NOEXCEPT
+    {
+      return GC_MALLOC_UNCOLLECTABLE(size);
+    }
+
+    void operator delete(void* obj, const std::nothrow_t&) GC_NOEXCEPT
+    {
+      GC_FREE(obj);
+    }
+# endif // GC_OPERATOR_NEW_NOTHROW
+
 # if defined(GC_OPERATOR_NEW_ARRAY) && !defined(CPPCHECK)
     void* operator new[](GC_SIZE_T size) GC_DECL_NEW_THROW
     {
@@ -100,6 +112,18 @@ built-in "new" and "delete".
     {
       GC_FREE(obj);
     }
+
+#   ifdef GC_OPERATOR_NEW_NOTHROW
+      void* operator new[](GC_SIZE_T size, const std::nothrow_t&) GC_NOEXCEPT
+      {
+        return GC_MALLOC_UNCOLLECTABLE(size);
+      }
+
+      void operator delete[](void* obj, const std::nothrow_t&) GC_NOEXCEPT
+      {
+        GC_FREE(obj);
+      }
+#   endif // GC_OPERATOR_NEW_NOTHROW
 # endif // GC_OPERATOR_NEW_ARRAY
 
 # ifdef GC_OPERATOR_SIZED_DELETE
diff --git a/include/gc/gc_cpp.h b/include/gc/gc_cpp.h
index d06a74d9..c8bd6fac 100644
--- a/include/gc/gc_cpp.h
+++ b/include/gc/gc_cpp.h
@@ -186,6 +186,16 @@ by UseGC.  GC is an alias for UseGC, unless GC_NAME_CONFLICT is defined.
 # define GC_OPERATOR_SIZED_DELETE
 #endif
 
+#if !defined(GC_OPERATOR_NEW_NOTHROW) \
+    && !defined(GC_NO_OPERATOR_NEW_NOTHROW) \
+    && ((defined(GC_INCLUDE_NEW) \
+         && (__cplusplus >= 201103L || _MSVC_LANG >= 201103L)) \
+        || defined(__NOTHROW_T_DEFINED))
+  // Note: this might require defining GC_INCLUDE_NEW by client
+  // before include gc_cpp.h (on Windows).
+# define GC_OPERATOR_NEW_NOTHROW
+#endif
+
 #if !defined(GC_NEW_DELETE_THROW_NOT_NEEDED) \
     && !defined(GC_NEW_DELETE_NEED_THROW) && GC_GNUC_PREREQ(4, 2) \
     && (__cplusplus < 201103L || defined(__clang__))
@@ -340,6 +350,20 @@ inline void* operator new(GC_SIZE_T, GC_NS_QUALIFY(GCPlacement),
     {
       GC_FREE(obj);
     }
+
+#   ifdef GC_OPERATOR_NEW_NOTHROW
+      inline /* GC_ATTR_MALLOC */ void* operator new[](GC_SIZE_T size,
+                                            const std::nothrow_t&) GC_NOEXCEPT
+      {
+        return GC_MALLOC_UNCOLLECTABLE(size);
+      }
+
+      inline void operator delete[](void* obj,
+                                    const std::nothrow_t&) GC_NOEXCEPT
+      {
+        GC_FREE(obj);
+      }
+#   endif // GC_OPERATOR_NEW_NOTHROW
 # endif // GC_OPERATOR_NEW_ARRAY
 
   inline void* operator new(GC_SIZE_T size) GC_DECL_NEW_THROW
@@ -354,6 +378,19 @@ inline void* operator new(GC_SIZE_T, GC_NS_QUALIFY(GCPlacement),
     GC_FREE(obj);
   }
 
+# ifdef GC_OPERATOR_NEW_NOTHROW
+    inline /* GC_ATTR_MALLOC */ void* operator new(GC_SIZE_T size,
+                                        const std::nothrow_t&) GC_NOEXCEPT
+    {
+      return GC_MALLOC_UNCOLLECTABLE(size);
+    }
+
+    inline void operator delete(void* obj, const std::nothrow_t&) GC_NOEXCEPT
+    {
+      GC_FREE(obj);
+    }
+# endif // GC_OPERATOR_NEW_NOTHROW
+
 # ifdef GC_OPERATOR_SIZED_DELETE
     inline void operator delete(void* obj, GC_SIZE_T) GC_NOEXCEPT
     {
@@ -403,6 +440,11 @@ inline void* operator new(GC_SIZE_T, GC_NS_QUALIFY(GCPlacement),
 # ifdef GC_OPERATOR_NEW_ARRAY
     void* operator new[](GC_SIZE_T) GC_DECL_NEW_THROW;
     void operator delete[](void*) GC_NOEXCEPT;
+#   ifdef GC_OPERATOR_NEW_NOTHROW
+      /* GC_ATTR_MALLOC */ void* operator new[](GC_SIZE_T,
+                                    const std::nothrow_t&) GC_NOEXCEPT;
+      void operator delete[](void*, const std::nothrow_t&) GC_NOEXCEPT;
+#   endif
 #   ifdef GC_OPERATOR_SIZED_DELETE
       void operator delete[](void*, GC_SIZE_T) GC_NOEXCEPT;
 #   endif
@@ -413,6 +455,11 @@ inline void* operator new(GC_SIZE_T, GC_NS_QUALIFY(GCPlacement),
 
   void* operator new(GC_SIZE_T) GC_DECL_NEW_THROW;
   void operator delete(void*) GC_NOEXCEPT;
+# ifdef GC_OPERATOR_NEW_NOTHROW
+    /* GC_ATTR_MALLOC */ void* operator new(GC_SIZE_T,
+                                    const std::nothrow_t&) GC_NOEXCEPT;
+    void operator delete(void*, const std::nothrow_t&) GC_NOEXCEPT;
+# endif
 # ifdef GC_OPERATOR_SIZED_DELETE
     void operator delete(void*, GC_SIZE_T) GC_NOEXCEPT;
 # endif