Reduce CoreCLR C++ exception cleanup overhead

eng/native/configureplatform.cmake

@@ -505,6 +505,10 @@ if(NOT CLR_CMAKE_TARGET_BROWSER AND NOT CLR_CMAKE_TARGET_WASI)
     set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 else()
     if(CLR_CMAKE_RUNTIME_CORECLR)
+        if(NOT CLR_CROSS_COMPONENTS_BUILD)
+            # CoreCLR does not use throwing exception object destructors.
+            add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-fassume-nothrow-exception-dtor>)
+        endif()
         if(CLR_CMAKE_TARGET_BROWSER AND NOT CLR_CROSS_COMPONENTS_BUILD)
             add_link_options(-fwasm-exceptions)
             add_link_options(-sWASM_LEGACY_EXCEPTIONS=0)

src/coreclr/binder/assemblyname.cpp

@@ -186,7 +186,7 @@ namespace BINDER_SPACE
         return InterlockedIncrement(&m_cRef);
     }
 
-    ULONG AssemblyName::Release()
+    ULONG AssemblyName::Release() noexcept
     {
         ULONG ulRef = InterlockedDecrement(&m_cRef);
         if (ulRef == 0)

src/coreclr/binder/inc/assemblyname.hpp

@@ -44,7 +44,7 @@ namespace BINDER_SPACE
         HRESULT Init(const AssemblyNameData &data);
 
         ULONG AddRef();
-        ULONG Release();
+        ULONG Release() noexcept;
 
         // Getters/Setters
         inline const SString &GetSimpleName();

src/coreclr/debug/daccess/reimpl.cpp

@@ -63,7 +63,7 @@ DacGetThread(ULONG32 osThread)
     return NULL;
 }
 
-Thread* GetThread()
+Thread* GetThread() noexcept
 {
     // In dac mode it's unlikely that the thread calling dac
     // is actually the same "current thread" that the runtime cares
@@ -75,7 +75,7 @@ Thread* GetThread()
     return NULL;
 }
 
-Thread* GetThreadNULLOk()
+Thread* GetThreadNULLOk() noexcept
 {
     return GetThread();
 }

src/coreclr/gc/env/volatile.h

@@ -190,6 +190,11 @@ T VolatileLoad(T const * pt)
 template<typename T>
 inline
 T VolatileLoadWithoutBarrier(T const * pt)
+#ifndef DACCESS_COMPILE
+    noexcept(noexcept(T(*(T volatile const*)pt)))
+#else
+    noexcept(noexcept(T(*pt)))
+#endif
 {
 #ifndef DACCESS_COMPILE
     T val = *(T volatile const *)pt;
@@ -268,6 +273,11 @@ void VolatileStore(T* pt, T val)
 template<typename T>
 inline
 void VolatileStoreWithoutBarrier(T* pt, T val)
+#ifndef DACCESS_COMPILE
+    noexcept(noexcept(*(T volatile*)pt = val))
+#else
+    noexcept(noexcept(*pt = val))
+#endif
 {
 #ifndef DACCESS_COMPILE
     *(T volatile *)pt = val;
@@ -330,6 +340,9 @@ class Volatile
     // Loads the value of the volatile variable atomically without erecting the memory barrier.
     //
     inline T LoadWithoutBarrier() const
+#ifndef DACCESS_COMPILE
+        noexcept(noexcept(T((volatile T&)m_val)))
+#endif
     {
         return ((volatile T &)m_val);
     }
@@ -348,6 +361,9 @@ class Volatile
     // Stores a new value to the volatile variable atomically without erecting the memory barrier.
     //
     inline void StoreWithoutBarrier(const T& val) const
+#ifndef DACCESS_COMPILE
+        noexcept(noexcept(((volatile T&)m_val) = val))
+#endif
     {
         ((volatile T &)m_val) = val;
     }

src/coreclr/inc/arraylist.h

@@ -98,7 +98,7 @@ class ArrayListBase
     enum { NOT_FOUND = -1 };
     DWORD FindElement(DWORD start, PTR_VOID element) const;
 
-    void Clear();
+    void Clear() noexcept;
 
     void Init()
     {
@@ -109,7 +109,7 @@ class ArrayListBase
         m_firstBlock.m_blockSize = ARRAY_BLOCK_SIZE_START;
     }
 
-    void Destroy()
+    void Destroy() noexcept
     {
         WRAPPER_NO_CONTRACT;
         Clear();

src/coreclr/inc/clrconfig.h

@@ -134,7 +134,7 @@ class CLRConfig
     static BOOL IsConfigOptionSpecified(LPCWSTR name);
 
     // Free a string returned by GetConfigValue
-    static void FreeConfigString(_In_ _In_z_ LPWSTR name);
+    static void FreeConfigString(_In_ _In_z_ LPWSTR name) noexcept;
 
     // Initialize the configuration.
     static void Initialize();
@@ -154,7 +154,7 @@ struct CLRConfigStringTraits final
 {
     using Type = LPWSTR;
     static constexpr Type Default() { return NULL; }
-    static void Free(Type value) { CLRConfig::FreeConfigString(value); }
+    static void Free(Type value) noexcept { CLRConfig::FreeConfigString(value); }
 };
 
 using CLRConfigStringHolder = LifetimeHolder<CLRConfigStringTraits>;

src/coreclr/inc/clrhost.h

@@ -30,12 +30,12 @@ using std::nothrow;
 
 struct PreserveLastErrorHolder
 {
-    PreserveLastErrorHolder()
+    PreserveLastErrorHolder() noexcept
     {
         m_dwLastError = ::GetLastError();
     }
 
-    ~PreserveLastErrorHolder()
+    ~PreserveLastErrorHolder() noexcept
     {
         ::SetLastError(m_dwLastError);
     }
@@ -78,7 +78,7 @@ HANDLE ClrGetProcessExecutableHeap();
 CRITSEC_COOKIE ClrCreateCriticalSection(CrstType type, CrstFlags flags);
 void ClrDeleteCriticalSection(CRITSEC_COOKIE cookie);
 void ClrEnterCriticalSection(CRITSEC_COOKIE cookie);
-void ClrLeaveCriticalSection(CRITSEC_COOKIE cookie);
+void ClrLeaveCriticalSection(CRITSEC_COOKIE cookie) noexcept;
 
 // Rather than use the above APIs directly, it is recommended that holder classes
 // be used.  This guarantees that the locks will be vacated when the scope is popped,
@@ -150,12 +150,12 @@ extern thread_local size_t t_CantStopCount;
 
 // For debugging, we can track arbitrary Can't-Stop regions.
 // In V1.0, this was on the Thread object, but we need to track this for threads w/o a Thread object.
-FORCEINLINE void IncCantStopCount()
+FORCEINLINE void IncCantStopCount() noexcept
 {
     t_CantStopCount++;
 }
 
-FORCEINLINE void DecCantStopCount()
+FORCEINLINE void DecCantStopCount() noexcept
 {
     t_CantStopCount--;
 }

src/coreclr/inc/ex.h

@@ -184,7 +184,7 @@ class Exception
 
  public:
     Exception() {LIMITED_METHOD_DAC_CONTRACT; m_innerException = NULL;}
-    virtual ~Exception() {LIMITED_METHOD_DAC_CONTRACT; if (m_innerException != NULL) Exception::Delete(m_innerException); }
+    virtual ~Exception() noexcept {LIMITED_METHOD_DAC_CONTRACT; if (m_innerException != NULL) Exception::Delete(m_innerException); }
 #ifdef DACCESS_COMPILE
     void * operator new(size_t size);
     void operator delete(void* ptr);
@@ -232,7 +232,7 @@ class Exception
 
         HandlerState();
 
-        void CleanupTry();
+        void CleanupTry() noexcept;
         void SetupCatch(INDEBUG_COMMA(_In_z_ const char * szFile) int lineNum);
         void SucceedCatch();
 
@@ -258,10 +258,10 @@ class Exception
     // Preallocated exceptions:  If there is a preallocated instance of some
     //  subclass of Exception, override this function and return a correct
     //  value.  The default implementation returns constant FALSE
-    virtual BOOL IsPreallocatedException();
+    virtual BOOL IsPreallocatedException() noexcept;
     BOOL IsPreallocatedOOMException();
 
-    static void Delete(Exception* pvMemory);
+    static void Delete(Exception* pvMemory) noexcept;
 
 protected:
 
@@ -285,7 +285,7 @@ struct ExceptionTraits final
 {
     using Type = Exception*;
     static constexpr Type Default() { return NULL; }
-    static void Free(Type value)
+    static void Free(Type value) noexcept
     {
         STATIC_CONTRACT_WRAPPER;
         Exception::Delete(value);
@@ -523,7 +523,7 @@ class OutOfMemoryException : public Exception
 
     virtual Exception *Clone();
 
-    virtual BOOL IsPreallocatedException() { return bIsPreallocated; }
+    virtual BOOL IsPreallocatedException() noexcept { return bIsPreallocated; }
 };
 
 template <typename STATETYPE>
@@ -546,7 +546,7 @@ class CAutoTryCleanup
 #endif
     }
 
-    DEBUG_NOINLINE ~CAutoTryCleanup()
+    DEBUG_NOINLINE ~CAutoTryCleanup() noexcept
     {
         WRAPPER_NO_CONTRACT;
 
@@ -1116,7 +1116,7 @@ inline Exception::HandlerState::HandlerState()
 #endif
 }
 
-inline void Exception::HandlerState::CleanupTry()
+inline void Exception::HandlerState::CleanupTry() noexcept
 {
     LIMITED_METHOD_DAC_CONTRACT;
 }

src/coreclr/inc/executableallocator.h

@@ -183,7 +183,7 @@ class ExecutableAllocator
     static bool IsDoubleMappingEnabled();
 
     // Release memory allocated via DoubleMapping for either templates or normal double mapped data
-    void ReleaseWorker(void* pRX, bool releaseTemplate);
+    void ReleaseWorker(void* pRX, bool releaseTemplate) noexcept;
 
     // Initialize the allocator instance
     bool Initialize();
@@ -211,7 +211,7 @@ class ExecutableAllocator
 #endif
 
     // Return the ExecuteAllocator singleton instance
-    static ExecutableAllocator* Instance();
+    static ExecutableAllocator* Instance() noexcept;
 
     // Initialize the static members of the Executable allocator and allocate
     // and initialize the instance of it.
@@ -258,13 +258,13 @@ class ExecutableAllocator
 
     // Release the executable memory block starting at the passed in address that was allocated
     // by one of the ReserveXXX methods.
-    void Release(void* pRX);
+    void Release(void* pRX) noexcept;
 
     // Map the specified block of executable memory as RW
     void* MapRW(void* pRX, size_t size, CacheableMapping cacheMapping);
 
     // Unmap the RW mapping at the specified address
-    void UnmapRW(void* pRW);
+    void UnmapRW(void* pRW) noexcept;
 
     // Allocate thunks from a template. pTemplate is the return value from CreateTemplate
     void* AllocateThunksFromTemplate(void *pTemplate, size_t templateSize, void (*dataPageGenerator)(uint8_t* pageBase, size_t size));
@@ -298,7 +298,7 @@ class ExecutableWriterHolder
         other.m_addressRW = NULL;
     }
 
-    void Unmap()
+    void Unmap() noexcept
     {
 #if defined(HOST_APPLE) && defined(HOST_ARM64) && !defined(DACCESS_COMPILE)
         if (m_addressRX != NULL)
@@ -344,7 +344,7 @@ class ExecutableWriterHolder
 #endif
     }
 
-    ~ExecutableWriterHolder()
+    ~ExecutableWriterHolder() noexcept
     {
         Unmap();
     }

src/coreclr/inc/holder.h

@@ -996,7 +996,7 @@ struct ReleaseHolderTraits final
 {
     using Type = TYPE*;
     static constexpr Type Default() { return NULL; }
-    static void Free(Type value)
+    static void Free(Type value) noexcept
     {
         CONTRACTL
         {
@@ -1021,7 +1021,7 @@ struct HandleTraits final
 {
     using Type = HANDLE;
     static Type Default() { return INVALID_HANDLE_VALUE; }
-    static void Free(Type h)
+    static void Free(Type h) noexcept
     {
         STATIC_CONTRACT_WRAPPER;
         if (h != NULL && h != Default())
@@ -1034,7 +1034,7 @@ struct MapViewTraits final
 {
     using Type = void*;
     static constexpr Type Default() { return NULL; }
-    static void Free(Type h)
+    static void Free(Type h) noexcept
     {
         STATIC_CONTRACT_WRAPPER;
         if (h != NULL)
@@ -1049,7 +1049,7 @@ struct LocalAllocTraits final
 {
     using Type = T;
     static constexpr Type Default() { return NULL; }
-    static void Free(Type h)
+    static void Free(Type h) noexcept
     {
         STATIC_CONTRACT_WRAPPER;
 #ifdef HOST_WINDOWS
@@ -1068,7 +1068,7 @@ struct HModuleTraits final
 {
     using Type = HMODULE;
     static constexpr Type Default() { return NULL; }
-    static void Free(Type h)
+    static void Free(Type h) noexcept
     {
         STATIC_CONTRACT_WRAPPER;
         if (h != NULL)
@@ -1092,7 +1092,7 @@ struct ResetPointerTraits final
 {
     using Type = T*;
     static constexpr Type Default() { return NULL; }
-    static void Free(Type p)
+    static void Free(Type p) noexcept
     {
         STATIC_CONTRACT_WRAPPER;
         if (p == NULL)
@@ -1121,7 +1121,7 @@ struct CoTaskMemTraits final
 {
     using Type = T*;
     static constexpr Type Default() { return NULL; }
-    static void Free(Type value)
+    static void Free(Type value) noexcept
     {
         STATIC_CONTRACT_WRAPPER;
         if (value != NULL)
@@ -1176,7 +1176,7 @@ struct HKEYTraits final
 {
     using Type = HKEY;
     static constexpr Type Default() { return NULL; }
-    static void Free(Type h)
+    static void Free(Type h) noexcept
     {
         STATIC_CONTRACT_WRAPPER;
         if (h != NULL)
@@ -1192,7 +1192,7 @@ struct BSTRTraits final
 {
     using Type = BSTR;
     static constexpr Type Default() { return NULL; }
-    static void Free(Type h)
+    static void Free(Type h) noexcept
     {
         STATIC_CONTRACT_WRAPPER;
         if (h != NULL)

src/coreclr/inc/metadata.h

@@ -151,7 +151,7 @@ struct HENUMInternal
 
     // This will only clear the content of enum and will not free the memory of enum
     static void ClearEnum(
-        HENUMInternal   *pmdEnum);
+        HENUMInternal   *pmdEnum) noexcept;
 
     // create a HENUMInternal. This will allocate the memory
     __checkReturn
@@ -293,6 +293,8 @@ EXTERN_GUID(IID_IMDInternalImport, 0x1b119f60, 0xc507, 0x4024, 0xbb, 0x39, 0xf8,
 #define INTERFACE IMDInternalImport
 DECLARE_INTERFACE_(IMDInternalImport, IUnknown)
 {
+    STDMETHOD_(ULONG, Release)() noexcept PURE;
+
     //*****************************************************************************
     // return the count of entries of a given kind in a scope
     // For example, pass in mdtMethodDef will tell you how many MethodDef
@@ -403,7 +405,7 @@ DECLARE_INTERFACE_(IMDInternalImport, IUnknown)
     } // MDInternalRW::EnumReset
 
     void EnumClose(
-        HENUMInternal *phEnum)        // [IN] the enumerator to be closed
+        HENUMInternal *phEnum) noexcept // [IN] the enumerator to be closed
     {
         _ASSERTE( phEnum->m_EnumType == MDSimpleEnum ||
             phEnum->m_EnumType == MDDynamicArrayEnum);