Reenable class-memaccess warning (#74363)

* Reenable class-memaccess warning

* Match x64 logic in emitarm.cpp

* Make GCProtect sections with "gc" variable consistent

Co-authored-by: Jan Kotas <jkotas@microsoft.com>

Author: AaronRobinsonMSFT

eng/native/configurecompiler.cmake

@@ -451,7 +451,6 @@ if (CLR_CMAKE_HOST_UNIX)
     add_compile_options(-Wno-uninitialized)
     add_compile_options(-Wno-strict-aliasing)
     add_compile_options(-Wno-array-bounds)
-    add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-Wno-class-memaccess>)
     add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-Wno-misleading-indentation>)
     add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-Wno-stringop-overflow>)
     add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-Wno-restrict>)

src/coreclr/classlibnative/bcltype/system.cpp

@@ -162,14 +162,12 @@ void SystemNative::GenericFailFast(STRINGREF refMesgString, EXCEPTIONREF refExce
         EXCEPTIONREF refExceptionForWatsonBucketing;
         STRINGREF refErrorSourceString;
     } gc;
-    ZeroMemory(&gc, sizeof(gc));
-
-    GCPROTECT_BEGIN(gc);
-
     gc.refMesgString = refMesgString;
     gc.refExceptionForWatsonBucketing = refExceptionForWatsonBucketing;
     gc.refErrorSourceString = refErrorSourceString;
 
+    GCPROTECT_BEGIN(gc);
+
     // Managed code injected FailFast maps onto the unmanaged version
     // (EEPolicy::HandleFatalError) in the following manner: the exit code is
     // always set to COR_E_FAILFAST and the address passed (usually a failing

src/coreclr/debug/daccess/request.cpp

@@ -2892,7 +2892,7 @@ ClrDataAccess::GetOOMStaticData(struct DacpOomData *oomData)
 
     SOSDacEnter();
 
-    memset(oomData, 0, sizeof(DacpOomData));
+    *oomData = {};
 
     if (!GCHeapUtilities::IsServerHeap())
     {
@@ -2921,7 +2921,7 @@ ClrDataAccess::GetOOMData(CLRDATA_ADDRESS oomAddr, struct DacpOomData *data)
         return E_INVALIDARG;
 
     SOSDacEnter();
-    memset(data, 0, sizeof(DacpOomData));
+    *data = {};
 
     if (!GCHeapUtilities::IsServerHeap())
         hr = E_FAIL; // doesn't make sense to call this on WKS mode
@@ -2974,7 +2974,7 @@ ClrDataAccess::GetGCInterestingInfoStaticData(struct DacpGCInterestingInfoData *
     static_assert_no_msg(DAC_MAX_GC_MECHANISM_BITS_COUNT == MAX_GC_MECHANISM_BITS_COUNT);
 
     SOSDacEnter();
-    memset(data, 0, sizeof(DacpGCInterestingInfoData));
+    *data = {};
 
     if (g_heap_type != GC_HEAP_SVR)
     {
@@ -3007,7 +3007,7 @@ ClrDataAccess::GetGCInterestingInfoData(CLRDATA_ADDRESS interestingInfoAddr, str
         return E_INVALIDARG;
 
     SOSDacEnter();
-    memset(data, 0, sizeof(DacpGCInterestingInfoData));
+    *data = {};
 
     if (!GCHeapUtilities::IsServerHeap())
         hr = E_FAIL; // doesn't make sense to call this on WKS mode

src/coreclr/debug/daccess/request_common.h

@@ -44,7 +44,7 @@ HeapTableIndex(DPTR(unused_gc_heap**) heaps, size_t index)
 
 // field_offset = g_gcDacGlobals->gc_heap_field_offsets
 // p_field_offset = field_offset[field_index]
-// p_field = BASE + p_field_offset 
+// p_field = BASE + p_field_offset
 // field_index++
 #define LOAD_BASE(field_name, field_type)                                                    \
     DPTR(int) p_##field_name##_offset = TableIndex(field_offsets, field_index, sizeof(int)); \
@@ -114,8 +114,7 @@ inline bool IsRegionGCEnabled()
 inline dac_gc_heap
 LoadGcHeapData(TADDR heap)
 {
-    dac_gc_heap result;
-    memset(&result, 0, sizeof(dac_gc_heap));
+    dac_gc_heap result = {};
 
     DPTR(int) field_offsets = g_gcDacGlobals->gc_heap_field_offsets;
     int field_index = 0;
@@ -163,9 +162,7 @@ inline void EnumGcHeap(TADDR heap)
 inline dac_generation
 LoadGeneration(TADDR generation)
 {
-    dac_generation result;
-    memset(&result, 0, sizeof(dac_generation));
-
+    dac_generation result = {};
     DPTR(int) field_offsets = g_gcDacGlobals->generation_field_offsets;
     int field_index = 0;
 

src/coreclr/debug/di/dbgtransportmanager.cpp

@@ -13,8 +13,9 @@
 DbgTransportTarget *g_pDbgTransportTarget = NULL;
 
 DbgTransportTarget::DbgTransportTarget()
+    : m_pProcessList{}
+    , m_sLock{}
 {
-    memset(this, 0, sizeof(*this));
 }
 
 // Initialization routine called only by the DbgTransportManager.

src/coreclr/debug/ee/controller.cpp

@@ -368,7 +368,7 @@ void ControllerStackInfo::SetReturnFrameWithActiveFrame()
 
     // Invalidate the active frame.
     m_activeFound = false;
-    memset(&(m_activeFrame), 0, sizeof(m_activeFrame));
+    m_activeFrame = {};
     m_activeFrame.fp = LEAF_MOST_FRAME;
 }
 

src/coreclr/debug/ee/funceval.cpp

@@ -3301,7 +3301,7 @@ static void DoNormalFuncEval( DebuggerEval *pDE,
         ThrowHR(COR_E_OVERFLOW);
     }
     FuncEvalArgInfo * pFEArgInfo = (FuncEvalArgInfo *)_alloca(cbAllocSize);
-    memset(pFEArgInfo, 0, cbAllocSize);
+    *pFEArgInfo = {};
 
     GatherFuncEvalArgInfo(pDE, mSig, argData, pFEArgInfo);
 
@@ -3483,7 +3483,7 @@ static void GCProtectArgsAndDoNormalFuncEval(DebuggerEval *pDE,
         ThrowHR(COR_E_OVERFLOW);
     }
     OBJECTREF * pObjectRefArray = (OBJECTREF*)_alloca(cbAllocSize);
-    memset(pObjectRefArray, 0, cbAllocSize);
+    *pObjectRefArray = {};
     GCPROTECT_ARRAY_BEGIN(*pObjectRefArray, pDE->m_argCount);
 
     //

src/coreclr/debug/inc/dbgappdomain.h

@@ -283,7 +283,7 @@ struct AppDomainEnumerationIPCBlock
         pADInfo->FreeEntry();
 
 #ifdef _DEBUG
-        memset(pADInfo, 0, sizeof(AppDomainInfo));
+        *pADInfo = {};
 #endif
 
         // decrement the used slot count

src/coreclr/debug/inc/dbgtransportsession.h

@@ -305,7 +305,7 @@ class DbgTransportSession
 {
 public:
     // No real work done in the constructor. Use Init() instead.
-    DbgTransportSession();
+    DbgTransportSession() = default;
 
     // Cleanup what is allocated/created in Init()
     ~DbgTransportSession();
@@ -422,7 +422,7 @@ class DbgTransportSession
     // error is raised) and which incoming messages are valid.
     enum SessionState
     {
-        SS_Closed,      // No session and no attempt is being made to form one
+        SS_Closed = 0,  // No session and no attempt is being made to form one
         SS_Opening_NC,  // Session is being formed but no connection is established yet
         SS_Opening,     // Session is being formed, the low level connection is in place
         SS_Open,        // Session is fully formed and normal transport messages can be sent and received

src/coreclr/debug/shared/dbgtransportsession.cpp

@@ -31,13 +31,6 @@ DbgTransportSession *g_pDbgTransport = NULL;
 #include "ddmarshalutil.h"
 #endif // !RIGHT_SIDE_COMPILE
 
-// No real work done in the constructor. Use Init() instead.
-DbgTransportSession::DbgTransportSession()
-{
-    m_ref = 1;
-    m_eState = SS_Closed;
-}
-
 DbgTransportSession::~DbgTransportSession()
 {
     DbgTransportLog(LC_Proxy, "DbgTransportSession::~DbgTransportSession() called");
@@ -81,7 +74,7 @@ HRESULT DbgTransportSession::Init(DebuggerIPCControlBlock *pDCB, AppDomainEnumer
 
     // Start with a blank slate so that Shutdown() on a partially initialized instance will only do the
     // cleanup necessary.
-    memset(this, 0, sizeof(*this));
+    *this = {};
 
     // Because of the above memset the embedded classes/structs need to be reinitialized especially
     // the two way pipe; it expects the in/out handles to be -1 instead of 0.