upb: reverse the polarity of the MiniTableField untyped data accessors

PiperOrigin-RevId: 590007603

upb/base/string_view.h

@@ -42,7 +42,7 @@ UPB_INLINE upb_StringView upb_StringView_FromString(const char* data) {
 }
 
 UPB_INLINE bool upb_StringView_IsEqual(upb_StringView a, upb_StringView b) {
-  return a.size == b.size && memcmp(a.data, b.data, a.size) == 0;
+  return (a.size == b.size) && (!a.size || !memcmp(a.data, b.data, a.size));
 }
 
 // LINT.ThenChange(

upb/message/internal/accessors.h

@@ -117,26 +117,32 @@ UPB_INLINE void UPB_PRIVATE(_upb_Message_SetPresence)(
   }
 }
 
-UPB_INLINE bool _upb_MiniTable_ValueIsNonZero(const void* default_val,
-                                              const upb_MiniTableField* field) {
-  char zero[16] = {0};
+UPB_INLINE bool UPB_PRIVATE(_upb_MiniTableField_DataEquals)(
+    const upb_MiniTableField* field, const void* a, const void* b) {
   switch (UPB_PRIVATE(_upb_MiniTableField_GetRep)(field)) {
     case kUpb_FieldRep_1Byte:
-      return memcmp(&zero, default_val, 1) != 0;
+      return memcmp(a, b, 1) == 0;
     case kUpb_FieldRep_4Byte:
-      return memcmp(&zero, default_val, 4) != 0;
+      return memcmp(a, b, 4) == 0;
     case kUpb_FieldRep_8Byte:
-      return memcmp(&zero, default_val, 8) != 0;
+      return memcmp(a, b, 8) == 0;
     case kUpb_FieldRep_StringView: {
-      const upb_StringView* sv = (const upb_StringView*)default_val;
-      return sv->size != 0;
+      const upb_StringView sa = *(const upb_StringView*)a;
+      const upb_StringView sb = *(const upb_StringView*)b;
+      return upb_StringView_IsEqual(sa, sb);
     }
   }
   UPB_UNREACHABLE();
 }
 
-UPB_INLINE void _upb_MiniTable_CopyFieldData(void* to, const void* from,
-                                             const upb_MiniTableField* field) {
+UPB_INLINE bool UPB_PRIVATE(_upb_MiniTableField_DataIsZero)(
+    const upb_MiniTableField* field, const void* val) {
+  const char zero[16] = {0};
+  return UPB_PRIVATE(_upb_MiniTableField_DataEquals)(field, val, zero);
+}
+
+UPB_INLINE void UPB_PRIVATE(_upb_MiniTableField_DataCopy)(
+    const upb_MiniTableField* field, void* to, const void* from) {
   switch (UPB_PRIVATE(_upb_MiniTableField_GetRep)(field)) {
     case kUpb_FieldRep_1Byte:
       memcpy(to, from, 1);
@@ -211,24 +217,26 @@ static UPB_FORCEINLINE void _upb_Message_GetNonExtensionField(
     const void* default_val, void* val) {
   UPB_ASSUME(!upb_MiniTableField_IsExtension(field));
   if ((upb_MiniTableField_IsInOneof(field) ||
-       _upb_MiniTable_ValueIsNonZero(default_val, field)) &&
+       !UPB_PRIVATE(_upb_MiniTableField_DataIsZero)(field, default_val)) &&
       !_upb_Message_HasNonExtensionField(msg, field)) {
-    _upb_MiniTable_CopyFieldData(val, default_val, field);
+    UPB_PRIVATE(_upb_MiniTableField_DataCopy)(field, val, default_val);
     return;
   }
-  _upb_MiniTable_CopyFieldData(val, _upb_MiniTableField_GetConstPtr(msg, field),
-                               field);
+  UPB_PRIVATE(_upb_MiniTableField_DataCopy)
+  (field, val, _upb_MiniTableField_GetConstPtr(msg, field));
 }
 
 UPB_INLINE void _upb_Message_GetExtensionField(
     const upb_Message* msg, const upb_MiniTableExtension* mt_ext,
     const void* default_val, void* val) {
-  UPB_ASSUME(upb_MiniTableField_IsExtension(&mt_ext->UPB_PRIVATE(field)));
   const upb_Message_Extension* ext = _upb_Message_Getext(msg, mt_ext);
+  const upb_MiniTableField* f = &mt_ext->UPB_PRIVATE(field);
+  UPB_ASSUME(upb_MiniTableField_IsExtension(f));
+
   if (ext) {
-    _upb_MiniTable_CopyFieldData(val, &ext->data, &mt_ext->UPB_PRIVATE(field));
+    UPB_PRIVATE(_upb_MiniTableField_DataCopy)(f, val, &ext->data);
   } else {
-    _upb_MiniTable_CopyFieldData(val, default_val, &mt_ext->UPB_PRIVATE(field));
+    UPB_PRIVATE(_upb_MiniTableField_DataCopy)(f, val, default_val);
   }
 }
 
@@ -263,8 +271,8 @@ UPB_INLINE void _upb_Message_SetNonExtensionField(
     upb_Message* msg, const upb_MiniTableField* field, const void* val) {
   UPB_ASSUME(!upb_MiniTableField_IsExtension(field));
   UPB_PRIVATE(_upb_Message_SetPresence)(msg, field);
-  _upb_MiniTable_CopyFieldData(_upb_MiniTableField_GetPtr(msg, field), val,
-                               field);
+  UPB_PRIVATE(_upb_MiniTableField_DataCopy)
+  (field, _upb_MiniTableField_GetPtr(msg, field), val);
 }
 
 UPB_INLINE bool _upb_Message_SetExtensionField(
@@ -274,7 +282,8 @@ UPB_INLINE bool _upb_Message_SetExtensionField(
   upb_Message_Extension* ext =
       _upb_Message_GetOrCreateExtension(msg, mt_ext, a);
   if (!ext) return false;
-  _upb_MiniTable_CopyFieldData(&ext->data, val, &mt_ext->UPB_PRIVATE(field));
+  UPB_PRIVATE(_upb_MiniTableField_DataCopy)
+  (&mt_ext->UPB_PRIVATE(field), &ext->data, val);
   return true;
 }
 
@@ -302,8 +311,8 @@ UPB_INLINE void _upb_Message_ClearNonExtensionField(
     *ptr = 0;
   }
   const char zeros[16] = {0};
-  _upb_MiniTable_CopyFieldData(_upb_MiniTableField_GetPtr(msg, field), zeros,
-                               field);
+  UPB_PRIVATE(_upb_MiniTableField_DataCopy)
+  (field, _upb_MiniTableField_GetPtr(msg, field), zeros);
 }
 
 UPB_INLINE void _upb_Message_AssertMapIsUntagged(

upb/reflection/message.c

@@ -131,7 +131,8 @@ bool upb_Message_Next(const upb_Message* msg, const upb_MessageDef* m,
           if (!val.array_val || upb_Array_Size(val.array_val) == 0) continue;
           break;
         case kUpb_FieldMode_Scalar:
-          if (!_upb_MiniTable_ValueIsNonZero(&val, field)) continue;
+          if (UPB_PRIVATE(_upb_MiniTableField_DataIsZero)(field, &val))
+            continue;
           break;
       }
     }