Removed checking custom attributes in the runtime each time the break…

…point is set and moved it to the constructor which is more efficient.

src/mono/wasm/debugger/BrowserDebugProxy/DebugStore.cs

@@ -330,6 +330,7 @@ internal class MethodInfo
         internal LocalScopeHandleCollection localScopes;
         public bool IsStatic() => (methodDef.Attributes & MethodAttributes.Static) != 0;
         public int IsAsync { get; set; }
+        public bool IsHiddenFromDebugger { get; }
         public MethodInfo(AssemblyInfo assembly, MethodDefinitionHandle methodDefHandle, int token, SourceFile source, TypeInfo type, MetadataReader asmMetadataReader, MetadataReader pdbMetadataReader)
         {
             this.IsAsync = -1;
@@ -363,6 +364,18 @@ public MethodInfo(AssemblyInfo assembly, MethodDefinitionHandle methodDefHandle,
 
                 StartLocation = new SourceLocation(this, start);
                 EndLocation = new SourceLocation(this, end);
+
+                foreach (var cattr in methodDef.GetCustomAttributes())
+                {
+                    var ctorHandle = asmMetadataReader.GetCustomAttribute(cattr).Constructor;
+                    if (ctorHandle.Kind == HandleKind.MemberReference)
+                    {
+                        var container = asmMetadataReader.GetMemberReference((MemberReferenceHandle)ctorHandle).Parent;
+                        var name = asmMetadataReader.GetString(asmMetadataReader.GetTypeReference((TypeReferenceHandle)container).Name);
+                        if (name == "DebuggerHiddenAttribute")
+                            this.IsHiddenFromDebugger = true;
+                    }
+                }
             }
             localScopes = pdbMetadataReader.GetLocalScopes(methodDefHandle);
         }

src/mono/wasm/debugger/BrowserDebugProxy/MonoProxy.cs

@@ -1153,10 +1153,6 @@ private async Task<Breakpoint> SetMonoBreakpoint(SessionId sessionId, string req
             var assembly_id = await SdbHelper.GetAssemblyId(sessionId, asm_name, token);
             var methodId = await SdbHelper.GetMethodIdByToken(sessionId, assembly_id, method_token, token);
             var breakpoint_id = await SdbHelper.SetBreakpoint(sessionId, methodId, il_offset, token);
-            var type_id = await SdbHelper.GetTypeIdFromToken(sessionId, assembly_id, method_token, token);
-            var isHidden = await SdbHelper.GetDebuggerHiddenAttribute(sessionId, type_id, token);
-            if (isHidden)
-                return bp;
 
             if (breakpoint_id > 0)
             {
@@ -1305,6 +1301,10 @@ private async Task SetBreakpoint(SessionId sessionId, DebugStore store, Breakpoi
             {
                 SourceLocation loc = sourceId.First();
                 req.Method = loc.CliLocation.Method;
+                if (req.Method.IsHiddenFromDebugger)
+                {
+                    continue;
+                }
 
                 Breakpoint bp = await SetMonoBreakpoint(sessionId, req.Id, loc, req.Condition, token);
 

src/mono/wasm/debugger/BrowserDebugProxy/MonoSDBHelper.cs

@@ -1327,32 +1327,6 @@ internal async Task<MonoBinaryReader> GetCAttrsFromType(SessionId sessionId, int
             return null;
         }
 
-        internal async Task<IEnumerable<string>> GetCAttrsFromMethod(SessionId sessionId, int typeId, CancellationToken token)
-        {
-            var customAttributeNames = new List<string>();
-            var invokeParams = new MemoryStream();
-            var invokeParamsWriter = new MonoBinaryWriter(invokeParams);
-            var commandParams = new MemoryStream();
-            var commandParamsWriter = new MonoBinaryWriter(commandParams);
-            commandParamsWriter.Write(typeId);
-            commandParamsWriter.Write(0);
-            var retDebuggerCmdReader = await SendDebuggerAgentCommand<CmdMethod>(sessionId, CmdMethod.GetCattrs, commandParams, token);
-            var count = retDebuggerCmdReader.ReadInt32();
-            if (count == 0)
-                return customAttributeNames;
-            for (int i = 0; i < count; i++)
-            {
-                var methodId = retDebuggerCmdReader.ReadInt32();
-                commandParams = new MemoryStream();
-                commandParamsWriter = new MonoBinaryWriter(commandParams);
-                commandParamsWriter.Write(methodId);
-                var retDebuggerCmdReader2 = await SendDebuggerAgentCommand<CmdMethod>(sessionId, CmdMethod.GetDeclaringType, commandParams, token);
-                var customAttributeTypeId = retDebuggerCmdReader2.ReadInt32();
-                customAttributeNames.Add(await GetTypeName(sessionId, customAttributeTypeId, token));
-            }
-            return customAttributeNames;
-        }
-
         public async Task<int> GetAssemblyFromType(SessionId sessionId, int type_id, CancellationToken token)
         {
             var commandParams = new MemoryStream();
@@ -1368,25 +1342,6 @@ public async Task<int> GetAssemblyFromType(SessionId sessionId, int type_id, Can
             return retDebuggerCmdReader.ReadInt32();
         }
 
-        public async Task<bool> GetDebuggerHiddenAttribute(SessionId sessionId, int type_id, CancellationToken token)
-        {
-            string expr = "";
-            try
-            {
-
-                var customMethodAttributes = await GetCAttrsFromMethod(sessionId, type_id, token);
-                if (customMethodAttributes.Any(a => a == "System.Diagnostics.DebuggerHiddenAttribute"))
-                {
-                    return true;
-                }
-            }
-            catch (Exception)
-            {
-                logger.LogDebug($"Could not evaluate DebuggerHiddenAttribute - {expr}");
-            }
-            return false;
-        }
-
         public async Task<string> GetValueFromDebuggerDisplayAttribute(SessionId sessionId, int objectId, int typeId, CancellationToken token)
         {
             string expr = "";