Fix PDB Symbol Resolution for Unmerged Windows Traces (#2407)

* Fix PDB symbol resolution for unmerged Windows traces

The ELF symbol work introduced a switch on BinaryFormat in
LookupSymbolsForModule that only handled PE and ELF cases. For
unmerged Windows traces, symbolInfo is null (no RSDS events in the
ETL), so BinaryFormat returns Unspecified, causing symbol resolution
to be skipped entirely.

Add a case for ModuleBinaryFormat.Unspecified that falls back to PDB
lookup on Windows. OpenPdbForModuleFile handles missing PDB signatures
gracefully by checking the local file on disk.

Also rename ModuleBinaryFormat.Unknown to Unspecified to better reflect
that the format was not specified in the trace data.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Bump version to 3.2.2

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: brianrob

src/Directory.Build.props

@@ -19,7 +19,7 @@
 
   <PropertyGroup>
     <!-- These are the versions of the things we are CREATING in this repository -->
-    <ReleaseVersion>3.2.1</ReleaseVersion>
+    <ReleaseVersion>3.2.2</ReleaseVersion>
     <FastSerializationVersion>$(ReleaseVersion)</FastSerializationVersion>
     <HeapDumpDllVersion>$(ReleaseVersion)</HeapDumpDllVersion>
     <MemoryGraphVersion>$(ReleaseVersion)</MemoryGraphVersion>

src/TraceEvent/TraceLog.cs

@@ -8970,10 +8970,34 @@ private void LookupSymbolsForModule(SymbolReader reader, TraceModuleFile moduleF
                     }
                     break;
 
+                case ModuleBinaryFormat.Unspecified:
+                    {
+                        // For unmerged Windows traces, symbolInfo is null because the ETL
+                        // didn't contain RSDS events with PDB identity info.
+                        // Fall back to PDB lookup on Windows, which handles missing signatures
+                        // gracefully and returns null if the file isn't a PE binary.
+                        if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+                        {
+                            reader.m_log.WriteLine("LookupSymbolsForModule: Binary format unspecified for {0}, looking up PDB info from local file.", moduleFile.FilePath);
+                            NativeSymbolModule moduleReader = OpenPdbForModuleFile(reader, moduleFile) as NativeSymbolModule;
+                            if (moduleReader != null)
+                            {
+                                symbolLookup = moduleReader;
+                            }
+                            // Standard PE RVA computation.
+                            computeRva = (address) => (uint)(address - moduleFile.ImageBase);
+                        }
+                        else
+                        {
+                            reader.m_log.WriteLine("LookupSymbolsForModule: Binary format unspecified for {0}, skipping.", moduleFile.FilePath);
+                        }
+                    }
+                    break;
+
                 default:
                     {
-                        Debug.Assert(false, "LookupSymbolsForModule: unknown binary format " + moduleFile.BinaryFormat);
-                        reader.m_log.WriteLine("LookupSymbolsForModule: Unknown binary format {0} for {1}, skipping.", moduleFile.BinaryFormat, moduleFile.FilePath);
+                        Debug.Assert(false, "LookupSymbolsForModule: unrecognized binary format " + moduleFile.BinaryFormat);
+                        reader.m_log.WriteLine("LookupSymbolsForModule: Unrecognized binary format {0} for {1}, skipping.", moduleFile.BinaryFormat, moduleFile.FilePath);
                     }
                     break;
             }
@@ -10568,7 +10592,7 @@ public string Name
         /// <summary>
         /// The binary format of this module file (PE, ELF, or Unknown).
         /// </summary>
-        public ModuleBinaryFormat BinaryFormat { get { return symbolInfo?.Format ?? ModuleBinaryFormat.Unknown; } }
+        public ModuleBinaryFormat BinaryFormat { get { return symbolInfo?.Format ?? ModuleBinaryFormat.Unspecified; } }
 
         /// <summary>
         /// PE-specific symbol info (PDB identity + R2R). Null if this is not a PE module.
@@ -10780,7 +10804,7 @@ void IFastSerializable.ToStream(Serializer serializer)
             serializer.WriteAddress(imageBase);
 
             // Write symbol info with format discriminator
-            byte format = (byte)(symbolInfo?.Format ?? ModuleBinaryFormat.Unknown);
+            byte format = (byte)(symbolInfo?.Format ?? ModuleBinaryFormat.Unspecified);
             serializer.Write(format);
             if (symbolInfo != null)
             {
@@ -10836,8 +10860,8 @@ void IFastSerializable.FromStream(Deserializer deserializer)
     /// </summary>
     public enum ModuleBinaryFormat : byte
     {
-        /// <summary>The module format is unknown.</summary>
-        Unknown = 0,
+        /// <summary>The module format was not specified in the trace.</summary>
+        Unspecified = 0,
         /// <summary>Windows Portable Executable format.</summary>
         PE = 1,
         /// <summary>Linux ELF (Executable and Linkable Format).</summary>