From 31e58809ccb9769d11c3085cf620f557264748c2 Mon Sep 17 00:00:00 2001
From: David Kaplan <david@2of1.org>
Date: Mon, 24 May 2021 22:24:01 +0100
Subject: [PATCH] Add cooked data read tracing (#10166)

Added trace to conhost to instrument buffers that are cooked prior to being passed to the console.
* [x] I've discussed this with core contributors already (internal)

VALIDATION
- Ensured trace is correctly logged in ETL (via TraceLog)
---
 src/host/readDataCooked.cpp |  2 ++
 src/host/tracing.cpp        | 13 ++++++++++++-
 src/host/tracing.hpp        |  2 ++
 src/inc/til.h               |  2 +-
 4 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/host/readDataCooked.cpp b/src/host/readDataCooked.cpp
index 641ca12b0..458f351b3 100644
--- a/src/host/readDataCooked.cpp
+++ b/src/host/readDataCooked.cpp
@@ -1030,6 +1030,8 @@ void COOKED_READ_DATA::SavePendingInput(const size_t index, const bool multiline
                                                    WI_IsFlagSet(gci.Flags, CONSOLE_HISTORY_NODUP)));
             }
 
+            Tracing::s_TraceCookedRead(_backupLimit);
+
             // check for alias
             ProcessAliases(LineCount);
         }
diff --git a/src/host/tracing.cpp b/src/host/tracing.cpp
index ec8eda589..6e20fe33e 100644
--- a/src/host/tracing.cpp
+++ b/src/host/tracing.cpp
@@ -20,7 +20,8 @@ enum TraceKeywords
     Input = 0x200,
     API = 0x400,
     UIA = 0x800,
-    All = 0xFFF
+    CookedRead = 0x1000,
+    All = 0x1FFF
 };
 DEFINE_ENUM_FLAG_OPERATORS(TraceKeywords);
 
@@ -404,6 +405,16 @@ void Tracing::s_TraceInputRecord(const INPUT_RECORD& inputRecord)
     }
 }
 
+void Tracing::s_TraceCookedRead(_In_z_ const wchar_t* pwszCookedBuffer)
+{
+    TraceLoggingWrite(
+        g_hConhostV2EventTraceProvider,
+        "CookedRead",
+        TraceLoggingWideString(pwszCookedBuffer, "ReadBuffer"),
+        TraceLoggingKeyword(TIL_KEYWORD_TRACE),
+        TraceLoggingKeyword(TraceKeywords::CookedRead));
+}
+
 void __stdcall Tracing::TraceFailure(const wil::FailureInfo& failure) noexcept
 {
     TraceLoggingWrite(
diff --git a/src/host/tracing.hpp b/src/host/tracing.hpp
index 40744ec21..36ae55423 100644
--- a/src/host/tracing.hpp
+++ b/src/host/tracing.hpp
@@ -62,6 +62,8 @@ public:
     static void s_TraceWindowMessage(const MSG& msg);
     static void s_TraceInputRecord(const INPUT_RECORD& inputRecord);
 
+    static void s_TraceCookedRead(_In_z_ const wchar_t* pwszCookedBuffer);
+
     static void __stdcall TraceFailure(const wil::FailureInfo& failure) noexcept;
 
 private:
diff --git a/src/inc/til.h b/src/inc/til.h
index c574da12b..9e8792b4c 100644
--- a/src/inc/til.h
+++ b/src/inc/til.h
@@ -44,7 +44,7 @@
 // See also https://osgwiki.com/wiki/TraceLogging#Semantics
 //
 // Note that Conhost had already defined some keywords
-// between bits 0..11 so be sure to not overlap those.
+// between bits 0..12 so be sure to not overlap those.
 // See `TraceKeywords`.
 // We will therefore try to reserve 32..42 for TIL
 // as common flags for the entire Terminal team projects.