From 962cc86b5626776fd19e8b878ff3cbd6357d192c Mon Sep 17 00:00:00 2001
From: Bruce Forstall <brucefo@microsoft.com>
Date: Thu, 12 Nov 2020 17:08:31 -0800
Subject: [PATCH] Fix SuperPMI for new altjit jit flag

---
 .../ToolBox/superpmi/superpmi/icorjitinfo.cpp | 11 ++++++-
 .../ToolBox/superpmi/superpmi/jitinstance.cpp | 31 ++++++++++++++++++-
 .../ToolBox/superpmi/superpmi/jitinstance.h   |  4 +++
 3 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/src/coreclr/src/ToolBox/superpmi/superpmi/icorjitinfo.cpp b/src/coreclr/src/ToolBox/superpmi/superpmi/icorjitinfo.cpp
index 6b8f4540a52285..789dfae1fd9400 100644
--- a/src/coreclr/src/ToolBox/superpmi/superpmi/icorjitinfo.cpp
+++ b/src/coreclr/src/ToolBox/superpmi/superpmi/icorjitinfo.cpp
@@ -1566,7 +1566,16 @@ void MyICJI::notifyInstructionSetUsage(CORINFO_InstructionSet instructionSet, bo
 DWORD MyICJI::getJitFlags(CORJIT_FLAGS* jitFlags, DWORD sizeInBytes)
 {
     jitInstance->mc->cr->AddCall("getJitFlags");
-    return jitInstance->mc->repGetJitFlags(jitFlags, sizeInBytes);
+    DWORD ret = jitInstance->mc->repGetJitFlags(jitFlags, sizeInBytes);
+    if (jitInstance->forceClearAltJitFlag)
+    {
+        jitFlags->Clear(CORJIT_FLAGS::CORJIT_FLAG_ALT_JIT);
+    }
+    else if (jitInstance->forceSetAltJitFlag)
+    {
+        jitFlags->Set(CORJIT_FLAGS::CORJIT_FLAG_ALT_JIT);
+    }
+    return ret;
 }
 
 // Runs the given function with the given parameter under an error trap
diff --git a/src/coreclr/src/ToolBox/superpmi/superpmi/jitinstance.cpp b/src/coreclr/src/ToolBox/superpmi/superpmi/jitinstance.cpp
index 5050f248fa479a..2379c467281d44 100644
--- a/src/coreclr/src/ToolBox/superpmi/superpmi/jitinstance.cpp
+++ b/src/coreclr/src/ToolBox/superpmi/superpmi/jitinstance.cpp
@@ -26,9 +26,38 @@ JitInstance* JitInstance::InitJit(char*                         nameOfJit,
     }
 
     jit->forceOptions = forceOptions;
-
     jit->options = options;
 
+    // The flag to cause the JIT to be invoked as an altjit is stored in the jit flags, not in
+    // the environment. If the user uses the "-jitoption force" flag to force AltJit off (it was
+    // probably on during collection), or to force it on, then propagate that to the jit flags.
+    jit->forceClearAltJitFlag = false;
+    jit->forceSetAltJitFlag = false;
+    const WCHAR* altJitFlag = jit->getForceOption(W("AltJit"));
+    if (altJitFlag != nullptr)
+    {
+        if (wcscmp(altJitFlag, W("")) == 0)
+        {
+            jit->forceClearAltJitFlag = true;
+        }
+        else
+        {
+            jit->forceSetAltJitFlag = true;
+        }
+    }
+    const WCHAR* altJitNgenFlag = jit->getForceOption(W("AltJitNgen"));
+    if (altJitNgenFlag != nullptr)
+    {
+        if (wcscmp(altJitNgenFlag, W("")) == 0)
+        {
+            jit->forceClearAltJitFlag = true;
+        }
+        else
+        {
+            jit->forceSetAltJitFlag = true;
+        }
+    }
+
     jit->environment.getIntConfigValue   = nullptr;
     jit->environment.getStingConfigValue = nullptr;
 
diff --git a/src/coreclr/src/ToolBox/superpmi/superpmi/jitinstance.h b/src/coreclr/src/ToolBox/superpmi/superpmi/jitinstance.h
index 1acec90792e3fc..d8755635d936b4 100644
--- a/src/coreclr/src/ToolBox/superpmi/superpmi/jitinstance.h
+++ b/src/coreclr/src/ToolBox/superpmi/superpmi/jitinstance.h
@@ -32,6 +32,10 @@ class JitInstance
     void timeResult(CORINFO_METHOD_INFO info, unsigned flags);
 
 public:
+
+    bool forceClearAltJitFlag;
+    bool forceSetAltJitFlag;
+
     enum Result
     {
         RESULT_ERROR,