From ba1d5b2de899bf6e09702f70c28e85b527bd1ea9 Mon Sep 17 00:00:00 2001
From: Alexandre Teoi <ateoi@users.noreply.github.com>
Date: Wed, 21 Feb 2018 20:32:46 -0300
Subject: [PATCH] Show the expected stack trace from a rethrown exception.
 (#16464)

* Show the expected stack trace from a rethrown exception.

Fix #15780

* Remove now unused methods

- StackTraceArray::AppendSkipLast
- StackTraceElement::PartiallyEqual
- StackTraceElement::PartialAtomicUpdate
---
 src/vm/clrex.h    | 10 ----------
 src/vm/excep.cpp  |  4 +---
 src/vm/object.cpp | 49 -------------------------------------------------
 src/vm/object.h   |  1 -
 4 files changed, 1 insertion(+), 63 deletions(-)

diff --git a/src/vm/clrex.h b/src/vm/clrex.h
index 12eb702..a550a71 100644
--- a/src/vm/clrex.h
+++ b/src/vm/clrex.h
@@ -42,16 +42,6 @@ struct StackTraceElement
     {
         return !(*this == rhs);
     }
-
-    bool PartiallyEqual(StackTraceElement const & rhs) const
-    {
-        return pFunc == rhs.pFunc;
-    }
-
-    void PartialAtomicUpdate(StackTraceElement const & rhs)
-    {
-        ip = rhs.ip;
-    }
 };
 
 class StackTraceInfo
diff --git a/src/vm/excep.cpp b/src/vm/excep.cpp
index 35a2074..09283f7 100644
--- a/src/vm/excep.cpp
+++ b/src/vm/excep.cpp
@@ -2428,9 +2428,7 @@ void StackTraceInfo::SaveStackTrace(BOOL bAllowAllocMem, OBJECTHANDLE hThrowable
                         }
                     }
 
-                    if (bSkipLastElement && gc.stackTrace.Size() != 0)
-                        gc.stackTrace.AppendSkipLast(m_pStackTrace, m_pStackTrace + m_dFrameCount);
-                    else
+                    if (!bSkipLastElement)
                         gc.stackTrace.Append(m_pStackTrace, m_pStackTrace + m_dFrameCount);
 
                     //////////////////////////////
diff --git a/src/vm/object.cpp b/src/vm/object.cpp
index 8659084..374fe19 100644
--- a/src/vm/object.cpp
+++ b/src/vm/object.cpp
@@ -1970,55 +1970,6 @@ void StackTraceArray::Append(StackTraceElement const * begin, StackTraceElement
 #endif
 }
 
-void StackTraceArray::AppendSkipLast(StackTraceElement const * begin, StackTraceElement const * end)
-{
-    CONTRACTL
-    {
-        THROWS;
-        GC_TRIGGERS;
-        MODE_COOPERATIVE;
-        PRECONDITION(IsProtectedByGCFrame((OBJECTREF*)this));
-    }
-    CONTRACTL_END;
-
-    // to skip the last element, we need to replace it with the first element
-    // from m_pStackTrace and do it atomically if possible,
-    // otherwise we'll create a copy of the entire array, which is bad for performance,
-    // and so should not be on the main path
-    //
-
-    // ensure that only one thread can write to the array
-    EnsureThreadAffinity();
-
-    assert(Size() > 0);
-
-    StackTraceElement & last = GetData()[Size() - 1];
-    if (last.PartiallyEqual(*begin))
-    {
-        // fast path: atomic update
-        last.PartialAtomicUpdate(*begin);
-
-        // append the rest
-        if (end - begin > 1)
-            Append(begin + 1, end);
-    }
-    else
-    {
-        // slow path: create a copy and append
-        StackTraceArray copy;
-        GCPROTECT_BEGIN(copy);
-            copy.CopyFrom(*this);
-            copy.SetSize(copy.Size() - 1);
-            copy.Append(begin, end);
-            this->Swap(copy);
-        GCPROTECT_END();
-    }
-
-#if defined(_DEBUG)
-    CheckState();
-#endif
-}
-
 void StackTraceArray::CheckState() const
 {
     CONTRACTL
diff --git a/src/vm/object.h b/src/vm/object.h
index 3ffbf79..e6e0c02 100644
--- a/src/vm/object.h
+++ b/src/vm/object.h
@@ -2910,7 +2910,6 @@ public:
     StackTraceElement & operator[](size_t index);
 
     void Append(StackTraceElement const * begin, StackTraceElement const * end);
-    void AppendSkipLast(StackTraceElement const * begin, StackTraceElement const * end);
 
     I1ARRAYREF Get() const
     {
-- 
2.7.4