Revert and Fix "Fix bug due to reusing cleanup blocks inside tasks. See more"

This reverts commit cea4335.

There's a execution path in CodeGen that removes cleanup.dest.slot if there's
only one use. We have to do the same.

Add test for the optimized and non-optimized cases

Author: mikaoP

clang/lib/CodeGen/CGCleanup.cpp

@@ -840,6 +840,11 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough) {
           NormalCleanupDestSlot->user_back()->eraseFromParent();
           NormalCleanupDestSlot->eraseFromParent();
           NormalCleanupDest = Address::invalid();
+
+          // OmpSs-2: Clean up the possibly dead store to the cleanup dest slot.
+          if (getContext().getLangOpts().OmpSs
+              && CGM.getOmpSsRuntime().inTaskBody())
+            CGM.getOmpSsRuntime().setTaskNormalCleanupDestSlot(Address::invalid());
         }
 
         llvm::BasicBlock *BranchAfter = Scope.getBranchAfterBlock(0);
@@ -1266,6 +1271,19 @@ void CodeGenFunction::DeactivateCleanupBlock(EHScopeStack::stable_iterator C,
 }
 
 Address CodeGenFunction::getNormalCleanupDestSlot() {
+  if (getContext().getLangOpts().OmpSs
+      && CGM.getOmpSsRuntime().inTaskBody()) {
+        Address NCleanupDest = CGM.getOmpSsRuntime().getTaskNormalCleanupDestSlot();
+        if (NCleanupDest.isValid())
+          return NCleanupDest;
+
+        NCleanupDest =
+          CreateDefaultAlignTempAlloca(Builder.getInt32Ty(), "cleanup.dest.slot");
+
+        CGM.getOmpSsRuntime().setTaskNormalCleanupDestSlot(NCleanupDest);
+        return NCleanupDest;
+
+  }
   if (!NormalCleanupDest.isValid())
     NormalCleanupDest =
       CreateDefaultAlignTempAlloca(Builder.getInt32Ty(), "cleanup.dest.slot");

clang/lib/CodeGen/CGOmpSsRuntime.cpp

@@ -1941,6 +1941,10 @@ Address CGOmpSsRuntime::getTaskEHSelectorSlot() {
   return TaskStack.back().EHSelectorSlot;
 }
 
+Address CGOmpSsRuntime::getTaskNormalCleanupDestSlot() {
+  return TaskStack.back().NormalCleanupDestSlot;
+}
+
 Address CGOmpSsRuntime::getTaskCaptureAddr(const VarDecl *VD) {
   for (auto ItMap = CaptureMapStack.rbegin();
        ItMap != CaptureMapStack.rend(); ++ItMap) {
@@ -1976,6 +1980,10 @@ void CGOmpSsRuntime::setTaskEHSelectorSlot(Address Addr) {
   TaskStack.back().EHSelectorSlot = Addr;
 }
 
+void CGOmpSsRuntime::setTaskNormalCleanupDestSlot(Address Addr) {
+  TaskStack.back().NormalCleanupDestSlot = Addr;
+}
+
 // Borrowed brom CodeGenFunction.cpp
 static void EmitIfUsed(CodeGenFunction &CGF, llvm::BasicBlock *BB) {
   if (!BB) return;

clang/lib/CodeGen/CGOmpSsRuntime.h

@@ -142,6 +142,7 @@ class CGOmpSsRuntime {
     llvm::BasicBlock *UnreachableBlock = nullptr;
     Address ExceptionSlot = Address::invalid();
     Address EHSelectorSlot = Address::invalid();
+    Address NormalCleanupDestSlot = Address::invalid();
   };
 
 private:
@@ -230,6 +231,8 @@ class CGOmpSsRuntime {
   Address getTaskExceptionSlot();
   // returns the innermost nested task EHSelectorSlot address
   Address getTaskEHSelectorSlot();
+  // returns the innermost nested task NormalCleanupDestSlot address
+  Address getTaskNormalCleanupDestSlot();
   // returns the captured address of VD
   Address getTaskCaptureAddr(const VarDecl *VD);
 
@@ -245,6 +248,8 @@ class CGOmpSsRuntime {
   void setTaskExceptionSlot(Address Addr);
   // sets the innermost nested task EHSelectorSlot address
   void setTaskEHSelectorSlot(Address Addr);
+  // returns the innermost nested task NormalCleanupDestSlot address
+  void setTaskNormalCleanupDestSlot(Address Addr);
 
   RValue emitTaskFunction(CodeGenFunction &CGF,
                           const FunctionDecl *FD,

clang/test/OmpSs-RT/Clang_OmpSs-2/success_task_cleanups.c

@@ -27,8 +27,8 @@
 // RUN: %oss-compile
 // RUN: %oss-O2-compile
 
-// This test was crashing because we were caching cleanup blocks, but
-// that is wrong
+// There's only one cleanup here, so codegen removes the cleanup.dest.slot.
+// We have to do the same in task context
 
 int main(int argc, char **argv)
 {

clang/test/OmpSs-RT/Clang_OmpSs-2/success_task_cleanups_01.c

@@ -0,0 +1,45 @@
+/*--------------------------------------------------------------------
+  (C) Copyright 2006-2013 Barcelona Supercomputing Center
+                          Centro Nacional de Supercomputacion
+
+  This file is part of Mercurium C/C++ source-to-source compiler.
+
+  See AUTHORS file in the top level directory for information
+  regarding developers and contributors.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 3 of the License, or (at your option) any later version.
+
+  Mercurium C/C++ source-to-source compiler is distributed in the hope
+  that it will be useful, but WITHOUT ANY WARRANTY; without even the
+  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+  PURPOSE.  See the GNU Lesser General Public License for more
+  details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with Mercurium C/C++ source-to-source compiler; if
+  not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+  Cambridge, MA 02139, USA.
+--------------------------------------------------------------------*/
+
+// RUN: %oss-compile
+// RUN: %oss-O2-compile
+
+// There's more than one cleanup here
+
+int main() {
+    #pragma oss task
+    {
+        for (int i = 0; i < 10; ++i)
+            for (int j = 0; j < 10; ++j)
+                ;
+    }
+    #pragma oss task
+    {
+        for (int i = 0; i < 10; ++i)
+            for (int j = 0; j < 10; ++j)
+                ;
+    }
+}