[cfe-commits] r151311 - in /cfe/trunk: lib/CodeGen/CGExprCXX.cpp test/CodeGenCXX/new-array-init-exceptions.cpp

[Chad Rosier]

Author: mcrosier
Date: Thu Feb 23 18:13:55 2012
New Revision: 151311

URL: http://llvm.org/viewvc/llvm-project?rev=151311&view=rev
Log:
Reapply r151172 - Unwind path cleanup for array new list initializers - with a
test case that only runs on debug builds.


Added:
    cfe/trunk/test/CodeGenCXX/new-array-init-exceptions.cpp
      - copied, changed from r151202, cfe/trunk/test/CodeGenCXX/new-array-init-exceptions.cpp
Modified:
    cfe/trunk/lib/CodeGen/CGExprCXX.cpp

Modified: cfe/trunk/lib/CodeGen/CGExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprCXX.cpp?rev=151311&r1=151310&r2=151311&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprCXX.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprCXX.cpp Thu Feb 23 18:13:55 2012
@@ -804,12 +804,32 @@
   unsigned initializerElements = 0;
 
   const Expr *Init = E->getInitializer();
+  llvm::AllocaInst *endOfInit = 0;
+  QualType::DestructionKind dtorKind = elementType.isDestructedType();
+  EHScopeStack::stable_iterator cleanup;
+  llvm::Instruction *cleanupDominator = 0;
   // If the initializer is an initializer list, first do the explicit elements.
   if (const InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
     initializerElements = ILE->getNumInits();
-    QualType elementType = E->getAllocatedType();
-    // FIXME: exception-safety for the explicit initializers
+
+    // Enter a partial-destruction cleanup if necessary.
+    if (needsEHCleanup(dtorKind)) {
+      // In principle we could tell the cleanup where we are more
+      // directly, but the control flow can get so varied here that it
+      // would actually be quite complex.  Therefore we go through an
+      // alloca.
+      endOfInit = CreateTempAlloca(beginPtr->getType(), "array.endOfInit");
+      cleanupDominator = Builder.CreateStore(beginPtr, endOfInit);
+      pushIrregularPartialArrayCleanup(beginPtr, endOfInit, elementType,
+                                       getDestroyer(dtorKind));
+      cleanup = EHStack.stable_begin();
+    }
+
     for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i) {
+      // Tell the cleanup that it needs to destroy up to this
+      // element.  TODO: some of these stores can be trivially
+      // observed to be unnecessary.
+      if (endOfInit) Builder.CreateStore(explicitPtr, endOfInit);
       StoreAnyExprIntoOneUnit(*this, ILE->getInit(i), elementType, explicitPtr);
       explicitPtr =Builder.CreateConstGEP1_32(explicitPtr, 1, "array.exp.next");
     }
@@ -825,7 +845,12 @@
   // anything left to initialize.
   if (llvm::ConstantInt *constNum = dyn_cast<llvm::ConstantInt>(numElements)) {
     // If all elements have already been initialized, skip the whole loop.
-    if (constNum->getZExtValue() <= initializerElements) return;
+    if (constNum->getZExtValue() <= initializerElements) {
+      // If there was a cleanup, deactivate it.
+      if (cleanupDominator)
+        DeactivateCleanupBlock(cleanup, cleanupDominator);;
+      return;
+    }
   } else {
     llvm::BasicBlock *nonEmptyBB = createBasicBlock("new.loop.nonempty");
     llvm::Value *isEmpty = Builder.CreateICmpEQ(explicitPtr, endPtr,
@@ -845,11 +870,11 @@
     Builder.CreatePHI(explicitPtr->getType(), 2, "array.cur");
   curPtr->addIncoming(explicitPtr, entryBB);
 
+  // Store the new cleanup position for irregular cleanups.
+  if (endOfInit) Builder.CreateStore(curPtr, endOfInit);
+
   // Enter a partial-destruction cleanup if necessary.
-  QualType::DestructionKind dtorKind = elementType.isDestructedType();
-  EHScopeStack::stable_iterator cleanup;
-  llvm::Instruction *cleanupDominator = 0;
-  if (needsEHCleanup(dtorKind)) {
+  if (!cleanupDominator && needsEHCleanup(dtorKind)) {
     pushRegularPartialArrayCleanup(beginPtr, curPtr, elementType,
                                    getDestroyer(dtorKind));
     cleanup = EHStack.stable_begin();

Copied: cfe/trunk/test/CodeGenCXX/new-array-init-exceptions.cpp (from r151202, cfe/trunk/test/CodeGenCXX/new-array-init-exceptions.cpp)
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/new-array-init-exceptions.cpp?p2=cfe/trunk/test/CodeGenCXX/new-array-init-exceptions.cpp&p1=cfe/trunk/test/CodeGenCXX/new-array-init-exceptions.cpp&r1=151202&r2=151311&rev=151311&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/new-array-init-exceptions.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/new-array-init-exceptions.cpp Thu Feb 23 18:13:55 2012
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++11 -triple i386-unknown-unknown -fexceptions -fcxx-exceptions %s -emit-llvm -o - | FileCheck %s
+// REQUIRES: asserts
 
 struct Throws {
   Throws(int);