[cfe-commits] r64046 - in /cfe/trunk/lib/CodeGen: CGObjC.cpp CGStmt.cpp CodeGenFunction.h

[Mike Stump]

Author: mrs
Date: Sat Feb  7 17:02:10 2009
New Revision: 64046

URL: http://llvm.org/viewvc/llvm-project?rev=64046&view=rev
Log:
Ensure we track all the stack depths for all break and continue points
correctly.  This should lay the ground work to throw the big switch
and start code gening break and continue in the presense of vlas.

Modified:
    cfe/trunk/lib/CodeGen/CGObjC.cpp
    cfe/trunk/lib/CodeGen/CGStmt.cpp
    cfe/trunk/lib/CodeGen/CodeGenFunction.h

Modified: cfe/trunk/lib/CodeGen/CGObjC.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGObjC.cpp?rev=64046&r1=64045&r2=64046&view=diff

==============================================================================
--- cfe/trunk/lib/CodeGen/CGObjC.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGObjC.cpp Sat Feb  7 17:02:10 2009
@@ -361,6 +361,11 @@
     return;
   }
 
+  // We want to ensure that any vlas between here and when we
+  // push the break and continue context below can be destroyed
+  // when we break 
+  llvm::Value *saveBreakStackDepth = StackDepth;
+
   if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) {
     EmitStmt(SD);
     assert(HaveInsertPoint() && "DeclStmt destroyed insert point!");
@@ -446,10 +451,6 @@
   llvm::BasicBlock *LoopStart = createBasicBlock("loopstart");
   EmitBlock(LoopStart);
 
-  // We want to ensure there are no vlas between here and when we
-  // push the break and continue context below.
-  llvm::Value *saveStackDepth = StackDepth;
-
   llvm::Value *CounterPtr = CreateTempAlloca(UnsignedLongLTy, "counter.ptr");
   Builder.CreateStore(Zero, CounterPtr);
   
@@ -519,9 +520,8 @@
   llvm::BasicBlock *LoopEnd = createBasicBlock("loopend");
   llvm::BasicBlock *AfterBody = createBasicBlock("afterbody");
   
-  assert (StackDepth == saveStackDepth && "vla unhandled in for");
-
-  BreakContinuePush(LoopEnd, AfterBody);
+  // Ensure any vlas created between there and here, are undone
+  BreakContinuePush(LoopEnd, AfterBody, saveBreakStackDepth, StackDepth);
 
   EmitStmt(S.getBody());
   

Modified: cfe/trunk/lib/CodeGen/CGStmt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGStmt.cpp?rev=64046&r1=64045&r2=64046&view=diff

==============================================================================
--- cfe/trunk/lib/CodeGen/CGStmt.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGStmt.cpp Sat Feb  7 17:02:10 2009
@@ -466,6 +466,8 @@
 
   EmitBlock(CondBlock);
 
+  llvm::Value *saveStackDepth = StackDepth;
+
   // Evaluate the condition if present.  If not, treat it as a
   // non-zero-constant according to 6.8.5.3p2, aka, true.
   if (S.getCond()) {
@@ -491,8 +493,10 @@
     ContinueBlock = CondBlock;  
   
   // Store the blocks to use for break and continue.
-  BreakContinuePush(AfterFor, ContinueBlock);
-  
+  // Ensure any vlas created between there and here, are undone
+  BreakContinuePush(AfterFor, ContinueBlock,
+                    saveStackDepth, saveStackDepth);
+
   // If the condition is true, execute the body of the for stmt.
   EmitStmt(S.getBody());
 
@@ -708,6 +712,9 @@
   llvm::SwitchInst *SavedSwitchInsn = SwitchInsn;
   llvm::BasicBlock *SavedCRBlock = CaseRangeBlock;
 
+  // Ensure any vlas created inside are destroyed on break.
+  llvm::Value *saveBreakStackDepth = StackDepth;
+
   // Create basic block to hold stuff that comes after switch
   // statement. We also need to create a default block now so that
   // explicit case ranges tests can have a place to jump to on
@@ -723,9 +730,14 @@
   // All break statements jump to NextBlock. If BreakContinueStack is non empty
   // then reuse last ContinueBlock.
   llvm::BasicBlock *ContinueBlock = NULL;
-  if (!BreakContinueStack.empty())
+  llvm::Value *saveContinueStackDepth = NULL;
+  if (!BreakContinueStack.empty()) {
     ContinueBlock = BreakContinueStack.back().ContinueBlock;
-  BreakContinuePush(NextBlock, ContinueBlock);
+    saveContinueStackDepth = BreakContinueStack.back().SaveContinueStackDepth;
+  }
+  // Ensure any vlas created between there and here, are undone
+  BreakContinuePush(NextBlock, ContinueBlock,
+                    saveBreakStackDepth, saveContinueStackDepth);
 
   // Emit switch body.
   EmitStmt(S.getBody());

Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.h?rev=64046&r1=64045&r2=64046&view=diff

==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.h (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.h Sat Feb  7 17:02:10 2009
@@ -156,6 +156,12 @@
   /// condition has possibly started a vla.
   void BreakContinuePush(llvm::BasicBlock *bb, llvm::BasicBlock *cb) {
     BreakContinueStack.push_back(BreakContinue(bb, cb, StackDepth,
+                                               StackDepth,
+                                               ObjCEHStack.size()));
+  }
+  void BreakContinuePush(llvm::BasicBlock *bb, llvm::BasicBlock *cb,
+                         llvm::Value *bsd, llvm::Value *csd) {
+    BreakContinueStack.push_back(BreakContinue(bb, cb, bsd, csd,
                                                ObjCEHStack.size()));
   }
 
@@ -169,13 +175,14 @@
   // of the eh stack.
   struct BreakContinue {
     BreakContinue(llvm::BasicBlock *bb, llvm::BasicBlock *cb,
-                  llvm::Value *sd, size_t ehss)
-      : BreakBlock(bb), ContinueBlock(cb), SaveStackDepth(sd),
-        EHStackSize(ehss) {}
+                  llvm::Value *bsd, llvm::Value *csd, size_t ehss)
+      : BreakBlock(bb), ContinueBlock(cb),  SaveBreakStackDepth(bsd),
+        SaveContinueStackDepth(csd), EHStackSize(ehss) {}
       
     llvm::BasicBlock *BreakBlock;
     llvm::BasicBlock *ContinueBlock;
-    llvm::Value *SaveStackDepth;
+    llvm::Value *SaveBreakStackDepth;
+    llvm::Value *SaveContinueStackDepth;
     size_t EHStackSize;
   }; 
   llvm::SmallVector<BreakContinue, 8> BreakContinueStack;