[cfe-commits] r166992 - in /cfe/trunk: lib/CodeGen/CGExpr.cpp test/CodeGen/atomic-ops.c

[Eli Friedman]

Author: efriedma
Date: Mon Oct 29 20:15:28 2012
New Revision: 166992

URL: http://llvm.org/viewvc/llvm-project?rev=166992&view=rev
Log:
Don't crash on bad atomic operations.  PR14176.


Modified:
    cfe/trunk/lib/CodeGen/CGExpr.cpp
    cfe/trunk/test/CodeGen/atomic-ops.c

Modified: cfe/trunk/lib/CodeGen/CGExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExpr.cpp?rev=166992&r1=166991&r2=166992&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExpr.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExpr.cpp Mon Oct 29 20:15:28 2012
@@ -3362,6 +3362,13 @@
     return ConvertTempToRValue(*this, E->getType(), Dest);
   }
 
+  bool IsStore = E->getOp() == AtomicExpr::AO__c11_atomic_store ||
+                 E->getOp() == AtomicExpr::AO__atomic_store ||
+                 E->getOp() == AtomicExpr::AO__atomic_store_n;
+  bool IsLoad = E->getOp() == AtomicExpr::AO__c11_atomic_load ||
+                E->getOp() == AtomicExpr::AO__atomic_load ||
+                E->getOp() == AtomicExpr::AO__atomic_load_n;
+
   llvm::Type *IPtrTy =
       llvm::IntegerType::get(getLLVMContext(), Size * 8)->getPointerTo();
   llvm::Value *OrigDest = Dest;
@@ -3379,14 +3386,20 @@
       break;
     case 1:  // memory_order_consume
     case 2:  // memory_order_acquire
+      if (IsStore)
+        break; // Avoid crashing on code with undefined behavior
       EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align,
                    llvm::Acquire);
       break;
     case 3:  // memory_order_release
+      if (IsLoad)
+        break; // Avoid crashing on code with undefined behavior
       EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align,
                    llvm::Release);
       break;
     case 4:  // memory_order_acq_rel
+      if (IsLoad || IsStore)
+        break; // Avoid crashing on code with undefined behavior
       EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align,
                    llvm::AcquireRelease);
       break;
@@ -3406,13 +3419,6 @@
 
   // Long case, when Order isn't obviously constant.
 
-  bool IsStore = E->getOp() == AtomicExpr::AO__c11_atomic_store ||
-                 E->getOp() == AtomicExpr::AO__atomic_store ||
-                 E->getOp() == AtomicExpr::AO__atomic_store_n;
-  bool IsLoad = E->getOp() == AtomicExpr::AO__c11_atomic_load ||
-                E->getOp() == AtomicExpr::AO__atomic_load ||
-                E->getOp() == AtomicExpr::AO__atomic_load_n;
-
   // Create all the relevant BB's
   llvm::BasicBlock *MonotonicBB = 0, *AcquireBB = 0, *ReleaseBB = 0,
                    *AcqRelBB = 0, *SeqCstBB = 0;

Modified: cfe/trunk/test/CodeGen/atomic-ops.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/atomic-ops.c?rev=166992&r1=166991&r2=166992&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/atomic-ops.c (original)
+++ cfe/trunk/test/CodeGen/atomic-ops.c Mon Oct 29 20:15:28 2012
@@ -311,4 +311,13 @@
   // CHECK: }
 }
 
+// CHECK: @invalid_atomic
+void invalid_atomic(_Atomic(int) *i) {
+  __c11_atomic_store(i, 1, memory_order_consume);
+  __c11_atomic_store(i, 1, memory_order_acquire);
+  __c11_atomic_store(i, 1, memory_order_acq_rel);
+  __c11_atomic_load(i, memory_order_release);
+  __c11_atomic_load(i, memory_order_acq_rel);
+}
+
 #endif