Implement stack protectors for structures with character arrays in them.
<rdar://problem/10545247>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162131 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/StackProtector.cpp b/lib/CodeGen/StackProtector.cpp
index f1eab1f..b31db5f 100644
--- a/lib/CodeGen/StackProtector.cpp
+++ b/lib/CodeGen/StackProtector.cpp
@@ -61,6 +61,11 @@
/// check fails.
BasicBlock *CreateFailBB();
+ /// ContainsProtectableArray - Check whether the type either is an array or
+ /// contains an array of sufficient size so that we need stack protectors
+ /// for it.
+ bool ContainsProtectableArray(Type *Ty, bool InStruct = false) const;
+
/// RequiresStackProtector - Check whether or not this function needs a
/// stack protector based upon the stack protector level.
bool RequiresStackProtector() const;
@@ -100,6 +105,39 @@
return InsertStackProtectors();
}
+/// ContainsProtectableArray - Check whether the type either is an array or
+/// contains a char array of sufficient size so that we need stack protectors
+/// for it.
+bool StackProtector::ContainsProtectableArray(Type *Ty, bool InStruct) const {
+ if (!Ty) return false;
+ if (ArrayType *AT = dyn_cast<ArrayType>(Ty)) {
+ if (!AT->getElementType()->isIntegerTy(8)) {
+ const TargetMachine &TM = TLI->getTargetMachine();
+ Triple Trip(TM.getTargetTriple());
+
+ // If we're on a non-Darwin platform or we're inside of a structure, don't
+ // add stack protectors unless the array is a character array.
+ if (InStruct || !Trip.isOSDarwin())
+ return false;
+ }
+
+ // If an array has more than SSPBufferSize bytes of allocated space, then we
+ // emit stack protectors.
+ if (SSPBufferSize <= TLI->getTargetData()->getTypeAllocSize(AT))
+ return true;
+ }
+
+ const StructType *ST = dyn_cast<StructType>(Ty);
+ if (!ST) return false;
+
+ for (StructType::element_iterator I = ST->element_begin(),
+ E = ST->element_end(); I != E; ++I)
+ if (ContainsProtectableArray(*I, true))
+ return true;
+
+ return false;
+}
+
/// RequiresStackProtector - Check whether or not this function needs a stack
/// protector based upon the stack protector level. The heuristic we use is to
/// add a guard variable to functions that call alloca, and functions with
@@ -111,10 +149,6 @@
if (!F->hasFnAttr(Attribute::StackProtect))
return false;
- const TargetData *TD = TLI->getTargetData();
- const TargetMachine &TM = TLI->getTargetMachine();
- Triple Trip(TM.getTargetTriple());
-
for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
BasicBlock *BB = I;
@@ -126,17 +160,8 @@
// protectors.
return true;
- if (ArrayType *AT = dyn_cast<ArrayType>(AI->getAllocatedType())) {
- // If we're on a non-Darwin platform, don't add stack protectors
- // unless the array is a character array.
- if (!Trip.isOSDarwin() && !AT->getElementType()->isIntegerTy(8))
- continue;
-
- // If an array has more than SSPBufferSize bytes of allocated space,
- // then we emit stack protectors.
- if (SSPBufferSize <= TD->getTypeAllocSize(AT))
- return true;
- }
+ if (ContainsProtectableArray(AI->getAllocatedType()))
+ return true;
}
}