Implement nonnull-attribute sanitizer

Summary:
This patch implements a new UBSan check, which verifies
that function arguments declared to be nonnull with __attribute__((nonnull))
are actually nonnull in runtime.

To implement this check, we pass FunctionDecl to CodeGenFunction::EmitCallArgs
(where applicable) and if function declaration has nonnull attribute specified
for a certain formal parameter, we compare the corresponding RValue to null as
soon as it's calculated.

Test Plan: regression test suite

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: cfe-commits, rnk

Differential Revision: http://reviews.llvm.org/D5082

llvm-svn: 217389

1 files changed, 11 insertions, 12 deletions

diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp
index 937a0438ad3..a3e444a3f51 100644
--- a/clang/lib/CodeGen/CGExprCXX.cpp
+++ b/clang/lib/CodeGen/CGExprCXX.cpp
@@ -55,20 +55,18 @@ RValue CodeGenFunction::EmitCXXMemberOrOperatorCall(
 
   const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
   RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, Args.size());
-  
+
   // And the rest of the call args.
-  CallExpr::const_arg_iterator ArgBeg, ArgEnd;
-  if (CE == nullptr) {
-    ArgBeg = ArgEnd = nullptr;
-  } else if (auto OCE = dyn_cast<CXXOperatorCallExpr>(CE)) {
+  if (CE) {
     // Special case: skip first argument of CXXOperatorCall (it is "this").
-    ArgBeg = OCE->arg_begin() + 1;
-    ArgEnd = OCE->arg_end();
+    unsigned ArgsToSkip = isa<CXXOperatorCallExpr>(CE) ? 1 : 0;
+    EmitCallArgs(Args, FPT, CE->arg_begin() + ArgsToSkip, CE->arg_end(),
+                 CE->getDirectCallee());
   } else {
-    ArgBeg = CE->arg_begin();
-    ArgEnd = CE->arg_end();
+    assert(
+        FPT->getNumParams() == 0 &&
+        "No CallExpr specified for function with non-zero number of arguments");
   }
-  EmitCallArgs(Args, FPT, ArgBeg, ArgEnd);
 
   return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required),
                   Callee, ReturnValue, Args, MD);
@@ -284,7 +282,7 @@ CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
   RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, 1);
   
   // And the rest of the call args
-  EmitCallArgs(Args, FPT, E->arg_begin(), E->arg_end());
+  EmitCallArgs(Args, FPT, E->arg_begin(), E->arg_end(), E->getDirectCallee());
   return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required),
                   Callee, ReturnValue, Args);
 }
@@ -1238,7 +1236,8 @@ llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
   // We start at 1 here because the first argument (the allocation size)
   // has already been emitted.
   EmitCallArgs(allocatorArgs, allocatorType, E->placement_arg_begin(),
-               E->placement_arg_end(), /*ParamsToSkip*/ 1);
+               E->placement_arg_end(), /* CalleeDecl */ nullptr,
+               /*ParamsToSkip*/ 1);
 
   // Emit the allocation call.  If the allocator is a global placement
   // operator, just "inline" it directly.