Bundle conditions checked by UBSan with sanitizer kinds they implement.

Summary:
This change makes CodeGenFunction::EmitCheck() take several
conditions that needs to be checked (all of them need to be true),
together with sanitizer kinds these checks are for. This would allow
to split one call into UBSan runtime into several calls in case
different sanitizer kinds would have different recoverability
settings.

Tests should be fixed accordingly, I'm working on it.

Test Plan: regression test suite.

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D6219

llvm-svn: 221716

1 files changed, 33 insertions, 34 deletions

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 877323bf926..0b8caa1e11a 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -476,10 +476,9 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
   if (Address->getType()->getPointerAddressSpace())
     return;
 
-  SmallVector<SanitizerKind, 3> Kinds;
   SanitizerScope SanScope(this);
 
-  llvm::Value *Cond = nullptr;
+  SmallVector<std::pair<llvm::Value *, SanitizerKind>, 3> Checks;
   llvm::BasicBlock *Done = nullptr;
 
   bool AllowNullPointers = TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
@@ -487,7 +486,7 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
   if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
       !SkipNullCheck) {
     // The glvalue must not be an empty glvalue.
-    Cond = Builder.CreateICmpNE(
+    llvm::Value *IsNonNull = Builder.CreateICmpNE(
         Address, llvm::Constant::getNullValue(Address->getType()));
 
     if (AllowNullPointers) {
@@ -495,11 +494,10 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
       // Skip the remaining checks in that case.
       Done = createBasicBlock("null");
       llvm::BasicBlock *Rest = createBasicBlock("not.null");
-      Builder.CreateCondBr(Cond, Rest, Done);
+      Builder.CreateCondBr(IsNonNull, Rest, Done);
       EmitBlock(Rest);
-      Cond = nullptr;
     } else {
-      Kinds.push_back(SanitizerKind::Null);
+      Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
     }
   }
 
@@ -517,8 +515,7 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
     llvm::Value *LargeEnough =
         Builder.CreateICmpUGE(Builder.CreateCall2(F, CastAddr, Min),
                               llvm::ConstantInt::get(IntPtrTy, Size));
-    Cond = Cond ? Builder.CreateAnd(Cond, LargeEnough) : LargeEnough;
-    Kinds.push_back(SanitizerKind::ObjectSize);
+    Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
   }
 
   uint64_t AlignVal = 0;
@@ -535,19 +532,18 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
                             llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
       llvm::Value *Aligned =
         Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
-      Cond = Cond ? Builder.CreateAnd(Cond, Aligned) : Aligned;
-      Kinds.push_back(SanitizerKind::Alignment);
+      Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
     }
   }
 
-  if (Cond) {
+  if (Checks.size() > 0) {
     llvm::Constant *StaticData[] = {
       EmitCheckSourceLocation(Loc),
       EmitCheckTypeDescriptor(Ty),
       llvm::ConstantInt::get(SizeTy, AlignVal),
       llvm::ConstantInt::get(Int8Ty, TCK)
     };
-    EmitCheck(Cond, "type_mismatch", StaticData, Address, Kinds);
+    EmitCheck(Checks, "type_mismatch", StaticData, Address);
   }
 
   // If possible, check that the vptr indicates that there is a subobject of
@@ -605,6 +601,7 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
       // hard work of checking whether the vptr is for an object of the right
       // type. This will either fill in the cache and return, or produce a
       // diagnostic.
+      llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
       llvm::Constant *StaticData[] = {
         EmitCheckSourceLocation(Loc),
         EmitCheckTypeDescriptor(Ty),
@@ -612,8 +609,8 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
         llvm::ConstantInt::get(Int8Ty, TCK)
       };
       llvm::Value *DynamicData[] = { Address, Hash };
-      EmitCheck(Builder.CreateICmpEQ(CacheVal, Hash), "dynamic_type_cache_miss",
-                StaticData, DynamicData, SanitizerKind::Vptr);
+      EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
+                "dynamic_type_cache_miss", StaticData, DynamicData);
     }
   }
 
@@ -701,8 +698,8 @@ void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
   };
   llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
                                 : Builder.CreateICmpULE(IndexVal, BoundVal);
-  EmitCheck(Check, "out_of_bounds", StaticData, Index,
-            SanitizerKind::ArrayBounds);
+  EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds), "out_of_bounds",
+            StaticData, Index);
 }
 
 
@@ -1181,8 +1178,9 @@ llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
         EmitCheckSourceLocation(Loc),
         EmitCheckTypeDescriptor(Ty)
       };
-      EmitCheck(Check, "load_invalid_value", StaticArgs, EmitCheckValue(Load),
-                NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool);
+      SanitizerKind Kind = NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
+      EmitCheck(std::make_pair(Check, Kind), "load_invalid_value", StaticArgs,
+                EmitCheckValue(Load));
     }
   } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
     if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
@@ -2221,32 +2219,33 @@ static CheckRecoverableKind getRecoverableKind(SanitizerKind Kind) {
   }
 }
 
-void CodeGenFunction::EmitCheck(llvm::Value *Checked, StringRef CheckName,
-                                ArrayRef<llvm::Constant *> StaticArgs,
-                                ArrayRef<llvm::Value *> DynamicArgs,
-                                ArrayRef<SanitizerKind> Kinds) {
+void CodeGenFunction::EmitCheck(
+    ArrayRef<std::pair<llvm::Value *, SanitizerKind>> Checked,
+    StringRef CheckName, ArrayRef<llvm::Constant *> StaticArgs,
+    ArrayRef<llvm::Value *> DynamicArgs) {
   assert(IsSanitizerScope);
-  assert(Kinds.size() > 0);
-  CheckRecoverableKind RecoverKind = getRecoverableKind(Kinds[0]);
-  for (int i = 1, n = Kinds.size(); i < n; ++i)
-    assert(RecoverKind == getRecoverableKind(Kinds[i]) &&
+  assert(Checked.size() > 0);
+  llvm::Value *Cond = Checked[0].first;
+  CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
+  assert(SanOpts.has(Checked[0].second));
+  for (int i = 1, n = Checked.size(); i < n; ++i) {
+    Cond = Builder.CreateAnd(Cond, Checked[i].first);
+    assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
            "All recoverable kinds in a single check must be same!");
-#ifndef NDEBUG
-  for (auto Kind : Kinds)
-    assert(SanOpts.has(Kind));
-#endif
+    assert(SanOpts.has(Checked[i].second));
+  }
 
   if (CGM.getCodeGenOpts().SanitizeUndefinedTrapOnError) {
     assert (RecoverKind != CheckRecoverableKind::AlwaysRecoverable &&
             "Runtime call required for AlwaysRecoverable kind!");
-    return EmitTrapCheck(Checked);
+    return EmitTrapCheck(Cond);
   }
 
   llvm::BasicBlock *Cont = createBasicBlock("cont");
 
   llvm::BasicBlock *Handler = createBasicBlock("handler." + CheckName);
 
-  llvm::Instruction *Branch = Builder.CreateCondBr(Checked, Cont, Handler);
+  llvm::Instruction *Branch = Builder.CreateCondBr(Cond, Cont, Handler);
 
   // Give hint that we very much don't expect to execute the handler
   // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
@@ -3321,8 +3320,8 @@ RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
         EmitCheckSourceLocation(E->getLocStart()),
         EmitCheckTypeDescriptor(CalleeType)
       };
-      EmitCheck(CalleeRTTIMatch, "function_type_mismatch", StaticData, Callee,
-                SanitizerKind::Function);
+      EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
+                "function_type_mismatch", StaticData, Callee);
 
       Builder.CreateBr(Cont);
       EmitBlock(Cont);