From: Vedant Kumar <vsk@apple.com>
Date: Fri, 17 Feb 2017 23:22:55 +0000 (+0000)
Subject: [ubsan] Pass a set of checks to skip to EmitTypeCheck() (NFC)
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=12792eba3f3844a8af19fe5d316cf1cc15397afe;p=clang

[ubsan] Pass a set of checks to skip to EmitTypeCheck() (NFC)

CodeGenFunction::EmitTypeCheck accepts a bool flag which controls
whether or not null checks are emitted. Make this a bit more flexible by
changing the bool to a SanitizerSet.

Needed for an upcoming change which deals with a scenario in which we
only want to emit null checks.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@295514 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index 03c3358bd8..65961db586 100644
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -309,8 +309,10 @@ Address CodeGenFunction::GetAddressOfBaseClass(
   // just do a bitcast; null checks are unnecessary.
   if (NonVirtualOffset.isZero() && !VBase) {
     if (sanitizePerformTypeCheck()) {
+      SanitizerSet SkippedChecks;
+      SkippedChecks.set(SanitizerKind::Null, !NullCheckValue);
       EmitTypeCheck(TCK_Upcast, Loc, Value.getPointer(),
-                    DerivedTy, DerivedAlign, !NullCheckValue);
+                    DerivedTy, DerivedAlign, SkippedChecks);
     }
     return Builder.CreateBitCast(Value, BasePtrTy);
   }
@@ -331,8 +333,10 @@ Address CodeGenFunction::GetAddressOfBaseClass(
   }
 
   if (sanitizePerformTypeCheck()) {
+    SanitizerSet SkippedChecks;
+    SkippedChecks.set(SanitizerKind::Null, true);
     EmitTypeCheck(VBase ? TCK_UpcastToVirtualBase : TCK_Upcast, Loc,
-                  Value.getPointer(), DerivedTy, DerivedAlign, true);
+                  Value.getPointer(), DerivedTy, DerivedAlign, SkippedChecks);
   }
 
   // Compute the virtual offset.
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index e5e34a5f3e..8661251000 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -534,7 +534,8 @@ bool CodeGenFunction::sanitizePerformTypeCheck() const {
 
 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
                                     llvm::Value *Ptr, QualType Ty,
-                                    CharUnits Alignment, bool SkipNullCheck) {
+                                    CharUnits Alignment,
+                                    SanitizerSet SkippedChecks) {
   if (!sanitizePerformTypeCheck())
     return;
 
@@ -552,7 +553,7 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
   bool AllowNullPointers = TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
                            TCK == TCK_UpcastToVirtualBase;
   if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
-      !SkipNullCheck) {
+      !SkippedChecks.has(SanitizerKind::Null)) {
     // The glvalue must not be an empty glvalue.
     llvm::Value *IsNonNull = Builder.CreateIsNotNull(Ptr);
 
@@ -568,7 +569,9 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
     }
   }
 
-  if (SanOpts.has(SanitizerKind::ObjectSize) && !Ty->isIncompleteType()) {
+  if (SanOpts.has(SanitizerKind::ObjectSize) &&
+      !SkippedChecks.has(SanitizerKind::ObjectSize) &&
+      !Ty->isIncompleteType()) {
     uint64_t Size = getContext().getTypeSizeInChars(Ty).getQuantity();
 
     // The glvalue must refer to a large enough storage region.
@@ -587,7 +590,8 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
 
   uint64_t AlignVal = 0;
 
-  if (SanOpts.has(SanitizerKind::Alignment)) {
+  if (SanOpts.has(SanitizerKind::Alignment) &&
+      !SkippedChecks.has(SanitizerKind::Alignment)) {
     AlignVal = Alignment.getQuantity();
     if (!Ty->isIncompleteType() && !AlignVal)
       AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
@@ -624,6 +628,7 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
   //       or call a non-static member function
   CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
   if (SanOpts.has(SanitizerKind::Vptr) &&
+      !SkippedChecks.has(SanitizerKind::Vptr) &&
       (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
        TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
        TCK == TCK_UpcastToVirtualBase) &&
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index b830df73ca..09f1763850 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -2252,7 +2252,7 @@ public:
   /// appropriate size and alignment for an object of type \p Type.
   void EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc, llvm::Value *V,
                      QualType Type, CharUnits Alignment = CharUnits::Zero(),
-                     bool SkipNullCheck = false);
+                     SanitizerSet SkippedChecks = SanitizerSet());
 
   /// \brief Emit a check that \p Base points into an array object, which
   /// we can access at index \p Index. \p Accessed should be \c false if we