[clang] Version support for UBSan handlers

This adds a way for us to version any UBSan handler by itself.
The patch overrides D21289 for a better implementation (we're able to
rev up a single handler).

After this, then we can land a slight modification of D19667+D19668.

We probably don't want to keep all the versions in compiler-rt (maybe we
want to deprecate on one release and remove the old handler on the next
one?), but with this patch we will loudly fail to compile when mixing
incompatible handler calls, instead of silently compiling and then
providing bad error messages.

Reviewers: kcc, samsonov, rsmith, vsk

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D21695

llvm-svn: 289444

1 files changed, 38 insertions, 16 deletions

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index dc147a1..a35b652 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -608,7 +608,7 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
       llvm::ConstantInt::get(SizeTy, AlignVal),
       llvm::ConstantInt::get(Int8Ty, TCK)
     };
-    EmitCheck(Checks, "type_mismatch", StaticData, Ptr);
+    EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData, Ptr);
   }
 
   // If possible, check that the vptr indicates that there is a subobject of
@@ -676,7 +676,8 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
       };
       llvm::Value *DynamicData[] = { Ptr, Hash };
       EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
-                "dynamic_type_cache_miss", StaticData, DynamicData);
+                SanitizerHandler::DynamicTypeCacheMiss, StaticData,
+                DynamicData);
     }
   }
 
@@ -766,8 +767,8 @@ void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
   };
   llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
                                 : Builder.CreateICmpULE(IndexVal, BoundVal);
-  EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds), "out_of_bounds",
-            StaticData, Index);
+  EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
+            SanitizerHandler::OutOfBounds, StaticData, Index);
 }
 
 
@@ -1339,8 +1340,8 @@ llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
         EmitCheckTypeDescriptor(Ty)
       };
       SanitizerMask Kind = NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
-      EmitCheck(std::make_pair(Check, Kind), "load_invalid_value", StaticArgs,
-                EmitCheckValue(Load));
+      EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
+                StaticArgs, EmitCheckValue(Load));
     }
   } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
     if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
@@ -2500,17 +2501,35 @@ static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
   }
 }
 
+namespace {
+struct SanitizerHandlerInfo {
+  char const *const Name;
+  unsigned Version;
+};
+};
+
+const SanitizerHandlerInfo SanitizerHandlers[] = {
+#define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
+    LIST_SANITIZER_CHECKS
+#undef SANITIZER_CHECK
+};
+
 static void emitCheckHandlerCall(CodeGenFunction &CGF,
                                  llvm::FunctionType *FnType,
                                  ArrayRef<llvm::Value *> FnArgs,
-                                 StringRef CheckName,
+                                 SanitizerHandler CheckHandler,
                                  CheckRecoverableKind RecoverKind, bool IsFatal,
                                  llvm::BasicBlock *ContBB) {
   assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
   bool NeedsAbortSuffix =
       IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
-  std::string FnName = ("__ubsan_handle_" + CheckName +
-                        (NeedsAbortSuffix ? "_abort" : "")).str();
+  const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
+  const StringRef CheckName = CheckInfo.Name;
+  std::string FnName =
+      ("__ubsan_handle_" + CheckName +
+       (CheckInfo.Version ? "_v" + std::to_string(CheckInfo.Version) : "") +
+       (NeedsAbortSuffix ? "_abort" : ""))
+          .str();
   bool MayReturn =
       !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
 
@@ -2536,10 +2555,13 @@ static void emitCheckHandlerCall(CodeGenFunction &CGF,
 
 void CodeGenFunction::EmitCheck(
     ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
-    StringRef CheckName, ArrayRef<llvm::Constant *> StaticArgs,
+    SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
     ArrayRef<llvm::Value *> DynamicArgs) {
   assert(IsSanitizerScope);
   assert(Checked.size() > 0);
+  assert(CheckHandler >= 0 &&
+         CheckHandler < sizeof(SanitizerHandlers) / sizeof(*SanitizerHandlers));
+  const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
 
   llvm::Value *FatalCond = nullptr;
   llvm::Value *RecoverableCond = nullptr;
@@ -2619,7 +2641,7 @@ void CodeGenFunction::EmitCheck(
   if (!FatalCond || !RecoverableCond) {
     // Simple case: we need to generate a single handler call, either
     // fatal, or non-fatal.
-    emitCheckHandlerCall(*this, FnType, Args, CheckName, RecoverKind,
+    emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
                          (FatalCond != nullptr), Cont);
   } else {
     // Emit two handler calls: first one for set of unrecoverable checks,
@@ -2629,10 +2651,10 @@ void CodeGenFunction::EmitCheck(
     llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
     Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
     EmitBlock(FatalHandlerBB);
-    emitCheckHandlerCall(*this, FnType, Args, CheckName, RecoverKind, true,
+    emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
                          NonFatalHandlerBB);
     EmitBlock(NonFatalHandlerBB);
-    emitCheckHandlerCall(*this, FnType, Args, CheckName, RecoverKind, false,
+    emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
                          Cont);
   }
 
@@ -2757,7 +2779,7 @@ void CodeGenFunction::EmitCfiCheckFail() {
     llvm::Value *Cond =
         Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
     if (CGM.getLangOpts().Sanitize.has(Mask))
-      EmitCheck(std::make_pair(Cond, Mask), "cfi_check_fail", {},
+      EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
                 {Data, Addr, ValidVtable});
     else
       EmitTrapCheck(Cond);
@@ -4127,7 +4149,7 @@ RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee
         EmitCheckTypeDescriptor(CalleeType)
       };
       EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
-                "function_type_mismatch", StaticData, CalleePtr);
+                SanitizerHandler::FunctionTypeMismatch, StaticData, CalleePtr);
 
       Builder.CreateBr(Cont);
       EmitBlock(Cont);
@@ -4160,7 +4182,7 @@ RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee
                            CastedCallee, StaticData);
     } else {
       EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
-                "cfi_check_fail", StaticData,
+                SanitizerHandler::CFICheckFail, StaticData,
                 {CastedCallee, llvm::UndefValue::get(IntPtrTy)});
     }
   }