From b7dd329f2f3ffdb8a1e5ec31e87e94a6038c2073 Mon Sep 17 00:00:00 2001
From: Alexey Samsonov <vonosmas@gmail.com>
Date: Wed, 9 Jul 2014 19:40:08 +0000
Subject: Decouple llvm::SpecialCaseList text representation and its LLVM IR
 semantics.

Turn llvm::SpecialCaseList into a simple class that parses text files in
a specified format and knows nothing about LLVM IR. Move this class into
LLVMSupport library. Implement two users of this class:
  * DFSanABIList in DFSan instrumentation pass.
  * SanitizerBlacklist in Clang CodeGen library.
The latter will be modified to use actual source-level information from frontend
(source file names) instead of unstable LLVM IR things (LLVM Module identifier).

Remove dependency edge from ClangCodeGen/ClangDriver to LLVMTransformUtils.

No functionality change.

llvm-svn: 212643
---
 .../Instrumentation/DataFlowSanitizer.cpp          | 61 +++++++++++++++++++---
 1 file changed, 53 insertions(+), 8 deletions(-)

(limited to 'llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp')

diff --git a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
index 7f468f7..3b9212a 100644
--- a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
@@ -59,9 +59,9 @@
 #include "llvm/IR/Value.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/SpecialCaseList.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Transforms/Utils/SpecialCaseList.h"
 #include <iterator>
 
 using namespace llvm;
@@ -120,6 +120,51 @@ static cl::opt<bool> ClDebugNonzeroLabels(
 
 namespace {
 
+StringRef GetGlobalTypeString(const GlobalValue &G) {
+  // Types of GlobalVariables are always pointer types.
+  Type *GType = G.getType()->getElementType();
+  // For now we support blacklisting struct types only.
+  if (StructType *SGType = dyn_cast<StructType>(GType)) {
+    if (!SGType->isLiteral())
+      return SGType->getName();
+  }
+  return "<unknown type>";
+}
+
+class DFSanABIList {
+  std::unique_ptr<SpecialCaseList> SCL;
+
+ public:
+  DFSanABIList(SpecialCaseList *SCL) : SCL(SCL) {}
+
+  /// Returns whether either this function or its source file are listed in the
+  /// given category.
+  bool isIn(const Function &F, const StringRef Category) const {
+    return isIn(*F.getParent(), Category) ||
+           SCL->inSection("fun", F.getName(), Category);
+  }
+
+  /// Returns whether this global alias is listed in the given category.
+  ///
+  /// If GA aliases a function, the alias's name is matched as a function name
+  /// would be.  Similarly, aliases of globals are matched like globals.
+  bool isIn(const GlobalAlias &GA, const StringRef Category) const {
+    if (isIn(*GA.getParent(), Category))
+      return true;
+
+    if (isa<FunctionType>(GA.getType()->getElementType()))
+      return SCL->inSection("fun", GA.getName(), Category);
+
+    return SCL->inSection("global", GA.getName(), Category) ||
+           SCL->inSection("type", GetGlobalTypeString(GA), Category);
+  }
+
+  /// Returns whether this module is listed in the given category.
+  bool isIn(const Module &M, const StringRef Category) const {
+    return SCL->inSection("src", M.getModuleIdentifier(), Category);
+  }
+};
+
 class DataFlowSanitizer : public ModulePass {
   friend struct DFSanFunction;
   friend class DFSanVisitor;
@@ -190,7 +235,7 @@ class DataFlowSanitizer : public ModulePass {
   Constant *DFSanSetLabelFn;
   Constant *DFSanNonzeroLabelFn;
   MDNode *ColdCallWeights;
-  std::unique_ptr<SpecialCaseList> ABIList;
+  DFSanABIList ABIList;
   DenseMap<Value *, Function *> UnwrappedFnMap;
   AttributeSet ReadOnlyNoneAttrs;
 
@@ -395,11 +440,11 @@ bool DataFlowSanitizer::doInitialization(Module &M) {
 }
 
 bool DataFlowSanitizer::isInstrumented(const Function *F) {
-  return !ABIList->isIn(*F, "uninstrumented");
+  return !ABIList.isIn(*F, "uninstrumented");
 }
 
 bool DataFlowSanitizer::isInstrumented(const GlobalAlias *GA) {
-  return !ABIList->isIn(*GA, "uninstrumented");
+  return !ABIList.isIn(*GA, "uninstrumented");
 }
 
 DataFlowSanitizer::InstrumentedABI DataFlowSanitizer::getInstrumentedABI() {
@@ -407,11 +452,11 @@ DataFlowSanitizer::InstrumentedABI DataFlowSanitizer::getInstrumentedABI() {
 }
 
 DataFlowSanitizer::WrapperKind DataFlowSanitizer::getWrapperKind(Function *F) {
-  if (ABIList->isIn(*F, "functional"))
+  if (ABIList.isIn(*F, "functional"))
     return WK_Functional;
-  if (ABIList->isIn(*F, "discard"))
+  if (ABIList.isIn(*F, "discard"))
     return WK_Discard;
-  if (ABIList->isIn(*F, "custom"))
+  if (ABIList.isIn(*F, "custom"))
     return WK_Custom;
 
   return WK_Warning;
@@ -500,7 +545,7 @@ bool DataFlowSanitizer::runOnModule(Module &M) {
   if (!DL)
     return false;
 
-  if (ABIList->isIn(M, "skip"))
+  if (ABIList.isIn(M, "skip"))
     return false;
 
   if (!GetArgTLSPtr) {
-- 
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