boga95 updated this revision to Diff 193175.
boga95 marked an inline comment as done.
boga95 added a comment.

Rebase after https://reviews.llvm.org/D59861.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D59555/new/

https://reviews.llvm.org/D59555

Files:
  lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp

Index: lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp
===================================================================
--- lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp
+++ lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp
@@ -15,14 +15,16 @@
 //===----------------------------------------------------------------------===//
 
 #include "Taint.h"
-#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
 #include "clang/AST/Attr.h"
 #include "clang/Basic/Builtins.h"
+#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
 #include "clang/StaticAnalyzer/Core/Checker.h"
 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/Support/YAMLTraits.h"
 #include <climits>
 #include <initializer_list>
 #include <utility>
@@ -47,11 +49,38 @@
   void printState(raw_ostream &Out, ProgramStateRef State,
                   const char *NL, const char *Sep) const override;
 
-private:
+  using ArgVector = SmallVector<unsigned, 2>;
+
+  enum class VariadicType { None, Src, Dst };
+
+  /// The ``TaintConfiguration`` is used to parse configuration file.
+  struct TaintConfiguration {
+    using NameArgsPair = std::pair<std::string, ArgVector>;
+
+    struct Propagation {
+      std::string Name;
+      ArgVector SrcArgs;
+      ArgVector DstArgs;
+      VariadicType VarType;
+      unsigned VarIndex;
+    };
+
+    std::vector<Propagation> Propagations;
+    std::vector<NameArgsPair> Filters;
+    std::vector<NameArgsPair> Sinks;
+  };
+
+  /// Get and read the config file.
+  static void getConfiguration(StringRef ConfigFile);
+
+  /// Parse the config.
+  static void parseConfiguration(TaintConfiguration &&Config);
+
   static const unsigned InvalidArgIndex = UINT_MAX;
   /// Denotes the return vale.
   static const unsigned ReturnValueIndex = UINT_MAX - 1;
 
+private:
   mutable std::unique_ptr<BugType> BT;
   void initBugType() const {
     if (!BT)
@@ -97,8 +126,6 @@
   bool generateReportIfTainted(const Expr *E, const char Msg[],
                                CheckerContext &C) const;
 
-  using ArgVector = SmallVector<unsigned, 2>;
-
   /// A struct used to specify taint propagation rules for a function.
   ///
   /// If any of the possible taint source arguments is tainted, all of the
@@ -109,8 +136,6 @@
   /// ReturnValueIndex is added to the dst list, the return value will be
   /// tainted.
   struct TaintPropagationRule {
-    enum class VariadicType { None, Src, Dst };
-
     using PropagationFuncType = bool (*)(bool IsTainted, const CallExpr *,
                                          CheckerContext &C);
 
@@ -131,8 +156,7 @@
         : VariadicIndex(InvalidArgIndex), VarType(VariadicType::None),
           PropagationFunc(nullptr) {}
 
-    TaintPropagationRule(std::initializer_list<unsigned> &&Src,
-                         std::initializer_list<unsigned> &&Dst,
+    TaintPropagationRule(ArgVector &&Src, ArgVector &&Dst,
                          VariadicType Var = VariadicType::None,
                          unsigned VarIndex = InvalidArgIndex,
                          PropagationFuncType Func = nullptr)
@@ -176,6 +200,19 @@
     static bool postSocket(bool IsTainted, const CallExpr *CE,
                            CheckerContext &C);
   };
+
+  using NameRuleMap = llvm::StringMap<TaintPropagationRule>;
+  using NameArgMap = llvm::StringMap<ArgVector>;
+
+  /// Defines a map between the propagation function's name and
+  /// TaintPropagationRule.
+  static NameRuleMap CustomPropagations;
+
+  /// Defines a map between the filter function's name and filtering args.
+  static NameArgMap CustomFilters;
+
+  /// Defines a map between the sink function's name and sinking args.
+  static NameArgMap CustomSinks;
 };
 
 const unsigned GenericTaintChecker::ReturnValueIndex;
@@ -194,14 +231,105 @@
     "(CERT/STR31-C. Guarantee that storage for strings has sufficient space "
     "for character data and the null terminator)";
 
+GenericTaintChecker::NameRuleMap GenericTaintChecker::CustomPropagations;
+
+GenericTaintChecker::NameArgMap GenericTaintChecker::CustomFilters;
+
+GenericTaintChecker::NameArgMap GenericTaintChecker::CustomSinks;
 } // end of anonymous namespace
 
+using TaintConfig = GenericTaintChecker::TaintConfiguration;
+
+LLVM_YAML_IS_SEQUENCE_VECTOR(TaintConfig::Propagation)
+LLVM_YAML_IS_SEQUENCE_VECTOR(TaintConfig::NameArgsPair)
+
+namespace llvm {
+namespace yaml {
+template <> struct MappingTraits<TaintConfig> {
+  static void mapping(IO &IO, TaintConfig &Config) {
+    IO.mapOptional("Propagations", Config.Propagations);
+    IO.mapOptional("Filters", Config.Filters);
+    IO.mapOptional("Sinks", Config.Sinks);
+  }
+};
+
+template <> struct MappingTraits<TaintConfig::Propagation> {
+  static void mapping(IO &IO, TaintConfig::Propagation &Propagation) {
+    IO.mapRequired("Name", Propagation.Name);
+    IO.mapOptional("SrcArgs", Propagation.SrcArgs);
+    IO.mapRequired("DstArgs", Propagation.DstArgs);
+    IO.mapOptional("VarType", Propagation.VarType,
+                   GenericTaintChecker::VariadicType::None);
+    IO.mapOptional("VarIndex", Propagation.VarIndex,
+                   GenericTaintChecker::InvalidArgIndex);
+  }
+};
+
+template <> struct ScalarEnumerationTraits<GenericTaintChecker::VariadicType> {
+  static void enumeration(IO &IO, GenericTaintChecker::VariadicType &Value) {
+    IO.enumCase(Value, "None", GenericTaintChecker::VariadicType::None);
+    IO.enumCase(Value, "Src", GenericTaintChecker::VariadicType::Src);
+    IO.enumCase(Value, "Dst", GenericTaintChecker::VariadicType::Dst);
+  }
+};
+
+template <> struct MappingTraits<TaintConfig::NameArgsPair> {
+  static void mapping(IO &IO, TaintConfig::NameArgsPair &NameArg) {
+    IO.mapRequired("Name", NameArg.first);
+    IO.mapRequired("Args", NameArg.second);
+  }
+};
+} // namespace yaml
+} // namespace llvm
+
 /// A set which is used to pass information from call pre-visit instruction
 /// to the call post-visit. The values are unsigned integers, which are either
 /// ReturnValueIndex, or indexes of the pointer/reference argument, which
 /// points to data, which should be tainted on return.
 REGISTER_SET_WITH_PROGRAMSTATE(TaintArgsOnPostVisit, unsigned)
 
+void GenericTaintChecker::getConfiguration(StringRef ConfigFile) {
+  if (ConfigFile.trim().empty())
+    return;
+
+  llvm::vfs::FileSystem *FS = llvm::vfs::getRealFileSystem().get();
+  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Buffer =
+      FS->getBufferForFile(ConfigFile.str());
+
+  if (std::error_code ec = Buffer.getError()) {
+    llvm::errs() << "Error when getting TaintPropagation's config file '"
+                 << ConfigFile << "': " << ec.message() << '\n';
+    return;
+  }
+
+  llvm::yaml::Input Input(Buffer.get()->getBuffer());
+  TaintConfiguration Config;
+  Input >> Config;
+
+  if (std::error_code ec = Input.error()) {
+    return;
+  }
+
+  parseConfiguration(std::move(Config));
+}
+
+void GenericTaintChecker::parseConfiguration(TaintConfiguration &&Config) {
+  for (auto &P : Config.Propagations) {
+    GenericTaintChecker::CustomPropagations.try_emplace(
+        P.Name, std::move(P.SrcArgs), std::move(P.DstArgs), P.VarType,
+        P.VarIndex);
+  }
+
+  for (auto &F : Config.Filters) {
+    GenericTaintChecker::CustomFilters.try_emplace(F.first,
+                                                   std::move(F.second));
+  }
+
+  for (auto &S : Config.Sinks) {
+    GenericTaintChecker::CustomSinks.try_emplace(S.first, std::move(S.second));
+  }
+}
+
 GenericTaintChecker::TaintPropagationRule
 GenericTaintChecker::TaintPropagationRule::getTaintPropagationRule(
     const FunctionDecl *FDecl, StringRef Name, CheckerContext &C) {
@@ -218,7 +346,8 @@
           .Case("freopen", TaintPropagationRule({}, {ReturnValueIndex}))
           .Case("getch", TaintPropagationRule({}, {ReturnValueIndex}))
           .Case("getchar", TaintPropagationRule({}, {ReturnValueIndex}))
-          .Case("getchar_unlocked", TaintPropagationRule({}, {ReturnValueIndex}))
+          .Case("getchar_unlocked",
+                TaintPropagationRule({}, {ReturnValueIndex}))
           .Case("getenv", TaintPropagationRule({}, {ReturnValueIndex}))
           .Case("gets", TaintPropagationRule({}, {0, ReturnValueIndex}))
           .Case("scanf", TaintPropagationRule({}, {}, VariadicType::Dst, 1))
@@ -454,7 +583,7 @@
   // Check for taint in variadic arguments.
   if (!IsTainted && VariadicType::Src == VarType) {
     // Check if any of the arguments is tainted
-    for (unsigned int i = VariadicIndex; i < CE->getNumArgs(); ++i) {
+    for (unsigned i = VariadicIndex; i < CE->getNumArgs(); ++i) {
       if ((IsTainted = isTaintedOrPointsToTainted(CE->getArg(i), State, C)))
         break;
     }
@@ -485,7 +614,7 @@
     //   If they are not pointing to const data, mark data as tainted.
     //   TODO: So far we are just going one level down; ideally we'd need to
     //         recurse here.
-    for (unsigned int i = VariadicIndex; i < CE->getNumArgs(); ++i) {
+    for (unsigned i = VariadicIndex; i < CE->getNumArgs(); ++i) {
       const Expr *Arg = CE->getArg(i);
       // Process pointer argument.
       const Type *ArgTy = Arg->getType().getTypePtr();
@@ -550,7 +679,7 @@
 
 static bool getPrintfFormatArgumentNum(const CallExpr *CE,
                                        const CheckerContext &C,
-                                       unsigned int &ArgNum) {
+                                       unsigned &ArgNum) {
   // Find if the function contains a format string argument.
   // Handles: fprintf, printf, sprintf, snprintf, vfprintf, vprintf, vsprintf,
   // vsnprintf, syslog, custom annotated functions.
@@ -603,7 +732,7 @@
 bool GenericTaintChecker::checkUncontrolledFormatString(
     const CallExpr *CE, CheckerContext &C) const {
   // Check if the function contains a format string argument.
-  unsigned int ArgNum = 0;
+  unsigned ArgNum = 0;
   if (!getPrintfFormatArgumentNum(CE, C, ArgNum))
     return false;
 
@@ -677,7 +806,10 @@
 }
 
 void ento::registerGenericTaintChecker(CheckerManager &mgr) {
-  mgr.registerChecker<GenericTaintChecker>();
+  const auto *Checker = mgr.registerChecker<GenericTaintChecker>();
+  StringRef ConfigFile =
+      mgr.getAnalyzerOptions().getCheckerStringOption(Checker, "Config", "");
+  GenericTaintChecker::getConfiguration(ConfigFile);
 }
 
 bool ento::shouldRegisterGenericTaintChecker(const LangOptions &LO) {
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