[analyzer] CStringChecker.cpp - Code refactoring on bug report.

Reviewers: NoQ, george.karpenkov, xazax.hun

Reviewed By: george.karpenkov	

Differential Revision: https://reviews.llvm.org/D44557

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@330589 91177308-0d34-0410-b5e6-96231b3b80d8

lib/StaticAnalyzer/Checkers/CStringChecker.cpp

@@ -194,6 +194,14 @@ public:
                       const Stmt *First,
                       const Stmt *Second) const;
 
+  void emitNullArgBug(CheckerContext &C, ProgramStateRef State, const Stmt *S,
+                      StringRef WarningMsg) const;
+  void emitOutOfBoundsBug(CheckerContext &C, ProgramStateRef State,
+                          const Stmt *S, StringRef WarningMsg) const;
+  void emitNotCStringBug(CheckerContext &C, ProgramStateRef State,
+                         const Stmt *S, StringRef WarningMsg) const;
+  void emitAdditionOverflowBug(CheckerContext &C, ProgramStateRef State) const;
+
   ProgramStateRef checkAdditionOverflow(CheckerContext &C,
                                             ProgramStateRef state,
                                             NonLoc left,
@@ -239,30 +247,14 @@ ProgramStateRef CStringChecker::checkNonNull(CheckerContext &C,
   std::tie(stateNull, stateNonNull) = assumeZero(C, state, l, S->getType());
 
   if (stateNull && !stateNonNull) {
-    if (!Filter.CheckCStringNullArg)
-      return nullptr;
-
-    ExplodedNode *N = C.generateErrorNode(stateNull);
-    if (!N)
-      return nullptr;
-
-    if (!BT_Null)
-      BT_Null.reset(new BuiltinBug(
-          Filter.CheckNameCStringNullArg, categories::UnixAPI,
-          "Null pointer argument in call to byte string function"));
-
-    SmallString<80> buf;
-    llvm::raw_svector_ostream os(buf);
-    assert(CurrentFunctionDescription);
-    os << "Null pointer argument in call to " << CurrentFunctionDescription;
-
-    // Generate a report for this bug.
-    BuiltinBug *BT = static_cast<BuiltinBug*>(BT_Null.get());
-    auto report = llvm::make_unique<BugReport>(*BT, os.str(), N);
+    if (Filter.CheckCStringNullArg) {
+      SmallString<80> buf;
+      llvm::raw_svector_ostream os(buf);
+      assert(CurrentFunctionDescription);
+      os << "Null pointer argument in call to " << CurrentFunctionDescription;
 
-    report->addRange(S->getSourceRange());
-    bugreporter::trackNullOrUndefValue(N, S, *report);
-    C.emitReport(std::move(report));
+      emitNullArgBug(C, stateNull, S, os.str());
+    }
     return nullptr;
   }
 
@@ -305,31 +297,14 @@ ProgramStateRef CStringChecker::CheckLocation(CheckerContext &C,
   ProgramStateRef StInBound = state->assumeInBound(Idx, Size, true);
   ProgramStateRef StOutBound = state->assumeInBound(Idx, Size, false);
   if (StOutBound && !StInBound) {
-    ExplodedNode *N = C.generateErrorNode(StOutBound);
-    if (!N)
-      return nullptr;
-
-    CheckName Name;
     // These checks are either enabled by the CString out-of-bounds checker
     // explicitly or the "basic" CStringNullArg checker support that Malloc
     // checker enables.
     assert(Filter.CheckCStringOutOfBounds || Filter.CheckCStringNullArg);
-    if (Filter.CheckCStringOutOfBounds)
-      Name = Filter.CheckNameCStringOutOfBounds;
-    else
-      Name = Filter.CheckNameCStringNullArg;
 
-    if (!BT_Bounds) {
-      BT_Bounds.reset(new BuiltinBug(
-          Name, "Out-of-bound array access",
-          "Byte string function accesses out-of-bound array element"));
-    }
-    BuiltinBug *BT = static_cast<BuiltinBug*>(BT_Bounds.get());
-
-    // Generate a report for this bug.
-    std::unique_ptr<BugReport> report;
+    // Emit a bug report.
     if (warningMsg) {
-      report = llvm::make_unique<BugReport>(*BT, warningMsg, N);
+      emitOutOfBoundsBug(C, StOutBound, S, warningMsg);
     } else {
       assert(CurrentFunctionDescription);
       assert(CurrentFunctionDescription[0] != '\0');
@@ -339,15 +314,8 @@ ProgramStateRef CStringChecker::CheckLocation(CheckerContext &C,
       os << toUppercase(CurrentFunctionDescription[0])
          << &CurrentFunctionDescription[1]
          << " accesses out-of-bound array element";
-      report = llvm::make_unique<BugReport>(*BT, os.str(), N);
+      emitOutOfBoundsBug(C, StOutBound, S, os.str());
     }
-
-    // FIXME: It would be nice to eventually make this diagnostic more clear,
-    // e.g., by referencing the original declaration or by saying *why* this
-    // reference is outside the range.
-
-    report->addRange(S->getSourceRange());
-    C.emitReport(std::move(report));
     return nullptr;
   }
 
@@ -567,6 +535,79 @@ void CStringChecker::emitOverlapBug(CheckerContext &C, ProgramStateRef state,
   C.emitReport(std::move(report));
 }
 
+void CStringChecker::emitNullArgBug(CheckerContext &C, ProgramStateRef State,
+                                    const Stmt *S, StringRef WarningMsg) const {
+  if (ExplodedNode *N = C.generateErrorNode(State)) {
+    if (!BT_Null)
+      BT_Null.reset(new BuiltinBug(
+          Filter.CheckNameCStringNullArg, categories::UnixAPI,
+          "Null pointer argument in call to byte string function"));
+
+    BuiltinBug *BT = static_cast<BuiltinBug *>(BT_Null.get());
+    auto Report = llvm::make_unique<BugReport>(*BT, WarningMsg, N);
+    bugreporter::trackNullOrUndefValue(N, S, *Report);
+    C.emitReport(std::move(Report));
+  }
+}
+
+void CStringChecker::emitOutOfBoundsBug(CheckerContext &C,
+                                        ProgramStateRef State, const Stmt *S,
+                                        StringRef WarningMsg) const {
+  if (ExplodedNode *N = C.generateErrorNode(State)) {
+    if (!BT_Bounds)
+      BT_Bounds.reset(new BuiltinBug(
+          Filter.CheckCStringOutOfBounds ? Filter.CheckNameCStringOutOfBounds
+                                         : Filter.CheckNameCStringNullArg,
+          "Out-of-bound array access",
+          "Byte string function accesses out-of-bound array element"));
+
+    BuiltinBug *BT = static_cast<BuiltinBug *>(BT_Bounds.get());
+
+    // FIXME: It would be nice to eventually make this diagnostic more clear,
+    // e.g., by referencing the original declaration or by saying *why* this
+    // reference is outside the range.
+    auto Report = llvm::make_unique<BugReport>(*BT, WarningMsg, N);
+    Report->addRange(S->getSourceRange());
+    C.emitReport(std::move(Report));
+  }
+}
+
+void CStringChecker::emitNotCStringBug(CheckerContext &C, ProgramStateRef State,
+                                       const Stmt *S,
+                                       StringRef WarningMsg) const {
+  if (ExplodedNode *N = C.generateNonFatalErrorNode(State)) {
+    if (!BT_NotCString)
+      BT_NotCString.reset(new BuiltinBug(
+          Filter.CheckNameCStringNotNullTerm, categories::UnixAPI,
+          "Argument is not a null-terminated string."));
+
+    auto Report = llvm::make_unique<BugReport>(*BT_NotCString, WarningMsg, N);
+
+    Report->addRange(S->getSourceRange());
+    C.emitReport(std::move(Report));
+  }
+}
+
+void CStringChecker::emitAdditionOverflowBug(CheckerContext &C,
+                                             ProgramStateRef State) const {
+  if (ExplodedNode *N = C.generateErrorNode(State)) {
+    if (!BT_NotCString)
+      BT_NotCString.reset(
+          new BuiltinBug(Filter.CheckNameCStringOutOfBounds, "API",
+                         "Sum of expressions causes overflow."));
+
+    // This isn't a great error message, but this should never occur in real
+    // code anyway -- you'd have to create a buffer longer than a size_t can
+    // represent, which is sort of a contradiction.
+    const char *WarningMsg =
+        "This expression will create a string whose length is too big to "
+        "be represented as a size_t";
+
+    auto Report = llvm::make_unique<BugReport>(*BT_NotCString, WarningMsg, N);
+    C.emitReport(std::move(Report));
+  }
+}
+
 ProgramStateRef CStringChecker::checkAdditionOverflow(CheckerContext &C,
                                                      ProgramStateRef state,
                                                      NonLoc left,
@@ -610,26 +651,7 @@ ProgramStateRef CStringChecker::checkAdditionOverflow(CheckerContext &C,
 
     if (stateOverflow && !stateOkay) {
       // We have an overflow. Emit a bug report.
-      ExplodedNode *N = C.generateErrorNode(stateOverflow);
-      if (!N)
-        return nullptr;
-
-      if (!BT_AdditionOverflow)
-        BT_AdditionOverflow.reset(
-            new BuiltinBug(Filter.CheckNameCStringOutOfBounds, "API",
-                           "Sum of expressions causes overflow"));
-
-      // This isn't a great error message, but this should never occur in real
-      // code anyway -- you'd have to create a buffer longer than a size_t can
-      // represent, which is sort of a contradiction.
-      const char *warning =
-        "This expression will create a string whose length is too big to "
-        "be represented as a size_t";
-
-      // Generate a report for this bug.
-      C.emitReport(
-          llvm::make_unique<BugReport>(*BT_AdditionOverflow, warning, N));
-
+      emitAdditionOverflowBug(C, stateOverflow);
       return nullptr;
     }
 
@@ -729,15 +751,7 @@ SVal CStringChecker::getCStringLength(CheckerContext &C, ProgramStateRef &state,
     // C string. In the context of locations, the only time we can issue such
     // a warning is for labels.
     if (Optional<loc::GotoLabel> Label = Buf.getAs<loc::GotoLabel>()) {
-      if (!Filter.CheckCStringNotNullTerm)
-        return UndefinedVal();
-
-      if (ExplodedNode *N = C.generateNonFatalErrorNode(state)) {
-        if (!BT_NotCString)
-          BT_NotCString.reset(new BuiltinBug(
-              Filter.CheckNameCStringNotNullTerm, categories::UnixAPI,
-              "Argument is not a null-terminated string."));
-
+      if (Filter.CheckCStringNotNullTerm) {
         SmallString<120> buf;
         llvm::raw_svector_ostream os(buf);
         assert(CurrentFunctionDescription);
@@ -745,14 +759,9 @@ SVal CStringChecker::getCStringLength(CheckerContext &C, ProgramStateRef &state,
            << " is the address of the label '" << Label->getLabel()->getName()
            << "', which is not a null-terminated string";
 
-        // Generate a report for this bug.
-        auto report = llvm::make_unique<BugReport>(*BT_NotCString, os.str(), N);
-
-        report->addRange(Ex->getSourceRange());
-        C.emitReport(std::move(report));
+        emitNotCStringBug(C, state, Ex, os.str());
       }
       return UndefinedVal();
-
     }
 
     // If it's not a region and not a label, give up.
@@ -789,15 +798,7 @@ SVal CStringChecker::getCStringLength(CheckerContext &C, ProgramStateRef &state,
     // Other regions (mostly non-data) can't have a reliable C string length.
     // In this case, an error is emitted and UndefinedVal is returned.
     // The caller should always be prepared to handle this case.
-    if (!Filter.CheckCStringNotNullTerm)
-      return UndefinedVal();
-
-    if (ExplodedNode *N = C.generateNonFatalErrorNode(state)) {
-      if (!BT_NotCString)
-        BT_NotCString.reset(new BuiltinBug(
-            Filter.CheckNameCStringNotNullTerm, categories::UnixAPI,
-            "Argument is not a null-terminated string."));
-
+    if (Filter.CheckCStringNotNullTerm) {
       SmallString<120> buf;
       llvm::raw_svector_ostream os(buf);
 
@@ -809,13 +810,8 @@ SVal CStringChecker::getCStringLength(CheckerContext &C, ProgramStateRef &state,
       else
         os << "not a null-terminated string";
 
-      // Generate a report for this bug.
-      auto report = llvm::make_unique<BugReport>(*BT_NotCString, os.str(), N);
-
-      report->addRange(Ex->getSourceRange());
-      C.emitReport(std::move(report));
+      emitNotCStringBug(C, state, Ex, os.str());
     }
-
     return UndefinedVal();
   }
 }