ValueFlow: Added utility functions getValueLE and getValueGE to simplify usage

lib/checkbufferoverrun.cpp

@@ -1182,17 +1182,9 @@ void CheckBufferOverrun::valueFlowCheckArrayIndex(const Token * const tok, const
             const Token *index = tok2->astOperand2();
             if (!index)
                 continue;
-            std::list<ValueFlow::Value>::const_iterator it;
-            const ValueFlow::Value *val = nullptr;
-            for (it = index->values.begin(); it != index->values.end(); ++it) {
-                if (it->intvalue < 0) {
-                    val = &*it;
-                    if (val->condition == nullptr)
-                        break;
-                }
-            }
-            if (val && !val->condition)
-                negativeIndexError(index, val->intvalue);
+            const ValueFlow::Value *value = index->getValueLE(-1LL,_settings);
+            if (value)
+                negativeIndexError(index, *value);
         }
 
         // Index out of bounds..
@@ -2046,6 +2038,15 @@ void CheckBufferOverrun::negativeIndexError(const Token *tok, MathLib::bigint in
     reportError(tok, Severity::error, "negativeIndex", ostr.str());
 }
 
+void CheckBufferOverrun::negativeIndexError(const Token *tok, const ValueFlow::Value &index)
+{
+    std::ostringstream ostr;
+    ostr << "Array index " << index.intvalue << " is out of bounds.";
+    if (index.condition)
+        ostr << " Otherwise there is useless condition at line " << index.condition->linenr() << ".";
+    reportError(tok, index.condition ? Severity::warning : Severity::error, "negativeIndex", ostr.str(), index.inconclusive);
+}
+
 CheckBufferOverrun::ArrayInfo::ArrayInfo()
     : _element_size(0), _declarationId(0)
 {

lib/checkbufferoverrun.h

@@ -223,6 +223,7 @@ private:
     void terminateStrncpyError(const Token *tok, const std::string &varname);
     void bufferNotZeroTerminatedError(const Token *tok, const std::string &varname, const std::string &function);
     void negativeIndexError(const Token *tok, MathLib::bigint index);
+    void negativeIndexError(const Token *tok, const ValueFlow::Value &index);
     void cmdLineArgsError(const Token *tok);
     void pointerOutOfBoundsError(const Token *tok, const std::string &object);  // UB when result of calculation is out of bounds
     void arrayIndexThenCheckError(const Token *tok, const std::string &indexName);

lib/checkother.cpp

@@ -3335,22 +3335,9 @@ void CheckOther::checkNegativeBitwiseShift()
             }
 
             // Get negative rhs value. preferably a value which doesn't have 'condition'.
-            const ValueFlow::Value *value = nullptr;
-            for (std::list<ValueFlow::Value>::const_iterator it = tok->astOperand2()->values.begin();
-                 it != tok->astOperand2()->values.end();
-                 ++it) {
-                if (it->intvalue < 0) {
-                    if (value == nullptr || it->condition == nullptr)
-                        value = &(*it);
-                    if (value->condition == nullptr)
-                        break;
-                }
-            }
-
-            if (!value)
-                continue;
-
-            negativeBitwiseShiftError(tok);
+            const ValueFlow::Value *value = tok->astOperand2()->getValueLE(-1LL, _settings);
+            if (value)
+                negativeBitwiseShiftError(tok);
         }
     }
 }

lib/token.cpp

@@ -19,6 +19,7 @@
 #include "token.h"
 #include "errorlogger.h"
 #include "check.h"
+#include "settings.h"
 #include <cassert>
 #include <cstdlib>
 #include <cstring>
@@ -1278,3 +1279,46 @@ void Token::printValueFlow() const
         std::cout << "}" << std::endl;
     }
 }
+
+const ValueFlow::Value * Token::getValueLE(const MathLib::bigint val, const Settings *settings) const
+{
+    const ValueFlow::Value *ret = nullptr;
+    std::list<ValueFlow::Value>::const_iterator it;
+    for (it = values.begin(); it != values.end(); ++it) {
+        if (it->intvalue <= val) {
+            if (!ret || ret->inconclusive || (ret->condition && !it->inconclusive))
+                ret = &(*it);
+            if (!ret->inconclusive && !ret->condition)
+                break;
+        }
+    }
+    if (settings && ret) {
+        if (ret->inconclusive && !settings->inconclusive)
+            return nullptr;
+        if (ret->condition && !settings->isEnabled("warning"))
+            return nullptr;
+    }
+    return ret;
+}
+
+const ValueFlow::Value * Token::getValueGE(const MathLib::bigint val, const Settings *settings) const
+{
+    const ValueFlow::Value *ret = nullptr;
+    std::list<ValueFlow::Value>::const_iterator it;
+    for (it = values.begin(); it != values.end(); ++it) {
+        if (it->intvalue >= val) {
+            if (!ret || ret->inconclusive || (ret->condition && !it->inconclusive))
+                ret = &(*it);
+            if (!ret->inconclusive && !ret->condition)
+                break;
+        }
+    }
+    if (settings && ret) {
+        if (ret->inconclusive && !settings->inconclusive)
+            return nullptr;
+        if (ret->condition && !settings->isEnabled("warning"))
+            return nullptr;
+    }
+    return ret;
+}
+

lib/token.h

@@ -32,6 +32,7 @@
 class Scope;
 class Function;
 class Variable;
+class Settings;
 
 /// @addtogroup Core
 /// @{
@@ -619,6 +620,9 @@ public:
         return ret;
     }
 
+    const ValueFlow::Value * getValueLE(const MathLib::bigint val, const Settings *settings) const;
+    const ValueFlow::Value * getValueGE(const MathLib::bigint val, const Settings *settings) const;
+
 private:
 
     void next(Token *nextToken) {