Fix issue 10378: FP derefInvalidIteratorRedundantCheck (#3353)

lib/programmemory.cpp

@@ -7,6 +7,7 @@
 #include "valueflow.h"
 #include <algorithm>
 #include <cassert>
+#include <functional>
 #include <limits>
 #include <memory>
 
@@ -458,14 +459,53 @@ ProgramMemory getProgramMemory(const Token* tok, nonneg int exprid, const ValueF
     return programMemory;
 }
 
-void execute(const Token *expr,
+static PMEvaluateFunction evaluateAsInt(PMEvaluateFunction f, ValueFlow::Value::ValueType t)
-             ProgramMemory * const programMemory,
+{
-             MathLib::bigint *result,
+    return [=](const Token* expr, ProgramMemory* const programMemory, MathLib::bigint* result) -> bool {
-             bool *error)
+        const ValueFlow::Value* value = expr->getKnownValue(t);
+        if (!value)
+            value = programMemory->getValue(expr->exprId());
+        if (value && value->valueType == t) {
+            *result = value->intvalue;
+            return true;
+        }
+        return f && f(expr, programMemory, result);
+    };
+}
+
+static std::set<ValueFlow::Value::ValueType> findIteratorTypes(const ProgramMemory& pm)
+{
+    std::set<ValueFlow::Value::ValueType> result;
+    for (auto&& p : pm.values) {
+        if (p.second.isIteratorValue())
+            result.insert(p.second.valueType);
+        if (result.size() == 2)
+            break;
+    }
+    return result;
+}
+
+static bool isIterator(const Token* expr)
+{
+    if (!expr)
+        return false;
+    if (astIsIterator(expr))
+        return true;
+    return std::any_of(expr->values().begin(), expr->values().end(), std::mem_fn(&ValueFlow::Value::isIteratorValue));
+}
+
+void execute(const Token* expr,
+             ProgramMemory* const programMemory,
+             MathLib::bigint* result,
+             bool* error,
+             const PMEvaluateFunction& f)
 {
     if (!expr)
         *error = true;
 
+    else if (f && f(expr, programMemory, result))
+        *error = false;
+
     else if (expr->hasKnownIntValue() && !expr->isAssignmentOp()) {
         *result = expr->values().front().intvalue;
     }
@@ -504,8 +544,16 @@ void execute(const Token *expr,
         MathLib::bigint result1(0), result2(0);
         bool error1 = false;
         bool error2 = false;
-        execute(expr->astOperand1(), programMemory, &result1, &error1);
+        execute(expr->astOperand1(), programMemory, &result1, &error1, f);
-        execute(expr->astOperand2(), programMemory, &result2, &error2);
+        execute(expr->astOperand2(), programMemory, &result2, &error2, f);
+        if (error1 && error2 && (isIterator(expr->astOperand1()) || isIterator(expr->astOperand2()))) {
+            for (ValueFlow::Value::ValueType t : findIteratorTypes(*programMemory)) {
+                execute(expr->astOperand1(), programMemory, &result1, &error1, evaluateAsInt(f, t));
+                execute(expr->astOperand2(), programMemory, &result2, &error2, evaluateAsInt(f, t));
+                if (!error1 && !error2)
+                    break;
+            }
+        }
         if (error1 && error2) {
             *error = true;
         } else if (error1 && !error2) {
@@ -533,7 +581,7 @@ void execute(const Token *expr,
     }
 
     else if (expr->isAssignmentOp()) {
-        execute(expr->astOperand2(), programMemory, result, error);
+        execute(expr->astOperand2(), programMemory, result, error, f);
         if (!expr->astOperand1() || !expr->astOperand1()->exprId())
             *error = true;
         if (*error)
@@ -588,8 +636,8 @@ void execute(const Token *expr,
 
     else if (expr->isArithmeticalOp() && expr->astOperand1() && expr->astOperand2()) {
         MathLib::bigint result1(0), result2(0);
-        execute(expr->astOperand1(), programMemory, &result1, error);
+        execute(expr->astOperand1(), programMemory, &result1, error, f);
-        execute(expr->astOperand2(), programMemory, &result2, error);
+        execute(expr->astOperand2(), programMemory, &result2, error, f);
         if (expr->str() == "+")
             *result = result1 + result2;
         else if (expr->str() == "-")
@@ -622,33 +670,33 @@ void execute(const Token *expr,
 
     else if (expr->str() == "&&") {
         bool error1 = false;
-        execute(expr->astOperand1(), programMemory, result, &error1);
+        execute(expr->astOperand1(), programMemory, result, &error1, f);
         if (!error1 && *result == 0)
             *result = 0;
         else {
             bool error2 = false;
-            execute(expr->astOperand2(), programMemory, result, &error2);
+            execute(expr->astOperand2(), programMemory, result, &error2, f);
             if (error1 || error2)
                 *error = true;
         }
     }
 
     else if (expr->str() == "||") {
-        execute(expr->astOperand1(), programMemory, result, error);
+        execute(expr->astOperand1(), programMemory, result, error, f);
         if (*result == 1 && *error == false)
             *result = 1;
         else if (*result == 0 && *error == false)
-            execute(expr->astOperand2(), programMemory, result, error);
+            execute(expr->astOperand2(), programMemory, result, error, f);
     }
 
     else if (expr->str() == "!") {
-        execute(expr->astOperand1(), programMemory, result, error);
+        execute(expr->astOperand1(), programMemory, result, error, f);
         *result = !(*result);
     }
 
     else if (expr->str() == "," && expr->astOperand1() && expr->astOperand2()) {
-        execute(expr->astOperand1(), programMemory, result, error);
+        execute(expr->astOperand1(), programMemory, result, error, f);
-        execute(expr->astOperand2(), programMemory, result, error);
+        execute(expr->astOperand2(), programMemory, result, error, f);
     }
 
     else if (expr->str() == "[" && expr->astOperand1() && expr->astOperand2()) {
@@ -669,7 +717,7 @@ void execute(const Token *expr,
         }
         const std::string strValue = tokvalue->strValue();
         MathLib::bigint index = 0;
-        execute(expr->astOperand2(), programMemory, &index, error);
+        execute(expr->astOperand2(), programMemory, &index, error, f);
         if (index >= 0 && index < strValue.size())
             *result = strValue[index];
         else if (index == strValue.size())

lib/programmemory.h

@@ -1,9 +1,10 @@
 #ifndef GUARD_PROGRAMMEMORY_H
 #define GUARD_PROGRAMMEMORY_H
 
+#include "mathlib.h"
 #include "utils.h"
 #include "valueflow.h" // needed for alias
-#include "mathlib.h"
+#include <functional>
 #include <map>
 #include <unordered_map>
 
@@ -57,10 +58,14 @@ struct ProgramMemoryState {
     ProgramMemory get(const Token* tok, const Token* ctx, const ProgramMemory::Map& vars) const;
 };
 
-void execute(const Token *expr,
+using PMEvaluateFunction =
-             ProgramMemory * const programMemory,
+    std::function<bool(const Token* expr, ProgramMemory* const programMemory, MathLib::bigint* result)>;
-             MathLib::bigint *result,
+
-             bool *error);
+void execute(const Token* expr,
+             ProgramMemory* const programMemory,
+             MathLib::bigint* result,
+             bool* error,
+             const PMEvaluateFunction& f = nullptr);
 
 /**
  * Is condition always false when variable has given value?

lib/token.cpp

@@ -2385,6 +2385,24 @@ bool Token::hasKnownValue() const
     return mImpl->mValues && std::any_of(mImpl->mValues->begin(), mImpl->mValues->end(), std::mem_fn(&ValueFlow::Value::isKnown));
 }
 
+bool Token::hasKnownValue(ValueFlow::Value::ValueType t) const
+{
+    return mImpl->mValues &&
+           std::any_of(mImpl->mValues->begin(), mImpl->mValues->end(), [&](const ValueFlow::Value& value) {
+               return value.isKnown() && value.valueType == t;
+           });
+}
+
+const ValueFlow::Value* Token::getKnownValue(ValueFlow::Value::ValueType t) const
+{
+    if (!mImpl->mValues)
+        return nullptr;
+    auto it = std::find_if(mImpl->mValues->begin(), mImpl->mValues->end(), [&](const ValueFlow::Value& value) {
+        return value.isKnown() && value.valueType == t;
+    });
+    return it == mImpl->mValues->end() ? nullptr : &*it;
+}
+
 bool Token::isImpossibleIntValue(const MathLib::bigint val) const
 {
     if (!mImpl->mValues)

lib/token.h

@@ -1133,7 +1133,9 @@ public:
 
     bool hasKnownIntValue() const;
     bool hasKnownValue() const;
+    bool hasKnownValue(ValueFlow::Value::ValueType t) const;
 
+    const ValueFlow::Value* getKnownValue(ValueFlow::Value::ValueType t) const;
     MathLib::bigint getKnownIntValue() const {
         return mImpl->mValues->front().intvalue;
     }

test/teststl.cpp

@@ -70,6 +70,7 @@ private:
         TEST_CASE(iterator24);
         TEST_CASE(iterator25); // #9742
         TEST_CASE(iterator26); // #9176
+        TEST_CASE(iterator27); // #10378
         TEST_CASE(iteratorExpression);
         TEST_CASE(iteratorSameExpression);
         TEST_CASE(mismatchingContainerIterator);
@@ -1392,6 +1393,21 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void iterator27()
+    { // #10378
+        check("struct A {\n"
+              "    int a;\n"
+              "    int b;\n"
+              "};\n"
+              "int f(std::map<int, A> m) {\n"
+              "    auto it =  m.find( 1 );\n"
+              "    const int a( it == m.cend() ? 0 : it->second.a );\n"
+              "    const int b( it == m.cend() ? 0 : it->second.b );\n"
+              "    return a + b;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void iteratorExpression() {
         check("std::vector<int>& f();\n"
               "std::vector<int>& g();\n"