Fix #11143 FP: unreadVariable (remove simplifyMathExpressions()) (#4227)

* Fix #11143 FP: unreadVariable (remove simplifyMathExpressions())

* Remove unused function, tests

lib/tokenize.cpp

@@ -4825,9 +4825,6 @@ bool Tokenizer::simplifyTokenList1(const char FileName[])
     // Combine tokens..
     combineOperators();
 
-    // replace 'sin(0)' to '0' and other similar math expressions
-    simplifyMathExpressions();
-
     // combine "- %num%"
     concatenateNegativeNumberAndAnyPositive();
 
@@ -8518,18 +8515,6 @@ bool Tokenizer::isOneNumber(const std::string &s)
     return isNumberOneOf(s, 1L, "1.0");
 }
 
-// ------------------------------------------------------------------------
-// Helper function to check whether number is two (2 or 0.2E+1 or 2E+0) or not?
-// @param s the string to check
-// @return true in case s is two and false otherwise.
-// ------------------------------------------------------------------------
-bool Tokenizer::isTwoNumber(const std::string &s)
-{
-    if (!MathLib::isPositive(s))
-        return false;
-    return isNumberOneOf(s, 2L, "2.0");
-}
-
 void Tokenizer::simplifyComma()
 {
     bool inReturn = false;
@@ -10912,96 +10897,6 @@ void Tokenizer::printUnknownTypes() const
     }
 }
 
-void Tokenizer::simplifyMathExpressions()
-{
-    for (Token *tok = list.front(); tok; tok = tok->next()) {
-
-        //simplify Pythagorean trigonometric identity: pow(sin(x),2)+pow(cos(x),2) = 1
-        //                                             pow(cos(x),2)+pow(sin(x),2) = 1
-        // @todo: sin(x) * sin(x) + cos(x) * cos(x) = 1
-        //        cos(x) * cos(x) + sin(x) * sin(x) = 1
-        //simplify Hyperbolic identity: pow(sinh(x),2)-pow(cosh(x),2) = -1
-        //                              pow(cosh(x),2)-pow(sinh(x),2) = -1
-        // @todo: sinh(x) * sinh(x) - cosh(x) * cosh(x) = -1
-        //        cosh(x) * cosh(x) - sinh(x) * sinh(x) = -1
-        if (Token::Match(tok, "pow|powf|powl (")) {
-            if (Token::Match(tok->tokAt(2), "sin|sinf|sinl (")) {
-                Token * const tok2 = tok->linkAt(3);
-                if (!Token::Match(tok2, ") , %num% ) + pow|powf|powl ( cos|cosf|cosl ("))
-                    continue;
-                const std::string& leftExponent = tok2->strAt(2);
-                if (!isTwoNumber(leftExponent))
-                    continue; // left exponent is not 2
-                const Token * const tok3 = tok2->tokAt(8);
-                Token * const tok4 = tok3->link();
-                if (!Token::Match(tok4, ") , %num% )"))
-                    continue;
-                const std::string& rightExponent = tok4->strAt(2);
-                if (!isTwoNumber(rightExponent))
-                    continue; // right exponent is not 2
-                if (tok->tokAt(3)->stringifyList(tok2->next()) == tok3->stringifyList(tok4->next())) {
-                    Token::eraseTokens(tok, tok4->tokAt(4));
-                    tok->str("1");
-                }
-            } else if (Token::Match(tok->tokAt(2), "cos|cosf|cosl (")) {
-                Token * const tok2 = tok->linkAt(3);
-                if (!Token::Match(tok2, ") , %num% ) + pow|powf|powl ( sin|sinf|sinl ("))
-                    continue;
-                const std::string& leftExponent = tok2->strAt(2);
-                if (!isTwoNumber(leftExponent))
-                    continue; // left exponent is not 2
-                const Token * const tok3 = tok2->tokAt(8);
-                Token * const tok4 = tok3->link();
-                if (!Token::Match(tok4, ") , %num% )"))
-                    continue;
-                const std::string& rightExponent = tok4->strAt(2);
-                if (!isTwoNumber(rightExponent))
-                    continue; // right exponent is not 2
-                if (tok->tokAt(3)->stringifyList(tok2->next()) == tok3->stringifyList(tok4->next())) {
-                    Token::eraseTokens(tok, tok4->tokAt(4));
-                    tok->str("1");
-                }
-            } else if (Token::Match(tok->tokAt(2), "sinh|sinhf|sinhl (")) {
-                Token * const tok2 = tok->linkAt(3);
-                if (!Token::Match(tok2, ") , %num% ) - pow|powf|powl ( cosh|coshf|coshl ("))
-                    continue;
-                const std::string& leftExponent = tok2->strAt(2);
-                if (!isTwoNumber(leftExponent))
-                    continue; // left exponent is not 2
-                const Token * const tok3 = tok2->tokAt(8);
-                Token * const tok4 = tok3->link();
-                if (!Token::Match(tok4, ") , %num% )"))
-                    continue;
-                const std::string& rightExponent = tok4->strAt(2);
-                if (!isTwoNumber(rightExponent))
-                    continue; // right exponent is not 2
-                if (tok->tokAt(3)->stringifyList(tok2->next()) == tok3->stringifyList(tok4->next())) {
-                    Token::eraseTokens(tok, tok4->tokAt(4));
-                    tok->str("-1");
-                }
-            } else if (Token::Match(tok->tokAt(2), "cosh|coshf|coshl (")) {
-                Token * const tok2 = tok->linkAt(3);
-                if (!Token::Match(tok2, ") , %num% ) - pow|powf|powl ( sinh|sinhf|sinhl ("))
-                    continue;
-                const std::string& leftExponent = tok2->strAt(2);
-                if (!isTwoNumber(leftExponent))
-                    continue; // left exponent is not 2
-                const Token * const tok3 = tok2->tokAt(8);
-                Token * const tok4 = tok3->link();
-                if (!Token::Match(tok4, ") , %num% )"))
-                    continue;
-                const std::string& rightExponent = tok4->strAt(2);
-                if (!isTwoNumber(rightExponent))
-                    continue; // right exponent is not 2
-                if (tok->tokAt(3)->stringifyList(tok2->next()) == tok3->stringifyList(tok4->next())) {
-                    Token::eraseTokens(tok, tok4->tokAt(4));
-                    tok->str("-1");
-                }
-            }
-        }
-    }
-}
-
 void Tokenizer::prepareTernaryOpForAST()
 {
     // http://en.cppreference.com/w/cpp/language/operator_precedence says about ternary operator:

lib/tokenize.h

@@ -431,11 +431,6 @@ public:
 
     void findComplicatedSyntaxErrorsInTemplates();
 
-    /**
-     * Simplify e.g. 'sin(0)' into '0'
-     */
-    void simplifyMathExpressions();
-
     /**
      * Modify strings in the token list by replacing hex and oct
      * values. E.g. "\x61" -> "a" and "\000" -> "\0"
@@ -757,13 +752,6 @@ public:
      */
     static bool isOneNumber(const std::string &s);
 
-    /**
-     * Helper function to check whether number is two (2 or 0.2E+1 or 2E+0) or not?
-     * @param s the string to check
-     * @return true in case is is two and false otherwise.
-     */
-    static bool isTwoNumber(const std::string &s);
-
     /**
      * Helper function to check for start of function execution scope.
      * Do not use this in checks.  Use the symbol database.

test/testtokenize.cpp

@@ -146,7 +146,6 @@ private:
         TEST_CASE(simplifyKeyword); // #5842 - remove C99 static keyword between []
 
         TEST_CASE(isOneNumber);
-        TEST_CASE(isTwoNumber);
 
         TEST_CASE(simplifyFunctionParameters);
         TEST_CASE(simplifyFunctionParameters1); // #3721
@@ -5643,22 +5642,6 @@ private:
         ASSERT_EQUALS(false, Tokenizer::isOneNumber("garbage"));
     }
 
-    void isTwoNumber() const {
-        ASSERT_EQUALS(true, Tokenizer::isTwoNumber("2.0"));
-        ASSERT_EQUALS(true, Tokenizer::isTwoNumber("+2.0"));
-        ASSERT_EQUALS(true, Tokenizer::isTwoNumber("2.0e+0"));
-        ASSERT_EQUALS(true, Tokenizer::isTwoNumber("+2L"));
-        ASSERT_EQUALS(true, Tokenizer::isTwoNumber("+2"));
-        ASSERT_EQUALS(true, Tokenizer::isTwoNumber("2"));
-        ASSERT_EQUALS(true, Tokenizer::isTwoNumber("+2E+0"));
-
-        ASSERT_EQUALS(false, Tokenizer::isTwoNumber("0.0"));
-        ASSERT_EQUALS(false, Tokenizer::isTwoNumber("+0.0"));
-        ASSERT_EQUALS(false, Tokenizer::isTwoNumber("-0"));
-        ASSERT_EQUALS(false, Tokenizer::isTwoNumber(""));
-        ASSERT_EQUALS(false, Tokenizer::isTwoNumber("garbage"));
-    }
-
     void simplifyStaticConst() {
         const char code1[]     = "class foo { public: bool const static c ; }";
         const char expected1[] = "class foo { public: static const bool c ; }";

test/testunusedvar.cpp

@@ -134,6 +134,7 @@ private:
         TEST_CASE(localvar63); // #6928
         TEST_CASE(localvar64); // #9997
         TEST_CASE(localvar65); // #9876, #10006
+        TEST_CASE(localvar66); // #11143
         TEST_CASE(localvarloops); // loops
         TEST_CASE(localvaralias1);
         TEST_CASE(localvaralias2); // ticket #1637
@@ -3560,6 +3561,14 @@ private:
         ASSERT_EQUALS("[test.cpp:2]: (style) Variable 's' is assigned a value that is never used.\n", errout.str());
     }
 
+    void localvar66() { // #11143
+        functionVariableUsage("void f() {\n"
+                              "    double phi = 42.0;\n"
+                              "    std::cout << pow(sin(phi), 2) + pow(cos(phi), 2) << std::endl;\n"
+                              "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void localvarloops() {
         // loops
         functionVariableUsage("void fun(int c) {\n"