Improve knownArgument to check arguments to any nary function (danmar…

…#5348)
chrchr-github · Aug 19, 2023 · d691450 · d691450
1 parent a92b10c
commit d691450
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Showing 2 changed files with 25 additions and 7 deletions.
diff --git a/lib/checkother.cpp b/lib/checkother.cpp
@@ -3647,17 +3647,23 @@ void CheckOther::checkKnownArgument()
     const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
     for (const Scope *functionScope : symbolDatabase->functionScopes) {
         for (const Token *tok = functionScope->bodyStart; tok != functionScope->bodyEnd; tok = tok->next()) {
-            if (!Token::simpleMatch(tok->astParent(), "("))
+            if (!tok->hasKnownIntValue())
                 continue;
-            if (!Token::Match(tok->astParent()->previous(), "%name%"))
+            if (Token::Match(tok, "++|--|%assign%"))
                 continue;
-            if (Token::Match(tok->astParent()->previous(), "if|while|switch|sizeof"))
+            if (!Token::Match(tok->astParent(), "(|{|,"))
                 continue;
-            if (tok == tok->astParent()->previous())
+            if (tok->astParent()->isCast())
                 continue;
-            if (!tok->hasKnownIntValue())
+            int argn = -1;
+            const Token* ftok = getTokenArgumentFunction(tok, argn);
+            if (!ftok)
                 continue;
-            if (tok->tokType() == Token::eIncDecOp)
+            if (ftok->isCast())
+                continue;
+            if (Token::Match(ftok, "if|while|switch|sizeof"))
+                continue;
+            if (tok == tok->astParent()->previous())
                 continue;
             if (isConstVarExpression(tok))
                 continue;
@@ -3668,6 +3674,10 @@ void CheckOther::checkKnownArgument()
                 tok2 = tok2->astOperand2();
             if (isVariableExpression(tok2))
                 continue;
+            if (tok->isComparisonOp() &&
+                isSameExpression(
+                    mTokenizer->isCPP(), true, tok->astOperand1(), tok->astOperand2(), mSettings->library, true, true))
+                continue;
             // ensure that there is a integer variable in expression with unknown value
             std::string varexpr;
             bool isVariableExprHidden = false;  // Is variable expression explicitly hidden
@@ -3706,7 +3716,7 @@ void CheckOther::checkKnownArgument()
             strTolower(funcname);
             if (funcname.find("assert") != std::string::npos)
                 continue;
-            knownArgumentError(tok, tok->astParent()->previous(), &tok->values().front(), varexpr, isVariableExprHidden);
+            knownArgumentError(tok, ftok, &tok->values().front(), varexpr, isVariableExprHidden);
         }
     }
 }

diff --git a/test/testother.cpp b/test/testother.cpp
@@ -10905,6 +10905,14 @@ class TestOther : public TestFixture {
               "}");
         ASSERT_EQUALS("[test.cpp:3]: (style) Argument '(int)((x&0x01)>>7)' to function g is always 0. It does not matter what value 'x' has.\n", errout.str());
 
+        check("void g(int, int);\n"
+              "void f(int x) {\n"
+              "   g(x, (x & 0x01) >> 7);\n"
+              "}");
+        ASSERT_EQUALS(
+            "[test.cpp:3]: (style) Argument '(x&0x01)>>7' to function g is always 0. It does not matter what value 'x' has.\n",
+            errout.str());
+
         check("void g(int);\n"
               "void f(int x) {\n"
               "    g(0);\n"