Fixed #2618 (Tokenizer::simplifyKnownVariables: Don't use known string value if address is wanted)

lib/tokenize.cpp

@@ -6636,6 +6636,12 @@ bool Tokenizer::simplifyKnownVariablesSimplify(Token **tok2, Token *tok3, unsign
             Token::Match(tok3, ("!|==|!=|<|<=|>|>= " + structname + " %varid% ==|!=|<|<=|>|>=|)|;").c_str(), varid) ||
             Token::Match(tok3->previous(), "strlen|free ( %varid% )", varid))
         {
+            if (value[0] == '\"' && tok3->strAt(-1) != "strlen")
+            {
+                // bail out if value is a string unless if it's just given
+                // as parameter to strlen
+                break;
+            }
             if (!structname.empty())
             {
                 tok3->deleteNext();

test/testtokenize.cpp

@@ -2052,6 +2052,7 @@ private:
     }
 
     void simplifyKnownVariables42()
+    {
         {
             const char code[] = "void f() {\n"
                                 "    char str1[10], str2[10];\n"
@@ -2066,6 +2067,21 @@ private:
             ASSERT_EQUALS(expected, tokenizeAndStringify(code, true));
         }
 
+        {
+            const char code[] = "void f() {"
+                                "    char *s = malloc(10);"
+                                "    strcpy(s, \"\");"
+                                "    free(s);"
+                                "}";
+            const char expected[] = "void f ( ) {"
+                                    " char * s ; s = malloc ( 10 ) ;"
+                                    " strcpy ( s , \"\" ) ;"
+                                    " free ( s ) ; "
+                                    "}";
+            ASSERT_EQUALS(expected, tokenizeAndStringify(code, true));
+        }
+    }
+
     void simplifyKnownVariablesBailOutAssign()
     {
         const char code[] = "int foo() {\n"