Support sizeof in preprocessor directives

Applied "patch" provided by michaeln123 in #4071

lib/preprocessor.cpp

@@ -1436,6 +1436,7 @@ void Preprocessor::simplifyCondition(const std::map<std::string, std::string> &c
     bool modified = true;
     while (modified) {
         modified = false;
+        modified |= tokenizer.simplifySizeof();
         modified |= tokenizer.simplifyCalculations();
         modified |= tokenizer.simplifyRedundantParenthesis();
         for (Token *tok = const_cast<Token *>(tokenizer.tokens()); tok; tok = tok->next()) {

lib/tokenize.cpp

@@ -3012,7 +3012,7 @@ void Tokenizer::createLinks2()
     }
 }
 
-void Tokenizer::simplifySizeof()
+bool Tokenizer::simplifySizeof()
 {
     for (Token *tok = list.front(); tok; tok = tok->next()) {
         if (Token::Match(tok, "class|struct %var%")) {
@@ -3069,6 +3069,7 @@ void Tokenizer::simplifySizeof()
         }
     }
 
+    bool ret = false;
     for (Token *tok = list.front(); tok; tok = tok->next()) {
         if (tok->str() != "sizeof")
             continue;
@@ -3089,6 +3090,7 @@ void Tokenizer::simplifySizeof()
             std::ostringstream sz;
             sz << sizeof 'x';
             tok->str(sz.str());
+            ret = true;
             continue;
         }
 
@@ -3100,6 +3102,7 @@ void Tokenizer::simplifySizeof()
             std::ostringstream sz;
             sz << sizeof 'x';
             tok->str(sz.str());
+            ret = true;
             continue;
         }
 
@@ -3109,6 +3112,7 @@ void Tokenizer::simplifySizeof()
             std::ostringstream ostr;
             ostr << (Token::getStrLength(tok) + 1);
             tok->str(ostr.str());
+            ret = true;
             continue;
         }
 
@@ -3120,6 +3124,7 @@ void Tokenizer::simplifySizeof()
             std::ostringstream ostr;
             ostr << (Token::getStrLength(tok) + 1);
             tok->str(ostr.str());
+            ret = true;
             continue;
         }
 
@@ -3192,6 +3197,7 @@ void Tokenizer::simplifySizeof()
         if (Token::simpleMatch(tok->next(), "( * )")) {
             tok->str(MathLib::toString<unsigned long>(sizeOfType(tok->tokAt(2))));
             tok->deleteNext(3);
+            ret = true;
         }
 
         // sizeof( a )
@@ -3201,6 +3207,7 @@ void Tokenizer::simplifySizeof()
                 tok->deleteThis();
                 tok->deleteNext();
                 tok->str(sizeOfVar[tok->varId()]);
+                ret = true;
             } else {
                 // don't try to replace size of variable if variable has
                 // similar name with type (#329)
@@ -3212,6 +3219,7 @@ void Tokenizer::simplifySizeof()
             if (size > 0) {
                 tok->str(MathLib::toString<unsigned int>(size));
                 tok->deleteNext(3);
+                ret = true;
             }
         }
 
@@ -3240,10 +3248,11 @@ void Tokenizer::simplifySizeof()
             if (sz > 0) {
                 tok->str(MathLib::toString<size_t>(sz));
                 Token::eraseTokens(tok, tok->next()->link()->next());
+                ret = true;
             }
         }
     }
-
+    return ret;
 }
 
 bool Tokenizer::simplifyTokenList()

lib/tokenize.h

@@ -207,8 +207,10 @@ public:
 
     /**
      * Replace sizeof() to appropriate size.
+     * @return true if modifications to token-list are done.
+     *         false if no modifications are done.
      */
-    void simplifySizeof();
+    bool simplifySizeof();
 
     /**
      * Simplify variable declarations (split up)

test/testpreprocessor.cpp

@@ -275,6 +275,8 @@ private:
         TEST_CASE(macroChar);
 
         TEST_CASE(validateCfg);
+
+        TEST_CASE(if_sizeof);
     }
 
 
@@ -3608,6 +3610,22 @@ private:
         ASSERT_EQUALS(true, preprocessor.validateCfg("#undef DEBUG", "DEBUG"));
     }
 
+    void if_sizeof() { // #4071
+        static const char* code = "#if sizeof(wchar_t) == 2\n"
+                                  "Fred & Wilma\n"
+                                  "#elif sizeof(wchar_t) == 4\n"
+                                  "Fred & Wilma\n"
+                                  "#else\n"
+                                  "#endif";
+
+        Settings settings;
+        Preprocessor preprocessor(&settings, this);
+        std::istringstream istr(code);
+        std::map<std::string, std::string> actual;
+        preprocessor.preprocess(istr, actual, "file.c");
+
+        ASSERT_EQUALS("\nFred & Wilma\n\n\n\n\n", actual[""]);
+    }
 };
 
 REGISTER_TEST(TestPreprocessor)