Fix #612: reject floating literals in preprocessor conditions

Author: Abusalah0

simplecpp.cpp

@@ -3032,12 +3032,26 @@ long long simplecpp::characterLiteralToLL(const std::string& str)
     return multivalue;
 }
 
+static bool isFloatingPointLiteral(const std::string &str)
+{
+    if (!simplecpp::Token::isNumberLike(str) &&
+        !(str.size() > 1U && str[0] == '.' && std::isdigit(static_cast<unsigned char>(str[1]))))
+        return false;
+
+    if (str.find('.') != std::string::npos)
+        return true;
+
+    return str.find_first_of(isHex(str) ? "pP" : "eE") != std::string::npos;
+}
+
 /**
  * @throws std::runtime_error thrown on invalid literal
  */
 static void simplifyNumbers(simplecpp::TokenList &expr)
 {
     for (simplecpp::Token *tok = expr.front(); tok; tok = tok->next) {
+        if (isFloatingPointLiteral(tok->str()))
+            throw std::runtime_error("floating point literal in preprocessor expression");
         if (tok->str().size() == 1U)
             continue;
         if (tok->str().compare(0,2,"0x") == 0)

test.cpp

@@ -2293,6 +2293,60 @@ static void ifA()
     ASSERT_EQUALS("\nX", preprocess(code, dui));
 }
 
+static void ifFloatingPointLiteral() // #612
+{
+    simplecpp::OutputList outputList;
+    simplecpp::DUI dui;
+    dui.defines.emplace_back("A=1");
+
+    const char issue[] = "#if A == 1.0\n"
+                         "int i;\n"
+                         "#endif\n";
+    ASSERT_EQUALS("", preprocess(issue, dui, &outputList));
+    ASSERT_EQUALS("file0,1,syntax_error,failed to evaluate #if condition, floating point literal in preprocessor expression\n", toString(outputList));
+
+    outputList.clear();
+
+    const char otherSpelling[] = "#if 0\n"
+                                 "#elif .5\n"
+                                 "int i;\n"
+                                 "#endif\n";
+    ASSERT_EQUALS("", preprocess(otherSpelling, &outputList));
+    ASSERT_EQUALS("file0,2,syntax_error,failed to evaluate #elif condition, floating point literal in preprocessor expression\n", toString(outputList));
+
+    outputList.clear();
+
+    const char exponent[] = "#if 1e3\n"
+                            "int i;\n"
+                            "#endif\n";
+    ASSERT_EQUALS("", preprocess(exponent, &outputList));
+    ASSERT_EQUALS("file0,1,syntax_error,failed to evaluate #if condition, floating point literal in preprocessor expression\n", toString(outputList));
+
+    outputList.clear();
+
+    const char suffix[] = "#if 1.f\n"
+                          "int i;\n"
+                          "#endif\n";
+    ASSERT_EQUALS("", preprocess(suffix, &outputList));
+    ASSERT_EQUALS("file0,1,syntax_error,failed to evaluate #if condition, floating point literal in preprocessor expression\n", toString(outputList));
+
+    outputList.clear();
+
+    const char hexadecimal[] = "#if 0x1p3\n"
+                               "int i;\n"
+                               "#endif\n";
+    ASSERT_EQUALS("", preprocess(hexadecimal, &outputList));
+    ASSERT_EQUALS("file0,1,syntax_error,failed to evaluate #if condition, floating point literal in preprocessor expression\n", toString(outputList));
+
+    outputList.clear();
+
+    const char integer[] = "#if A == 1\n"
+                           "int i;\n"
+                           "#endif\n";
+    ASSERT_EQUALS("\nint i ;", preprocess(integer, dui, &outputList));
+    ASSERT_EQUALS("", toString(outputList));
+}
+
 static void ifCharLiteral()
 {
     const char code[] = "#if ('A'==0x41)\n"
@@ -4717,6 +4771,7 @@ static void runTests(int argc, char **argv, Input input)
     TEST_CASE(ifdef2);
     TEST_CASE(ifndef);
     TEST_CASE(ifA);
+    TEST_CASE(ifFloatingPointLiteral); // #612
     TEST_CASE(ifCharLiteral);
     TEST_CASE(ifDefined);
     TEST_CASE(ifDefinedNoPar);