Merge pull request #4004 from sahiljain/fix-3909

Return error when full string cannot be parsed into int

include/flatbuffers/util.h

@@ -95,20 +95,20 @@ inline std::string IntToStringHex(int i, int xdigits) {
 }
 
 // Portable implementation of strtoll().
-inline int64_t StringToInt(const char *str, int base = 10) {
+inline int64_t StringToInt(const char *str, char **endptr = nullptr, int base = 10) {
   #ifdef _MSC_VER
-    return _strtoi64(str, nullptr, base);
+    return _strtoi64(str, endptr, base);
   #else
-    return strtoll(str, nullptr, base);
+    return strtoll(str, endptr, base);
   #endif
 }
 
 // Portable implementation of strtoull().
-inline int64_t StringToUInt(const char *str, int base = 10) {
+inline int64_t StringToUInt(const char *str, char **endptr = nullptr, int base = 10) {
   #ifdef _MSC_VER
-    return _strtoui64(str, nullptr, base);
+    return _strtoui64(str, endptr, base);
   #else
-    return strtoull(str, nullptr, base);
+    return strtoull(str, endptr, base);
   #endif
 }
 

src/idl_parser.cpp

@@ -219,7 +219,7 @@ CheckedError Parser::ParseHexNum(int nibbles, int64_t *val) {
       return Error("escape code must be followed by " + NumToString(nibbles) +
                    " hex digits");
   std::string target(cursor_, cursor_ + nibbles);
-  *val = StringToUInt(target.c_str(), 16);
+  *val = StringToUInt(target.c_str(), nullptr, 16);
   cursor_ += nibbles;
   return NoError();
 }
@@ -447,7 +447,7 @@ CheckedError Parser::Next() {
               cursor_++;
               while (isxdigit(static_cast<unsigned char>(*cursor_))) cursor_++;
               attribute_.append(start + 2, cursor_);
-              attribute_ = NumToString(StringToUInt(attribute_.c_str(), 16));
+              attribute_ = NumToString(StringToUInt(attribute_.c_str(), nullptr, 16));
               token_ = kTokenIntegerConstant;
               return NoError();
           }
@@ -1093,10 +1093,15 @@ CheckedError Parser::ParseSingleValue(Value &e) {
       NEXT();
     } else {  // Numeric constant in string.
       if (IsInteger(e.type.base_type)) {
-        // TODO(wvo): do we want to check for garbage after the number?
-        e.constant = NumToString(StringToInt(attribute_.c_str()));
+        char *end;
+        e.constant = NumToString(StringToInt(attribute_.c_str(), &end));
+        if (*end)
+          return Error("invalid integer: " + attribute_);
       } else if (IsFloat(e.type.base_type)) {
-        e.constant = NumToString(strtod(attribute_.c_str(), nullptr));
+        char *end;
+        e.constant = NumToString(strtod(attribute_.c_str(), &end));
+        if (*end)
+          return Error("invalid float: " + attribute_);
       } else {
         assert(0);  // Shouldn't happen, we covered all types.
         e.constant = "0";