# V2587\. MISRA\. The '//' and '/\*' character sequences should not appear within comments\.

This diagnostic rule is based on the [MISRA](https://www.misra.org.uk/) \(Motor Industry Software Reliability Association\) software development standard\.

This rule applies only to C\. Comments must not contain character sequences that are reserved to indicate a comment's beginning\. This is possible if a comment block was not closed with the '\*/' sequence or if a block was commented out line\-by\-line with the '//' sequences\.

For example:

```cpp
/* this comment is not closed
some_critical_function();
/* We're still inside the comment */
```

In the code above, the first comment block is not closed and the second block of comments is opened inside the first one\. In this scenario, crucial code may end up inside comments\.

The problem extends to single\-line comments as well\. For example:

```cpp
int some_function(int x, int y)
{
    return x // /*
               + y
             // */
            ;
}
```

A single\-line comment takes precedence over the multi\-line one\. Thus, the resulting expression is the following:

```cpp
return x + y;
```

instead of the expected one:

```cpp
int x = y;
```

The analyzer does not issue a warning if the '//' sequence is inside a single\-line comment:

```cpp
....
// some_unecessary_call_1(); // probably, should not do this
// some_unecessary_call_2(); // probably, should not do this too
....
```

In the code above, somebody must have added comments after method calls \- and then commented out the entire code block as single\-line comments\.