open source

Example of How New Diagnostics Appear in PVS-Studio

Users sometimes ask how new diagnostics appear in the PVS-Studio static analyzer. We answer that we draw inspiration from a variety of sources: books, coding standards, our own mistakes, our users' emails, and others. Recently we came up with an interesting idea of a new diagnostic.

Example of How New Diagnostics Appear in PVS-Studio

by Andrey Karpov

From the article:

As for application software development, it doesn't make sense to enable them. The CovidSim project could do without them. Otherwise, a user will simply drown in a huge number of messages that are of little use in this case. For example, when experimenting with this set of diagnostics, we received more than a million warnings for some medium-sized open projects. Roughly speaking, every third line of code might be faulty in the view of MISRA. No one will scrape through all warnings, much less fix them. The project is either developed immediately taking into account MISRA recommendations, or this coding standard is irrelevant for it.
 

Checking Clang 11 with PVS-Studio

It's no secret that compilers employ their own built-in static code analyzers, and those are developing as well. That's why we write articles every now and then to show that our static analyzer, PVS-Studio, can find bugs even inside compilers and that we are worth our salt.

Checking Clang 11 with PVS-Studio

by Andrey Karpov

From the article:

The programmer is using a modulo operation to get a random value of either 0 or 1. But the value 1 seems to confuse developers and make them write the classic anti-pattern in which the modulo operation is performed on 1 instead of 2. The X % 1 operation is meaningless as it always evaluates to 0.

Checking a Header-Only C++ Library Collection (awesome-hpp)

Somehow, we've happened to check most of the libraries making up a collection called "Awesome hpp". These are small header-only projects in C++. Hopefully, the information about the bugs we've found will help make the libraries better.

Checking a Header-Only C++ Library Collection (awesome-hpp)

by Andrey Karpov

From the article:

A note for library developers. You can use PVS-Studio to check open-source projects for free. To get a free license to use with your open-source project, please fill in this form.

Why it is important to apply static analysis for open libraries that you add to your project

If there are several options, it is useful to take time to analyze open libraries in order to choose the best one.

Why it is important to apply static analysis for open libraries that you add to your project

by Andrey Karpov

From the article:

Because of a typo, the original vector is returned, not the new scaledVector container. The same error occurs in the division operator. Facepalm. Again, these errors don't mean anything separately. Although, this is a hint that this library isn't used much and there is highly likely that there are other serious undetected errors in it.

Top 10 Bugs Found in C++ Projects in 2019

Another year is drawing to an end, and it's a perfect time to make yourself a cup of coffee and reread the reviews of bugs collected across open-source projects over this year.

Top 10 Bugs Found in C++ Projects in 2019

by Maxim Zvyagintsev

From the article:

float yScale = 1.0 / tan((3.141592538 / 180.0) * fov / 2);

There's a tiny typo in the Pi number (3,141592653...): the number "6" is missing at the 7th decimal place.
 

Finding bugs in the code of LLVM project with the help of PVS-Studio

Let's take a look at the suspicious fragments in the LLVM code which PVS-Studio detected.

Finding bugs in the code of LLVM project with the help of PVS-Studio

by Andrey Karpov

From the article:

LLVM developers, of course, will be able to understand if there is a bug here or not. I have to play detective. Looking at the code, I was thinking in the following direction: The function should read the opening bracket '<', then it reads the identifiers and commas in the loop. If there is no comma, we expected a closing bracket. If something goes wrong, then the function returns an error code. I reckon there was supposed to be the following algorithm of the function work (pseudocode).