To get a trial key
fill out the form below
Team License (a basic version)
Enterprise License (extended version)
* By clicking this button you agree to our Privacy Policy statement

Request our prices
New License
License Renewal
--Select currency--
USD
EUR
GBP
RUB
* By clicking this button you agree to our Privacy Policy statement

Free PVS-Studio license for Microsoft MVP specialists
* By clicking this button you agree to our Privacy Policy statement

To get the licence for your open-source project, please fill out this form
* By clicking this button you agree to our Privacy Policy statement

I am interested to try it on the platforms:
* By clicking this button you agree to our Privacy Policy statement

Message submitted.

Your message has been sent. We will email you at


If you haven't received our response, please do the following:
check your Spam/Junk folder and click the "Not Spam" button for our message.
This way, you won't miss messages from our team in the future.

>
>
Just a Few Bugs in 514K Lines of Code -…

Just a Few Bugs in 514K Lines of Code - Amazon Web Services SDK for C++

Mar 03 2016

Amazon Web Services open-sourced C++ SDK, a modern C++ interface with lightweight dependencies. This prompted our team to apply PVS-Studio static analysis tool to the source code in order to try to reveal some interesting code fragments.

0378_AmazonSDK/image1.png

The developers of AWS SDK for C++ state that it is meant to be fully functioning, with both low-level and high-level interfaces; at the same time having minimum dependencies and providing platform portability (Windows, OSX, Linux, and mobile).The source code is available at GitHub repository.

PVS-Studio is a static analyzer for bug detection in the source code of programs, written in C, C++ and C#.

The size of the project to be analyzed is 5415 files, more than 514 thousand lines of code. Usually projects of that size contain a significant number of high and low-severity bugs, making a nice addition to our error collection.

This time, there is nothing much to say, but to give a big round of applause to the AWeSome developers for the quality of this project. They really did a great job: the analyzer managed to detect only a couple of low-severity bugs. Here they are, with the analyzer warnings:

V547 Expression 'pathname_.c_str() == 0' is always false. Pointer 'pathname_.c_str()' != NULL. gtest-all.cc 8189

std::string pathname_;
void FilePath::Normalize() {
  if (pathname_.c_str() == NULL) {  // <=
    pathname_ = "";
    return;
  }
  const char* src = pathname_.c_str();
  char* const dest = new char[pathname_.length() + 1];
  ....
}

The string::c_str() function returns the pointer to the c-string that cannot be equal to NULL. Even if an empty string will be created - like "string buf;", for instance; then the "buf.c_str()" will return a valid pointer to the empty string.

Thus, the condition "pathname_.c_str() == NULL" will always be false and the function will never exit in this fragment. Most likely this function has to be exited if the "pathname_" string is empty. Then the check should be as follows:

std::string pathname_;
void FilePath::Normalize() {
  if (pathname_.empty()) {
    return;
  }
  ....
}

Two more similar fragments:

  • V547 Expression 'output_file_.c_str() == 0' is always false. Pointer 'output_file_.c_str()' != NULL. gtest-all.cc 4575
  • V547 Expression 'os_stack_trace.c_str() != 0' is always true. Pointer 'os_stack_trace.c_str()' != NULL. gtest-all.cc 5286

That's it! Just a couple of suspicious fragments in a project with more than 514 k lines of code. There were several examples of fragments that seemed a little strange, but they aren't even worth mentioning here. That is truly impressive. We have to admit - having checked more than 200 projects we are more than surprised to see such a tiny number of bugs. Way to go, Amazon!

Popular related articles
Static analysis as part of the development process in Unreal Engine

Date: Jun 27 2017

Author: Andrey Karpov

Unreal Engine continues to develop as new code is added and previously written code is changed. What is the inevitable consequence of ongoing development in a project? The emergence of new bugs in th…
The Ultimate Question of Programming, Refactoring, and Everything

Date: Apr 14 2016

Author: Andrey Karpov

Yes, you've guessed correctly - the answer is "42". In this article you will find 42 recommendations about coding in C++ that can help a programmer avoid a lot of errors, save time and effort. The au…
Free PVS-Studio for those who develops open source projects

Date: Dec 22 2018

Author: Andrey Karpov

On the New 2019 year's eve, a PVS-Studio team decided to make a nice gift for all contributors of open-source projects hosted on GitHub, GitLab or Bitbucket. They are given free usage of PVS-Studio s…
Appreciate Static Code Analysis!

Date: Oct 16 2017

Author: Andrey Karpov

I am really astonished by the capabilities of static code analysis even though I am one of the developers of PVS-Studio analyzer myself. The tool surprised me the other day as it turned out to be sma…
Characteristics of PVS-Studio Analyzer by the Example of EFL Core Libraries, 10-15% of False Positives

Date: Jul 31 2017

Author: Andrey Karpov

After I wrote quite a big article about the analysis of the Tizen OS code, I received a large number of questions concerning the percentage of false positives and the density of errors (how many erro…
The Last Line Effect

Date: May 31 2014

Author: Andrey Karpov

I have studied many errors caused by the use of the Copy-Paste method, and can assure you that programmers most often tend to make mistakes in the last fragment of a homogeneous code block. I have ne…
How PVS-Studio Proved to Be More Attentive Than Three and a Half Programmers

Date: Oct 22 2018

Author: Andrey Karpov

Just like other static analyzers, PVS-Studio often produces false positives. What you are about to read is a short story where I'll tell you how PVS-Studio proved, just one more time, to be more atte…
Technologies used in the PVS-Studio code analyzer for finding bugs and potential vulnerabilities

Date: Nov 21 2018

Author: Andrey Karpov

A brief description of technologies used in the PVS-Studio tool, which let us effectively detect a large number of error patterns and potential vulnerabilities. The article describes the implementati…
PVS-Studio for Java

Date: Jan 17 2019

Author: Andrey Karpov

In the seventh version of the PVS-Studio static analyzer, we added support of the Java language. It's time for a brief story of how we've started making support of the Java language, how far we've co…
The way static analyzers fight against false positives, and why they do it

Date: Mar 20 2017

Author: Andrey Karpov

In my previous article I wrote that I don't like the approach of evaluating the efficiency of static analyzers with the help of synthetic tests. In that article, I give the example of a code fragment…

Comments (0)

Next comments
This website uses cookies and other technology to provide you a more personalized experience. By continuing the view of our web-pages you accept the terms of using these files. If you don't want your personal data to be processed, please, leave this site.
Learn More →
Accept