games

Command & Conquer

/ hownot2code / Leave a comment

270599

Suspicious formatting

V705 It is possible that ‘else’ block was forgotten or commented out, thus altering the program’s operation logics. NETDLG.CPP 1506

static int Net_Join_Dialog(void)
{
  ....
  /*...............................................................
  F4/SEND/'M' = edit a message
  ...............................................................*/
  if (Messages.Get_Edit_Buf()==NULL) {
    ....
  } else  /*...............................................................
  If we're already editing a message and the user clicks on
  'Send', translate our input to a Return so Messages.Input() will
  work properly.
  ...............................................................*/
  if (input==(BUTTON_SEND | KN_BUTTON)) {
    input = KN_RETURN;
  }
  ....
}

Due to a large comment, the developer hasn’t seen the above unfinished conditional operator. The remaining else keyword forms the else if construction with the condition below, which most likely changes the original logic.

Please click here to see more bugs from this project.

Command & Conquer

/ hownot2code / Leave a comment

270599

Array overrun

V557 Array overrun is possible. The ‘QuantityB’ function processes value ‘[0..86]’. Inspect the first argument. Check lines: ‘HOUSE.H:928’, ‘CELL.CPP:2337’. HOUSE.H 928

typedef enum StructType : char {
  STRUCT_NONE=-1,
  ....
  STRUCT_COUNT,   // <= 87
  STRUCT_FIRST=0
} StructType;
int BQuantity[STRUCT_COUNT-3];
int QuantityB(int index) {return(BQuantity[index]);}
bool CellClass::Goodie_Check(FootClass * object)
{
  ....
  int bcount = 0;
  for( j=0; j < STRUCT_COUNT; j++) {     bcount += hptr->QuantityB(j);
  }
  ....
}

There are a lot of global variables in the code and it is obvious that they are easy to get confused. The analyzer’s warning about an array index out of bounds is issued at the point of accessing the BQuantity array by index. The array size is 84 elements. Algorithms for analyzing the data flow in the analyzer helped to find out that the index value comes from another function – Goodie_Check. There, a loop is executed with a final value of 86. Therefore, 12 bytes of “someone’s” memory (3 int elements) are constantly being read in this place.

Please click here to see more bugs from this project.

“Why is there no artificial intelligence yet?” Or, analysis of CNTK tool kit from Microsoft Research.

/ hownot2code / Leave a comment

Microsoft have given open access to the source code of a tool kit that is used in the company to speed up the development of artificial intelligence: Computational Network Toolkit is now available at Github. The developers had to create their own custom solution, because the existing tools did not work fast enough.

Let’s have a look at the analysis results of the source code of this project, as done by our static code analyzer.

1e4e9l

Continue reading →

Finding bugs in the code of LLVM project

/ hownot2code / Leave a comment

About two months ago I wrote an article about the analysis of GCC using PVS-Studio. The idea of the article was as follows: GCC warnings are great, but they’re not enough. As proof of my words I showed errors that PVS-Studio was able to find the GCC code. A number of readers have noticed that the quality of the GCC code, and its diagnosis, aren’t really great; while Clang compiler is up to date, of high quality, and fresh. In general Clang is awesome! Well, apparently, it’s time to check LLVM project.

image1

Continue reading →

5 inspiring examples – programming languages that popular computer games are written on

/ hownot2code / 3 Comments

Video games are a big business. Total revenue for the U.S. video game industry reached $23.5 billion last year, a 5 percent increase from 2014. Behind every video game are programmers who help develop the product. Although programming languages vary by game, a few are the most popular. Here’s a look at the languages powering video game development.

Continue reading →