I hope you have already rested from the 13-th lesson and now are ready to study one more important error pattern related to arithmetic expressions in which types of different capacities participate.
In a poorly written code you may often see magic numeric constants whose presence is dangerous by itself. When porting code to a 64-bit platform, these constants may make the code inefficient if they participate in address computation, object size computation or bit operations.
The document discusses operators and casts in C#. It covers various types of operators like arithmetic, comparison, conditional, etc. It explains implicit and explicit type conversions between primitive and reference types. It also discusses overloading operators for custom types and implementing user-defined casts.
The document discusses 10 important C programming interview questions. It provides detailed solutions to questions such as swapping two variables without a temporary variable, solving the 8 queens problem, printing a matrix helically, reversing words in a sentence in-place, generating permutations, and calculating the factorial of a number recursively. For each question, it explains the algorithm and provides sample C code to implement the solution.
The document discusses control statements in C++, specifically if, if-else, and nested if-else statements. It provides examples of using these conditional statements to evaluate conditions and execute code blocks accordingly. Key topics covered include using if statements to check conditions and run code, if-else statements to choose between two code blocks based on a condition being true or false, and nested if-else statements to evaluate multiple conditions in sequence. The for loop is also introduced as a way to repeat code a set number of times in C++.
The document contains 100 multiple choice questions about C programming concepts along with explanations for many of the answers. The questions cover a wide range of topics including data types, operators, arrays, pointers, functions, structures and more. For each question, the possible answer options and sometimes the reason for the correct answer are provided.
The document discusses control statements in C++, specifically if, if-else, and nested if-else statements. It provides examples of each type of if statement and how they work. The key points are:
- If statements allow executing code conditionally based on whether an expression is true or false.
- If-else statements add an "else" block that executes if the condition is false.
- Nested if statements allow placing if statements inside other if statements to create multiple levels of conditional logic.
- Examples demonstrate how each type of if statement evaluates conditions and executes the appropriate code blocks.
This document provides an overview of advanced data types in C programming, including arrays, strings, and 2D arrays. It discusses how to define and initialize arrays, access array elements, and store and print values in arrays. It also covers string operations like copying, comparing, converting between strings and other data types, and manipulating string case and length. The document concludes with references for further reading on controlling program flow and variable scope in C.
This document discusses numerical concepts in C++ including NaN, IND, INF, and DEN. It provides:
- Definitions and examples of each concept
- Non-standard and standard representations of each in memory
- How each appears when displayed or printed
- Properties like comparison and calculations involving each value
- Notes that the representations shown are not definitive and the IEEE standard specifies floating point formats
The document is intended to share knowledge of how these special numerical values are handled in C++ for those dealing with floating point arithmetic and extensive calculations.
In a poorly written code you may often see magic numeric constants whose presence is dangerous by itself. When porting code to a 64-bit platform, these constants may make the code inefficient if they participate in address computation, object size computation or bit operations.
The document discusses operators and casts in C#. It covers various types of operators like arithmetic, comparison, conditional, etc. It explains implicit and explicit type conversions between primitive and reference types. It also discusses overloading operators for custom types and implementing user-defined casts.
The document discusses 10 important C programming interview questions. It provides detailed solutions to questions such as swapping two variables without a temporary variable, solving the 8 queens problem, printing a matrix helically, reversing words in a sentence in-place, generating permutations, and calculating the factorial of a number recursively. For each question, it explains the algorithm and provides sample C code to implement the solution.
The document discusses control statements in C++, specifically if, if-else, and nested if-else statements. It provides examples of using these conditional statements to evaluate conditions and execute code blocks accordingly. Key topics covered include using if statements to check conditions and run code, if-else statements to choose between two code blocks based on a condition being true or false, and nested if-else statements to evaluate multiple conditions in sequence. The for loop is also introduced as a way to repeat code a set number of times in C++.
The document contains 100 multiple choice questions about C programming concepts along with explanations for many of the answers. The questions cover a wide range of topics including data types, operators, arrays, pointers, functions, structures and more. For each question, the possible answer options and sometimes the reason for the correct answer are provided.
The document discusses control statements in C++, specifically if, if-else, and nested if-else statements. It provides examples of each type of if statement and how they work. The key points are:
- If statements allow executing code conditionally based on whether an expression is true or false.
- If-else statements add an "else" block that executes if the condition is false.
- Nested if statements allow placing if statements inside other if statements to create multiple levels of conditional logic.
- Examples demonstrate how each type of if statement evaluates conditions and executes the appropriate code blocks.
This document provides an overview of advanced data types in C programming, including arrays, strings, and 2D arrays. It discusses how to define and initialize arrays, access array elements, and store and print values in arrays. It also covers string operations like copying, comparing, converting between strings and other data types, and manipulating string case and length. The document concludes with references for further reading on controlling program flow and variable scope in C.
This document discusses numerical concepts in C++ including NaN, IND, INF, and DEN. It provides:
- Definitions and examples of each concept
- Non-standard and standard representations of each in memory
- How each appears when displayed or printed
- Properties like comparison and calculations involving each value
- Notes that the representations shown are not definitive and the IEEE standard specifies floating point formats
The document is intended to share knowledge of how these special numerical values are handled in C++ for those dealing with floating point arithmetic and extensive calculations.
C Programming Language is the most popular computer language and most used programming language till now. It is very simple and elegant language. This lecture series will give you basic concepts of structured programming language with C.
64-bit computers have been around and well for a long time already. Most applications have 64-bit versions that can benefit from larger memory capacity and improved performance thanks to the architectural capabilities of 64-bit processors. Developing 64-bit application in C/C++ requires much attention from a programmer. There is a number of reasons for 32-bit code to fail to work properly when recompiled for the 64-bit platform. There are a lot of articles on this subject, so we will focus on some other thing. Let's find out if the new features introduced in C++11 have made 64-bit software programmers' life any better and easier.
Note. The article was originally published in Software Developer's Journal (April 25, 2014) and is published here by the editors' permission.
Type Conversion in C++ and C# Arithmetic ExpressionsPVS-Studio
In arithmetic expressions, the types of operands can be converted to a common type. Such conversions are described in the language standard, and in C# they are much simpler than in C++. However, I'm not sure that many programmers know all the details.
This document contains a C programming assignment submitted by Vijayananda D Mohire for their Post Graduate Diploma in Information Technology. The assignment contains 11 questions on basic C programming concepts like data types, variables, functions, structures, file handling etc. For each question, the code for the algorithm/program is provided as the answer. The questions cover topics like checking odd/even numbers, calculating sum of numbers, interest calculation, number divisibility, swapping values, month to word conversion using switch case, structure to store employee data, reading and writing to files.
The document discusses C programming concepts including operators, loops, functions, pointers, and file handling. It contains sample code to demonstrate:
1) Summing integers entered interactively using a while loop.
2) Calculating the average length of text lines using global variables and functions.
3) Adding and subtracting numbers using pointer variables and dereferencing operators.
4) Checking for a null pointer and using it as a placeholder.
5) Searching a specified file for a given character using command line arguments.
Analyzing the Quake III Arena GPL projectPVS-Studio
As you know, the id Software company has laid out source codes of many of their games. We already checked some of these projects earlier. This time we decided to analyze the Quake III Arena GPL source code. Analysis was performed with PVS-Studio 4.54.
Bit is the smallest unit of information in a computer. Multiple bits can represent more complex data through binary encoding. Programmers must consider how many bits are needed to store each data item efficiently. Most computers handle bits in bytes, which are 8-bit chunks. A byte can store one of 256 possible values. Higher-level data types like integers are usually stored across multiple bytes, with the most significant byte first or last depending on the endianness of the architecture.
C Programming Language is the most popular computer language and most used programming language till now. It is very simple and elegant language. This lecture series will give you basic concepts of structured programming language with C.
The document discusses one-dimensional and multidimensional arrays in C. It covers declaring and initializing arrays, accessing array elements using subscripts, and built-in functions like sizeof that operate on arrays. It also introduces variable-length arrays, a C99 feature that allows arrays to have non-constant lengths specified at runtime rather than compilation. Examples are provided for common array operations like copying, initializing, and traversing arrays with for loops. Restrictions on variable-length arrays and potential issues with goto statements are also noted.
Bit-fields allow access to individual bits within registers or bytes. They define the number of bits for a field within a structure. Bit-fields are useful for storing Boolean values or device status encoded in bits. Pointers store the address of another variable in memory. They allow passing data to functions without copying values and enable functions to modify caller's variables. Pointer arithmetic can be used to access elements in an array using pointers.
This document provides an introduction to C++ programming. It covers basic concepts like variables, data types, input/output statements, conditional statements, loops, arrays, functions, and classes. Some key points:
- A C++ program consists of variable declarations, input/output statements, computations, and printing output. Comments begin with //.
- Variables are declared with a data type like int or double followed by the name. Input is done with cin and output with cout.
- Conditional statements like if-else and loops like while are used to control program flow. Boolean conditions use comparison and logical operators.
- Arrays allow storing multiple values of a type. Functions can be predefined or programmer-
This document summarizes the basic types in C including integer types, floating types, and character types. It discusses integer types like short, int, long, and their signed and unsigned variants. It also covers floating point types float, double, long double. Character types are discussed along with escape sequences and character operations. Integer constants, floating constants, and the sizeof operator are also summarized.
A pointer is a variable that stores the memory address of another variable. A double pointer stores the address of a pointer variable. In the example code, a double pointer p2 stores the address of a single pointer p1, which stores the address of an integer variable v. The code then prints the value of v using the single and double pointers to demonstrate this. Pointers allow arithmetic operations like incrementing and decrementing to move the pointer to the next memory location without changing the actual variable value. A function pointer is a pointer that points to executable code in memory, allowing a function to be indirectly called through the pointer variable.
This chapter discusses different types of repetition statements in Java including while, do-while, for, and nested loops. It covers implementing repetition using these statements, choosing the appropriate one for a given task, and avoiding common pitfalls like off-by-one errors and infinite loops. Examples are provided to demonstrate generating tables with nested for loops and formatting output using the Formatter class.
The document provides an overview of the C programming language. It discusses that C was developed in 1972 at Bell Labs and the Unix operating system was written in C. It then summarizes some basic elements of C like data types (int, char, float), variables, operators, conditional statements like if-else, loops like for and while loops, and functions. The document gives examples of many common functions in C like printf(), scanf(), getch() etc.
The document provides an outline and overview of key concepts in C++ basics, including variables and assignments, identifiers, keywords, input and output, data types and expressions, and arithmetic. It discusses how variables represent memory locations, how to declare and initialize variables of different data types like int, double, char, and bool, and how to perform input and output using cout and cin.
C programming, RTS Tech. Indore
This is a presentation to take your skills to next level. Hope you will like our work to make programming easier for you.
Feel free to contact for the online/offline batches.
C Programming Language is the most popular computer language and most used programming language till now. It is very simple and elegant language. This lecture series will give you basic concepts of structured programming language with C.
The document provides an overview of fundamental programming concepts in C language. It begins by comparing the steps to learning English and C, then discusses algorithms, flowcharts, tokens, data types, operators, control structures like if/else, switch, loops (while, do-while, for). It also covers nested loops, and illustrates an infinite loop that repeats until the user enters 'n'. The key topics covered include basic syntax, flow control, and programming constructs in C.
Difficulties of comparing code analyzers, or don't forget about usabilityPVS-Studio
Users' desire to compare different code analyzers is natural and understandable. However, it's not so easy to fulfill this desire as it may seem at first sight. The point is that you don't know what particular factors must be compared.
Potential errors in 64-bit code may occur depending on compiler optimizations and input data sizes. Slight code changes can expose or hide errors, making them difficult to find. Optimizations may use 64-bit registers to avoid overflows, but minor code alterations could cause 32-bit registers and overflows. Therefore, code with potential errors is unstable and hard to test thoroughly.
C Programming Language is the most popular computer language and most used programming language till now. It is very simple and elegant language. This lecture series will give you basic concepts of structured programming language with C.
64-bit computers have been around and well for a long time already. Most applications have 64-bit versions that can benefit from larger memory capacity and improved performance thanks to the architectural capabilities of 64-bit processors. Developing 64-bit application in C/C++ requires much attention from a programmer. There is a number of reasons for 32-bit code to fail to work properly when recompiled for the 64-bit platform. There are a lot of articles on this subject, so we will focus on some other thing. Let's find out if the new features introduced in C++11 have made 64-bit software programmers' life any better and easier.
Note. The article was originally published in Software Developer's Journal (April 25, 2014) and is published here by the editors' permission.
Type Conversion in C++ and C# Arithmetic ExpressionsPVS-Studio
In arithmetic expressions, the types of operands can be converted to a common type. Such conversions are described in the language standard, and in C# they are much simpler than in C++. However, I'm not sure that many programmers know all the details.
This document contains a C programming assignment submitted by Vijayananda D Mohire for their Post Graduate Diploma in Information Technology. The assignment contains 11 questions on basic C programming concepts like data types, variables, functions, structures, file handling etc. For each question, the code for the algorithm/program is provided as the answer. The questions cover topics like checking odd/even numbers, calculating sum of numbers, interest calculation, number divisibility, swapping values, month to word conversion using switch case, structure to store employee data, reading and writing to files.
The document discusses C programming concepts including operators, loops, functions, pointers, and file handling. It contains sample code to demonstrate:
1) Summing integers entered interactively using a while loop.
2) Calculating the average length of text lines using global variables and functions.
3) Adding and subtracting numbers using pointer variables and dereferencing operators.
4) Checking for a null pointer and using it as a placeholder.
5) Searching a specified file for a given character using command line arguments.
Analyzing the Quake III Arena GPL projectPVS-Studio
As you know, the id Software company has laid out source codes of many of their games. We already checked some of these projects earlier. This time we decided to analyze the Quake III Arena GPL source code. Analysis was performed with PVS-Studio 4.54.
Bit is the smallest unit of information in a computer. Multiple bits can represent more complex data through binary encoding. Programmers must consider how many bits are needed to store each data item efficiently. Most computers handle bits in bytes, which are 8-bit chunks. A byte can store one of 256 possible values. Higher-level data types like integers are usually stored across multiple bytes, with the most significant byte first or last depending on the endianness of the architecture.
C Programming Language is the most popular computer language and most used programming language till now. It is very simple and elegant language. This lecture series will give you basic concepts of structured programming language with C.
The document discusses one-dimensional and multidimensional arrays in C. It covers declaring and initializing arrays, accessing array elements using subscripts, and built-in functions like sizeof that operate on arrays. It also introduces variable-length arrays, a C99 feature that allows arrays to have non-constant lengths specified at runtime rather than compilation. Examples are provided for common array operations like copying, initializing, and traversing arrays with for loops. Restrictions on variable-length arrays and potential issues with goto statements are also noted.
Bit-fields allow access to individual bits within registers or bytes. They define the number of bits for a field within a structure. Bit-fields are useful for storing Boolean values or device status encoded in bits. Pointers store the address of another variable in memory. They allow passing data to functions without copying values and enable functions to modify caller's variables. Pointer arithmetic can be used to access elements in an array using pointers.
This document provides an introduction to C++ programming. It covers basic concepts like variables, data types, input/output statements, conditional statements, loops, arrays, functions, and classes. Some key points:
- A C++ program consists of variable declarations, input/output statements, computations, and printing output. Comments begin with //.
- Variables are declared with a data type like int or double followed by the name. Input is done with cin and output with cout.
- Conditional statements like if-else and loops like while are used to control program flow. Boolean conditions use comparison and logical operators.
- Arrays allow storing multiple values of a type. Functions can be predefined or programmer-
This document summarizes the basic types in C including integer types, floating types, and character types. It discusses integer types like short, int, long, and their signed and unsigned variants. It also covers floating point types float, double, long double. Character types are discussed along with escape sequences and character operations. Integer constants, floating constants, and the sizeof operator are also summarized.
A pointer is a variable that stores the memory address of another variable. A double pointer stores the address of a pointer variable. In the example code, a double pointer p2 stores the address of a single pointer p1, which stores the address of an integer variable v. The code then prints the value of v using the single and double pointers to demonstrate this. Pointers allow arithmetic operations like incrementing and decrementing to move the pointer to the next memory location without changing the actual variable value. A function pointer is a pointer that points to executable code in memory, allowing a function to be indirectly called through the pointer variable.
This chapter discusses different types of repetition statements in Java including while, do-while, for, and nested loops. It covers implementing repetition using these statements, choosing the appropriate one for a given task, and avoiding common pitfalls like off-by-one errors and infinite loops. Examples are provided to demonstrate generating tables with nested for loops and formatting output using the Formatter class.
The document provides an overview of the C programming language. It discusses that C was developed in 1972 at Bell Labs and the Unix operating system was written in C. It then summarizes some basic elements of C like data types (int, char, float), variables, operators, conditional statements like if-else, loops like for and while loops, and functions. The document gives examples of many common functions in C like printf(), scanf(), getch() etc.
The document provides an outline and overview of key concepts in C++ basics, including variables and assignments, identifiers, keywords, input and output, data types and expressions, and arithmetic. It discusses how variables represent memory locations, how to declare and initialize variables of different data types like int, double, char, and bool, and how to perform input and output using cout and cin.
C programming, RTS Tech. Indore
This is a presentation to take your skills to next level. Hope you will like our work to make programming easier for you.
Feel free to contact for the online/offline batches.
C Programming Language is the most popular computer language and most used programming language till now. It is very simple and elegant language. This lecture series will give you basic concepts of structured programming language with C.
The document provides an overview of fundamental programming concepts in C language. It begins by comparing the steps to learning English and C, then discusses algorithms, flowcharts, tokens, data types, operators, control structures like if/else, switch, loops (while, do-while, for). It also covers nested loops, and illustrates an infinite loop that repeats until the user enters 'n'. The key topics covered include basic syntax, flow control, and programming constructs in C.
Difficulties of comparing code analyzers, or don't forget about usabilityPVS-Studio
Users' desire to compare different code analyzers is natural and understandable. However, it's not so easy to fulfill this desire as it may seem at first sight. The point is that you don't know what particular factors must be compared.
Potential errors in 64-bit code may occur depending on compiler optimizations and input data sizes. Slight code changes can expose or hide errors, making them difficult to find. Optimizations may use 64-bit registers to avoid overflows, but minor code alterations could cause 32-bit registers and overflows. Therefore, code with potential errors is unstable and hard to test thoroughly.
Viva64: working up of 64-bit applicationsPVS-Studio
Viva64 is a static code analysis tool that helps detect errors and issues when porting C/C++ applications to 64-bit platforms. It integrates directly with Visual Studio 2005, allowing developers to check for 64-bit portability issues and incorrect code constructions. Viva64 can analyze entire projects and provides detailed diagnostics and references to help developers understand and fix issues. While it cannot replace full testing, using Viva64 during development can significantly improve code quality and reduce bugs when porting to 64-bit.
Development of a static code analyzer for detecting errors of porting program...PVS-Studio
The article concerns the task of developing a program tool called static analyzer. The tool being developed is used for diagnosing potentially unsafe syntactic structures of C++ from the viewpoint of porting program code on 64-bit systems. Here we focus not on the problems of porting occurring in programs, but on the peculiarities of creating a specialized code analyzer. The analyzer is intended for working with the code of C/C++ programs.
The article is a report about testing of portability of Loki library with 64-bit systems with the help of Viva64 code analyzer performed by OOO "Program Verification Systems" Company. It contains recommendations for users of the library. The article will be also useful for the users of other libraries built on templates for it describes the peculiarities of analysis of such libraries.
Case Study: Porting a set of point cloud and triangle mesh processing C++ lib...PVS-Studio
The document discusses porting a C++ library for processing point clouds and triangle meshes from 32-bit to 64-bit. An Italian company called E.G.S. S.r.l. that develops 3D simulation solutions used a library called Leios Components that it wanted to port to 64-bit. They hired a company called OOO "Program Verification Systems" to help with the port using their code analyzer Viva64. Viva64 found and corrected issues allowing the large library to be successfully ported to 64-bit in a short timeframe.
Comparing PVS-Studio with other code analyzersPVS-Studio
The article discusses comparison of PVS-Studio code analyzer with other solutions in this sphere. As PVS-Studio contains modules for diagnosing 64-bit and parallel errors, it is compared to various types of tools.
VivaMP, system of detecting errors in the code of parallel C++ programs using...PVS-Studio
The article lists the results of investigation of mistakes made by programmers using C++ and OpenMP. Static analysis is offered for automatic detection of these errors. The description of VivaMP analyzer integrating into Visual Studio environment and implementing the set task is described.
Comparing the general static analysis in Visual Studio 2010 and PVS-Studio by...PVS-Studio
The article demonstrates errors detected with the static code analyzer integrated into Visual Studio 2010. The research was performed on five open source projects. The same projects were also checked with PVS-Studio. Results of comparing these two tools are presented at the end of the article.
Questions concerned with the release of drivers for 64-bit versions of Windows are considered in this article. Some typical problems and the ways of their solutions are listed in the article as well as tools which simplify the process of drivers developing.
Comparison of analyzers' diagnostic possibilities at checking 64-bit codePVS-Studio
The article compares a specialized static analyzer Viva64 with universal static analyzers Parasoft C++Test and Gimpel Software PC-Lint. The comparison is carried within the framework of the task of porting 32-bit C/C++ code on 64-bit systems or developing new code with taking into account peculiarities of 64-bit architecture.
Since multi-core systems are spreading fast, the problem of parallel programming becomes more and more urgent. However, even the majority of experienced developers are new to this sphere. The existing compilers and code analyzers allow finding some bugs, which appear during parallel code development. However, many errors are not diagnosed. The article contains description of a number of errors, which lead to incorrect behavior of parallel programs created with OpenMP.
Mobile CRM Webinar: 6 Steps to Mobile ROI for Government AgenciesWaterfall Mobile
Given the importance of delivering meaningful content to a broad audience within the government sector, mobile presents a critical investment for government agencies. However, the mobile ecosystem’s complexity makes it challenging to scope a detailed roadmap. This webinar, from the Msgme Industry Insights series, details exactly how government agencies can be successful using mobile to engage their audience.
The tool for programmers VivaMP is intended for helping OpenMP-based parallel software developers. The article gives a brief description of the program product.
Optimization in the world of 64-bit errorsPVS-Studio
1. The document discusses the difficulty of demonstrating 64-bit errors through simple examples due to compiler optimizations.
2. An example code is provided that contains two errors by using 32-bit integers to index into a large 64-bit array, but it works correctly due to compiler optimizations.
3. A small change is made to the code to prevent the optimizations and cause it to crash as expected when run with the errors.
4. The author notes that 64-bit errors can be hidden by optimizations and evade detection in debugging and testing, but still cause failures when changes are made or on new compiler versions. Close inspection is needed to find these subtle errors.
The article describes the main preconditions and stages of development of open VivaCore library intended for code analysis and creation of metaprogramming systems. VivaCore project is a development of OpenC++ library in which support of C and C++ language peculiarities specific for Visual Studio 2005/2008 is implemented.
We have chosen the 13-th lesson to discuss the errors related to address arithmetic deliberately. The errors related to pointer arithmetic in 64-bit systems are the most insidious and it would be good that number 13 made you more attentive.
The article will help the readers understand what size_t and ptrdiff_t types are, what they are used for and when they must be used. The article will be interesting for those developers who begin creation of 64-bit applications where use of size_t and ptrdiff_t types provides high performance, possibility to operate large data sizes and portability between different platforms.
This document discusses various concepts related to C programming including data types, operators, decision making statements, and loops. It begins with an example "Hello World" C program and explains each part. It then covers various data types in C like integer, float, char, etc. along with their sizes and ranges. Different types of operators like arithmetic, logical, assignment, increment/decrement are described. Decision making statements like if, if-else, if-else ladder, nested if, switch case are explained with examples. Finally, it briefly introduces the three types of loops in C - while, do-while, and for loops.
C++ Basics discusses variables, identifiers, keywords, variable declarations, assignment, output, input, and escape sequences in C++. Key points include:
- Variables hold data in memory locations labeled with their name. Common types are int for whole numbers and double for fractional numbers.
- Identifiers name variables and must start with a letter or underscore. Keywords are reserved for language use.
- Variables must be declared before use, specifying their type and name. They can be declared at the beginning or close to use.
- Assignment sets a variable's value using the = operator. Output streams like cout send data to the screen. Input streams like cin get data from the user.
Monitoring a program that monitors computer networksAndrey Karpov
There exists the NetXMS project, which is a software product designed to monitor computer systems and networks. It can be used to monitor the whole IT-infrastructure, from SNMP-compatible devices to server software. And I am naturally going to monitor the code of this project with the PVS-Studio analyzer.
We have successfully created and continue developing PVS-Studio analyzer for C/C++ languages. Over the time, it became clear that many of the diagnostics that we have implemented are not related to a specific programming language, so we decided to apply our experience to another programming language, namely C#. In this article, we are talking about the analysis of Code Contracts project by Microsoft done by our C# analyzer
A collection of examples of 64 bit errors in real programsMichael Scovetta
This document provides 30 examples of common 64-bit errors found in real C/C++ programs. The examples cover a wide range of issues like buffer overflows, unnecessary type conversions, incorrect preprocessor directives, pointer/integer confusion, use of deprecated functions, truncation of values during type conversions, undefined functions, legacy code practices, and more. The goal is to help developers identify and avoid such 64-bit porting issues when moving applications to 64-bit systems.
The document provides 20 programming problems and their solutions. Some of the key problems include: writing programs to calculate factorial using recursion, determine if a number is even or odd, swap two numbers using temporary/bitwise operators, find greatest of 3/10 numbers, check if a number is prime/palindromic, and check if a string is a palindrome. The solutions provide sample code snippets and explanations with examples to illustrate the logic.
C++ Basics introduces variables, identifiers, assignments, and input/output. Variables hold data of a specified type and are accessed by name. Identifiers name variables and follow specific naming rules. Variables are declared with a type and can be assigned values. Output streams like cout display data, while input streams like cin get user input assigned to variables. Escape sequences represent special characters in output.
C++ Basics introduces variables, identifiers, assignments, and input/output. Variables hold data of a specified type and are accessed by name. Identifiers name variables and follow specific naming rules. Variables are declared with a type and can be assigned values. Output streams like cout display data, while input streams like cin get user input assigned to variables. Escape sequences represent special characters in output.
The document provides instructions for a C++ programming assignment involving functions, pointers, arrays, and calculating pi. It includes 6 problems to solve:
1. Write functions to demonstrate default arguments, constant arguments, and random number generation.
2. Analyze sample code and identify errors in provided code snippets.
3. Write functions to calculate sums of various data types.
4. Use a Monte Carlo simulation to approximate pi by simulating dart throws on a circle and square.
5. Write functions to print, reverse, and transpose arrays.
6. Write functions to operate on strings and pointers.
Tesseract. Recognizing Errors in Recognition SoftwareAndrey Karpov
Tesseract is a free software program for text recognition developed by Google. According to the project description, "Tesseract is probably the most accurate open source OCR engine available". And what if we try to catch some bugs there with the help of the CppCat analyzer?
This document provides information about the C# programming language. It discusses that C# is an object-oriented language that can be used to build a variety of applications like Windows and web. Visual C# .NET is Microsoft's integrated development environment (IDE) for building C# applications and is part of the Visual Studio suite. The document also covers C# language fundamentals like variables, data types, operators, and conditional statements.
This document provides a quick introduction to the C programming language. It discusses basic C syntax like main functions, header files, comments, and variables. It also covers data types, memory, functions, scopes, expressions, control flow statements like if/else and loops. Functions can access arguments and global variables from their own scope but not variables from outer scopes unless passing their addresses.
The document provides a quick introduction to C programming, covering topics like functions, variables, memory, expressions, and recursion. It uses a recursive pow() function to demonstrate recursion and the call stack. Each function call gets its own copy of arguments and local variables, stored on the call stack.
The document provides a quick introduction to C programming. It discusses some key concepts in C including functions, variables, memory, data types, expressions and evaluation, and recursion. It provides an example of a recursive pow() function to calculate powers and discusses how function calls are handled through the stack.
I am Baddie K. I am a C++ Homework Expert at cpphomeworkhelp.com. I hold a Masters in Programming from The University of Queensland. I have been helping students with their homework for the past 9 years. I solve homework related to C++.
Visit cpphomeworkhelp.com or email info@cpphomeworkhelp.com. You can also call on +1 678 648 4277 for any assistance with C++ Homework.
How to make fewer errors at the stage of code writing. Part N1.PVS-Studio
I've arrived at the source code of a widely know instant messenger Miranda IM. Together with various plugins, this is a rather large project whose size is about 950 thousand code lines in C and C++. And like any other considerable project with a long development history, it has rather many errors and misprints.
A Collection of Examples of 64-bit Errors in Real ProgramsAndrey Karpov
This article is the most complete collection of examples of 64-bit errors in the C and C++ languages. The article is intended for Windows-application developers who use Visual C++, however, it will be useful for other programmers as well.
A Collection of Examples of 64-bit Errors in Real ProgramsPVS-Studio
This article is the most complete collection of examples of 64-bit errors in the C and C++ languages. The article is intended for Windows-application developers who use Visual C++, however, it will be useful for other programmers as well.
Similar to Lesson 17. Pattern 9. Mixed arithmetic (20)
Threats to mobile devices are more prevalent and increasing in scope and complexity. Users of mobile devices desire to take full advantage of the features
available on those devices, but many of the features provide convenience and capability but sacrifice security. This best practices guide outlines steps the users can take to better protect personal devices and information.
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
Webinar: Designing a schema for a Data WarehouseFederico Razzoli
Are you new to data warehouses (DWH)? Do you need to check whether your data warehouse follows the best practices for a good design? In both cases, this webinar is for you.
A data warehouse is a central relational database that contains all measurements about a business or an organisation. This data comes from a variety of heterogeneous data sources, which includes databases of any type that back the applications used by the company, data files exported by some applications, or APIs provided by internal or external services.
But designing a data warehouse correctly is a hard task, which requires gathering information about the business processes that need to be analysed in the first place. These processes must be translated into so-called star schemas, which means, denormalised databases where each table represents a dimension or facts.
We will discuss these topics:
- How to gather information about a business;
- Understanding dictionaries and how to identify business entities;
- Dimensions and facts;
- Setting a table granularity;
- Types of facts;
- Types of dimensions;
- Snowflakes and how to avoid them;
- Expanding existing dimensions and facts.
Your One-Stop Shop for Python Success: Top 10 US Python Development Providersakankshawande
Simplify your search for a reliable Python development partner! This list presents the top 10 trusted US providers offering comprehensive Python development services, ensuring your project's success from conception to completion.
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
Programming Foundation Models with DSPy - Meetup SlidesZilliz
Prompting language models is hard, while programming language models is easy. In this talk, I will discuss the state-of-the-art framework DSPy for programming foundation models with its powerful optimizers and runtime constraint system.
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
Taking AI to the Next Level in Manufacturing.pdfssuserfac0301
Read Taking AI to the Next Level in Manufacturing to gain insights on AI adoption in the manufacturing industry, such as:
1. How quickly AI is being implemented in manufacturing.
2. Which barriers stand in the way of AI adoption.
3. How data quality and governance form the backbone of AI.
4. Organizational processes and structures that may inhibit effective AI adoption.
6. Ideas and approaches to help build your organization's AI strategy.
Salesforce Integration for Bonterra Impact Management (fka Social Solutions A...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on integration of Salesforce with Bonterra Impact Management.
Interested in deploying an integration with Salesforce for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
Monitoring and Managing Anomaly Detection on OpenShift.pdfTosin Akinosho
Monitoring and Managing Anomaly Detection on OpenShift
Overview
Dive into the world of anomaly detection on edge devices with our comprehensive hands-on tutorial. This SlideShare presentation will guide you through the entire process, from data collection and model training to edge deployment and real-time monitoring. Perfect for those looking to implement robust anomaly detection systems on resource-constrained IoT/edge devices.
Key Topics Covered
1. Introduction to Anomaly Detection
- Understand the fundamentals of anomaly detection and its importance in identifying unusual behavior or failures in systems.
2. Understanding Edge (IoT)
- Learn about edge computing and IoT, and how they enable real-time data processing and decision-making at the source.
3. What is ArgoCD?
- Discover ArgoCD, a declarative, GitOps continuous delivery tool for Kubernetes, and its role in deploying applications on edge devices.
4. Deployment Using ArgoCD for Edge Devices
- Step-by-step guide on deploying anomaly detection models on edge devices using ArgoCD.
5. Introduction to Apache Kafka and S3
- Explore Apache Kafka for real-time data streaming and Amazon S3 for scalable storage solutions.
6. Viewing Kafka Messages in the Data Lake
- Learn how to view and analyze Kafka messages stored in a data lake for better insights.
7. What is Prometheus?
- Get to know Prometheus, an open-source monitoring and alerting toolkit, and its application in monitoring edge devices.
8. Monitoring Application Metrics with Prometheus
- Detailed instructions on setting up Prometheus to monitor the performance and health of your anomaly detection system.
9. What is Camel K?
- Introduction to Camel K, a lightweight integration framework built on Apache Camel, designed for Kubernetes.
10. Configuring Camel K Integrations for Data Pipelines
- Learn how to configure Camel K for seamless data pipeline integrations in your anomaly detection workflow.
11. What is a Jupyter Notebook?
- Overview of Jupyter Notebooks, an open-source web application for creating and sharing documents with live code, equations, visualizations, and narrative text.
12. Jupyter Notebooks with Code Examples
- Hands-on examples and code snippets in Jupyter Notebooks to help you implement and test anomaly detection models.
Have you ever been confused by the myriad of choices offered by AWS for hosting a website or an API?
Lambda, Elastic Beanstalk, Lightsail, Amplify, S3 (and more!) can each host websites + APIs. But which one should we choose?
Which one is cheapest? Which one is fastest? Which one will scale to meet our needs?
Join me in this session as we dive into each AWS hosting service to determine which one is best for your scenario and explain why!
Ivanti’s Patch Tuesday breakdown goes beyond patching your applications and brings you the intelligence and guidance needed to prioritize where to focus your attention first. Catch early analysis on our Ivanti blog, then join industry expert Chris Goettl for the Patch Tuesday Webinar Event. There we’ll do a deep dive into each of the bulletins and give guidance on the risks associated with the newly-identified vulnerabilities.
Cosa hanno in comune un mattoncino Lego e la backdoor XZ?Speck&Tech
ABSTRACT: A prima vista, un mattoncino Lego e la backdoor XZ potrebbero avere in comune il fatto di essere entrambi blocchi di costruzione, o dipendenze di progetti creativi e software. La realtà è che un mattoncino Lego e il caso della backdoor XZ hanno molto di più di tutto ciò in comune.
Partecipate alla presentazione per immergervi in una storia di interoperabilità, standard e formati aperti, per poi discutere del ruolo importante che i contributori hanno in una comunità open source sostenibile.
BIO: Sostenitrice del software libero e dei formati standard e aperti. È stata un membro attivo dei progetti Fedora e openSUSE e ha co-fondato l'Associazione LibreItalia dove è stata coinvolta in diversi eventi, migrazioni e formazione relativi a LibreOffice. In precedenza ha lavorato a migrazioni e corsi di formazione su LibreOffice per diverse amministrazioni pubbliche e privati. Da gennaio 2020 lavora in SUSE come Software Release Engineer per Uyuni e SUSE Manager e quando non segue la sua passione per i computer e per Geeko coltiva la sua curiosità per l'astronomia (da cui deriva il suo nickname deneb_alpha).
How to Interpret Trends in the Kalyan Rajdhani Mix Chart.pdfChart Kalyan
A Mix Chart displays historical data of numbers in a graphical or tabular form. The Kalyan Rajdhani Mix Chart specifically shows the results of a sequence of numbers over different periods.
How to Interpret Trends in the Kalyan Rajdhani Mix Chart.pdf
Lesson 17. Pattern 9. Mixed arithmetic
1. Lesson 17. Pattern 9. Mixed arithmetic
I hope you have already rested from the 13-th lesson and now are ready to study one more important
error pattern related to arithmetic expressions in which types of different capacities participate.
Mixed use of memsize-types and non-memsize types in expressions may lead to incorrect results on 64-
bit systems and concern changes of the range of the input values. Consider some examples:
size_t Count = BigValue;
for (unsigned Index = 0; Index != Count; ++Index)
{ ... }
This is an example of an eternal loop occurring if Count > UINT_MAX. Suppose that this code works well
on a 32-bit system with fewer iterations than UINT_MAX. But the 64-bit version of the program can
process more data and may need more iterations. Since the values of Index variable lie within the range
[0..UINT_MAX], the condition "Index != Count" will never be fulfilled and it leads to the eternal loop.
Note. Consider that this sample may work well at some particular settings of the compiler. Sometimes it
is a source of much confusion because the code seems to be correct. In one of the following lessons we
will tell you about phantom errors that reveal themselves only some time later. If you are already longing
to learn why the code behaves so strangely, see the article "A 64-bit horse that can count".
To correct the code you should use only memsize-types in the expressions. In our example we may
change the type of the variable Index from "unsigned" to size_t.
Another frequent error is using expressions of the following kind:
int x, y, z;
ptrdiff_t SizeValue = x * y * z;
We have already examined such examples with an arithmetic overflow that occurs when calculating
expressions using non-memsize types. The result was incorrect of course. The search and detection of
this code fragment was complicated by the fact that compilers usually do not generate any warnings on
it. From the viewpoint of C++ language it is an absolutely correct construct: several variables of "int"
type are multiplied together, after that the result is implicitly extended to the type ptrdiff_t and is
assigned to a variable.
Here is a small code sample that shows the danger of inaccurate expressions with mixed types (these
results were obtained in Microsoft Visual C++ 2005 in the 64-bit compilation mode):
int x = 100000;
int y = 100000;
int z = 100000;
ptrdiff_t size = 1; // Result:
ptrdiff_t v1 = x * y * z; // -1530494976
2. ptrdiff_t v2 = ptrdiff_t (x) * y * z; // 1000000000000000
ptrdiff_t v3 = x * y * ptrdiff_t (z); // 141006540800000
ptrdiff_t v4 = size * x * y * z; // 1000000000000000
ptrdiff_t v5 = x * y * z * size; // -1530494976
ptrdiff_t v6 = size * (x * y * z); // -1530494976
ptrdiff_t v7 = size * (x * y) * z; // 141006540800000
ptrdiff_t v8 = ((size * x) * y) * z; // 1000000000000000
ptrdiff_t v9 = size * (x * (y * z)); // -1530494976
All the operands in such expressions must be cast to a type of a larger capacity while performing the
calculations. Remember that an expression like
ptrdiff_t v2 = ptrdiff_t (x) + y * z;
does not guarantee a correct result at all. It guarantees only that the expression "ptrdiff_t (x) + y * z" will
have the type "ptrdiff_t".
So, if the expression's result must have a memsize-type, there must be only memsize-types in the
expression too. Here is the correct version:
ptrdiff_t v2 = ptrdiff_t (x) + ptrdiff_t (y) * ptrdiff_t (z); // OK!
However, it is not always necessary to convert all the arguments to a memsize-type. If an expression
consists of identical operators, you may convert only the first argument to the memsize-type. Consider
an example:
int c();
int d();
int a, b;
ptrdiff_t v2 = ptrdiff_t (a) * b * c() * d();
The order of calculating the expression with the operators of the same priority has not been defined.
More exactly, the compiler may choose any order of calculating the subexpressions (for example the
calls of the functions c() and d()) it considers the most efficient, even if the subexpressions may cause
side effects. The order of appearance of side effects has not been defined either. But since the
multiplication operation refers to left-associative operators, the procedure of calculation will be
performed in the following way:
ptrdiff_t v2 = ((ptrdiff_t (a) * b) * c()) * d();
As a result, each of the operators will be cast to the type "ptrdiff_t" before the multiplication and we
will get the correct result.
Note. If there are integer calculations in your program and they need the control over overflows, resort
to the class SafeInt - you may learn about its implementation and see its description in MSDN.
3. Mixed use of types may also result in the changes in program logic:
ptrdiff_t val_1 = -1;
unsigned int val_2 = 1;
if (val_1 > val_2)
printf ("val_1 is greater than val_2n");
else
printf ("val_1 is not greater than val_2n");
//Output on 32-bit system: "val_1 is greater than val_2"
//Output on 64-bit system: "val_1 is not greater than val_2"
According to C++ rules, the variable val_1 is extended to the type "unsigned int" and becomes the value
0xFFFFFFFFu on a 32-bit system - the condition "0xFFFFFFFFu > 1" is fulfilled. On a 64-bit system,
however, it is the variable val_2 that gets extended to the type "ptrdiff_t" - in this case it is the
expression "-1 > 1" which is checked. Figures 1 and 2 give the outlines of the transformations that take
place.
Figure 1 - Transformations taking place in the 32-bit version of the code
4. Figure 2 - Transformations taking place in the 64-bit version of the code
If you need to make the code behave in the same way as before, you should change the type of the
variable val_2:
ptrdiff_t val_1 = -1;
size_t val_2 = 1;
if (val_1 > val_2)
printf ("val_1 is greater than val_2n");
else
printf ("val_1 is not greater than val_2n");
Actually, it would be more correct not to compare signed and unsigned types at all, but this issue lies
beyond the current topic.
We have considered only simple expressions. But the described issues may occur when using other C++
constructs too:
extern int Width, Height, Depth;
size_t GetIndex(int x, int y, int z) {
return x + y * Width + z * Width * Height;
}
...
MyArray[GetIndex(x, y, z)] = 0.0f;
If there is a large array (containing more than INT_MAX items), this code will be incorrect and we will be
directed to the wrong items of the array MyArray. Although it is the value of "size_t" type which is
5. returned, the expression "x + y * Width + z * Width * Height" is calculated using the type "int". I think
you have already guessed what the corrected code will look like:
extern int Width, Height, Depth;
size_t GetIndex(int x, int y, int z) {
return (size_t)(x) +
(size_t)(y) * (size_t)(Width) +
(size_t)(z) * (size_t)(Width) * (size_t)(Height);
}
Or a bit simpler:
extern int Width, Height, Depth;
size_t GetIndex(int x, int y, int z) {
return (size_t)(x) +
(size_t)(y) * Width +
(size_t)(z) * Widt) * Height;
}
In the next example again we have a mixture of a memsize-type (the pointer) and a 32-bit "unsigned"
type:
extern char *begin, *end;
unsigned GetSize() {
return end - begin;
}
The result of the expression "end - begin" has the type "ptrdiff_t". Since the function returns the type
"unsigned", there occurs an implicit type conversion that leads to a loss of the more significant bits of
the result. So, if the pointers begin and end refer to the beginning and the end of the array whose size is
more than UINT_MAX (4Gb), the function will return an incorrect result.
And one more example. Here we are going to consider not a returned value but a formal argument of a
function:
void foo(ptrdiff_t delta);
int i = -2;
unsigned k = 1;
foo(i + k);
6. This code resembles an example with incorrect pointer arithmetic discussed in the 13-th lesson, does
not it? Right, here we have the same. We get the incorrect result when the actual argument, equaling
0xFFFFFFFF and having the type "unsigned", is implicitly extended to the type "ptrdiff_t".
Diagnosis
Errors occurring in 64-bit systems when integer types and memsize-types are used together are
presented in many C++ syntactic constructs. To diagnose these errors several diagnostic warnings are
used. PVS-Studio analyzer warns the programmer about possible errors with the help of these warnings:
V101, V103, V104, V105, V106, V107, V109, V110, V121.
Let us return to the example we have considered earlier:
int c();
int d();
int a, b;
ptrdiff_t x = ptrdiff_t(a) * b * c() * d();
Although the expression itself multiplies together the arguments extending their types to "ptrdiff_t", an
error may hide in the procedure of calculating these arguments. That is why the analyzer still warns you
about the mixed types: "V104: Implicit type conversion to memsize type in an arithmetic expression".
PVS-Studio tool also allows you to find potentially unsafe expressions which hide behind explicit type
conversions. To enable this function you should enable the warnings V201 and V202. By default, the
analyzer does not generate warnings concerning explicit type conversions. For example:
TCHAR *begin, *end;
unsigned size = static_cast<unsigned>(end - begin);
The warnings V201 and V202 will help you detect such incorrect code fragments.
Still the analyzer will pay no attention to type conversions which are safe from the viewpoint of the 64-
bit code:
const int *constPtr;
int *ptr = const_cast<int>(constPtr);
float f = float(constPtr[0]);
char ch = static_cast<char>(sizeof(double));
The course authors: Andrey Karpov (karpov@viva64.com), Evgeniy Ryzhkov (evg@viva64.com).
The rightholder of the course "Lessons on development of 64-bit C/C++ applications" is OOO "Program
Verification Systems". The company develops software in the sphere of source program code analysis.
The company's site: http://www.viva64.com.
Contacts: e-mail: support@viva64.com, Tula, 300027, PO box 1800.