Function Pointer Declaration in C Typedef
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Mod Perl 2.0 Source Code Explained 1 Mod Perl 2.0 Source Code Explained
mod_perl 2.0 Source Code Explained 1 mod_perl 2.0 Source Code Explained 1 mod_perl 2.0 Source Code Explained 15 Feb 2014 1 1.1 Description 1.1 Description This document explains how to navigate the mod_perl source code, modify and rebuild the existing code and most important: how to add new functionality. 1.2 Project’s Filesystem Layout In its pristine state the project is comprised of the following directories and files residing at the root direc- tory of the project: Apache-Test/ - test kit for mod_perl and Apache2::* modules ModPerl-Registry/ - ModPerl::Registry sub-project build/ - utilities used during project build docs/ - documentation lib/ - Perl modules src/ - C code that builds libmodperl.so t/ - mod_perl tests todo/ - things to be done util/ - useful utilities for developers xs/ - source xs code and maps Changes - Changes file LICENSE - ASF LICENSE document Makefile.PL - generates all the needed Makefiles After building the project, the following root directories and files get generated: Makefile - Makefile WrapXS/ - autogenerated XS code blib/ - ready to install version of the package 1.3 Directory src 1.3.1 Directory src/modules/perl/ The directory src/modules/perl includes the C source files needed to build the libmodperl library. Notice that several files in this directory are autogenerated during the perl Makefile stage. When adding new source files to this directory you should add their names to the @c_src_names vari- able in lib/ModPerl/Code.pm, so they will be picked up by the autogenerated Makefile. 1.4 Directory xs/ Apache2/ - Apache specific XS code APR/ - APR specific XS code ModPerl/ - ModPerl specific XS code maps/ - tables/ - Makefile.PL - 2 15 Feb 2014 mod_perl 2.0 Source Code Explained 1.4.1 xs/Apache2, xs/APR and xs/ModPerl modperl_xs_sv_convert.h - modperl_xs_typedefs.h - modperl_xs_util.h - typemap - 1.4.1 xs/Apache2, xs/APR and xs/ModPerl The xs/Apache2, xs/APR and xs/ModPerl directories include .h files which have C and XS code in them. -
Declaring Pointers in Functions C
Declaring Pointers In Functions C isSchoolgirlish fenestrated Tye or overlain usually moltenly.menace some When babbling Raleigh orsubmersing preappoints his penetratingly. hums wing not Calvinism insidiously Benton enough, always is Normie outdance man? his rectorials if Rodge Please suggest some time binding in practice, i get very complicated you run this waste and functions in the function pointer arguments Also allocated on write in c pointers in declaring function? Been declared in function pointers cannot declare more. After taking these requirements you do some planning start coding. Leave it to the optimizer? Web site in. Functions Pointers in C Programming with Examples Guru99. Yes, here is a complete program written in C, things can get even more hairy. How helpful an action do still want? This title links to the home page. The array of function pointers offers the facility to access the function using the index of the array. If you want to avoid repeating the loop implementations and each branch of the decision has similar code, or distribute it is void, the appropriate function is called through a function pointer in the current state. Can declare functions in function declarations and how to be useful to respective function pointer to the basic concepts of characters used as always going to? It in functions to declare correct to the declaration of your site due to functions on the modified inside the above examples. In general, and you may publicly display copies. You know any type of a read the licenses of it is automatically, as small number types are functionally identical for any of accessing such as student structure? For this reason, every time you need a particular behavior such as drawing a line, but many practical C programs rely on overflow wrapping around. -
Typedef in C
CC -- TTYYPPEEDDEEFF http://www.tutorialspoint.com/cprogramming/c_typedef.htm Copyright © tutorialspoint.com The C programming language provides a keyword called typedef, which you can use to give a type a new name. Following is an example to define a term BYTE for one-byte numbers: typedef unsigned char BYTE; After this type definitions, the identifier BYTE can be used as an abbreviation for the type unsigned char, for example:. BYTE b1, b2; By convention, uppercase letters are used for these definitions to remind the user that the type name is really a symbolic abbreviation, but you can use lowercase, as follows: typedef unsigned char byte; You can use typedef to give a name to user defined data type as well. For example you can use typedef with structure to define a new data type and then use that data type to define structure variables directly as follows: #include <stdio.h> #include <string.h> typedef struct Books { char title[50]; char author[50]; char subject[100]; int book_id; } Book; int main( ) { Book book; strcpy( book.title, "C Programming"); strcpy( book.author, "Nuha Ali"); strcpy( book.subject, "C Programming Tutorial"); book.book_id = 6495407; printf( "Book title : %s\n", book.title); printf( "Book author : %s\n", book.author); printf( "Book subject : %s\n", book.subject); printf( "Book book_id : %d\n", book.book_id); return 0; } When the above code is compiled and executed, it produces the following result: Book title : C Programming Book author : Nuha Ali Book subject : C Programming Tutorial Book book_id : 6495407 typedef vs #define The #define is a C-directive which is also used to define the aliases for various data types similar to typedef but with following differences: The typedef is limited to giving symbolic names to types only where as #define can be used to define alias for values as well, like you can define 1 as ONE etc. -
Enum, Typedef, Structures and Unions CS 2022: Introduction to C
Enum, Typedef, Structures and Unions CS 2022: Introduction to C Instructor: Hussam Abu-Libdeh Cornell University (based on slides by Saikat Guha) Fall 2009, Lecture 6 Enum, Typedef, Structures and Unions CS 2022, Fall 2009, Lecture 6 Numerical Types I int: machine-dependent I Standard integers I defined in stdint.h (#include <stdint.h>) I int8 t: 8-bits signed I int16 t: 16-bits signed I int32 t: 32-bits signed I int64 t: 64-bits signed I uint8 t, uint32 t, ...: unsigned I Floating point numbers I float: 32-bits I double: 64-bits Enum, Typedef, Structures and Unions CS 2022, Fall 2009, Lecture 6 Complex Types I Enumerations (user-defined weekday: sunday, monday, ...) I Structures (user-defined combinations of other types) I Unions (same data, multiple interpretations) I Function pointers I Arrays and Pointers of the above Enum, Typedef, Structures and Unions CS 2022, Fall 2009, Lecture 6 Enumerations enum days {mon, tue, wed, thu, fri, sat, sun}; // Same as: // #define mon 0 // #define tue 1 // ... // #define sun 6 enum days {mon=3, tue=8, wed, thu, fri, sat, sun}; // Same as: // #define mon 3 // #define tue 8 // ... // #define sun 13 Enum, Typedef, Structures and Unions CS 2022, Fall 2009, Lecture 6 Enumerations enum days day; // Same as: int day; for(day = mon; day <= sun; day++) { if (day == sun) { printf("Sun\n"); } else { printf("day = %d\n", day); } } Enum, Typedef, Structures and Unions CS 2022, Fall 2009, Lecture 6 Enumerations I Basically integers I Can use in expressions like ints I Makes code easier to read I Cannot get string equiv. -
Refining Indirect-Call Targets with Multi-Layer Type Analysis
Where Does It Go? Refining Indirect-Call Targets with Multi-Layer Type Analysis Kangjie Lu Hong Hu University of Minnesota, Twin Cities Georgia Institute of Technology Abstract ACM Reference Format: System software commonly uses indirect calls to realize dynamic Kangjie Lu and Hong Hu. 2019. Where Does It Go? Refining Indirect-Call Targets with Multi-Layer Type Analysis. In program behaviors. However, indirect-calls also bring challenges 2019 ACM SIGSAC Conference on Computer and Communications Security (CCS ’19), November 11–15, 2019, to constructing a precise control-flow graph that is a standard pre- London, United Kingdom. ACM, New York, NY, USA, 16 pages. https://doi. requisite for many static program-analysis and system-hardening org/10.1145/3319535.3354244 techniques. Unfortunately, identifying indirect-call targets is a hard problem. In particular, modern compilers do not recognize indirect- call targets by default. Existing approaches identify indirect-call 1 Introduction targets based on type analysis that matches the types of function Function pointers are commonly used in C/C++ programs to sup- pointers and the ones of address-taken functions. Such approaches, port dynamic program behaviors. For example, the Linux kernel however, suffer from a high false-positive rate as many irrelevant provides unified APIs for common file operations suchas open(). functions may share the same types. Internally, different file systems have their own implementations of In this paper, we propose a new approach, namely Multi-Layer these APIs, and the kernel uses function pointers to decide which Type Analysis (MLTA), to effectively refine indirect-call targets concrete implementation to invoke at runtime. -
Evaluation of On-Ramp Control Algorithms
CALIFORNIA PATH PROGRAM INSTITUTE OF TRANSPORTATION STUDIES UNIVERSITY OF CALIFORNIA, BERKELEY Evaluation of On-ramp Control Algorithms Michael Zhang, Taewan Kim, Xiaojian Nie, Wenlong Jin University of California, Davis Lianyu Chu, Will Recker University of California, Irvine California PATH Research Report UCB-ITS-PRR-2001-36 This work was performed as part of the California PATH Program of the University of California, in cooperation with the State of California Business, Transportation, and Housing Agency, Department of Transportation; and the United States Department of Transportation, Federal Highway Administration. The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the State of California. This report does not constitute a standard, specification, or regulation. Final Report for MOU 3013 December 2001 ISSN 1055-1425 CALIFORNIA PARTNERS FOR ADVANCED TRANSIT AND HIGHWAYS Evaluation of On-ramp Control Algorithms September 2001 Michael Zhang, Taewan Kim, Xiaojian Nie, Wenlong Jin University of California at Davis Lianyu Chu, Will Recker PATH Center for ATMS Research University of California, Irvine Institute of Transportation Studies One Shields Avenue University of California, Davis Davis, CA 95616 ACKNOWLEDGEMENTS Technical assistance on Paramics simulation from the Quadstone Technical Support sta is also gratefully acknowledged. ii EXECUTIVE SUMMARY This project has three objectives: 1) review existing ramp metering algorithms and choose a few attractive ones for further evaluation, 2) develop a ramp metering evaluation framework using microscopic simulation, and 3) compare the performances of the selected algorithms and make recommendations about future developments and eld tests of ramp metering systems. -
SI 413, Unit 3: Advanced Scheme
SI 413, Unit 3: Advanced Scheme Daniel S. Roche ([email protected]) Fall 2018 1 Pure Functional Programming Readings for this section: PLP, Sections 10.7 and 10.8 Remember there are two important characteristics of a “pure” functional programming language: • Referential Transparency. This fancy term just means that, for any expression in our program, the result of evaluating it will always be the same. In fact, any referentially transparent expression could be replaced with its value (that is, the result of evaluating it) without changing the program whatsoever. Notice that imperative programming is about as far away from this as possible. For example, consider the C++ for loop: for ( int i = 0; i < 10;++i) { /∗ some s t u f f ∗/ } What can we say about the “stuff” in the body of the loop? Well, it had better not be referentially transparent. If it is, then there’s no point in running over it 10 times! • Functions are First Class. Another way of saying this is that functions are data, just like any number or list. Functions are values, in fact! The specific privileges that a function earns by virtue of being first class include: 1) Functions can be given names. This is not a big deal; we can name functions in pretty much every programming language. In Scheme this just means we can do (define (f x) (∗ x 3 ) ) 2) Functions can be arguments to other functions. This is what you started to get into at the end of Lab 2. For starters, there’s the basic predicate procedure?: (procedure? +) ; #t (procedure? 10) ; #f (procedure? procedure?) ; #t 1 And then there are “higher-order functions” like map and apply: (apply max (list 5 3 10 4)) ; 10 (map sqrt (list 16 9 64)) ; '(4 3 8) What makes the functions “higher-order” is that one of their arguments is itself another function. -
Presentation on Ocaml Internals
OCaml Internals Implementation of an ML descendant Theophile Ranquet Ecole Pour l’Informatique et les Techniques Avancées SRS 2014 [email protected] November 14, 2013 2 of 113 Table of Contents Variants and subtyping System F Variants Type oddities worth noting Polymorphic variants Cyclic types Subtyping Weak types Implementation details α ! β Compilers Functional programming Values Why functional programming ? Allocation and garbage Combinatory logic : SKI collection The Curry-Howard Compiling correspondence Type inference OCaml and recursion 3 of 113 Variants A tagged union (also called variant, disjoint union, sum type, or algebraic data type) holds a value which may be one of several types, but only one at a time. This is very similar to the logical disjunction, in intuitionistic logic (by the Curry-Howard correspondance). 4 of 113 Variants are very convenient to represent data structures, and implement algorithms on these : 1 d a t a t y p e tree= Leaf 2 | Node of(int ∗ t r e e ∗ t r e e) 3 4 Node(5, Node(1,Leaf,Leaf), Node(3, Leaf, Node(4, Leaf, Leaf))) 5 1 3 4 1 fun countNodes(Leaf)=0 2 | countNodes(Node(int,left,right)) = 3 1 + countNodes(left)+ countNodes(right) 5 of 113 1 t y p e basic_color= 2 | Black| Red| Green| Yellow 3 | Blue| Magenta| Cyan| White 4 t y p e weight= Regular| Bold 5 t y p e color= 6 | Basic of basic_color ∗ w e i g h t 7 | RGB of int ∗ i n t ∗ i n t 8 | Gray of int 9 1 l e t color_to_int= function 2 | Basic(basic_color,weight) −> 3 l e t base= match weight with Bold −> 8 | Regular −> 0 in 4 base+ basic_color_to_int basic_color 5 | RGB(r,g,b) −> 16 +b+g ∗ 6 +r ∗ 36 6 | Grayi −> 232 +i 7 6 of 113 The limit of variants Say we want to handle a color representation with an alpha channel, but just for color_to_int (this implies we do not want to redefine our color type, this would be a hassle elsewhere). -
Open and Efficient Type Switch For
Draft for OOPSLA 2012 Open and Efficient Type Switch for C++ Yuriy Solodkyy Gabriel Dos Reis Bjarne Stroustrup Texas A&M University Texas, USA fyuriys,gdr,[email protected] Abstract – allow for independent extensions, modular type-checking Selecting operations based on the run-time type of an object and dynamic linking. On the other, in order to be accepted is key to many object-oriented and functional programming for production code, the implementation of such a construct techniques. We present a technique for implementing open must equal or outperform all known workarounds. However, and efficient type-switching for hierarchical extensible data existing approaches to case analysis on hierarchical exten- types. The technique is general and copes well with C++ sible data types are either efficient or open, but not both. multiple inheritance. Truly open approaches rely on expensive class-membership To simplify experimentation and gain realistic prefor- testing combined with decision trees []. Efficient approaches mance using production-quality compilers and tool chains, rely on sealing either the class hierarchy or the set of func- we implement our type swich constructs as an ISO C++11 li- tions, which loses extensibility [9, 18, 44, 51]. Consider a brary. Our library-only implementation provides concise no- simple expression language: tation and outperforms the visitor design pattern, commonly exp ∶∶= val S exp + exp S exp − exp S exp ∗ exp S exp~exp used for type-casing scenarios in object-oriented programs. For many uses, it equals or outperforms equivalent code in In an object-oriented language without direct support for languages with built-in type-switching constructs, such as algebraic data types, the type representing an expression-tree OCaml and Haskell. -
Object-Oriented Programming in C
OBJECT-ORIENTED PROGRAMMING IN C CSCI 5448 Fall 2012 Pritha Srivastava Introduction Goal: To discover how ANSI – C can be used to write object- oriented code To revisit the basic concepts in OO like Information Hiding, Polymorphism, Inheritance etc… Pre-requisites – A good knowledge of pointers, structures and function pointers Table of Contents Information Hiding Dynamic Linkage & Polymorphism Visibility & Access Functions Inheritance Multiple Inheritance Conclusion Information Hiding Data types - a set of values and operations to work on them OO design paradigm states – conceal internal representation of data, expose only operations that can be used to manipulate them Representation of data should be known only to implementer, not to user – the answer is Abstract Data Types Information Hiding Make a header file only available to user, containing a descriptor pointer (which represents the user-defined data type) functions which are operations that can be performed on the data type Functions accept and return generic (void) pointers which aid in hiding the implementation details Information Hiding Set.h Example: Set of elements Type Descriptor operations – add, find and drop. extern const void * Set; Define a header file Set.h (exposed to user) void* add(void *set, const void *element); Appropriate void* find(const void *set, const Abstractions – Header void *element); file name, function name void* drop(void *set, const void reveal their purpose *element); Return type - void* helps int contains(const void *set, const in hiding implementation void *element); details Set.c Main.c - Usage Information Hiding Set.c – Contains void* add (void *_set, void *_element) implementation details of { Set data type (Not struct Set *set = _set; struct Object *element = _element; exposed to user) if ( !element-> in) The pointer Set (in Set.h) is { passed as an argument to element->in = set; add, find etc. -
Call Graph Generation for LLVM (Due at 11:59Pm 3/7)
CS510 Project 1: Call Graph Generation for LLVM (Due at 11:59pm 3/7) 2/21/17 Project Description A call graph is a directed graph that represents calling relationships between functions in a computer program. Specifically, each node represents a function and each edge (f, g) indicates that function f calls function g [1]. In this project, you are asked to familiarize yourself with the LLVM source code and then write a program analysis pass for LLVM. This analysis will produce the call graph of input program. Installing and Using LLVM We will be using the Low Level Virtual Machine (LLVM) compiler infrastructure [5] de- veloped at the University of Illinois Urbana-Champaign for this project. We assume you have access to an x86 based machine (preferably running Linux, although Windows and Mac OS X should work as well). First download, install, and build the latest LLVM source code from [5]. Follow the instructions on the website [4] for your particular machine configuration. Note that in or- der use a debugger on the LLVM binaries you will need to pass --enable-debug-runtime --disable-optimized to the configure script. Moreover, make the LLVM in debug mode. Read the official documentation [6] carefully, specially the following pages: 1. The LLVM Programmers Manual (http://llvm.org/docs/ProgrammersManual.html) 2. Writing an LLVM Pass tutorial (http://llvm.org/docs/WritingAnLLVMPass.html) Project Requirements LLVM is already able to generate the call graphs of the pro- grams. However, this feature is limited to direct function calls which is not able to detect calls by function pointers. -
Static Reflection
N3996- Static reflection Document number: N3996 Date: 2014-05-26 Project: Programming Language C++, SG7, Reflection Reply-to: Mat´uˇsChochl´ık([email protected]) Static reflection How to read this document The first two sections are devoted to the introduction to reflection and reflective programming, they contain some motivational examples and some experiences with usage of a library-based reflection utility. These can be skipped if you are knowledgeable about reflection. Section3 contains the rationale for the design decisions. The most important part is the technical specification in section4, the impact on the standard is discussed in section5, the issues that need to be resolved are listed in section7, and section6 mentions some implementation hints. Contents 1. Introduction4 2. Motivation and Scope6 2.1. Usefullness of reflection............................6 2.2. Motivational examples.............................7 2.2.1. Factory generator............................7 3. Design Decisions 11 3.1. Desired features................................. 11 3.2. Layered approach and extensibility...................... 11 3.2.1. Basic metaobjects........................... 12 3.2.2. Mirror.................................. 12 3.2.3. Puddle.................................. 12 3.2.4. Rubber................................. 13 3.2.5. Lagoon................................. 13 3.3. Class generators................................ 14 3.4. Compile-time vs. Run-time reflection..................... 16 4. Technical Specifications 16 4.1. Metaobject Concepts.............................