C Programming Linker Error
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Practice Problems Quizzes Resources Source Code Source Code Snippets C and C++ Tips Finding a Job References Function Reference Syntax Reference Programming FAQ Getting Help Message Board Email About Us Dealing with Compiler Errors - linker error in c graphics program Surviving the Compilation Process By Alex Allain It's your first C (or C++) c linker error undefined reference program--it's not that long, and you're about to compile it. You hit compile (or enter the build command) and wait. Your linker error in turbo c compiler spits out fifty lines of text. You pick out words like "warning and "error". Does that mean it worked? you wonder. You look for the resulting executable. Nothing. Damn, you think, I guess linker error in c undefined symbol I have to figure out what this all means... The Types of Compilation Errors First, let's distinguish between the types of errors: most compilers will give three types of compile-time alerts: compiler warnings, compiler errors, and linker errors. Although you don't want to ignore them, compiler warnings aren't something severe enough to actually keep your program from compiling. Usually, compiler warnings are an indication that something might go wrong
Linker Error Xcode
at runtime. How can the compiler know this at all? You might be making a typical mistake that the compiler knows about. A common example is using the assignment operator ('=') instead of the equality operator ('==') inside an if statement. Your compiler may also warn you about using variables that haven't been initialized and other similar mistakes. Generally, you can set the warning level of your compiler--I like to keep it at its highest level so that my compiler warnings don't turn in to bugs in the running program ('runtime bugs'). Nevertheless, compiler warnings aren't going to stop you from getting your program working (unless you tell your compiler to treat warnings as errors), so they're probably a bit less frustrating than errors. Errors are conditions that prevent the compiler from completing the compilation of your files. Compiler errors are restricted to single source code files and are the result of 'syntax errors'. What this really means is that you've done something that the compiler cannot understand. For instance, the statement "for(;)" isn't correct syntax because a for loop always needs to have three parts. Although the compiler would have expected a semicolon, it would also have expected a conditional expression, so th
Fatal Errors Logic Errors Note that the error messages shown below may be specific to our compiler/linker or machines. Nonetheless, other systems
Linker Error In C++ Undefined Symbol
and compilers will provide similar information. Compiler Messages When the compilation error in c compiler is compiling your code (i.e., converting your code into instructions the machine understands), it will report linker error ios problems that it finds in your code. Aside: Here, we are being technical and refer to compiling as the stage before linking. Linking is when all http://www.cprogramming.com/tutorial/compiler_linker_errors.html the compiled pieces of a program and the libraries it uses (e.g., for cin) are put together to form an executable. Often, compiling and linking together are just referred to as compiling. There are two severities of messages the compiler can give: Compiler Warnings A compiler warning indicates you've done something bad, but not https://www.cs.bu.edu/teaching/cpp/debugging/errors/ something that will prevent the code from being compiled. You should fix whatever causes warnings since they often lead to other problems that will not be so easy to find. Example: Your code calls the pow() (raise to a power) library function, but you forgot to include math.h. Because you've supplied no prototype for the pow() function (its in math.h), the compiler warns you that it assumes pow() returns an int and that it assumes nothing about pow()'s parameters: somefile.cpp:6: warning: implicit declaration of function `int pow(...)' This is a problem since pow() actually returns a double. In addition, the compiler can't type-check (and possibly convert) values passed to pow() if it doesn't know how many and what type those parameters are supposed to be. Note: The compiler will label warnings with the word warning so that you can distinguish them from errors. Compiler Errors A compiler error indicates something that must be fixed before the code can be com
Tips/Tricks Top Articles Beginner Articles Technical Blogs Posting/Update Guidelines Article Help Forum Article Competition Submit an article or tip Post your Blog quick http://www.codeproject.com/Questions/264025/Linker-error-in-c-program answersQ&A Ask a Question View Unanswered Questions View All Questions... C# http://stackoverflow.com/questions/15257120/undefined-reference-to-linker-error questions Linux questions ASP.NET questions SQL questions VB.NET questions discussionsforums All Message Boards... Application Lifecycle> Running a Business Sales / Marketing Collaboration / Beta Testing Work Issues Design and Architecture ASP.NET JavaScript C / C++ / MFC> ATL / WTL / STL Managed C++/CLI C# linker error Free Tools Objective-C and Swift Database Hardware & Devices> System Admin Hosting and Servers Java .NET Framework Android iOS Mobile SharePoint Silverlight / WPF Visual Basic Web Development Site Bugs / Suggestions Spam and Abuse Watch features Competitions News The Insider Newsletter The Daily Build Newsletter Newsletter archive Surveys Product Showcase Research Library CodeProject Stuff communitylounge Who's linker error in Who Most Valuable Professionals The Lounge The Insider News The Weird & The Wonderful The Soapbox Press Releases Non-English Language > General Indian Topics General Chinese Topics help What is 'CodeProject'? General FAQ Ask a Question Bugs and Suggestions Article Help Forum Site Map Advertise with us About our Advertising Employment Opportunities About Us Ask a Question All Questions All Unanswered FAQ Linker error in c program Rate this: Please Sign up or sign in to vote. See more: C I am the beginner for c program... what is mean by Linker Error: undefined symbol print in module anyone explain Posted 4-Oct-11 5:24am kschandru371 Add a Solution 4 solutions Top Rated Most Recent Rate this: Please Sign up or sign in to vote. Solution 2 Accept Solution Reject Solution Did you mis-spell printf? Permalink Posted 4-Oct-11 7:19am Richard MacCutchan570.5K Comments Simon Bang Terkildsen 4-Oct-11 13:23pm hehe, most likely Rate this: Please Sign up or sign in to vote. Solution 1 Accept Solution Rejec
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Undefined reference to '_*' linker error up vote 0 down vote favorite I am having trouble compiling/linking the following C code. The linker throws errors that look like the following: pso.o:pso.c:(.text+0x41): undefined reference to '_ps' ... pso.o:pso.c:(.text+0x93): more undefined references to '_ps' follow This is my first time writing C code for gcc, so I'm unsure how to fix this problem. I am assuming that because struct PS is defined my header file, it is somehow not linked to pso.c. However, I did use a #include "ps.h" statement at the top of that source file. I have included the relevant source files and header file below, as well as the make file I am using. Is there a fundamental concept I am missing for writing linkable C code? Thank you! Oh, and it's a particle swarm optimizer, if you were wondering :) The main.c file: #define MAIN #include