Search Results

Search found 39069 results on 1563 pages for 'without compiler'.

Page 251/1563 | < Previous Page | 247 248 249 250 251 252 253 254 255 256 257 258  | Next Page >

• apt-get works with --force-yes but cannot reproduce the issue on a fresh box

  - by deepak

  apt-get does not work the first time but works the second time i install ntp like: apt-get -q -y install ntp=1:4.2.6.p3+dfsg-1ubuntu3.1 It failed saying: WARNING: The following packages cannot be authenticated! libcap2 libopts25 ntp E: There are problems and -y was used without --force-yes Afterwards i ran, apt-key update and ran the same commad with --force-yes: apt-get -q -y --force-yes install ntp=1:4.2.6.p3+dfsg-1ubuntu3.1 Thereafter running apt-get purge and reinstalling ntp runs. "without" --force-yes apt-get purge libcap2 libopts25 ntp apt-get -q -y install ntp=1:4.2.6.p3+dfsg-1ubuntu3.1 Also i created a fresh VM and could not reproduce the issue. On a fresh VM, the same apt-get command runs the first time, without "--force-yes" Two questions, why does running apt-get work the second time and cannot reproduce the error ? full errors and sequential steps at, https://gist.github.com/3017966

  Read the article

• Why do we need REST service security if we have HTTPS

  - by Vangel

  I refer to this excellent article http://www.thebuzzmedia.com/designing-a-secure-rest-api-without-oauth-authentication/ which speaks of amazon like security for web service. However I was asked a question in the team of why do we need it if we already use HTTPS. I was unable to answer as it really seems to me they may be right although gut tells me otherwise. Also is there places when providing REST services where HTTPS may not work? Like 3rd party websites? If anyone has experience in securing Web Services over the public interwebs please shed some light with your experience. Thanks in advance. EDIT: To clarify I am not speaking of user authentication but more of client authentication. The user authentication can be assumed to be plain text over HTTPS+ REST. My worry is that this still allows anyone to use the web service without my client to access it since everything is plai text although over HTTPS the client end point can still use my web service without the client application.

  Read the article

• To same computer Remote desktop thrue WRT54G router

  - by Kangarooo

  Cant access from my Same comp same comp to test if all is ok. Tryd all mentioned posibilities. Tryd my ip xxx.xxx.xxx.xxx / localhost with / without :5900 added with / without in "Remote desktop" checked "Configure network automatically to accept connection" with / without in router WRT54G enabled port 5900 forwardet to my comp 192.168.1.3 UPNP is enabled. I can connect to one other comp witch isnt using router and checked "Configure network automatically to accept connection" and to one thrue TENDA W311R+ router where ive put port forwarding to 5900 and there works xxx.xxx.xxx.xxx:5900 Whats wrong? What ive missed?

  Read the article

• HTML5-Canvas: worth using ImpactJS or other framework?

  - by John

  I've been making an HTML5 game without any type of external framework. I haven't found a reason to use one so far. However, there is one thing I'm wondering about. On my Galaxy Nexus, I get about ~40fps. While that would usually be a decent framerate, my game is a rather fast paced game with a gamepad. Because of this, it feels very unsatisfying to play when not capped at 60fps. Are there frameworks out there that can improve performance without toning down on graphics? Or is there something I could do myself without necessarily having to use a framework? I've looked over the basic things such as sticking to integer coordinates, but I didn't see an increase in performance whatsoever? I did some testing with jsperf and results were virtually identical. Does this depend more on the browser?

  Read the article

• ADF Business Components

  - by Arda Eralp

  ADF Business Components and JDeveloper simplify the development, delivery, and customization of business applications for the Java EE platform. With ADF Business Components, developers aren't required to write the application infrastructure code required by the typical Java EE application to: Connect to the database Retrieve data Lock database records Manage transactions   ADF Business Components addresses these tasks through its library of reusable software components and through the supporting design time facilities in JDeveloper. Most importantly, developers save time using ADF Business Components since the JDeveloper design time makes typical development tasks entirely declarative. In particular, JDeveloper supports declarative development with ADF Business Components to: Author and test business logic in components which automatically integrate with databases Reuse business logic through multiple SQL-based views of data, supporting different application tasks Access and update the views from browser, desktop, mobile, and web service clients Customize application functionality in layers without requiring modification of the delivered application The goal of ADF Business Components is to make the business services developer more productive.   ADF Business Components provides a foundation of Java classes that allow your business-tier application components to leverage the functionality provided in the following areas: Simplifying Data Access Design a data model for client displays, including only necessary data Include master-detail hierarchies of any complexity as part of the data model Implement end-user Query-by-Example data filtering without code Automatically coordinate data model changes with business services layer Automatically validate and save any changes to the database   Enforcing Business Domain Validation and Business Logic Declaratively enforce required fields, primary key uniqueness, data precision-scale, and foreign key references Easily capture and enforce both simple and complex business rules, programmatically or declaratively, with multilevel validation support Navigate relationships between business domain objects and enforce constraints related to compound components   Supporting Sophisticated UIs with Multipage Units of Work Automatically reflect changes made by business service application logic in the user interface Retrieve reference information from related tables, and automatically maintain the information when the user changes foreign-key values Simplify multistep web-based business transactions with automatic web-tier state management Handle images, video, sound, and documents without having to use code Synchronize pending data changes across multiple views of data Consistently apply prompts, tooltips, format masks, and error messages in any application Define custom metadata for any business components to support metadata-driven user interface or application functionality Add dynamic attributes at runtime to simplify per-row state management   Implementing High-Performance Service-Oriented Architecture Support highly functional web service interfaces for business integration without writing code Enforce best-practice interface-based programming style Simplify application security with automatic JAAS integration and audit maintenance "Write once, run anywhere": use the same business service as plain Java class, EJB session bean, or web service   Streamlining Application Customization Extend component functionality after delivery without modifying source code Globally substitute delivered components with extended ones without modifying the application   ADF Business Components implements the business service through the following set of cooperating components: Entity object An entity object represents a row in a database table and simplifies modifying its data by handling all data manipulation language (DML) operations for you. These are basically your 1 to 1 representation of a database table. Each table in the database will have 1 and only 1 EO. The EO contains the mapping between columns and attributes. EO's also contain the business logic and validation. These are you core data services. They are responsible for updating, inserting and deleting records. The Attributes tab displays the actual mapping between attributes and columns, the mapping has following fields: Name : contains the name of the attribute we expose in our data model. Type : defines the data type of the attribute in our application. Column : specifies the column to which we want to map the attribute with Column Type : contains the type of the column in the database   View object A view object represents a SQL query. You use the full power of the familiar SQL language to join, filter, sort, and aggregate data into exactly the shape required by the end-user task. The attributes in the View Objects are actually coming from the Entity Object. In the end the VO will generate a query but you basically build a VO by selecting which EO need to participate in the VO and which attributes of those EO you want to use. That's why you have the Entity Usage column so you can see the relation between VO and EO. In the query tab you can clearly see the query that will be generated for the VO. At this stage we don't need it and just use it for information purpose. In later stages we might use it. Application module An application module is the controller of your data layer. It is responsible for keeping hold of the transaction. It exposes the data model to the view layer. You expose the VO's through the Application Module. This is the abstraction of your data layer which you want to show to the outside word.It defines an updatable data model and top-level procedures and functions (called service methods) related to a logical unit of work related to an end-user task. While the base components handle all the common cases through built-in behavior, customization is always possible and the default behavior provided by the base components can be easily overridden or augmented. When you create EO's, a foreign key will be translated into an association in our model. It defines the type of relation and who is the master and child as well as how the visibility of the association looks like. A similar concept exists to identify relations between view objects. These are called view links. These are almost identical as association except that a view link is based upon attributes defined in the view object. It can also be based upon an association. Here's a short summary: Entity Objects: representations of tables Association: Relations between EO's. Representations of foreign keys View Objects: Logical model View Links: Relationships between view objects Application Model: interface to your application  

  Read the article

• Using paypal to process credit cards in Sweden through an API [on hold]

  - by Mastikator

  I'm looking for a Paypal API that lets me process credit cards to make payments without being redirected to a paypal site and without enforcing consumers to use their paypal account. And it needs to work in Sweden. The ones I've looked at (dodirectpayment, expresscheckout, paypalpro gateway) and none of them have let me process credit cards in Sweden via an API that doesn't force the user to visit the paypal login site. I have a form on my webpage that the user types their credit card number, ccv2, expiration, name, address, etc. I need an API that works in Sweden that simply processes the request, and it has to be without the step of being redirected into a paypal website. The ones that I have found only worked in a select few countries, is there an international solution? I've already spent over 12 work hours just looking for an API that meets my requirements.

  Read the article

• Best practice for SEO "special characters" in products pages

  - by rhodesit

  Whats a best practice for creating websites do to the fact that i need to enter "ö" within the content/title/meta. Should I spell it without, and just use a "normal" character or do i put in this code everywhere. or do i spell it half the time with and half the time without. whats the best practice for seo? Google takes into account user intent. Which makes things complicated(in my mind). The user will be searching without the "special characters" but because of the whole "user intent" thing, I don't know the best practice for this situation is. Should I use a mix of both spellings? Should I use the special characters in anchortext/headers/title/metadescription?

  Read the article

• To same computer Remote desktop thrue WRT54G router

  - by Kangarooo

  Can't access from my Same comp to same comp to test if all is ok. Tried all mentioned posibilities. Tryd my ip xxx.xxx.xxx.xxx / localhost with / without :5900 added with / without in "Remote desktop" checked "Configure network automatically to accept connection" with / without in router WRT54G enabled port 5900 forwardet to my comp 192.168.1.3 UPNP is enabled. I can connect to one other comp whitch isn't using router and checked "Configure network automatically to accept connection" and to one through TENDA W311R+ router where i've put port forwarding to 5900 and there works xxx.xxx.xxx.xxx:5900 What's wrong? What have i missed?

  Read the article

• Real Widget Adds WP7-like Tiles to Android

  - by Jason Fitzpatrick

  Android: If you want the look of Windows Phone 7 tiles on your Android phone without completely replacing your launcher and interface, Real Widget offers the shortcut tiles without the total overhaul. You can customize the widgets to launch apps, system functions, and more to enjoy the WP7 tiled look without sacrificing the functionality of your current Android launcher. Hit up the link below to check out more screenshots and free copy to take for a spin. Real Widget is Android 4.0+ only. Real Widget [via Addictive Tips] HTG Explains: How Antivirus Software Works HTG Explains: Why Deleted Files Can Be Recovered and How You Can Prevent It HTG Explains: What Are the Sys Rq, Scroll Lock, and Pause/Break Keys on My Keyboard?

  Read the article

• How do non-coders do simple local templating to avoid redundant HTML? [closed]

  - by Max Cantor

  I'm a web developer. When I start designing a site, I use a framework to handle templating for me, even if it's just rack + erubis. What do non-developers do? If you want to implement a site in HTML and CSS without a framework running on a webserver, without frames, and without WYSYWIG tools like Dreamweaver... how do you avoid copy-and-pasting the HTML of your navigation (for example) on every single page you're writing? I feel stupid asking this because it seems like their must be an obvious answer, but for the life of me, I can't think of one right now.

  Read the article

• Trying to boot from USB on Asus q200e-bhi3t45 just brings me to grub menu

  - by Krash Kharma

  It's been a struggle every time I've tried to change my OS on this machine. I honestly don't even know how it works whenever it does. I've somehow managed to get Windows 7, Windows 8, Mint 14, Ubuntu 12.04, and 12.10 to work at random times but it's always after struggling with it and googling for random chance fixes and suddenly something clicks and it loads from usb, but 99% of the time, every time I try to boot from USB to install a distro (in this case, I'm trying to get ubuntu-12.04.2-desktop-amd64.iso to work) my pc just comes up with a grub menu ("Minimal bash-like blahblahblah - grub ") I don't know why it works when it works. Right now I've tried everything from with/without Fast Boot in BIOS, with/without CSM, with/without secure boot, to changing BOOTx64.EFI to bootx64.efi to downloading a new bootx64.efi to copying it to every folder on the usb.... It makes no sense to me. Sorry if this has been asked before but I can't find anything

  Read the article

• Using Nemerle in asp.net App_Code directory

  - by Andrew Davey

  I want to use Nemerle in an ASP.NET application. Specifically, putting .n files into App_Code. I added this to my web.config system.codedom/compilers section: <compiler language="n;Nemerle" extension=".n" type="Nemerle.Compiler.NemerleCodeProvider, Nemerle.Compiler"/> When running I get this exception: The assembly '' is already loaded in another appdomain. Setting in machine.config can help solve this issue. Stack trace [HttpException (0x80004005): The assembly '' is already loaded in another appdomain. Setting <deployment retail="true" /> in machine.config can help solve this issue.] System.Web.Compilation.CodeDirectoryCompiler.GetCodeDirectoryAssembly(VirtualPath virtualDir, CodeDirectoryType dirType, String assemblyName, StringSet excludedSubdirectories, Boolean isDirectoryAllowed) +8809675 System.Web.Compilation.BuildManager.CompileCodeDirectory(VirtualPath virtualDir, CodeDirectoryType dirType, String assemblyName, StringSet excludedSubdirectories) +128 System.Web.Compilation.BuildManager.CompileCodeDirectories() +265 System.Web.Compilation.BuildManager.EnsureTopLevelFilesCompiled() +320 [HttpException (0x80004005): The assembly '' is already loaded in another appdomain. Setting <deployment retail="true" /> in machine.config can help solve this issue.] System.Web.Compilation.BuildManager.ReportTopLevelCompilationException() +58 System.Web.Compilation.BuildManager.EnsureTopLevelFilesCompiled() +512 System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters) +729 [HttpException (0x80004005): The assembly '' is already loaded in another appdomain. Setting <deployment retail="true" /> in machine.config can help solve this issue.] System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +8890735 System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +85 System.Web.HttpRuntime.ProcessRequestInternal(HttpWorkerRequest wr) +259 What am I doing wrong?

  Read the article

• Enable LLVM + Clang in Xcode new project causes linking errors

  - by Ger Teunis

  I've done a complete clean uninstall of XCode and deleted the prefs and deleted complete /Developer folder and reinstalled XCode again. I create a new Cocoa application, go over to Target, doing a "Get info" in the target and enable "C / C++ compiler version" to "LLVM compiler 1.0.2" and press Build. I get: ld: warning: directory '/usr/lib/gcc/i686-apple-darwin10/4.2.1/x86_64' following -L not found ld: warning: directory '/usr/lib/gcc/i686-apple-darwin10/4.2.1/x86_64' following -L not found ld: warning: directory '/usr/lib/i686-apple-darwin10/4.2.1' following -L not found ld: warning: directory '/usr/lib/gcc/i686-apple-darwin10/4.2.1' following -L not found ld: warning: directory '/usr/lib/gcc/i686-apple-darwin10/4.2.1' following -L not found ld: warning: directory '/usr/lib/gcc/i686-apple-darwin10/4.2.1/../../../i686-apple-darwin10/4.2.1' following -L not found ld: warning: directory '/usr/lib/gcc/i686-apple-darwin10/4.2.1/../../..' following -L not found ld: library not found for -lgcc Command /Developer/usr/bin/clang failed with exit code 1 Anyone able to help me here? LLVM + GCC frontend does work though but I really would like to use Clang (LLVM compiler 1.0.2). New XCode install, new Cocoa project still have this issue.

  Read the article

• Problems compiling peazip on OSX

  - by Yansky

  I'm having some problems with compiling Peazip on OSX (10.6). I emailed the Peazip developer and he said he probably couldn't help me too much as the error seems to be OSX specific and he doesn't have access to an OSX machine any more. The compiler I'm using is Lazarus as the source is in Pascal. The actual compile process seems to go ok, but when I run the peazip.app program launcher, I get the following error: http://img.photobucket.com/albums/v215/thegooddale/Screen-shot-2010-05-22-at-71907-PM.png Here is the app launcher that the compile made: http://forboden.com/coding/peazip.app.zip - you can use an unzip program to look at the files inside (i.e. unzip it twice). I also tried just running the peazip unix file executable that was produced after the compile from the terminal and I got this: http://img.photobucket.com/albums/v215/thegooddale/Screen-shot-2010-05-22-at-72148-PM.png Here are the messages from the compile log from Lazarus while compiling Peazip: http://pastebin.com/qK4bdncL (I asked on the Lazarus forums and they said I can just ignore those "ld: warning: unknown stabs type" warnings). Here is the info from the project_peach.compiled file: <?xml version="1.0"?> <CONFIG> <Compiler Value="/usr/local/bin/ppc386" Date="1238949773"/> <Params Value=" -MObjFPC -Sgi -O1 -gl -k-framework -kCarbon -k-framework -kOpenGL -k'-dylib_file' -k'/System/Library/Frameworks/OpenGL.framework/Versions/A/Libraries/libGL.dylib:/System/Library/Frameworks/OpenGL.framework/Versions/A/Libraries/libGL.dylib' -WG -vewnhi -l -Fu/Users/yansky/Desktop/peazip-3.1.src/res/themes/crystalc/ -Fu/Developer/lazarus/components/synedit/units/i386-darwin/ -Fu/Developer/lazarus/ideintf/units/i386-darwin/ -Fu/Developer/lazarus/lcl/units/i386-darwin/ -Fu/Developer/lazarus/lcl/units/i386-darwin/carbon/ -Fu/Developer/lazarus/packager/units/i386-darwin/ -Fu/Users/yansky/Desktop/peazip-3.1.src/ -Fu. -opeazip -dLCL -dLCLcarbon project_peach.lpr"/> </CONFIG> I guess there's little chance that anyone here has experience with Pascal and Lazarus since it's not that popular a language and the compiler is still in beta, but I thought I would post here in the hopes that someone might point me in the right general direction about where/how the peazip.app launcher is breaking.

  Read the article

• Generating scala AST for recursive method.

  - by scout

  I am generating the scala AST using the following code: val setting = new Settings(error) val reporter = new ConsoleReporter(setting, in, out) { override def displayPrompt = () } val compiler = new Global(setting, reporter) with ASTExtractor{ override def onlyPresentation = true } //setting.PhasesSetting("parser", "parserPhase") val run = new compiler.Run val sourceFiles:List[String] = List("Test.scala") run.compile(sourceFiles.toList) I guess this is the standard code used to run the compiler in the code and generate the AST to work with. The above code worked fine for any valid scala code in Test.scala till now. When I use a recursive function in Test.scala, like def xMethod(x:Int):Int = if(x == 0) -1 else xMethod(x-1) It gives me a java.lang.NullPointerException. The top few lines of the stack trace look like this at scala.tools.nsc.typechecker.Typers$Typer.checkNoDoubleDefsAndAddSynthetics$1(Typers.scala:2170) at scala.tools.nsc.typechecker.Typers$Typer.typedStats(Typers.scala:2196) at scala.tools.nsc.typechecker.Typers$Typer.typedBlock(Typers.scala:1951) at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:3815) at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:4124) at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:4177) at scala.tools.nsc.transform.TailCalls$TailCallElimination.transform(TailCalls.scala:199) The code works fine for a method like def aMethod(c:Int):Int = { bMethod(c) } def bMethod(x:Int):Int = aMethod(x) Please let me know if recursive functions need any other setting.

  Read the article

• x86 opcode alignment references and guidelines

  - by mrjoltcola

  I'm generating some opcodes dynamically in a JIT compiler and I'm looking for guidelines for opcode alignment. 1) I've read comments that briefly "recommend" alignment by adding nops after calls 2) I've also read about using nop for optimizing sequences for parallelism. 3) I've read that alignment of ops is good for "cache" performance Usually these comments don't give any supporting references. Its one thing to read a blog or a comment that says, "its a good idea to do such and such", but its another to actually write a compiler that implements specific op sequences and realize most material online, especially blogs, are not useful for practical application. So I'm a believer in finding things out myself (disassembly, etc. to see what real world apps do). This is one case where I need some outside info. I notice compilers will usually start an odd byte instruction immediately after whatever previous instruction sequence there was. So the compiler is not taking any special care in most cases. I see "nop" here or there, but usually it seems nop is used sparingly, if at all. How critical is opcode alignment? Can you provide references for cases that I can actually use for implementation? Thanks.

  Read the article

• force delete row on django app after migration

  - by unsorted

  After a migration with south, I ended up deleting a column. Now the current data in one of my tables is screwed up and I want to delete it, but attempts to delete just result in an error: >>> d = Degree.objects.all() >>> d.delete() Traceback (most recent call last): File "<console>", line 1, in <module> File "C:\Python26\lib\site-packages\django\db\models\query.py", line 440, in d elete for i, obj in izip(xrange(CHUNK_SIZE), del_itr): File "C:\Python26\lib\site-packages\django\db\models\query.py", line 106, in _ result_iter self._fill_cache() File "C:\Python26\lib\site-packages\django\db\models\query.py", line 760, in _ fill_cache self._result_cache.append(self._iter.next()) File "C:\Python26\lib\site-packages\django\db\models\query.py", line 269, in i terator for row in compiler.results_iter(): File "C:\Python26\lib\site-packages\django\db\models\sql\compiler.py", line 67 2, in results_iter for rows in self.execute_sql(MULTI): File "C:\Python26\lib\site-packages\django\db\models\sql\compiler.py", line 72 7, in execute_sql cursor.execute(sql, params) File "C:\Python26\lib\site-packages\django\db\backends\util.py", line 15, in e xecute return self.cursor.execute(sql, params) File "C:\Python26\lib\site-packages\django\db\backends\sqlite3\base.py", line 200, in execute return Database.Cursor.execute(self, query, params) DatabaseError: no such column: students_degree.abbrev >>> Is there a simple way to just force a delete? Do I drop the table and then rerun manage.py schemamigration to recreate the table in south?

  Read the article

• sqrt(int_value + 0.0) -- Does it have a purpose?

  - by Earlz

  Hello, while doing some homework in my very strange C++ book, which I've been told before to throw away, had a very peculiar code segment. I know homework stuff always throws in extra "mystery" to try to confuse you like indenting 2 lines after a single-statement for-loop. But this one I'm confused on because it seems to serve some real-purpose. basically it is like this: int counter=10; ... if(pow(floor(sqrt(counter+0.0)),2) == counter) ... I'm interested in this part especially: sqrt(counter+0.0) Is there some purpose to the +0.0? Is this the poormans way of doing a static cast to a double? Does this avoid some compiler warning on some compiler I do not use? The entire program printed the exact same thing and compiled without warnings on g++ whenever I left out the +0.0 part. Maybe I'm not using a weird enough compiler? Edit: Also, does gcc just break standard and not make an error for Ambiguous reference since sqrt can take 3 different types of parameters? [earlz@EarlzBeta-~/projects/homework1] $ cat calc.cpp #include <cmath> int main(){ int counter=0; sqrt(counter); } [earlz@EarlzBeta-~/projects/homework1] $ g++ calc.cpp /usr/lib/libstdc++.so.47.0: warning: strcpy() is almost always misused, please use strlcpy() /usr/lib/libstdc++.so.47.0: warning: strcat() is almost always misused, please use strlcat() [earlz@EarlzBeta-~/projects/homework1] $

  Read the article

• Just introducing myself to TMPing, and came across a quirk

  - by Justen

  I was just trying to learn the syntax of the beginner things, and how it worked when I was making this short bit of code. The code below works in adding numbers 1 to 499, but if I add 1 to 500, the compiler bugs out giving me: fatal error C1001: An internal error has occurred in the compiler. And I was just wondering why that is. Is there some limit to how much code the compiler can generate or something and it just happened to be a nice round number of 500 for me? #include <iostream> using namespace std; template < int b > struct loop { enum { sum = loop< b - 1 >::sum + b }; }; template <> struct loop< 0 > { enum { sum = 0 }; }; int main() { cout << "Adding the numbers from 1 to 499 = " << loop< 499 >::sum << endl; return 0; }

  Read the article

• What does it mean that "Lisp can be written in itself?"

  - by Mason Wheeler

  Paul Graham wrote that "The unusual thing about Lisp-- in fact, the defining quality of Lisp-- is that it can be written in itself." But that doesn't seem the least bit unusual or definitive to me. ISTM that a programming language is defined by two things: Its compiler or interpreter, which defines the syntax and the semantics for the language by fiat, and its standard library, which defines to a large degree the idioms and techniques that skilled users will use when writing code in the language. With a few specific exceptions, (the non-C# members of the .NET family, for example,) most languages' standard libraries are written in that language for two very good reasons: because it will share the same set of syntactical definitions, function calling conventions, and the general "look and feel" of the language, and because the people who are likely to write a standard library for a programming language are its users, and particularly its designer(s). So there's nothing unique there; that's pretty standard. And again, there's nothing unique or unusual about a language's compiler being written in itself. C compilers are written in C. Pascal compilers are written in Pascal. Mono's C# compiler is written in C#. Heck, even some scripting languages have implementations "written in itself". So what does it mean that Lisp is unusual in being written in itself?

  Read the article

• Compile and optimize for different target architectures

  - by Peter Smit

  Summary: I want to take advantage of compiler optimizations and processor instruction sets, but still have a portable application (running on different processors). Normally I could indeed compile 5 times and let the user choose the right one to run. My question is: how can I can automate this, so that the processor is detected at runtime and the right executable is executed without the user having to chose it? I have an application with a lot of low level math calculations. These calculations will typically run for a long time. I would like to take advantage of as much optimization as possible, preferably also of (not always supported) instruction sets. On the other hand I would like my application to be portable and easy to use (so I would not like to compile 5 different versions and let the user choose). Is there a possibility to compile 5 different versions of my code and run dynamically the most optimized version that's possible at execution time? With 5 different versions I mean with different instruction sets and different optimizations for processors. I don't care about the size of the application. At this moment I'm using gcc on Linux (my code is in C++), but I'm also interested in this for the Intel compiler and for the MinGW compiler for compilation to Windows. The executable doesn't have to be able to run on different OS'es, but ideally there would be something possible with automatically selecting 32 bit and 64 bit as well. Edit: Please give clear pointers how to do it, preferably with small code examples or links to explanations. From my point of view I need a super generic solution, which is applicable on any random C++ project I have later. Edit I assigned the bounty to ShuggyCoUk, he had a great number of pointers to look out for. I would have liked to split it between multiple answers but that is not possible. I'm not having this implemented yet, so the question is still 'open'! Please, still add and/or improve answers, even though there is no bounty to be given anymore. Thanks everybody!

  Read the article

• What is the general feeling about reflection extensions in std::type_info?

  - by Evan Teran

  I've noticed that reflection is one feature that developers from other languages find very lacking in c++. For certain applications I can really see why! It is so much easier to write things like an IDE's auto-complete if you had reflection. And certainly serialization APIs would be a world easier if we had it. On the other side, one of the main tenets of c++ is don't pay for what you don't use. Which makes complete sense. That's something I love about c++. But it occurred to me there could be a compromise. Why don't compilers add extensions to the std::type_info structure? There would be no runtime overhead. The binary could end up being larger, but this could be a simple compiler switch to enable/disable and to be honest, if you are really concerned about the space savings, you'll likely disable exceptions and RTTI anyway. Some people cite issues with templates, but the compiler happily generates std::type_info structures for template types already. I can imagine a g++ switch like -fenable-typeinfo-reflection which could become very popular (and mainstream libs like boost/Qt/etc could easily have a check to generate code which uses it if there, in which case the end user would benefit with no more cost than flipping a switch). I don't find this unreasonable since large portable libraries like this already depend on compiler extensions. So why isn't this more common? I imagine that I'm missing something, what are the technical issues with this?

  Read the article

• F#, Linux and makefiles

  - by rwallace

  I intend to distribute an F# program as both binary and source so the user has the option of recompiling it if desired. On Windows, I understand how to do this: provide .fsproj and .sln files, which both Visual Studio and MSBuild can understand. On Linux, the traditional solution for C programs is a makefile. This depends on gcc being directly available, which it always is. The F# compiler can be installed on Linux and works under Mono, so that's fine so far. However, as far as I can tell, it doesn't create a scenario where fsc runs the compiler, instead the command is mono ...path.../fsc.exe. This is also fine, except I don't know what the path is going to be. So the full command to run the compiler in my case could be mono ~/FSharp-2.0.0.0/bin/fsc.exe types.fs tptp.fs main.fs -r FSharp.PowerPack.dll except that I'm not sure where fsc.exe will actually be located on the user's machine. Is there a way to find that out within a makefile, or would it be better to fall back on just explaining the above in the documentation and relying on the user to modify the command according to his setup?

  Read the article

• Fatal error when using FILE* in Windows from DLL

  - by AlannY

  Hi there. Recently, I found a problem with Visual C++ 2008 compiler, but using minor hack avoid it. Currently, I cannot use the same hack, but problem exists as in 2008 as in 2010 (Express). So, I've prepared for you 2 simple C file: one for DLL, one for program: DLL (file-dll.c): #include <stdio.h> __declspec(dllexport) void print_to_stream (FILE *stream) { fprintf (stream, "OK!\n"); } And for program, which links this DLL via file-dll.lib: Program: #include <stdio.h> __declspec(dllimport) void print_to_stream (FILE *stream); int main (void) { print_to_stream (stdout); return 0; } To compile and link DLL: cl /LD file-dll.c To compile and link program: cl file-test.c file-dll.lib When invoking file-test.exe, I got the fatal error (similar to segmentation fault in UNIX). As I said early, I had that the same problem before: about transferring FILE* pointer to DLL. I thought, that it may be because of compiler mismatch, but now I'm using one compiler for everything and it's not the problem. ;-( What can I do now? UPD: I've found solution: cl /LD /MD file-dll.c cl /MD file-test.c file-dll.lib The key is to link to dynamic library, but (I did not know it) by default it links staticaly and (hencefore) error occurs (I see why). P.S. Thanks for patience.

  Read the article

• C: 8x8 -> 16 bit multiply precision guaranteed by integer promotions?

  - by craig-blome

  I'm trying to figure out if the C Standard (C90, though I'm working off Derek Jones' annotated C99 book) guarantees that I will not lose precision multiplying two unsigned 8-bit values and storing to a 16-bit result. An example statement is as follows: unsigned char foo; unsigned int foo_u16 = foo * 10; Our Keil 8051 compiler (v7.50 at present) will generate a MUL AB instruction which stores the MSB in the B register and the LSB in the accumulator. If I cast foo to a unsigned int first: unsigned int foo_u16 = (unsigned int)foo * 10; then the compiler correctly decides I want a unsigned int there and generates an expensive call to a 16x16 bit integer multiply routine. I would like to argue beyond reasonable doubt that this defensive measure is not necessary. As I read the integer promotions described in 6.3.1.1, the effect of the first line shall be as if foo and 10 were promoted to unsigned int, the multiplication performed, and the result stored as unsigned int in foo_u16. If the compiler knows an instruction that does 8x8-16 bit multiplications without loss of precision, so much the better; but the precision is guaranteed. Am I reading this correctly? Best regards, Craig Blome

  Read the article

< Previous Page | 247 248 249 250 251 252 253 254 255 256 257 258  | Next Page >