Search Results

Search found 5842 results on 234 pages for 'compiler warnings'.

Page 167/234 | < Previous Page | 163 164 165 166 167 168 169 170 171 172 173 174  | Next Page >

• How few a files does it take to load a program on Linux?

  - by BCS

  The (hypothetical for now) situation is the user of my system is going to be given a chunk of C code and needs my system to compile and run it in a chroot sandbox that is generated on the fly and I want to require the fewest files in the box as possible. I'm only willing to play with compiler and linker settings (e.g. static link everything I can expect to be able to find) and make some moderate restriction on what the code can expect use (e.g. they can't use arbitrary libs). The question is how simple can I get the sandbox. Clearly I need the executable, but what about an ELF loader and a .so for the system calls? Can I dump either of them and is there something else I'll need?

  Read the article

• How to free memory in try-catch blocks?

  - by Kra

  Hi, I have a simple question hopefully - how does one free memory which was allocated in the try block when the exception occurs? Consider the following code: try { char *heap = new char [50]; //let exception occur here delete[] heap; } catch (...) { cout << "Error, leaving function now"; //delete[] heap; doesn't work of course, heap is unknown to compiler return 1; } How can I free memory after the heap was allocated and exception occurred before calling delete[] heap? Is there a rule not to allocate memory on heap in these try .. catch blocks? Thanks

  Read the article

• C#: Why only integral enums?

  - by JamesBrownIsDead

  I've been writing C# for seven years now, and I keep wondering, why do enums have to be of an integral type? Wouldn't it be nice to do something like: enum ErrorMessage { NotFound: "Could not find", BadRequest: "Malformed request" } Is this a language design choice, or are there fundamental incompatibilities on a compiler, CLR, or IL level? Do other languages have enums with string or complex (i.e. object) types? What languages? (I'm aware of workarounds; my question is, why are they needed?) EDIT: "workarounds" = attributes or static classes with consts :)

  Read the article

• Why do Java source files go into a directory structure?

  - by bdhar

  Suppose that I am creating a Java project with the following classes com.bharani.ClassOne com.bharani.ClassTwo com.bharani.helper.HelperOne com.bharani.helper.support.HelperTwo with files put immediately under the folder 'src' src/ClassOne.java src/ClassTwo.java src/HelperOne.java src/HelperTwo.java and compile them using the command $ javac src/*.java -d classes (assuming that classes directory exists) The compiler compiles these files and put the class files in appropriate sub-directories inside the 'classes' directory like this classes/com/bharani/ClassOne.class classes/com/bharani/ClassTwo.class classes/com/bharani/helper/HelperOne.class classes/com/bharani/helper/support/HelperTwo.class Because the spec mandates that the classes should go inside appropriate directory structure. Fine. My question is this: When I use an IDE such as Eclipse or NetBeans, they create the directory structure for the source code directory ('src' directory here) also. Why is that? Is it mandatory? Or, is it just a convention? Thanks.

  Read the article

• C++ Header file questions

  - by Karl

  So I'm trying to learn C++ and I've gotten as far as using header files. They really make no sense to me. I've tried many combinations of this but nothing so far has worked: Main.cpp: #include "test.h" int main() { testClass Player1; return 0; } test.h: #ifndef TEST_H_INCLUDED #define TEST_H_INCLUDED class testClass { private: int health; public: testClass(); ~testClass(); int getHealth(); void setHealth(int inH); }; #endif // TEST_H_INCLUDED test.cpp: #include "test.h" testClass::testClass() { health = 100; } testClass::~testClass() {} int testClass::getHealth() { return(health); } void testClass::setHealth(int inH) { health = inH; } What I'm trying to do is pretty simple, but the way the header files work just makes no sense to me at all. Code blocks returns the following on build: obj\Debug\main.o(.text+0x131)||In function main':| *voip*\test\main.cpp |6|undefined reference totestClass::testClass()'| obj\Debug\main.o(.text+0x13c):voip\test\main.cpp|7|undefined reference to `testClass::~testClass()'| ||=== Build finished: 2 errors, 0 warnings ===| I'd appreciate any help. Or if you have a decent tutorial for it, that would be fine too (most of the tutorials I've googled haven't helped)

  Read the article

• Mysql for update

  - by shantanuo

  MySQL supports "for update" keyword. Here is how I tested that it is working as expected. I opened 2 browser tabs and executed the following commands in one window. mysql> start transaction; Query OK, 0 rows affected (0.00 sec) mysql> select * from myxml where id = 2 for update; .... mysql> update myxml set id = 3 where id = 2 limit 1; Query OK, 1 row affected, 1 warning (0.00 sec) Rows matched: 1 Changed: 1 Warnings: 0 mysql> commit; Query OK, 0 rows affected (0.08 sec) In another window, I started the transaction and tried to take an update lock on the same record. mysql> start transaction; Query OK, 0 rows affected (0.00 sec) mysql> select * from myxml where id = 2 for update; Empty set (43.81 sec) As you can see from the above example, I could not select the record for 43 seconds as the transaction was being processed by another application in the Window No 1. Once the transaction was over, I got to select the record, but since the id 2 was changed to id 3 by the transaction that was executed first, no record was returned. My question is what are the disadvantages of using "for update" syntax? If I do not commit the transaction that is running in window 1 will the record be locked for-ever?

  Read the article

• EHsc vc EHa (synchronous vs asynchronous exception handling)

  - by watson1180

  Could you give a bullet list of practical differences/implication? I read relevant MSDN article, but my understanding asynchronous exceptions is still a bit hazy. I am writing a test suite using Boost.Test and my compiler emits a warning that EHa should be enabled: warning C4535: calling _set_se_translator() requires /EHa The project itself uses only plain exceptions (from STL) and doesn't need /EHa switch. Do I have to recompile it with /EHa switch to make the test suite work properly? My feeling is that I need /EHa for the test suit only. Thank you and happy new year.

  Read the article

• ASP.NET UserControl not defined?

  - by BryanG

  I've just inherited an app that utilizes usercontrols in a couple ways which I'm not too familiar with. The problem I have right now is that when I attempt to publish this code base, I get a few errors which boil down to where some referenced usercontrols are not defined. Here's an example of one line: Private clientControl As New ASP.usercontrols_clientcontrol_ascx This is a tab strip usercontrol which references other usercontrols to dynamically create the tabs. Now, on the surface I get what is going on here...but the compiler is not accepting this. This tab strip usercontrol is in the root of the project, and the other usercontrols are in a sub folder. error BC30002: Type 'ASP.usercontrols_clientcontrol_ascx' is not defined. I'm sure this is 101 stuff here, but the build works and the publish fails. Any direction would be appreciated.

  Read the article

• Scala: Mixing traits with private fields

  - by Vilius Normantas

  It's not much of a question, it's rather my excitement that it's possible at all! I wrote this little example just to prove the opposite - I expected either a compiler error or one of the values (111 or 222, I wasn't sure). scala> trait T1 { private val v = 111; def getValueT1 = v } scala> trait T2 { private val v = 222; def getValueT2 = v } scala> class T12 extends T1 with T2 scala> val t = new T12 scala> t.getValueT1 res9: Int = 111 scala> t.getValueT2 res10: Int = 222 Why doesn't the v get overridden? Off course this works only as long as vs are private, but still.

  Read the article

• Why am I getting this warning about my app delegate and CLLocationManageDelegate?

  - by Dan Ray

  Observe this perfectly simple UIViewController subclass method: -(IBAction)launchSearch { OffersSearchController *search = [[OffersSearchController alloc] initWithNibName:@"OffersSearchView" bundle:nil]; EverWondrAppDelegate *del = [UIApplication sharedApplication].delegate; [del.navigationController pushViewController:search animated:YES]; [search release]; } On the line where I get *del, I am getting a compiler warning that reads, Type 'id <UIApplicationDelegate>' does not conform to the 'CLLocationManagerDelegate' protocol. In fact, my app delegate DOES conform to that protocol, AND what I'm doing here has nothing at all to do with that. So what's up with that message? Secondary question: sometimes I can get to my navigationController via self.navigationController, and sometimes I can't, and have to go to my app delegate's property to get it like I'm doing here. Any hint about why that is would be very useful.

  Read the article

• Why aren't operator conversions implicitly called for templated functions? (C++)

  - by John Gordon

  I have the following code: template <class T> struct pointer { operator pointer<const T>() const; }; void f(pointer<const float>); template <typename U> void tf(pointer<const float>); void g() { pointer<float> ptr; f(ptr); tf(ptr); } When I compile the code with gcc 4.3.3 I get a message (aaa.cc:17: error: no matching function for call to ‘tf(pointer<float>&)’) indicating that the compiler called 'operator pointer<const T>' for the non-templated function f(), but didn't for the templated function tf(). Why and is there any workaround short of overloading tf() with a const and non-const version? Thanks in advance for any help.

  Read the article

• HOW TO understand the programmming of operation system..!!!

  - by piemesons

  Hello, I want to learn the operating system. How it works. I dont want to make my own operating system. I just want to learn how it works. As i can find out source code of any open source OS. But how to start. Like stating from the first elementary kernal(what ever it is). Some body suggested me try to implement linux from scratch.etc etc.Please guide me in a proper way. i want to know about the proper path to follow. I am ready to invest three four years just to understand the basics. I am having good fundamentals of c c++,php, Oops, compiler design

  Read the article

• Create Generic Class Instance from Static Method in a Derived Class

  - by user343547

  I have a class in C# with a template and static method similar to class BClass<T> { public static BClass<T> Create() { return new BClass<T>(); } } From this I derive a class and specify a template parameter to the base class class DClass : BClass<int> { } A problem occurs when I try to use the static method to create an instance of D class Program { static void Main(string[] args) { DClass d = DClass.Create(); } } Gives a compiler error "Cannot implicitly convert type 'Test.BClass<int ' to 'Test.DClass'." Adding the below cast leads to a runtime casting exception. DClass d = (DClass)DClass.Create(); Is there any succint way to allow the static method to create instances of the derived class? Ideally I would like the equivalent of a c++ typedef and I don't want the below syntax (which does work). BClass<int> d = DClass.Create();

  Read the article

• How should open source libraries be used on Windows?

  - by Jason Owen

  There are many open-source libraries that can be compiled with Visual Studio. I'm porting a program from Linux to Windows, but it depends on a number of libraries. I don't know what the best practices regarding libraries are on Windows. On Linux, these libraries are typically part of the distribution. To use sqlite on Debian, for example, you need only to install libsqlite3-dev and the include files and libraries (both static and dynamic) are automatically installed and available to your program. If you need a different version than your distribution supplies, you can compile it in your home directory, install it to ~/include and ~/lib, and set the appropriate environment variables so that your compiler includes those directories in its search path. What is the best way to use libraries that are distributed as source on Windows? If I link dynamically rather than statically, is there an easy way to copy required DLLs into the output directory to ease redistribution (assuming license requirements are met)?

  Read the article

• How to make Visual C++ 9 not emit code that is actually never called?

  - by sharptooth

  My native C++ COM component uses ATL. In DllRegisterServer() I call CComModule::RegisterServer(): STDAPI DllRegisterServer() { return _Module.RegisterServer(FALSE); // <<< notice FALSE here } FALSE is passed to indicate to not register the type library. ATL is available as sources, so I in fact compile the implementation of CComModule::RegisterServer(). Somewhere down the call stack there's an if statement: if( doRegisterTypeLibrary ) { //<< FALSE goes here // do some stuff, then call RegisterTypeLib() } The compiler sees all of the above code and so it can see that in fact the if condition is always false, yet when I inspect the linker progress messages I see that the reference to RegisterTypeLib() is still there, so the if statement is not eliminated. Can I make Visual C++ 9 perform better static analysis and actually see that some code is never called and not emit that code?

  Read the article

• Why is forwarding variadic parameters invalid?

  - by awesomeyi

  Consider the variadic function parameter: func foo(bar:Int...) -> () { } Here foo can accept multiple arguments, eg foo(5,4). I am curious about the type of Int... and its supported operations. For example, why is this invalid? func foo2(bar2:Int...) -> () { foo(bar2); } Gives a error: Could not find an overload for '_conversion' that accepts the supplied arguments Why is forwarding variadic parameters invalid? What is the "conversion" the compiler is complaining about?

  Read the article

• Checking lazy loaded properties have been instantiated

  - by PaulG

  In a class which has a lazy loaded property, such as: private Collection<int> someInts; public Collection<int> SomeInts { get { if (this.someInts == null) this.someInts = new Collection<int>(); return this.someInts; } } Is it worth also having a property such as: public bool SomeIntsExist { get { return (this.someInts != null && this.someInts.Count > 0); } } And then using that property.. eg: if (thatClass.SomeIntsExist) { // do something with thatClass.SomeInts collection } or is this premature optimisation. Its certainly easier to roll with something like below, but it will instantiate the collection needlessly: if (thatClass.SomeInts.Count > 0) { // do something with thatClass.SomeInts collection } Is the compiler smart enough to figure things like this out? Is there a better way?

  Read the article

• How do I include extremely long literals in C++ source?

  - by BillyONeal

  Hello everyone :) I've got a bit of a problem. Essentially, I need to store a large list of whitelisted entries inside my program, and I'd like to include such a list directly -- I don't want to have to distribute other libraries and such, and I don't want to embed the strings into a Win32 resource, for a bunch of reasons I don't want to go into right now. I simply included my big whitelist in my .cpp file, and was presented with this error: 1>ServicesWhitelist.cpp(2807): fatal error C1091: compiler limit: string exceeds 65535 bytes in length The string itself is about twice this allowed limit by VC++. What's the best way to include such a large literal in a program?

  Read the article

• C++ - Resources in static library question

  - by HardCoder1986

  Hello! This isn't a duplicate of http://stackoverflow.com/questions/531502/vc-resources-in-a-static-library because it didn't help :) I have a static library with TWO .rc files in it's project. When I build my project using the Debug configuration, I retrieve the following error (MSVS2008): fatal error LNK1241: resource file res_yyy.res already specified Note, that this happens only in Debug and Release library builds without any troubles. The command line for Resources page in project configuration looks the same for every build: /fo"...(Path here)/Debug/project_name.res" /fo"...(Path here)/Release/project_name.res" and I can't understand what's the trouble. Any ideas? UPDATE I don't know why this happens, but when I turn "Use Link-Time Code Generation" option on the problem goes away. Could somebody explain why does this happen? I feel like MS-compiler is doing something really strange here. Thanks.

  Read the article

• Has anyone been successful at a assembler based led blinker for an xcore?

  - by dwelch

  I am liking the http://www.xmos.com chips but want to get a lower level understanding of what is going on. Basically assembler. I am trying to sort out something as simple as an led blinker, set the led, count to N clear the led, count to N, loop forever. Sure I can disassemble a 10 line XC program, but if you have tried that you will see there is a lot of bloat in there that is in every program, what bits are to support the compiler output and what bits are actually setting up the gpio?

  Read the article

• Explicit initialization of struct/class members

  - by Zephon

  struct some_struct{ int a; }; some_struct n = {}; n.a will be 0 after this; I know this braces form of initialization is inherited from C and is supported for compatibility with C programs, but this only compiles with C++, not with the C compiler. I'm using Visual C++ 2005. In C this type of initialization struct some_struct n = {0}; is correct and will zero-initialize all members of a structure. Is the empty pair of braces form of initialization standard? I first saw this form of initialization in a WinAPI tutorial from msdn.

  Read the article

• UIImagePickerController crashes on rapid scrolling, slower than photos app

  - by vvanhee

  Most of the time, my image picker works perfectly (iOS 4.2.1). However, if I scroll very rapidly up and down about 4-6 times through my camera roll of about 300 photos, I get a crash. This never happens with the "photos" app on the same iPhone 3Gs. Also, I'm noticing that the stock "photos" app scrolls much more smoothly than my image picker. Has anyone else noticed this behavior? I'd be interested if others could attempt this in their own apps and see if they crash. I don't think it's related to other objects hogging memory on my iPhone because it's a simple app, and this happens right after I start the app. It also doesn't seem to be related to messages sent to other released objects or overreleasing of other objects in viewdidunload, based on my crash logs and the fact that the simulator responds well to simulated memory warnings. I think it might be a bug in the internal implementation of the UIImagePickerController... This is how I start the picker. I've done this multiple ways (including setting a retain property for the UIImagePickerController in my header and releasing on dealloc). This seems to be the best way (crashes least): UIImagePickerController *picker = [[UIImagePickerController alloc] init]; picker.delegate = self; picker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum; picker.allowsEditing = YES; [self presentModalViewController:picker animated:YES]; [picker release]; This is the crashed thread (I get various exception types): Exception Type: SIGSEGV Exception Codes: SEGV_ACCERR at 0xfffffffff4faafa4 Crashed Thread: 8 ... Thread 8 Crashed: 0 CoreFoundation 0x000494ea -[__NSArrayM replaceObjectAtIndex:withObject:] + 98 1 PhotoLibrary 0x00008e0f -[PLImageTable _segmentAtIndex:] + 527 2 PhotoLibrary 0x00008a21 -[PLImageTable _mappedImageDataAtIndex:] + 221 3 PhotoLibrary 0x0000893f -[PLImageTable dataForEntryAtIndex:] + 15 4 PhotoLibrary 0x000087e7 PLThumbnailManagerImageDataAtIndex + 35 5 PhotoLibrary 0x00008413 -[PLThumbnailManager _dataForPhoto:format:width:height:bytesPerRow:dataWidth:dataHeight:imageDataOffset:imageDataFormat:preheat:] + 299 6 PhotoLibrary 0x000b6c13 __-[PLThumbnailManager preheatImageDataForImages:withFormat:]_block_invoke_1 + 159 7 libSystem.B.dylib 0x000d6680 _dispatch_call_block_and_release + 20 8 libSystem.B.dylib 0x000d6ba0 _dispatch_worker_thread2 + 128 9 libSystem.B.dylib 0x0007b251 _pthread_wqthread + 265

  Read the article

• Cross-platform SOA framework

  - by ByteMR

  I'm looking for a good cross-platform SOA framework that preferably works with several programming languages like C++, Python, and C#. I recently learned about Thrift, but that doesn't seem to work with MSVC from the documentation I've read and requires the use of Cygwin or MinGW to even compile the Thrift compiler. Does Thrift work with MSVC and if not, are there any alternatives that would meet my needs? Such as being able to generate C# and Python bindings and work on Linux, Mac, and Windows. Any suggestions would be greatly appreciated!

  Read the article

• How do I compile variadic templates conditionally?

  - by FredOverflow

  Is there a macro that tells me whether or not my compiler supports variadic templates? #ifdef VARIADIC_TEMPLATES_AVAILABLE template<typename... Args> void coolstuff(Args&&... args); #else ??? #endif If they are not supported, I guess I would simulate them with a bunch of overloads. Any better ideas? Maybe there are preprocessor libraries that can ease the job?

  Read the article

• Should I use C++0x Features Now?

  - by svu2g

  With the official release of VS 2010, is it safe for me to start using the partially-implemented C++0x feature set in my new code? The features that are of interest to me right now are both implemented by VC++ 2010 and recent versions of GCC. These are the only two that I have to support. In terms of the "safety" mentioned in the first sentence: can I start using these features (e.g., lambda functions) and still be guaranteed that my code will compile in 10 years on a compiler that properly conforms to C++0x when it is officially released? I guess I'm asking if there is any chance that VC++ 2010 or GCC will end up like VC++ 6; it was released before the language was officially standardized and consequently allowed grossly ill-formed code to compile. After all, Microsoft does say that "10 is the new 6". ;)

  Read the article

< Previous Page | 163 164 165 166 167 168 169 170 171 172 173 174  | Next Page >