cast to void *' from smaller integer type 'int cast to void *' from smaller integer type 'int

../lib/odp-util.c:5658:9: note: expanded from macro 'SCAN_END_SINGLE' So,solution #3 works just fine. @jackdoe: It's a waste of human life to write code that "you may need in the future". [Solved] Error "Cast from pointer to smaller type 'int' | 9to5Answer I cannot reverse my upvote of user384706's answer, but it's wrong. If the object expression refers or points to is actually a base class subobject of an object of type D, the result refers to the enclosing object of type D. Otherwise, the behavior is undefined: When the target type is bool (possibly cv-qualified), the result is false if the original value is zero and true for all other values. That could create all kinds of trouble. privacy statement. Floating-point conversions All character types are to be converted to an integer. Most answers just try to extract 32 useless bits out of the argument. To learn more, see our tips on writing great answers. Again, all of the answers above missed the point badly. Thanks. The program can be set in such a way to ask the user to inform the type of data and . 1. I wish that you write those answer first than the explanation. eg. What video game is Charlie playing in Poker Face S01E07? Euler: A baby on his lap, a cat on his back thats how he wrote his immortal works (origin? */ >> -bool >> +enum conversion_safety >> unsafe_conversion_p (tree type, tree expr, bool . Projects. You can use any other pointer, or you can use (size_t), which is 64 bits. For integer casts in specific, using into() signals that . In 64-bit programs, the size of the pointer is 64 bits, and cannot be put into the int type, which remains 32-bit in almost all systems. Not the answer you're looking for? This page was last modified on 12 February 2023, at 18:25. If it's anything like cocos2d-iphone v2.x and just based on this slice of code in a core class I wager it's safe to say that cocos2d-x 2.x also is not compatible with 64 bit code, and you can expect all kinds of issues (not just compile-time but also runtime). There exist two main syntaxes for generic type-casting: functional and c-like: 1 2 3 4 double x = 10.3; int y; y = int (x); // functional notation y = (int) x; // c-like cast notation The functionality of these generic forms of type-casting is enough for most needs with fundamental data types. this way I convert an int to a void* which is much better than converting a void* to an int. Java Type Casting (With Examples) - Programiz What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? He should pass the address of the integer, the thread should get that address, Note: This is only appropriate is you cast the. Anw, the project still build and run normally when i use Xcode 5.0 with iOS 7.0. c - type casting integer to void* - Stack Overflow Just edited. SCAN_SINGLE("skb_priority(", uint32_t, u32, OVS_KEY_ATTR_PRIORITY); Please note that the error I am receiving is "cast to smaller integer type 'int' from 'string' (aka 'char *')" referencing line of code: while (isalpha (residents [i].name) == 0). Cast a smaller integer to a larger integer - community - The Rust I am an entry level C programmer. Implicit Type Conversion is also known as 'automatic type conversion'. If you convert (void*) to (long) no precision is lost, then by assigning the (long) to an (int), it properly truncates the number to fit. Here is some piece of code where that error occur: /cocos2d-x-2.2.2/cocos2dx/platform/ios/EAGLView.mm:408:18: Cast from pointer to smaller type 'int' loses information. This will only compile if the destination type is long enough. Casting arguments inside the function is a lot safer. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. what does it mean to convert int to void* or vice versa? ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ While working with Threads in C, I'm facing the warning, "warning: cast to pointer from integer of different size". I'm new to coding and am trying to implement a simple program on my own, that prompts the user the number of residents in an apt complex, the prompts the user to enter the names and apt numbers of each resident. If the value in a pointer is cast to a different type and it does not have the correct alignment for the new type, the behavior is undefined. Netdev Archive on lore.kernel.org help / color / mirror / Atom feed * [mst-vhost:vhost 5/52] drivers/block/virtio_blk.c:539:21: warning: assignment to 'void *' from . You need to cast the void* pointer to a char* pointer - and then dereference that char* pointer to give you the char that it points to! Can Martian regolith be easily melted with microwaves? A nit: in your version, the cast to void * is unnecessary. To perform a cast, specify the type that you are casting to in parentheses in front of the value or variable to be converted. static_cast conversion - cppreference.com The difference between the phonemes /p/ and /b/ in Japanese. Disconnect between goals and daily tasksIs it me, or the industry? Casting type void to uint8_t - Arduino Forum How to correctly cast a pointer to int in a 64-bit application? So you know you can cast it back like this. This is flat out wrong. "I think what you should do is actually pass the address of the variable to the function" Not necessarily. */void **MatrixIB (unsigned long x, unsigned long y, int size){ void *ptr; void **returnPtr; register unsigned long i, j; returnPtr = (void **) malloc (x * sizeof(void *)); ptr = (void *) malloc (x * y * size); for (i=0, j=0; j returnPtr[j] = (void *) (ptr + i); // <<< Compile Errors, Error1error C2036: 'void *' : unknown sizec:\temp\testone\lib\utils.c57, 2> returnPtr[j] = (void *) ((long*)ptr + i); // <<< No compile errors, 3> returnPtr[j] = (void *) ((char*)ptr + i); // <<< No compile errors. If your code has the chance to ever be ported to some platform where this doesn't hold, this won't work. byte -> short -> char -> int -> long -> float -> double. A cast converts an object or value from one type to another. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, Xcode 5 and iOS 7: Architecture and Valid architectures, xcode build error: Semantic issue cast from pointer to smaller type 'int' loses information, Issues in handling touches on subviews(uiviews) in UIScrollView, Architecture linking error after Xcode 5.1 upgrade, iOS 7.1 gives error after updating to Xcode 5.1, Linker error in Xcode 5.1 with cocos2d-x 3 beta 2. From what I read about casting in the C11 standard, my feeling is, that it is arguable to emit a warning on an explicit conversion. Asking for help, clarification, or responding to other answers. @LearnCocos2D: so, how can i "overcome" the error without editing any not-my-code or in-library-file lines? There's probably little you can do except look or hope for a fixed 2.x version or upgrade to 3.x (I would assume it's 64-bit safe but this is just a guess, do research this issue before you upgrade). But you seem to suggest by your answer that the user can pass 5 to pthread_create and then perform the above cast to get it back. void* -> integer -> void* rather than integer -> void* -> integer. Why is this sentence from The Great Gatsby grammatical? This allows you to reinterpret the void * as an int. I usually have all automatic conversion warnings effective when developing in C, and I use explicit casting in order to suppress a specific . Visit Microsoft Q&A to post new questions. Or, they are all wrong. If pointers are 64 bits and ints are 32 bits, an int is too small to hold a pointer value. Why did Ukraine abstain from the UNHRC vote on China? What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? But then you need to cast your arguments inside your thread function which is quite unsafe cf. I'm trying to create a void* from an int. @Xax: Here's a fixed version, without the race condition: gist.github.com/depp/241d6f839b799042c409, gist.github.com/depp/3f04508a88a114734195, How Intuit democratizes AI development across teams through reusability. I would create a structure and pass that as void* to pthread_create. This method will not work on 64 bit Big Endian platform, so it unnecessarily breaks portability. this way you won't get any warning. Not the answer you're looking for? To learn more, see our tips on writing great answers. error: cast from pointer to smaller type 'unsigned int' loses information. C - Type Casting - tutorialspoint.com The problem was there before, you just are being notified of it. Casting a pointer to void* and back is valid use of reinterpret_cast<>. Thanks Jonathan, I was thinking about my answer in another thread: AraK is correct, passing integers a pointers are not necessarily interchangeable. It is commonly called a pointer to T and its type is T*. How to tell which packages are held back due to phased updates, Identify those arcade games from a 1983 Brazilian music video. Your first example is risky because you have to be very careful about the object lifetimes. } SCAN_END_SINGLE(ATTR) This returns the first 32 bits of the pointer which may be the top or the bottom depending on big versus little endian, as comment #2 said. So, when you cast a (void*) to (long), you are losing 32 bits of data in the conversion. You are right! What is the difference between const int*, const int * const, and int const *? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. For the second example you can make sure that sizeof (int) <= sizeof (void *) by using a static_assert -- this way at least you'll get a notice about it. The compiler issues the "cast from integer to pointer of different size" warning whenever the value of an integer is converted to a pointer, especially when the memory allocated to a pointer is smaller than the memory allocated to an integer data type. Before I update Xcode, my project still can build and run normally with all devices. to the original pointer: The following type designates an unsigned integer type with the Fix for objc/45925 Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Java Type Casting. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. reinterpret_cast conversion - cppreference.com You could use this code, and it would do the same thing as casting ptr to (char*). Replacing broken pins/legs on a DIP IC package, AC Op-amp integrator with DC Gain Control in LTspice. This page has been accessed 1,655,678 times. Thus as a result it may be less error prone to generate a pointer dynamcially and use that. The mapping in pointer<->integer casts is implementation defined, but the intent was that if the pointer type is large enough and isn't forcefully aligned (, But that's different. reinterpret_cast<void *>(42)). Update: Today, i download the latest version of cocos2d-x (cocos2d-x 2.2.3). And then assign it to the double variable. ), Styling contours by colour and by line thickness in QGIS. Wrong. Surely the solution is to change the type of ids from int to type that is sufficiently large to hold a pointer. vegan) just to try it, does this inconvenience the caterers and staff? "-I.." "-Iinclude\openflow" "-I..\include\openflow" "-Iinclude\openvswitch" "-I..\include\openvsw That's probably going to be true for most platforms you will ever encounter, but it's not a guarantee; it's implementation-dependent. If the value is ever used as pointer again that will prove to be an extremely bad idea. In C (int)b is called an explicit conversion, i.e. you can just change architecture to support 32 bit compilation by all below in in Build Settings. this way you won't get any warning. Based on the design of this function, which modification is right. [PATCH] platform/x86: hp-wmi: Fix cast to smaller integer type warning use $(ARCHS_STANDARD_32_BIT) at Architecture instead of $(ARCHS_STANDARD). How to correctly cast a pointer to int in a 64-bit application? what happens when we typecast normal variable to void* or any pointer variable? Put your define inside a bracket: without a problem. This will get you a pointer from a 32 bit offset: A function pointer is incompatible to void* (and any other non function pointer). How can this new ban on drag possibly be considered constitutional? You use the address-of operator & to do that int x = 10; void *pointer = &x; And in the function you get the value of the pointer by using the dereference operator *: int y = * ( (int *) pointer); Share Improve this answer Follow edited Apr 15, 2013 at 13:58 answered Apr 15, 2013 at 13:53 Some programmer dude 394k 35 393 602 1 Euler: A baby on his lap, a cat on his back thats how he wrote his immortal works (origin?). The preprocessor will replace your code by this: This is unlikely what you are trying to do. As was pointed out by Martin, this presumes that sizeof(void*)>=sizeof(int). The int data type is the primary integer data type in SQL Server. Safe downcast may be done with dynamic_cast. On all of them int is 32bit, not 16bit. B programing language is a language based on basic combined programming or a BCPL, and it is the precursor of the C programming language. lexborisov Modest Public. Since the 'size' argument for your function is the number of bytes each element in the array needs, I think casting the pointerto (char*) is appropriate. XCode 5.1 is change all architecture to 64 bit. What is the point of Thrower's Bandolier? Evaluate integer expressions in a larger size before comparing or assigning to that size.Note that (time_+t)-1 also complies with INT31-C-EX3. What is the purpose of non-series Shimano components? Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. FAILED: lib/libopenvswitch.a.p/odp-util.c.obj The best way is, if one can, do not do such casting, instead, if the same memory address has to be shared for pointer and int (e.g. Thanks for contributing an answer to Stack Overflow! How do I set, clear, and toggle a single bit? You can fix this error by replacing this line of code. int, bigint, smallint, and tinyint (Transact-SQL) - SQL Server If the destination type is bool, this is a boolean conversion (see below). ncdu: What's going on with this second size column? c - How to cast an integer to void pointer? - Stack Overflow I have a two functions, one that returns an int, and one that takes a const void* as an argument. In this case, casting the pointer back to an integer is meaningless, because . pthread create managing values generated in function (in c), Establishing TCP socket connection between PHP client and C server on Ubuntu. If you are planning to use pthreads and you are planning to pass the pass function to pthread_create, you have to malloc/free the arguments you are planning to use (even if the threaded function just need a single int). for (i=0, j=0; jType Casting Of Pointers in C - Computer Notes In Java, there are two types of casting: Widening Casting (automatically) - converting a smaller type to a larger type size. Yeah, the tutorial is doing it wrong. Getting Command /bin/sh failed with exit code 65 Error with Xcode 5.1 . The pointer doesn't actually point to anything, but it's the result of an earlier cast from an integer to a pointer (e.g. Using printf with a pointer to float gives an error, Meaning of int (*) (int *) = 5 (or any integer value), Casting int to void* loses precision, and what is the solution in required cases, Acidity of alcohols and basicity of amines. Referring to N1570 7.20.1.4/p1 (Integer types capable of holding object pointers): The following type designates a signed integer type with the property The proper way is to cast it to another pointer type. The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. Remembering to delete the pointer after use so that we don't leak. 10) A prvalue of type pointer to void (possibly cv-qualified) can be converted to pointer to any object type. windows meson: cast to smaller integer type 'unsigned long' from 'void Implicit Type Conversion in C with Examples - GeeksforGeeks Unless you have a valid address at that value, you are going to invoke undefined behaviour when try to use that pointer. casting from int to void* and back to int. Casting int to void* : r/C_Programming - reddit clang warnings in v1.42 Issue #265 ocornut/imgui GitHub ), For those who are interested. Why does setupterm terminate the program? What is the correct method to cast an int to a void*? It is purely a compile-time directive which instructs the compiler to treat expression as if it had . How create a simple program using threads in C? iphone - Error "Cast from pointer to smaller type 'int' loses You just need to suppress the warning, and this will do it: This may offend your sensibilities, but it's very short and has no race conditions (as you'd have if you used &i). This is a fine way to pass integers to new pthreads, if that is what you need. Keep in mind that thrArg should exist till the myFcn() uses it. Find centralized, trusted content and collaborate around the technologies you use most. Using Kolmogorov complexity to measure difficulty of problems? However, I believe that even if the define was for the "65536", it would not be what @kaetzacoatl wanted. ncdu: What's going on with this second size column? Find centralized, trusted content and collaborate around the technologies you use most. @BlueMoon Thanks a lot! Why do small African island nations perform better than African continental nations, considering democracy and human development? I guess the other important fact is that the cast operator has higher precedence that the multiplication operator. Have a question about this project? ../lib/odp-util.c:5601:9: note: expanded from macro 'SCAN_PUT' ../lib/odp-util.c:5665:7: note: expanded from macro 'SCAN_SINGLE' ^~~~~~~~~~~~~~~~~~~ Asking for help, clarification, or responding to other answers. "-D_FILE_OFFSET_BITS=64" "-Wall" "-Winvalid-pch" "-g" "-Wthread-safety" "-Wno-microsoft-enum-forward-reference" "-Wno-unused-function" "-Wno-sometimes-unini I'm using cocos2d-x-2.2.2. The difference between the phonemes /p/ and /b/ in Japanese, Styling contours by colour and by line thickness in QGIS. Do new devs get fired if they can't solve a certain bug? The point is (probably) that the value passed to the thread is an integer value, not really a 'void *'. To cast such pointers to 32-bit types and vice versa special functions are used: void * Handle64ToHandle ( const void * POINTER_64 h ) void * POINTER_64 HandleToHandle64 ( const void *h ) long HandleToLong ( const void *h ) unsigned long HandleToUlong ( const void *h ) Since gcc compiles that you are performing arithmetic between void* and an int (1024). What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? You are correct, but cocos actually only uses that address as a unique id. The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. SQL Server does not automatically promote . I understood, but that would introduce dynamic memory and ugly lifetime issues (an object allocated by one thread must be freed by some other) - all just to pass an. Does melting sea ices rises global sea level? Implementing From will result in the Into implementation but not vice-versa. unsigned long call_fn = (unsigned long)FUNC; Type conversions - cplusplus.com It's an int type guaranteed to be big enough to contain a pointer. Java Type Casting - W3Schools SCAN_SINGLE("skb_priority(", uint32_t, u32, OVS_KEY_ATTR_PRIORITY); Click to see the query in the CodeQL repository. Casting Pointers - IBM If you preorder a special airline meal (e.g. I have the following function and when I compile it under VS.NET 2005, the following compile warnings show up: Warning1warning C4311: 'type cast' : pointer truncation from 'void *' to 'long'c:\temp\testone\lib\utils.c56Warning2warning C4312: 'type cast' : conversion from 'unsigned long' to 'void *' of greater sizec:\temp\testone\lib\utils.c56, Code Snippet ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For example, the main thread could wait for all of the other threads to end before terminating. From the question I presume the OP does. If the original type is a void *, converting to an int may lose date on platforms where sizeof(void *) != sizeof(int) (which is true of LP64 programming model). c - Cast int to void* - Stack Overflow Use of Void pointers in C programming language It generally takes place when in an expression more than one data type is present. As a result of the integer division 3/2 we get the value 1, which is of the int type. GitHub Skip to content Product Solutions Open Source Pricing Sign in Sign up smadaminov / ovs-dpdk-meson-issues Public Notifications Fork 1 Star 1 Code Issues 66 Pull requests Actions Projects 1 Security Insights New issue SCAN_PUT(ATTR, NULL); Any expression can be cast to type void (which means that the result of the expression is ignored), but it's not legal to cast an expression of type void to type int not least because the result of such a cast wouldn't make any sense. C99 standard library provides intptr_t and uintptr_t typedefs, which are supposed to be used whenever the need to perform such a cast comes about. How can this new ban on drag possibly be considered constitutional? property that any valid pointer to void can be converted to this type, Passing arguments to pthread_create - invalid conversion from void(*)() to void(*)(void*). [Solved] Properly casting a `void*` to an integer in C++ As with all cast expressions, the result is: Two objects a and b are pointer-interconvertible if: static_cast may also be used to disambiguate function overloads by performing a function-to-pointer conversion to specific type, as in. Find centralized, trusted content and collaborate around the technologies you use most. Thanks for contributing an answer to Stack Overflow! how to cascade 2d int array to 2d void pointer array? Now, what happens when I run it with the thread sanitizer? I get the error: "cast to smaller integer type 'int' from 'string' (aka 'char *')" referencing line of code: while (isalpha(residents[i].name) == 0), How Intuit democratizes AI development across teams through reusability. . What I am trying to emphasis that conversion from int to pointer and back again can be frough with problems as you move from platform to platform. I don't see how anything bad can happen . On many systems, an 8-bit unsigned int can be stored at any address while an unsigned 32-bit int must be aligned on an address that is a multiple of 4. Remarks. Apparently the clang version in Xcode 5.1 and above is more strict about potential 32bit vs. 64 bit incompatibilities in source code than older clang versions have been. Hence there is no loss in data. error: comparison between pointer and integer ('int' and 'string' (aka 'char *')), CS50 Caesar program is working but check50 says it isn't. Here is my code: I already tried (void*)M_TABLE_SIZE but then I get an error that I cannot use the * operator. Using an integer address (like &x) is probably wrong, indeed each modification you will execute on x will affect the pass behaviour. The bigint data type is intended for use when integer values might exceed the range that is supported by the int data type.. bigint fits between smallmoney and int in the data type precedence chart.. Can we typecast void into int? - Quora Difficulties with estimation of epsilon-delta limit proof. As Ferruccio said, int must be replaced with intptr_t to make the program meaningful. LLNL's tutorial is bad and they should feel bad. ../lib/odp-util.c:5834:5: error: cast to smaller integer type 'unsigned long' from 'void *' [-Werror,-Wvoid-pointer-to-int-cast] cast operators [edit] When an expression is used in the context where a value of a different type is expected, conversionmay occur: intn =1L;// expression 1L has type long, int is expectedn =2.1;// expression 2.1 has type double, int is expectedchar*p =malloc(10);// expression malloc(10) has type void*, char* is expected If the original pointer value represents an address of a byte in memory that does not satisfy the alignment requirement of the target type, then the resulting pointer value is unspecified. If this is the data to a thread procedure, then you quite commonly want to pass by value. An object pointer (including void*) or function pointer can be converted to an integer type using reinterpret_cast. Is it possible to create a concave light? Yesterday, I updated Xcode to the newest version (5.1 (5B130a)) to compatible with iOS 7.1. This is not a conversion at all. Typically, long or unsigned long is . In such condition type conversion (type promotion) takes place to avoid loss of data. C / C++ Forums on Bytes. How to get the error message from the error code returned by GetLastError()? In the best case this will give the same results as the original code, with no advantages, but in the worst case it will fail in multiple catastrophic ways (type punning, endianness, less efficient, etc. /** Dynamically allocate a 2d (x*y) array of elements of size _size_ bytes. Pd = Pa; Similarly, Pc may be type cast to type int and assigned the value Pa. 1. Changing the type of ids would be the cleanest solution, but I decided against it when being confronted with this issue myself, as it only introduced a lot of issues with other code that is relying on ids being an int-array. static const void* M_OFFSET = (void*)64*1024; Since gcc compiles that you are performing arithmetic between void* and an int ( 1024 ).