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

I need to convert the argument to an int for later use: The compiler (GCC version 4.2.4) returns the error: You can cast it to an intptr_t type. a is of type int[4], which can be implicitly cast to int* (ie, a pointer to an int) &a is of type int(*)[4] (ie: a pointer to an array of 4 ints). It is done by the compiler on its own, without any external trigger from the user. ", "!"? My code is all over the place now but I appreciate you all helping me on my journey to mastery! It was derived from the BCPL, and the name of the b language is possibly from the BCPL contraction. (Also, check out how it prints "5" twice), passing a unique pointer to each thread wont race, and you can get/save any kind of information in the th struct. 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. ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Alternatively, if you choose to castthe ptr variableto (size_t) instead, then you don't need to worry about the pointer typeanymore. 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. ../lib/odp-util.c:5834:5: error: cast to smaller integer type 'unsigned long' from 'void *' [-Werror,-Wvoid-pointer-to-int-cast] 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. You need to pass an actual pointer. If any, how can the original function works without errors if we just ignore the warning. 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.. A cast specifies a conversion from one type to another. 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 ) Fork 63. I personally upvoted this answer because by it's first line of text it helped me to understand the reason of this strange error message and what am I, poor idiot, doing :D. Not valid on Windows 64 - long is still 32-bit but pointers are 64-bit. What does casting to void* does when passing arguments to variadic functions? clang warnings in v1.42 Issue #265 ocornut/imgui GitHub For example, the main thread could wait for all of the other threads to end before terminating. STR34-C. Cast characters to unsigned char before converting to larger Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. should we also have a diagnostic for the (presumed) user error? rev2023.3.3.43278. C/C++ , Cerror: cast to 'void *' from smaller integer type 'int'. 7.1 New Cast Operations The C++ standard defines new cast operations that provide finer control than previous cast operations. We have to pass address of the variable to the function because in function definition argument is pointer variable. INT31-C. Ensure that integer conversions do not result in lost or This is not even remotely "the correct answer". clang11 report error: cast to smaller integer type #82 - GitHub And, most of these will not even work on gcc4. /** Dynamically allocate a 2d (x*y) array of elements of size _size_ bytes. If your code has the chance to ever be ported to some platform where this doesn't hold, this won't work. I have a two functions, one that returns an int, and one that takes a const void* as an argument. Share Improve this answer Follow answered May 6, 2018 at 7:24 Rahul For a fairly recent compiler (that supports C99) you should not store or represent address as plain int value. long guarantees a pointer size on Linux on any machine. Java Type Casting - W3Schools Did i have to face to unexpected runtime issues, i guess not, i've found another discussion on this -. iphone - Error "Cast from pointer to smaller type 'int' loses cast to 'double *' from smaller integer type 'unsigned int' The C compiler is gcc, clang version 3.9.1, target aarch64--linux-android, thread model posix. Not the answer you're looking for? Thanks. The reinterpret_cast makes the int the size of a pointer and the warning will stop. It's always a good practice to put your #define's in brackets to avoid such surprise. Replacing broken pins/legs on a DIP IC package, How to handle a hobby that makes income in US. 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. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. If we want to get the exact value of 7/5 then we need explicit casting from int to float: Example: int x=7, y=5; To perform a cast, specify the type that you are casting to in parentheses in front of the value or variable to be converted. rev2023.3.3.43278. warning C4311: 'type cast': pointer truncation from 'void *' to 'long' in ECPG test files. A nit: in your version, the cast to void * is unnecessary. Such a downcast makes no runtime checks to ensure that the object's runtime type is actually D, and may only be used safely if this precondition is guaranteed by other means, such as when implementing static polymorphism. ", "? A cast is a way of explicitly informing the compiler that you intend to make the conversion and that you are aware that data loss might occur, or the cast may fail at run time. Asking for help, clarification, or responding to other answers. This is not a conversion at all. with ids being an array of ints and touch being a pointer. Casting type void to uint8_t - Arduino Forum I have a function with prototype void* myFcn(void* arg) which is used as the starting point for a pthread. Making statements based on opinion; back them up with references or personal experience. Difficulties with estimation of epsilon-delta limit proof. Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. [PATCH] platform/x86: hp-wmi: Fix cast to smaller integer type warning It is purely a compile-time directive which instructs the compiler to treat expression as if it had . Can Martian regolith be easily melted with microwaves? @DietrichEpp can you explain what is race condition with using. what does it mean to convert int to void* or vice versa? error: cast from pointer to smaller type 'unsigned int' loses 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 In the first example, the variable c1 of the char type is converted to a temporary variable of the int type, because the second operand in the division operation, the constant 2, is of the higher type int. Before I update Xcode, my project still can build and run normally with all devices. 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. For the Nozomi from Shinagawa to Osaka, say on a Saturday afternoon, would tickets/seats typically be available - or would you need to book? SCAN_SINGLE("skb_priority(", uint32_t, u32, OVS_KEY_ATTR_PRIORITY); If that happens soon after the call to pthread_create() then you have a race condition, because there's a chance that the thread will attempt to read x's value after it's life has ended, which invokes undefined behavior. FAILED: lib/libopenvswitch.a.p/odp-util.c.obj As for the stack, I've written a few libraries using pthreds, thus I don't agree that what you describe "is quite often the case". *sound/soc/codecs/tlv320aic32x4.c:1202:18: warning: cast to smaller integer type 'enum aic32x4_type' from 'void *' @ 2022-04-22 9:48 kernel test robot 0 siblings, 0 . The main point is: a pointer has a platform dependent size. Pull requests. Identify those arcade games from a 1983 Brazilian music video, Relation between transaction data and transaction id, The difference between the phonemes /p/ and /b/ in Japanese. Cast unsigned char (uint8 *) pointer to unsigned long (uint32 *) pointer error: comparison between pointer and integer ('int' and 'string' (aka 'char *')), CS50 Caesar program is working but check50 says it isn't. LLNL's tutorial is bad and they should feel bad. "After the incident", I started to be more careful not to trip over things. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. a cast of which the programmer should be aware of what (s)he is doing. you can pass the int value as void pointer like (void *)&n where n is integer, and in the function accept void pointer as parameter like void foo(void *n);and finally inside the function convert void pointer to int like, int num = *(int *)n;. In the case of Widening Type Casting, the lower data type (having smaller size) is converted into the higher data type (having larger size). Don't pass your int as a void*, pass a int* to your int, so you can cast the void* to an int* and copy the dereferenced pointer to your int. Api says this is how i should create thread: So if I want to pass an int what I think I should do is: The second example assumes that a pointer is wide enough to store an int. [that could be a TODO - not to delay solving the ICE]. The preprocessor will replace your code by this: This is unlikely what you are trying to do. ), For those who are interested. eg. Does a summoned creature play immediately after being summoned by a ready action? You cannot just cast the 32-bit variable to a pointer, because that pointer on a 64-bit machine is twice as long. Asking for help, clarification, or responding to other answers. The difference between the phonemes /p/ and /b/ in Japanese. This will only compile if the destination type is long enough. Disconnect between goals and daily tasksIs it me, or the industry? Since gcc compiles that you are performing arithmetic between void* and an int (1024). From that point on, you are dealing with 32 bits. 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. equal to the original pointer: First you are using a define, which is not a variable. Basically its a better version of (void *)i. So you could do this: Note: As sbi points out this would require a change on the OP call to create the thread. Please tell me error: cast from 'void*' to 'int' loses precision, How Intuit democratizes AI development across teams through reusability. Thank you all for your feedback. Anw, the project still build and run normally when i use Xcode 5.0 with iOS 7.0. The following behavior-changing defect reports were applied retroactively to previously published C++ standards. Are there tables of wastage rates for different fruit and veg? I guess the other important fact is that the cast operator has higher precedence that the multiplication operator. 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! And then assign it to the double variable. A cast converts an object or value from one type to another. *PATCH] platform/x86: hp-wmi: Fix cast to smaller integer type warning @ 2023-01-23 13:28 Hans de Goede 2023-01-23 13:56 ` Hans de Goede 0 siblings, 1 reply; 2+ messages in thread From: Hans de Goede @ 2023-01-23 13:28 UTC (permalink / raw) To: Mark Gross Cc: Hans de Goede, Andy Shevchenko, platform-driver-x86, kernel test robot Fix the following . By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. 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. cast to void *' from smaller integer type 'int What I am trying to do in that line of code is check to make sure each character in my string is alphabetical. ^~~~~~~~~~~~~~~~~~~~ But this code pass the normal variable .. Casting int to void* loses precision, and what is the solution in required cases, c++: cast from "const variable*" to "uint32" loses precision, Recovering from a blunder I made while emailing a professor, Relation between transaction data and transaction id. And when assigning to a void pointer, all type information is lost. Identify those arcade games from a 1983 Brazilian music video. If you preorder a special airline meal (e.g. It solved my problem too. rev2023.3.3.43278. ^~~~~~~~~~~~~~~~~~~~~ ../lib/odp-util.c:5658:9: note: expanded from macro 'SCAN_END_SINGLE' If you are going to pass the address you typically need to exert some more control over the lifetime of the object. Mutually exclusive execution using std::atomic? How Intuit democratizes AI development across teams through reusability. How to tell which packages are held back due to phased updates, Identify those arcade games from a 1983 Brazilian music video. Therefore, you need to change it to long long instead of long in windows for 64 bits. ../lib/odp-util.c:5665:7: note: expanded from macro 'SCAN_SINGLE' } SCAN_END_SINGLE(ATTR) use $(ARCHS_STANDARD_32_BIT) at Architecture instead of $(ARCHS_STANDARD). 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. Just re-enforcing the old behavior of Xcode 5.0 and earlier versions, that already cut away parts of the address by casting it to int, won't introduce any new bugs and avoids the need to learn and understand lots of implementation-internal cocos code. Yeah, the tutorial is doing it wrong. How do I count the number of sentences in C using ". Why does Mister Mxyzptlk need to have a weakness in the comics? Making statements based on opinion; back them up with references or personal experience. 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. To learn more, see our tips on writing great answers. cast to 'void *' from smaller integer type 'int' You can fix this error by replacing this line of code. to the original pointer: The following type designates an unsigned integer type with the The point is (probably) that the value passed to the thread is an integer value, not really a 'void *'. Then i can continue compiling. Thanks for contributing an answer to Stack Overflow! 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 Counterspell prevent from any further spells being cast on a given turn? SQL Server does not automatically promote . Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? Find centralized, trusted content and collaborate around the technologies you use most. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? This allows you to reinterpret the void * as an int. Well it does this because you are converting a 64 bits pointer to an 32 bits integer so you loose information. Note that it's not guaranteed that casting an, Generally this kind of type casting does not lead to any concern as long as the addresses are encoded using the same length as the "variable type" (. That could create all kinds of trouble. Disconnect between goals and daily tasksIs it me, or the industry? In Java, there are two types of casting: Widening Casting (automatically) - converting a smaller type to a larger type size. rev2023.3.3.43278. Put your define inside a bracket: without a problem. actually no, as int my be a smaller type than a pointer ;-) But, of course with int64_t it works fine. Can I tell police to wait and call a lawyer when served with a search warrant? But I'm nitpicking .. The program can be set in such a way to ask the user to inform the type of data and . 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.