Find centralized, trusted content and collaborate around the technologies you use most. ../lib/odp-util.c:5489:33: note: expanded from macro 'SCAN_PUT_ATTR' @Martin York: No, it doesn't depend on endiannness. So the compiler is very picky here and the correct solution to make the code compile again and still let it show the exact same behavior like in Xcode 5.0 is to first cast to an integer type with a size that matches the one of a pointer and to then do a second cast to the int that we actually want: ids [i] = (int) (size_t)touch; Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? Connect and share knowledge within a single location that is structured and easy to search. [] ExplanatioUnlike static_cast, but like const_cast, the reinterpret_cast expression does not compile to any CPU instructions (except when converting between integers and pointers or on obscure architectures where pointer representation depends on its type). To avoid truncating your pointer, cast it to a type of identical size. That could create all kinds of trouble. Whats the grammar of "For those whose stories they are"? 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. 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). Thanks for contributing an answer to Stack Overflow! 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. I guess the other important fact is that the cast operator has higher precedence that the multiplication operator. Casting Pointers - IBM iphone - Error "Cast from pointer to smaller type 'int' loses ../lib/odp-util.c:5658:9: note: expanded from macro 'SCAN_END_SINGLE' If this is the data to a thread procedure, then you quite commonly want to pass by value. If you are going to pass the address you typically need to exert some more control over the lifetime of the object. unsigned long call_fn = (unsigned long)FUNC; Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? ), For those who are interested. I wish that you write those answer first than the explanation. Making statements based on opinion; back them up with references or personal experience. But gcc always give me a warning, that i cannot cast an int to a void*. ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Why do academics stay as adjuncts for years rather than move around? 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. Thanks. Is pthread_join a must when using pthread in linux? Surely the solution is to change the type of ids from int to type that is sufficiently large to hold a pointer. The text was updated successfully, but these errors were encountered: An open (void) pointer can hold a pointer of any type. Functions return bigint only if the parameter expression is a bigint data type. Why is there a voltage on my HDMI and coaxial cables? So the compiler is very picky here and the correct solution to make the code compile again and still let it show the exact same behavior like in Xcode 5.0 is to first cast to an integer type with a size that matches the one of a pointer and to then do a second cast to the int that we actually want: I am using size_t here, because it is always having the same size as a pointer, no matter the platform. 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. Identify those arcade games from a 1983 Brazilian music video. 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. Since all pointers on 64-bit Windows are 64 bits, you are growing the data size from 32 bits backto 64 bits. In such condition type conversion (type promotion) takes place to avoid loss of data. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? However even though their types are different, the address is going to be the same. Use returnPtr[j] = (void *) ((long)ptr + i); ). Java Type Casting (With Examples) - Programiz tialized" "-Wno-format" "-Wno-incompatible-pointer-types" "-Werror" "-dM" "-U_MSC_VER" "-D_TIMESPEC_DEFINED" "-D_CRT_NONSTDC_NO_DEPRECATE -D_CRT_SECURE_NO_WA I assumed that gcc makes a 65536 out of my define, but I was wrong. For example, the main thread could wait for all of the other threads to end before terminating. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. This is memory reinterpretation - a completely unacceptable way to do what the OP is trying to do. I'm using cocos2d-x-2.2.2. Only the following conversions can be done with static_cast, except when such conversions would cast away constness or volatility. Therefore, you need to change it to long long instead of long in windows for 64 bits. You could use this code, and it would do the same thing as casting ptr to (char*). To subscribe to this RSS feed, copy and paste this URL into your RSS reader. It solved my problem too. INT36-C. Converting a pointer to integer or integer to pointer Terrible solution. It is purely a compile-time directive which instructs the compiler to treat expression as if it had . For the remaining integral types, the result is the value of the enum if it can be represented by the target type and unspecified otherwise. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. I have a function with prototype void* myFcn(void* arg) which is used as the starting point for a pthread. */ >> -bool >> +enum conversion_safety >> unsafe_conversion_p (tree type, tree expr, bool . ^~~~~~~~~~~~~~~~~~~ But assuming that it is, as long as the caller and the callee agree, you can do that sort of thing. actually no, as int my be a smaller type than a pointer ;-) But, of course with int64_t it works fine. @Artelius: Which, presumably, is exactly what Joshua did: A C++ reinterpret cast will not solve the problem. int, bigint, smallint, and tinyint (Transact-SQL) - SQL Server But I don't want to edit code in "EAGLView.mm" because it's a "library file". Cast Operations - Oracle Don't do that. Even though what you say regarding the lifetime of the object is true, integral types are too limited for a generic API. Casting and type conversions - C# Programming Guide If you write ((char*)ptr + 1), it will advance the pointer 1 byte, because a "char" is 1 byte. Euler: A baby on his lap, a cat on his back thats how he wrote his immortal works (origin? So you could do this: Note: As sbi points out this would require a change on the OP call to create the thread. Making statements based on opinion; back them up with references or personal experience. What is the purpose of non-series Shimano components? Can Martian regolith be easily melted with microwaves? You are getting warnings due to casting a void* to a type of a different size. No idea how it amassed 27 upvotes?! FAILED: lib/libopenvswitch.a.p/odp-util.c.obj Sign up for a free GitHub account to open an issue and contact its maintainers and the community. @DietrichEpp can you explain what is race condition with using. Find centralized, trusted content and collaborate around the technologies you use most. itch" "-I..\include\windows" "-Iinclude" "-I..\include" "-I..\datapath-windows\include" "-IC:\PTHREADS-BUILT\include" "-Xclang" "-fcolor-diagnostics" "-pipe" Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. SCAN_PUT(ATTR, NULL); BUT converting a pointer to void* and back again is well supported (everywhere). Why is there a voltage on my HDMI and coaxial cables? As a result of the integer division 3/2 we get the value 1, which is of the int type. Click to see the query in the CodeQL repository. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? On most platforms pointers and longs are the same size, but ints and pointers often are not the same size on 64bit platforms. this way you won't get any warning. . This allows you to reinterpret the void * as an int. The only alternative is really to take time and fix all 64-bit code issues, of which there may be some non-trivial issues. pthread create managing values generated in function (in c), Establishing TCP socket connection between PHP client and C server on Ubuntu. */void **MatrixIB (unsigned long x, unsigned long y, int size){ void *ptr; void **returnPtr; register unsigned long i, j; You are right! Have a question about this project? @DavidHeffernan, sane thread APIs wouldn't send integral data to the thread procedures, they would send pointers. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. As Ferruccio said, int must be replaced with intptr_t to make the program meaningful. 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 The point is (probably) that the value passed to the thread is an integer value, not really a 'void *'. 471,961 Members | 900 Online. That's probably going to be true for most platforms you will ever encounter, but it's not a guarantee; it's implementation-dependent. Casting int to void* : r/C_Programming - reddit The 32 remaining bits stored inside int are insufficient to reconstruct a pointer to the thread function. rev2023.3.3.43278. Does melting sea ices rises global sea level? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Before I update Xcode, my project still can build and run normally with all devices. How to tell which packages are held back due to phased updates, Identify those arcade games from a 1983 Brazilian music video. Is a PhD visitor considered as a visiting scholar. "because the type "int" supports only -32768 ~ 32768" This is not true for any modern desktop or mobile OS or any OS that is targeted by cocos2d-x. error: comparison between pointer and integer ('int' and 'string' (aka 'char *')), CS50 Caesar program is working but check50 says it isn't. equal to the original pointer: First you are using a define, which is not a variable. Is it possible to create a concave light? For integer casts in specific, using into() signals that . to the original pointer: The following type designates an unsigned integer type with the Connect and share knowledge within a single location that is structured and easy to search. Usually that means the pointer is allocated with. Casting arguments inside the function is a lot safer. B Programming Language | What is the History and Concept? A missing cast in the new fast > enumeration code. Casting a pointer to void* and back is valid use of reinterpret_cast<>. Floating-point conversions By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. This solution is in accordance with INT18-C. Just want to point out that the purpose of threads is, +1 absolutely true, but if you take you time to write struct {}, you can save a lot of troubles in the future when you want to receive/send more data then just an int. 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; Why is this sentence from The Great Gatsby grammatical? Cast characters to unsigned char before converting to larger integer sizes Created by Robert Seacord, last modified by Jill Britton on Oct 03, 2022 Signed character data must be converted to unsigned char before being assigned or converted to a larger signed type. It is commonly called a pointer to T and its type is T*. } SCAN_END_SINGLE(ATTR) 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. It's an int type guaranteed to be big enough to contain a pointer. You should perform type conversion based on 64bit build system because the type "int" supports only -32768 ~ 32768. LLNL's tutorial is bad and they should feel bad. The only exception is exotic systems with the SILP64 data model, where the size of int is also 64 bits. I have a two functions, one that returns an int, and one that takes a const void* as an argument. c - How to cast an integer to void pointer? - Stack Overflow A nit: in your version, the cast to void * is unnecessary. What is the purpose of non-series Shimano components? Acidity of alcohols and basicity of amines. reinterpret_cast<void *>(42)). The high-order 9 bits of the number are used to hold a flag value, and the result is converted back into a pointer. "After the incident", I started to be more careful not to trip over things. @kshegunov said in Number Type Cast: const void * x; int y = int (x); compiles just fine. How to use Slater Type Orbitals as a basis functions in matrix method correctly? Maybe you can try this too. ../lib/odp-util.c:5601:9: note: expanded from macro 'SCAN_PUT' "I think what you should do is actually pass the address of the variable to the function" Not necessarily. Not the answer you're looking for? How create a simple program using threads in C? Asking for help, clarification, or responding to other answers. arrays - I get the error: "cast to smaller integer type 'int' from static const void* M_OFFSET = (void*)64*1024; Since gcc compiles that you are performing arithmetic between void* and an int ( 1024 ). And you can't pass a pointer to a stack based object from the other thread as it may no longer be valid. A cast specifies a conversion from one type to another. to your account, [87/252] Compiling C object lib/libopenvswitch.a.p/odp-util.c.obj Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. with ids being an array of ints and touch being a pointer. STR34-C. Cast characters to unsigned char before converting to larger Why did Ukraine abstain from the UNHRC vote on China? Do new devs get fired if they can't solve a certain bug? How Intuit democratizes AI development across teams through reusability. that any valid pointer to void can be converted to this type, then How to make compiler not show int to void pointer cast warnings, incompatible pointer types assigning to 'void (*)(void *)' from 'int (int *)'. If any, how can the original function works without errors if we just ignore the warning.