"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. 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 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; What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? If you need to keep the returned address, just keep it as void*. Already on GitHub? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. The only alternative is really to take time and fix all 64-bit code issues, of which there may be some non-trivial issues. The program can be set in such a way to ask the user to inform the type of data and . How to correctly type cast (void*)? - social.msdn.microsoft.com ncdu: What's going on with this second size column? What does it mean to convert int to void* or vice versa? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. c - How to cast an integer to void pointer? - Stack Overflow what happens when we typecast normal variable to void* or any pointer variable? B language was designed to develop . The OP wanted to convert a pointer value to a int value, instead, most the answers, one way or the other, tried to wrongly convert the content of arg points to to a int value. It is easier to understand and write than any other assembly language. Is it possible to create a concave light? If your standard library (even if it is not C99) happens to provide these types - use them. See also this documentation.. From and Into are generally intended to be lossless, infalliable conversions.as on the other hand can discard data and lead to bugs in some situations, for example casting a u64 to a usize may truncate the value on a 32-bit host. Implicit Type Conversion is also known as 'automatic type conversion'. 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. clang11 report error: cast to smaller integer type #82 - GitHub SQL Server does not automatically promote . How can this new ban on drag possibly be considered constitutional? Why is there a voltage on my HDMI and coaxial cables? Then i can continue compiling. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? Difficulties with estimation of epsilon-delta limit proof. whether it was an actual problem is a different matter though. The following behavior-changing defect reports were applied retroactively to previously published C++ standards. Making statements based on opinion; back them up with references or personal experience. The calculated expression consists of two operations. Recovering from a blunder I made while emailing a professor. How create a simple program using threads in C? The dynamic_cast<>operator provides a way to check the actual type of a pointer to a polymorphic class. C99 defines the types "intptr_t" and "uintptr_t" which do . x is a local variable and its lifetime ends as soon as control leaves the scope it was defined in. Casting type int to const void* - C / C++ Press question mark to learn the rest of the keyboard shortcuts. . Losing bytes like thisis called 'truncation', and that's what the first warning is telling you. STR34-C. Cast characters to unsigned char before converting to larger If you preorder a special airline meal (e.g. Whats the grammar of "For those whose stories they are"? 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. Thanks for contributing an answer to Stack Overflow! for (i=0, j=0; j to define it. 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. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. (int) pthread_self() 64int48intuintptr_t (unsigned int) If your standard library (even if it is not C99) happens to provide these types - use them. The reinterpret_cast makes the int the size of a pointer and the warning will stop. How to use Slater Type Orbitals as a basis functions in matrix method correctly? [PATCH] platform/x86: hp-wmi: Fix cast to smaller integer type warning Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? If any, how can the original function works without errors if we just ignore the warning. Is it possible to create a concave light? So you could do this: Note: As sbi points out this would require a change on the OP call to create the thread. returnPtr = (void **) malloc (x * sizeof(void *)); ptr = (void *) malloc (x * y * size); The problem was there before, you just are being notified of it. If you do this, you have the thread reference a value that (hopefully still) lives in some other thread. To avoid truncating your pointer, cast it to a type of identical size. Hence there is no loss in data. How do I force make/GCC to show me the commands? It modifies >> Wconversion-real.c, Wconversion-real-integer.c and pr35635.c to be more >> specific > > If the patch passes existing tests, I'd be inclined to leave them > tests alone and add new ones that are specific to what this patch > changes. 471,961 Members | 900 Online. /** Dynamically allocate a 2d (x*y) array of elements of size _size_ bytes. This is a fine way to pass integers to new pthreads, if that is what you need. 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. Most answers just try to extract 32 useless bits out of the argument. 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. c - Cast int to void* - Stack Overflow void* -> integer -> void* rather than integer -> void* -> integer. Replacing broken pins/legs on a DIP IC package, AC Op-amp integrator with DC Gain Control in LTspice. privacy statement. ^~~~~~~~~~~~~~~~~~~~ Why did Ukraine abstain from the UNHRC vote on China? 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;. "After the incident", I started to be more careful not to trip over things. rev2023.3.3.43278. The main point is: a pointer has a platform dependent size. @BlueMoon Thanks a lot! @DavidHeffernan, sane thread APIs wouldn't send integral data to the thread procedures, they would send pointers. Type casting is when you assign a value of one primitive data type to another type. rev2023.3.3.43278. Actions. 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. ../lib/odp-util.c:5834:5: error: cast to smaller integer type 'unsigned long' from 'void *' [-Werror,-Wvoid-pointer-to-int-cast] But the problem has still happened. 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. 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 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). You need to pass an actual pointer. Does Counterspell prevent from any further spells being cast on a given turn? How to tell which packages are held back due to phased updates, Identify those arcade games from a 1983 Brazilian music video. ../lib/odp-util.c:5489:33: note: expanded from macro 'SCAN_PUT_ATTR' Not the answer you're looking for? for saving RAM), use union, and make sure, if the mem address is treated as an int only if you know it was last set as an int. In this case, casting the pointer back to an integer is meaningless, because . By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. 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. 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. Next, when doing pointer arithmetic, the addition operation will use the pointer's type to determine how many bytes to add to it when incrementing it. : iPhone Retina 4-inch 64-bit) is selected. ../lib/odp-util.c:5601:9: note: expanded from macro 'SCAN_PUT' p-util.c.obj "-c" ../lib/odp-util.c What video game is Charlie playing in Poker Face S01E07? But, sure, in that specific case you can pass a local variable address, type casting integer to void* [duplicate]. Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? ../lib/odp-util.c:5603:13: note: expanded from macro 'SCAN_PUT' "-I.." "-Iinclude\openflow" "-I..\include\openflow" "-Iinclude\openvswitch" "-I..\include\openvsw ../lib/odp-util.c:5665:7: note: expanded from macro 'SCAN_SINGLE' Maybe you can try this too. When is casting void pointer needed in C? If you write ((char*)ptr + 1), it will advance the pointer 1 byte, because a "char" is 1 byte. Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded? If this is the data to a thread procedure, then you quite commonly want to pass by value. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. C++ how to get the address stored in a void pointer? a cast of which the programmer should be aware of what (s)he is doing. INT31-C. Ensure that integer conversions do not result in lost or 10) A prvalue of type pointer to void (possibly cv-qualified) can be converted to pointer to any object type. Even though what you say regarding the lifetime of the object is true, integral types are too limited for a generic API. There's no proper way to cast this to int in general case. That's not a good idea if the original object (that was cast to void*) was an integer. Connect and share knowledge within a single location that is structured and easy to search. Keep in mind that thrArg should exist till the myFcn() uses it. arrays - I get the error: "cast to smaller integer type 'int' from Basically its a better version of (void *)i. @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. You cannot just cast the 32-bit variable to a pointer, because that pointer on a 64-bit machine is twice as long. Well occasionally send you account related emails. Clang warnings for an invalid casting? - The FreeBSD Forums The subreddit for the C programming language, Press J to jump to the feed. If pointers are 64 bits and ints are 32 bits, an int is too small to hold a pointer value. It is purely a compile-time directive which instructs the compiler to treat expression as if it had . /** 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. For example, the main thread could wait for all of the other threads to end before terminating. SCAN_PUT(ATTR, NULL); Thus as a result it may be less error prone to generate a pointer dynamcially and use that. What you do here is undefined behavior, and undefined behavior of very practical sort. It is commonly called a pointer to T and its type is T*. Is a PhD visitor considered as a visiting scholar. I'm unfamiliar with XCode, but the solution should be something like follows: Most of the "solutions" above can lose part of the pointer address when casting to a smaller type. Does a summoned creature play immediately after being summoned by a ready action? 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. The only exception is exotic systems with the SILP64 data model, where the size of int is also 64 bits. reinterpret_cast<void *>(42)). A cast specifies a conversion from one type to another. How to Cast a void* ponter to a char without a warning? Fork 63. This page has been accessed 1,655,678 times. 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. Getting Command /bin/sh failed with exit code 65 Error with Xcode 5.1 . 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. Pull requests. SCAN_SINGLE("skb_priority(", uint32_t, u32, OVS_KEY_ATTR_PRIORITY); how to cascade 2d int array to 2d void pointer array? Narrowing Casting (manually) - converting a larger type to a . Your first example is risky because you have to be very careful about the object lifetimes. The problem just occur with Xcode 5.1. We have to pass address of the variable to the function because in function definition argument is pointer variable. ERROR: incompatible integer to pointer conversion assigning to 'string' (aka 'char *') from 'int', error: cast to 'string' (aka 'char *') from smaller integer type 'int' [-Werror,-Wint-to-pointer-cast], error: incompatible integer to pointer conversion assigning to 'string' (aka 'char *') from 'int' C, warning: initialization of 'unsigned char' from 'uint8_t *' {aka 'unsigned char *'} makes integer from pointer without a cast [-Wint-conversion], Minimising the environmental effects of my dyson brain. This will only compile if the destination type is long enough. The high-order 9 bits of the number are used to hold a flag value, and the result is converted back into a pointer. It's always a good practice to put your #define's in brackets to avoid such surprise. Click to see the query in the CodeQL repository. Why does Mister Mxyzptlk need to have a weakness in the comics? Since gcc compiles that you are performing arithmetic between void* and an int (1024). 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. unsigned long call_fn = (unsigned long)FUNC; You can convert the values from one type to another explicitly using the cast operator as follows (type_name) expression Why is there a voltage on my HDMI and coaxial cables? Fix for objc/45925 Using Kolmogorov complexity to measure difficulty of problems? vegan) just to try it, does this inconvenience the caterers and staff? Can we typecast void into int? - Quora What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? How Intuit democratizes AI development across teams through reusability. [] 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). you can just change architecture to support 32 bit compilation by all below in in Build Settings. error: cast from pointer to smaller type 'unsigned int' loses information. The proper way is to cast it to another pointer type. c - type casting integer to void* - Stack Overflow If the destination type is bool, this is a boolean conversion (see below). Converting a pointer to an integer whose result cannot represented in the integer type is undefined behavior is C and prohibited in C++. Bulk update symbol size units from mm to map units in rule-based symbology. An object pointer (including void*) or function pointer can be converted to an integer type using reinterpret_cast. ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Just edited. How do I check if a string represents a number (float or int)? What I am trying to do in that line of code is check to make sure each character in my string is alphabetical. 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. Are there tables of wastage rates for different fruit and veg? So make sure you understand what you are doing! Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? 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. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. As a result of the integer division 3/2 we get the value 1, which is of the int type. Casting int to void* : r/C_Programming - reddit You can use a 64 bits integer instead howerver I usually use a function with the right prototype and I cast the function type : what does it mean to convert int to void* or vice versa? pthread create managing values generated in function (in c), Establishing TCP socket connection between PHP client and C server on Ubuntu. This is why you got Error 1 C2036, from your post. A nit: in your version, the cast to void * is unnecessary. I would create a structure and pass that as void* to pthread_create. Usually that means the pointer is allocated with. How to make compiler not show int to void pointer cast warnings, incompatible pointer types assigning to 'void (*)(void *)' from 'int (int *)'. To subscribe to this RSS feed, copy and paste this URL into your RSS reader.
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