There's no proper way to cast this to int in general case. The following behavior-changing defect reports were applied retroactively to previously published C++ standards. Note the difference between the type casting of a variable and type casting of a pointer.
Use of Void pointers in C programming language Since gcc compiles that you are performing arithmetic between void* and an int (1024). itch" "-I..\include\windows" "-Iinclude" "-I..\include" "-I..\datapath-windows\include" "-IC:\PTHREADS-BUILT\include" "-Xclang" "-fcolor-diagnostics" "-pipe" 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; An open (void) pointer can hold a pointer of any type. Does Counterspell prevent from any further spells being cast on a given turn? that any valid pointer to void can be converted to this type, then This solution is in accordance with INT18-C. XCode 5.1 is change all architecture to 64 bit. This is flat out wrong. Find centralized, trusted content and collaborate around the technologies you use most. This will get you a pointer from a 32 bit offset: A function pointer is incompatible to void* (and any other non function pointer). 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" (. 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. ^~~~~~~~~~~~~~~~~~~ SCAN_SINGLE("skb_priority(", uint32_t, u32, OVS_KEY_ATTR_PRIORITY); In C (int)b is called an explicit conversion, i.e. to your account, [87/252] Compiling C object lib/libopenvswitch.a.p/odp-util.c.obj
void* to an array - C++ Forum - cplusplus.com By clicking Sign up for GitHub, you agree to our terms of service and Issues. SCAN_SINGLE("skb_priority(", uint32_t, u32, OVS_KEY_ATTR_PRIORITY); ../lib/odp-util.c:5658:9: note: expanded from macro 'SCAN_END_SINGLE' 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. ../lib/odp-util.c:5658:9: note: expanded from macro 'SCAN_END_SINGLE' If the sizes are different then endianess comes into play. 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. Star 675. Asking for help, clarification, or responding to other answers. Casting an open pointer to other pointer types and casting other pointer types to an open pointer does not result in a compile time error. long guarantees a pointer size on Linux on any machine.
[PATCH] platform/x86: hp-wmi: Fix cast to smaller integer type warning Why is there a voltage on my HDMI and coaxial cables? But the problem has still happened. Connect and share knowledge within a single location that is structured and easy to search. Projects. How Intuit democratizes AI development across teams through reusability. What happens if you typecast as unsigned first? 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. But assuming that it is, as long as the caller and the callee agree, you can do that sort of thing. Thanks. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA.
Clang warnings for an invalid casting? - The FreeBSD Forums Is a PhD visitor considered as a visiting scholar. From the question I presume the OP does. 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. I have a function with prototype void* myFcn(void* arg) which is used as the starting point for a pthread. Find centralized, trusted content and collaborate around the technologies you use most. Properly casting a `void*` to an integer in C++ 24,193 Solution 1 I think using intptr_t is the correct intermediate here, since it's guaranteed to be large enough to contain the integral value of the void*, and once I have an integer value I can then truncate it without causing the compiler to complain. This is why you got Error 1 C2036, from your post. 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. Converting a void* to an int is non-portable way that may work or may not! Then I build my project, I get the error "Cast from pointer to smaller type 'int' loses information" in EAGLView.mm file (line 408) when 64-bit simulators (e.g. 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 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. vegan) just to try it, does this inconvenience the caterers and staff? Euler: A baby on his lap, a cat on his back thats how he wrote his immortal works (origin?). Share Improve this answer Follow answered May 6, 2018 at 7:24 Rahul Thanks for pointing that out. vegan) just to try it, does this inconvenience the caterers and staff? The high-order 9 bits of the number are used to hold a flag value, and the result is converted back into a pointer. ../lib/odp-util.c:5834:5: error: cast to smaller integer type 'unsigned long' from 'void *' [-Werror,-Wvoid-pointer-to-int-cast] 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. Converting one datatype into another is known as type casting or, type-conversion. How to notate a grace note at the start of a bar with lilypond? You need to pass an actual pointer. */ >> -bool >> +enum conversion_safety >> unsafe_conversion_p (tree type, tree expr, bool . equal to the original pointer: First you are using a define, which is not a variable. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? For a fairly recent compiler (that supports C99) you should not store or represent address as plain int value. Basically its a better version of (void *)i. Why does setupterm terminate the program? Functions return bigint only if the parameter expression is a bigint data type. Noncompliant Code Example (memset())For historical reasons, certain C Standard functions accept an argument of type int and convert it to either unsigned char or plain char. 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. No idea how it amassed 27 upvotes?! 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). 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. Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, "what happen when typcating normal variable to void* or any pointer variable?" Making statements based on opinion; back them up with references or personal experience.
[Solved] Error "Cast from pointer to smaller type 'int' | 9to5Answer Does Counterspell prevent from any further spells being cast on a given turn? 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. "I think what you should do is actually pass the address of the variable to the function" Not necessarily. and how to print the thread id of 2d array argument? @Shahbaz you could but I will not suggest to a C newbie to use globals. Connect and share knowledge within a single location that is structured and easy to search. Recovering from a blunder I made while emailing a professor. That could create all kinds of trouble. 10) A prvalue of type pointer to void (possibly cv-qualified) can be converted to pointer to any object type. should we also have a diagnostic for the (presumed) user error? Use returnPtr[j] = (void *) ((long)ptr + i); ). The difference between the phonemes /p/ and /b/ in Japanese, Styling contours by colour and by line thickness in QGIS, AC Op-amp integrator with DC Gain Control in LTspice, Identify those arcade games from a 1983 Brazilian music video. 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). Note:You might receive a runtime exception if the pointer contains a value unsuitable for the context. use $(ARCHS_STANDARD_32_BIT) at Architecture instead of $(ARCHS_STANDARD). ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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; 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;. FAILED: lib/libopenvswitch.a.p/odp-util.c.obj Identify those arcade games from a 1983 Brazilian music video. Replacing broken pins/legs on a DIP IC package, How to handle a hobby that makes income in US. 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. Since all pointers on 64-bit Windows are 64 bits, you are growing the data size from 32 bits backto 64 bits. Not the answer you're looking for? Maybe you can try this too. 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. 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 . For the Nozomi from Shinagawa to Osaka, say on a Saturday afternoon, would tickets/seats typically be available - or would you need to book? I'm using cocos2d-x-2.2.2. If your standard library (even if it is not C99) happens to provide these types - use them. How to tell which packages are held back due to phased updates, Identify those arcade games from a 1983 Brazilian music video. rev2023.3.3.43278. 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). Even if you are compiling your program for a 32-bit computer, you should fix your code to remove these warnings, to ensure your code is easily portable to 64-bit.
c - How to cast an integer to void pointer? - Stack Overflow You should perform type conversion based on 64bit build system because the type "int" supports only -32768 ~ 32768. 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.
cast to 'void *' from smaller integer type 'int' You are correct, but cocos actually only uses that address as a unique id. This is memory reinterpretation - a completely unacceptable way to do what the OP is trying to do.
Implicit Type Conversion in C with Examples - GeeksforGeeks Just edited. 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. Windows has 32 bit long only on 64 bit as well. Such pointers can be stored in 32-bit data types (for instance, int, DWORD). Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA.
STR34-C. Cast characters to unsigned char before converting to larger How to use Slater Type Orbitals as a basis functions in matrix method correctly? how to cascade 2d int array to 2d void pointer array? I usually have all automatic conversion warnings effective when developing in C, and I use explicit casting in order to suppress a specific . Thanks for contributing an answer to Stack Overflow! How can this new ban on drag possibly be considered constitutional? How to make compiler not show int to void pointer cast warnings, incompatible pointer types assigning to 'void (*)(void *)' from 'int (int *)'. But gcc always give me a warning, that i cannot cast an int to a void*. Please unaccept the answer you have chosen as it is wrong (as the comments below it say) and will lead to bugs.
windows meson: cast to 'HANDLE' (aka 'void *') from smaller integer for (i=0, j=0; j
Cast a smaller integer to a larger integer - community - The Rust @Artelius: Which, presumably, is exactly what Joshua did: A C++ reinterpret cast will not solve the problem. Disconnect between goals and daily tasksIs it me, or the industry? SCAN_PUT(ATTR, NULL); This is known as implicit type casting or type promotion, compiler automatically converts smaller data type to larger data type.