cast to void *' from smaller integer type 'intprotest behavior avoidant attachment
It is done by the compiler on its own, without any external trigger from the user. Note the difference between the type casting of a variable and type casting of a pointer. Disconnect between goals and daily tasksIs it me, or the industry? 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. If your code has the chance to ever be ported to some platform where this doesn't hold, this won't work. If your standard library (even if it is not C99) happens to provide these types - use them. What is the purpose of non-series Shimano components? : iPhone Retina 4-inch 64-bit) is selected. 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. "I think what you should do is actually pass the address of the variable to the function" Not necessarily. The text was updated successfully, but these errors were encountered: 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. 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; The main point is: a pointer has a platform dependent size. Once you manage to make this cast, then what?! Again, all of the answers above missed the point badly. Can Martian regolith be easily melted with microwaves? How can this new ban on drag possibly be considered constitutional? Instead of using a long cast, you should cast to size_t. ../lib/odp-util.c:5658:9: note: expanded from macro 'SCAN_END_SINGLE' Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? with ids being an array of ints and touch being a pointer. Windows has 32 bit long only on 64 bit as well. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Since all pointers on 64-bit Windows are 64 bits, you are growing the data size from 32 bits backto 64 bits. If not, check the pointer size on your platform, define these typedefs accordingly yourself and use them. Half your pointer will be garbage. ../lib/odp-util.c:5834:5: error: cast to smaller integer type 'unsigned long' from 'void *' [-Werror,-Wvoid-pointer-to-int-cast] return ((void **) returnPtr);} /* Matrix() */. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Asking for help, clarification, or responding to other answers. how to cascade 2d int array to 2d void pointer array? Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. vegan) just to try it, does this inconvenience the caterers and staff? It was derived from the BCPL, and the name of the b language is possibly from the BCPL contraction. C/C++ , Cerror: cast to 'void *' from smaller integer type 'int'. ../lib/odp-util.c:5665:7: note: expanded from macro 'SCAN_SINGLE' @LearnCocos2D: so, how can i "overcome" the error without editing any not-my-code or in-library-file lines? Why does setupterm terminate the program? There's no proper way to cast this to int in general case. What I am trying to do in that line of code is check to make sure each character in my string is alphabetical. Recovering from a blunder I made while emailing a professor. Asking for help, clarification, or responding to other answers. Well it does this because you are converting a 64 bits pointer to an 32 bits integer so you loose information. How to notate a grace note at the start of a bar with lilypond? It's an int type guaranteed to be big enough to contain a pointer. On a 64-bit Windows computer, 'long' is a 32-bit type, and all pointers are 64-bit types. Your first example is risky because you have to be very careful about the object lifetimes. pthread passes the argument as a void*. Connect and share knowledge within a single location that is structured and easy to search. (int) pthread_self() 64int48intuintptr_t (unsigned int) A nit: in your version, the cast to void * is unnecessary. I cannot reverse my upvote of user384706's answer, but it's wrong. Does Counterspell prevent from any further spells being cast on a given turn? Connect and share knowledge within a single location that is structured and easy to search. 10) A prvalue of type pointer to void (possibly cv-qualified) can be converted to pointer to any object type. Get the address of a callback function to call dynamically in C++, error: call of overloaded function ambiguous, error: cast from to unsigned int loses precision [-fpermissive]. Any help with this is appreciated. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A void pointer can be really useful if the programmer is not sure about the data type of data inputted by the end user. Using indicator constraint with two variables. Is pthread_join a must when using pthread in linux? What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? Floating-point conversions Not the answer you're looking for? 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. I assumed that gcc makes a 65536 out of my define, but I was wrong.
Use returnPtr[j] = (void *) ((long)ptr + i); ). If the source type is bool, the value false is converted to zero and the value true is converted to the value one of the destination type (note that if the destination type is int, this is an integer promotion, not an integer conversion). 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. If you need to keep the returned address, just keep it as void*. I agree passing a dynamically allocated pointer is fine (and I think the best way). what happens when we typecast normal variable to void* or any pointer variable? If you are going to pass the address you typically need to exert some more control over the lifetime of the object. Using Kolmogorov complexity to measure difficulty of problems? And when assigning to a void pointer, all type information is lost. What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? 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. How to use Slater Type Orbitals as a basis functions in matrix method correctly? property that any valid pointer to void can be converted to this type, So you know you can cast it back like this. A cast specifies a conversion from one type to another. In both cases, converting the pointer to an integer type that's too small to represent all pointer values is a bug. For example, the main thread could wait for all of the other threads to end before terminating. 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). This solution is in accordance with INT18-C. ", "!"? In C (int)b is called an explicit conversion, i.e. This is what the second warning is telling you. The point is (probably) that the value passed to the thread is an integer value, not really a 'void *'. But then you need to cast your arguments inside your thread function which is quite unsafe cf. Basically its a better version of (void *)i. ../lib/odp-util.c:5665:7: note: expanded from macro 'SCAN_SINGLE' Find centralized, trusted content and collaborate around the technologies you use most. 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. this way I convert an int to a void* which is much better than converting a void* to an int. 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. Why is there a voltage on my HDMI and coaxial cables? While working with Threads in C, I'm facing the warning, "warning: cast to pointer from integer of different size". Projects. There is absolutely not gurantee that sizeof(int) <= sizeof(void*). @jackdoe: It's a waste of human life to write code that "you may need in the future". rev2023.3.3.43278. 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. 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. So you could do this: Note: As sbi points out this would require a change on the OP call to create the thread. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. No sense in writing a few dozen lines of extra code just to get a bunch of numbered threads. Typically, long or unsigned long is . 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. Making statements based on opinion; back them up with references or personal experience. Anw, the project still build and run normally when i use Xcode 5.0 with iOS 7.0. Thanks for contributing an answer to Stack Overflow! By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. If this is the data to a thread procedure, then you quite commonly want to pass by value. 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. I guess the other important fact is that the cast operator has higher precedence that the multiplication operator. From that point on, you are dealing with 32 bits. *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 . Linear regulator thermal information missing in datasheet. Keep in mind that thrArg should exist till the myFcn() uses it. For example, if youwrite ((int*)ptr + 1), it will add 4 bytes to the pointer, because "ints" are 4 bytes each. Based on the design of this function, which modification is right. Did i have to face to unexpected runtime issues, i guess not, i've found another discussion on this -. A long long would not work for 32bit systems and a long would not work for 64 bit Windows (while 64bit Unix and Unix-like systems like OS X use the LP64 data model, in which a long is 64bit, 64bit Windows uses the LLP64 data model, in which a long has a size of 32bit (http://en.wikipedia.org/wiki/64-bit_computing#64-bit_data_models)). what does it mean to convert int to void* or vice versa? Bulk update symbol size units from mm to map units in rule-based symbology. When is casting void pointer needed in C? 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). This will only compile if the destination type is long enough. Is it possible to create a concave light? The problem just occur with Xcode 5.1. 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. The reinterpret_cast makes the int the size of a pointer and the warning will stop. How do I check if a string represents a number (float or int)? Asking for help, clarification, or responding to other answers. For example, if you want to store a 'long' value into a simple integer then you can type cast 'long' to 'int'. What is the purpose of non-series Shimano components? for (i=0, j=0; j