cast to void *' from smaller integer type 'int

While working with Threads in C, I'm facing the warning, "warning: cast to pointer from integer of different size". Why does Mister Mxyzptlk need to have a weakness in the comics? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Not the answer you're looking for? Why do academics stay as adjuncts for years rather than move around? SCAN_PUT_ATTR(mask, ATTR, smask, FUNC); Evaluate integer expressions in a larger size before comparing or assigning to that size.Note that (time_+t)-1 also complies with INT31-C-EX3. Find centralized, trusted content and collaborate around the technologies you use most. Actions. Thanks. A pointer converted to an integer of sufficient size and back to the same pointer type is guaranteed to have its original value, otherwise the resulting pointer cannot be dereferenced safely ( the round-trip conversion in the opposite direction is not guaranteed [.]) By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? static_cast on the other hand should deny your stripping away the const qualifier. 7.1 New Cast Operations The C++ standard defines new cast operations that provide finer control than previous cast operations. @DavidHeffernan I rephrased that sentence a little. ../lib/odp-util.c:5665:7: note: expanded from macro 'SCAN_SINGLE' This example is noncompliant on an implementation where pointers are 64 bits and unsigned integers are 32 bits because the result of converting the 64-bit ptr cannot be represented in the 32-bit integer type. Using an integer address (like &x) is probably wrong, indeed each modification you will execute on x will affect the pass behaviour. 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. I agree passing a dynamically allocated pointer is fine (and I think the best way). I have looked around and can't seem to find any information on how to do this. What is the difference between const int*, const int * const, and int const *? linux c-pthreads: problem with local variables. ../lib/odp-util.c:5834:5: error: cast to smaller integer type 'unsigned long' from 'void *' [-Werror,-Wvoid-pointer-to-int-cast] Making statements based on opinion; back them up with references or personal experience. Converting one datatype into another is known as type casting or, type-conversion. If the destination type is bool, this is a boolean conversion (see below). Example: int x=7, y=5; float z; z=x/y; /*Here the value of z is 1*/. ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Share Improve this answer Follow answered May 6, 2018 at 7:24 Rahul Functions return bigint only if the parameter expression is a bigint data type. Sign in ../lib/odp-util.c:5834:5: error: cast to smaller integer type 'unsigned long' from 'void *' [-Werror,-Wvoid-pointer-to-int-cast] Acidity of alcohols and basicity of amines. There's probably little you can do except look or hope for a fixed 2.x version or upgrade to 3.x (I would assume it's 64-bit safe but this is just a guess, do research this issue before you upgrade). If this is the data to a thread procedure, then you quite commonly want to pass by value. rev2023.3.3.43278. The difference between a and &a is the type. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. 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). Using printf with a pointer to float gives an error, Meaning of int (*) (int *) = 5 (or any integer value), Casting int to void* loses precision, and what is the solution in required cases, Acidity of alcohols and basicity of amines. Replacing broken pins/legs on a DIP IC package, How to handle a hobby that makes income in US. To learn more, see our tips on writing great answers. Infact I know several systems where that does not hold. 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;. Basically its a better version of (void *)i. This will get you a pointer from a 32 bit offset: A function pointer is incompatible to void* (and any other non function pointer). We have to pass address of the variable to the function because in function definition argument is pointer variable. How Intuit democratizes AI development across teams through reusability. An object pointer (including void*) or function pointer can be converted to an integer type using reinterpret_cast. If the original type is a void *, converting to an int may lose date on platforms where sizeof(void *) != sizeof(int) (which is true of LP64 programming model). Visit Microsoft Q&A to post new questions. Thanks for contributing an answer to Stack Overflow! Keep in mind that thrArg should exist till the myFcn() uses it. Bulk update symbol size units from mm to map units in rule-based symbology. Therefore it is perfectly valid for the compiler to throw an error for a line like. But I don't want to edit code in "EAGLView.mm" because it's a "library file". Getting Command /bin/sh failed with exit code 65 Error with Xcode 5.1 . Narrowing Casting (manually) - converting a larger type to a . Mutually exclusive execution using std::atomic? In my case, I was using a 32-bit value that needed to be passed to an OpenGL function as a void * representing an offset into a buffer. Pull requests. If your standard library (even if it is not C99) happens to provide these types - use them. "-I.." "-Iinclude\openflow" "-I..\include\openflow" "-Iinclude\openvswitch" "-I..\include\openvsw By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. 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. Click to see the query in the CodeQL repository. Connect and share knowledge within a single location that is structured and easy to search. Wrong. Usually that means the pointer is allocated with. To learn more, see our tips on writing great answers. But gcc always give me a warning, that i cannot cast an int to a void*. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? And you can't pass a pointer to a stack based object from the other thread as it may no longer be valid. The program can be set in such a way to ask the user to inform the type of data and . How can this new ban on drag possibly be considered constitutional? 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. I recall there was a TreeNode(int) early on prior to 1.0 release I can't remember why I removed it, if I should felt it was easy enough to cast to (void*) or if it was because it created type inference conflict at the call site. converted back to pointer to void, and the result will compare equal Passing arguments to pthread_create - invalid conversion from void(*)() to void(*)(void*). So reinterpret_cast has casted it to long type and then static_cast safely casts long to int, if you are ready do truncte the data. Yesterday, I updated Xcode to the newest version (5.1 (5B130a)) to compatible with iOS 7.1. And in this context, it is very very very common to see programmers lazily type cast the. 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. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. rev2023.3.3.43278. 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). Java Type Casting. RNINGS" "-D_CRT_SECURE_NO_DEPRECATE" -MD -MQ lib/libopenvswitch.a.p/odp-util.c.obj -MF "lib\libopenvswitch.a.p\odp-util.c.obj.d" -o lib/libopenvswitch.a.p/od eg. SCAN_SINGLE("skb_priority(", uint32_t, u32, OVS_KEY_ATTR_PRIORITY); Thus as a result it may be less error prone to generate a pointer dynamcially and use that. 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. You use the address-of operator & to do that. Bulk update symbol size units from mm to map units in rule-based symbology. The preprocesor absolutely will not perform arithmetic. Remembering to delete the pointer after use so that we don't leak. 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. How to get the error message from the error code returned by GetLastError()? 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). Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. 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". for (i=0, j=0; j to define it. 471,961 Members | 900 Online. This is not a conversion at all. The high-order 9 bits of the number are used to hold a flag value, and the result is converted back into a pointer. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? This is a fine way to pass integers to new pthreads, if that is what you need. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. The problem is not with casting, but with the target type loosing half of the pointer. From the question I presume the OP does. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, Setting a buffer of char* with intermediate casting to int*. @kshegunov said in Number Type Cast: const void * x; int y = int (x); compiles just fine. 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. } SCAN_END_SINGLE(ATTR) Returns a value of type new-type. Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, "what happen when typcating normal variable to void* or any pointer variable?"