cast to void *' from smaller integer type 'int

Identify those arcade games from a 1983 Brazilian music video, Relation between transaction data and transaction id, The difference between the phonemes /p/ and /b/ in Japanese. Basically its a better version of (void *)i. This allows you to reinterpret the void * as an int. Find centralized, trusted content and collaborate around the technologies you use most. What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? 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. 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. Issues. error: cast from pointer to smaller type 'unsigned int' loses information. Anw, the project still build and run normally when i use Xcode 5.0 with iOS 7.0. @BlueMoon Thanks a lot! Can I tell police to wait and call a lawyer when served with a search warrant? When is casting void pointer needed in C? SCAN_PUT_ATTR(mask, ATTR, smask, FUNC); Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. No sense in writing a few dozen lines of extra code just to get a bunch of numbered threads. 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; 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. Not the answer you're looking for? ^~~~~~~~~~~~~~~~~~~~ "-D_FILE_OFFSET_BITS=64" "-Wall" "-Winvalid-pch" "-g" "-Wthread-safety" "-Wno-microsoft-enum-forward-reference" "-Wno-unused-function" "-Wno-sometimes-unini 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 While working with Threads in C, I'm facing the warning, "warning: cast to pointer from integer of different size". Does a summoned creature play immediately after being summoned by a ready action? Not the answer you're looking for? Asking for help, clarification, or responding to other answers. It generally takes place when in an expression more than one data type is present. You can convert the values from one type to another explicitly using the cast operator as follows (type_name) expression Please help me compile Chez Scheme. It's an int type guaranteed to be big enough to contain a pointer. This solution is in accordance with INT18-C. This is a fine way to pass integers to new pthreads, if that is what you need. The 32 remaining bits stored inside int are insufficient to reconstruct a pointer to the thread function. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. If your standard library (even if it is not C99) happens to provide these types - use them. If you cast an int pointer int, you might get back a different integer. What video game is Charlie playing in Poker Face S01E07? rev2023.3.3.43278. 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 main point is: a pointer has a platform dependent size. If this is the data to a thread procedure, then you quite commonly want to pass by value. . ../lib/odp-util.c:5658:9: note: expanded from macro 'SCAN_END_SINGLE' Difficulties with estimation of epsilon-delta limit proof. The preprocesor absolutely will not perform arithmetic. Note the difference between the type casting of a variable and type casting of a pointer. ../lib/odp-util.c:5665:7: note: expanded from macro 'SCAN_SINGLE' The only exception is exotic systems with the SILP64 data model, where the size of int is also 64 bits. If pointers are 64 bits and ints are 32 bits, an int is too small to hold a pointer value. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? The difference between a and &a is the type. I am an entry level C programmer. Replacing broken pins/legs on a DIP IC package, AC Op-amp integrator with DC Gain Control in LTspice. 1. Mutually exclusive execution using std::atomic? 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. But I don't want to edit code in "EAGLView.mm" because it's a "library file". 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. It was derived from the BCPL, and the name of the b language is possibly from the BCPL contraction. 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). For a fairly recent compiler (that supports C99) you should not store or represent address as plain int value. B language was designed to develop . What does casting to void* does when passing arguments to variadic functions? However, I believe that even if the define was for the "65536", it would not be what @kaetzacoatl wanted. Here, the Java first converts the int type data into the double type. "clang" "-Ilib\libopenvswitch.a.p" "-Ilib" "-I..\lib" "-I." All float types are to be converted to double. A cast converts an object or value from one type to another. Yeah, the tutorial is doing it wrong. You may declare a const int variable and cast its reference to the void*. Put your define inside a bracket: without a problem. Already on GitHub? On most platforms pointers and longs are the same size, but ints and pointers often are not the same size on 64bit platforms. So you could do this: Note: As sbi points out this would require a change on the OP call to create the thread. Java Type Casting. C99 defines the types "intptr_t" and "uintptr_t" which do . Mutually exclusive execution using std::atomic? You can also convert values from one type to another explicitly using the cast operator (see Chapter 5 ): ( type_name) expression In the following example, the cast operator causes the division of one integer variable by another to be performed as a floating-point operation: int sum = 22, count = 5; double mean = (double)sum / count; Floating-point conversions (void *)i Error: cast to 'void *' from smaller integer type 'int' PS: UBUNTUCLANG3.5 clang -O0 -std=gnu11 -march=native -lm -lpthread pagerank.c -o pagerank c pthreads 4 10.3k 2 21 2015-06-05 Infact I know several systems where that does not hold. In such a case the programmer can use a void pointer to point to the location of the unknown data type. 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. Making statements based on opinion; back them up with references or personal experience. What I am saying is that it would be safer to use new(5) rather than 5 and deal with it appropriately at the other end. Using indicator constraint with two variables. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, error: cast from void* to int loses precision, cast to pointer from integer of different size, pthread code. Making statements based on opinion; back them up with references or personal experience. A missing cast in the new fast > enumeration code. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, Setting a buffer of char* with intermediate casting to int*. Sign up for a free GitHub account to open an issue and contact its maintainers and the community. ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Euler: A baby on his lap, a cat on his back thats how he wrote his immortal works (origin?). Can Martian regolith be easily melted with microwaves? Thus as a result it may be less error prone to generate a pointer dynamcially and use that. 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. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. 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 perform a cast, specify the type that you are casting to in parentheses in front of the value or variable to be converted. ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. 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. error: comparison between pointer and integer ('int' and 'string' (aka 'char *')), CS50 Caesar program is working but check50 says it isn't. Find centralized, trusted content and collaborate around the technologies you use most. If you call your thread creation function like this, then the void* arriving inside of myFcn has the value of the int you put into it. Did i have to face to unexpected runtime issues, i guess not, i've found another discussion on this -. Passing arguments to pthread_create - invalid conversion from void(*)() to void(*)(void*). What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? The difference between the phonemes /p/ and /b/ in Japanese, Styling contours by colour and by line thickness in QGIS. XCode 5.1 is change all architecture to 64 bit. He should pass the address of the integer, the thread should get that address, Note: This is only appropriate is you cast the. I'm only guessing here, but I think what you are supposed to do is actually pass the address of the variable to the function. 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. . Why is this sentence from The Great Gatsby grammatical? even though the compiler doesn't know you only ever pass myFcn to pthread_create in conjunction with an integer. I agree passing a dynamically allocated pointer is fine (and I think the best way). Or, they are all wrong. vegan) just to try it, does this inconvenience the caterers and staff? Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, You should be doing int x = *((int *)arg); You are casting from void * to int that is why you get the warning. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. How do I check if a string represents a number (float or int)? The bigint data type is intended for use when integer values might exceed the range that is supported by the int data type.. bigint fits between smallmoney and int in the data type precedence chart.. What is the difference between const int*, const int * const, and int const *? You cannot just cast the 32-bit variable to a pointer, because that pointer on a 64-bit machine is twice as long. 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 [.]) whether it was an actual problem is a different matter though. 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. For the Nozomi from Shinagawa to Osaka, say on a Saturday afternoon, would tickets/seats typically be available - or would you need to book? My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? I have a two functions, one that returns an int, and one that takes a const void* as an argument. I'm trying to learn pthreads and thing that keeps bugging me is how do i really pass argument to the function. If the value is ever used as pointer again that will prove to be an extremely bad idea. For integer casts in specific, using into() signals that . Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. This forum has migrated to Microsoft Q&A. I need to convert the argument to an int for later use: The compiler (GCC version 4.2.4) returns the error: You can cast it to an intptr_t type. LLNL's tutorial is bad and they should feel bad. 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. that any valid pointer to void can be converted to this type, then SQL Server does not automatically promote . Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Why are Suriname, Belize, and Guinea-Bissau classified as "Small Island Developing States"? What I am trying to do in that line of code is check to make sure each character in my string is alphabetical. Well it does this because you are converting a 64 bits pointer to an 32 bits integer so you loose information. And, most of these will not even work on gcc4. I think the solution 3> should be the correct one. Why do academics stay as adjuncts for years rather than move around? GitHub Skip to content Product Solutions Open Source Pricing Sign in Sign up smadaminov / ovs-dpdk-meson-issues Public Notifications Fork 1 Star 1 Code Issues 66 Pull requests Actions Projects 1 Security Insights New issue Press question mark to learn the rest of the keyboard shortcuts. Fork 63. unsigned long call_fn = (unsigned long)FUNC; To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Visit Microsoft Q&A to post new questions. Thank you all for your feedback. Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? Is it possible to create a concave light? Is it possible to create a concave light? You are correct, but cocos actually only uses that address as a unique id. Acidity of alcohols and basicity of amines. Update: Today, i download the latest version of cocos2d-x (cocos2d-x 2.2.3). 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. Why is there a voltage on my HDMI and coaxial cables? A sane compiler may throw a warning on lines like this but by no way it should throw an error, because this code is NOT wrong, it is just potentially error-prone, but can be perfectly valid. 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. "After the incident", I started to be more careful not to trip over things. Can Martian regolith be easily melted with microwaves? 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. But then you need to cast your arguments inside your thread function which is quite unsafe cf. to your account, [87/252] Compiling C object lib/libopenvswitch.a.p/odp-util.c.obj It is done by the compiler on its own, without any external trigger from the user. to the original pointer: The following type designates an unsigned integer type with the This is not even remotely "the correct answer". Identify those arcade games from a 1983 Brazilian music video. Well occasionally send you account related emails. this way you won't get any warning. How can this new ban on drag possibly be considered constitutional? The only alternative is really to take time and fix all 64-bit code issues, of which there may be some non-trivial issues. Why did Ukraine abstain from the UNHRC vote on China? Whats the grammar of "For those whose stories they are"? Can I tell police to wait and call a lawyer when served with a search warrant? } SCAN_END_SINGLE(ATTR) You need to pass an actual pointer. Replacing broken pins/legs on a DIP IC package, How to handle a hobby that makes income in US. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, "what happen when typcating normal variable to void* or any pointer variable?" Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded? Therefore, you need to change it to long long instead of long in windows for 64 bits. As was pointed out by Martin, this presumes that sizeof(void*)>=sizeof(int). If the sizes are different then endianess comes into play. There are ways to prevent this: pass a dynamic allocated argument if your not the passing thread is not static or if your argument is a local variable, otherwise there is no issue. ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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. It's always a good practice to put your #define's in brackets to avoid such surprise. property that any valid pointer to void can be converted to this type, I understood, but that would introduce dynamic memory and ugly lifetime issues (an object allocated by one thread must be freed by some other) - all just to pass an. "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. Find centralized, trusted content and collaborate around the technologies you use most. What is the point of Thrower's Bandolier? @DietrichEpp can you explain what is race condition with using. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? should we also have a diagnostic for the (presumed) user error? Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, Xcode 5 and iOS 7: Architecture and Valid architectures, xcode build error: Semantic issue cast from pointer to smaller type 'int' loses information, Issues in handling touches on subviews(uiviews) in UIScrollView, Architecture linking error after Xcode 5.1 upgrade, iOS 7.1 gives error after updating to Xcode 5.1, Linker error in Xcode 5.1 with cocos2d-x 3 beta 2. Remarks. 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. Hence there is no loss in data. Such pointers can be stored in 32-bit data types (for instance, int, DWORD). 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. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. what does it mean to convert int to void* or vice versa? ^~~~~~~~~~~~~~~~~~~~ SCAN_SINGLE("skb_priority(", uint32_t, u32, OVS_KEY_ATTR_PRIORITY); Alternatively, if you choose to castthe ptr variableto (size_t) instead, then you don't need to worry about the pointer typeanymore. Not the answer you're looking for? 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. Converting a void* to an int is non-portable way that may work or may not! 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 Why does setupterm terminate the program? 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. You are getting warnings due to casting a void* to a type of a different size. And in this context, it is very very very common to see programmers lazily type cast the. The most general answer is - in no way. Safe downcast may be done with dynamic_cast. p-util.c.obj "-c" ../lib/odp-util.c I would create a structure and pass that as void* to pthread_create. But gcc always give me a warning, that i cannot cast an int to a void*. On a 64-bit Windows computer, 'long' is a 32-bit type, and all pointers are 64-bit types.