windows meson: cast to 'HANDLE' (aka 'void *') from smaller integer "clang" "-Ilib\libopenvswitch.a.p" "-Ilib" "-I..\lib" "-I." Or, they are all wrong. Thanks for contributing an answer to Stack Overflow! Offline ImPer Westermark over 11 years ago in reply to Andy Neil Except that you sometimes stores an integer in the pointer itself. error: comparison between pointer and integer ('int' and 'string' (aka 'char *')), CS50 Caesar program is working but check50 says it isn't. Sign in What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? vegan) just to try it, does this inconvenience the caterers and staff? Asking for help, clarification, or responding to other answers. Recovering from a blunder I made while emailing a professor. Disconnect between goals and daily tasksIs it me, or the industry? 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; It generally takes place when in an expression more than one data type is present. to your account, [87/252] Compiling C object lib/libopenvswitch.a.p/odp-util.c.obj 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. But assuming that it is, as long as the caller and the callee agree, you can do that sort of thing. 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. Windows has 32 bit long only on 64 bit as well. byte -> short -> char -> int -> long -> float -> double. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. In simple example code like this it's very easy to convince yourself that there's no problem, but in more elaborate real-world scenarios it's very easy to make this mistake inadvertently. Issues. ncdu: What's going on with this second size column? This is a fine way to pass integers to new pthreads, if that is what you need. pthread passes the argument as a void*. 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. Use returnPtr[j] = (void *) ((long)ptr + i); ). Here is some piece of code where that error occur: /cocos2d-x-2.2.2/cocos2dx/platform/ios/EAGLView.mm:408:18: Cast from pointer to smaller type 'int' loses information. Now, what happens when I run it with the thread sanitizer? Acidity of alcohols and basicity of amines. Type casting is when you assign a value of one primitive data type to another type. Click to see the query in the CodeQL repository. How to get the error message from the error code returned by GetLastError()? Why does flowing off the end of a non-void function without returning a value not produce a compiler error? If your standard library (even if it is not C99) happens to provide these types - use them. ^~~~~~~~~~~~~~~~~~~ As a result of the integer division 3/2 we get the value 1, which is of the int type. My code is all over the place now but I appreciate you all helping me on my journey to mastery! LLNL's tutorial is bad and they should feel bad. Thank you all for your feedback. @BlueMoon Thanks a lot! this way you won't get any warning. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. You are correct, but cocos actually only uses that address as a unique id. Fix for objc/45925 Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, Setting a buffer of char* with intermediate casting to int*. 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. You are just making it bigger by tricking the compiler and the ABI. Maybe you can try this too. Replacing broken pins/legs on a DIP IC package, AC Op-amp integrator with DC Gain Control in LTspice. What I am trying to do in that line of code is check to make sure each character in my string is alphabetical. Converting one datatype into another is known as type casting or, type-conversion. Pull requests. Thanks Jonathan, I was thinking about my answer in another thread: AraK is correct, passing integers a pointers are not necessarily interchangeable. The following program casts a double to an int. /** Dynamically allocate a 2d (x*y) array of elements of size _size_ bytes. This is an old C callback mechanism so you can't change that. How create a simple program using threads in C? actually no, as int my be a smaller type than a pointer ;-) But, of course with int64_t it works fine. I cannot reverse my upvote of user384706's answer, but it's wrong. How to use Slater Type Orbitals as a basis functions in matrix method correctly? Implicit Type Conversion in C with Examples - GeeksforGeeks (Also, check out how it prints "5" twice), passing a unique pointer to each thread wont race, and you can get/save any kind of information in the th struct. Does melting sea ices rises global sea level? Pd = Pa; Similarly, Pc may be type cast to type int and assigned the value Pa. 1. : iPhone Retina 4-inch 64-bit) is selected. void* to an array - C++ Forum - cplusplus.com Can I tell police to wait and call a lawyer when served with a search warrant? FAILED: lib/libopenvswitch.a.p/odp-util.c.obj The difference between the phonemes /p/ and /b/ in Japanese, Styling contours by colour and by line thickness in QGIS. You can fix this error by replacing this line of code. Find centralized, trusted content and collaborate around the technologies you use most. You use the address-of operator & to do that. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. I agree passing a dynamically allocated pointer is fine (and I think the best way). To learn more, see our tips on writing great answers. 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. Connect and share knowledge within a single location that is structured and easy to search. Find centralized, trusted content and collaborate around the technologies you use most. Sign up for a free GitHub account to open an issue and contact its maintainers and the community. C++ Tutorial => Conversion between pointer and integer and how to print the thread id of 2d array argument? 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. So make sure you understand what you are doing! By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. To learn more, see our tips on writing great answers. Why do small African island nations perform better than African continental nations, considering democracy and human development? Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, "what happen when typcating normal variable to void* or any pointer variable?" int, bigint, smallint, and tinyint (Transact-SQL) - SQL Server You can use a 64 bits integer instead howerver I usually use a function with the right prototype and I cast the function type : error: cast from 'void*' to 'int' loses precision - Stack Overflow No sense in writing a few dozen lines of extra code just to get a bunch of numbered threads. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. (void *)i Error: cast to 'void *' from smaller integer type 'int'. 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. You could use this code, and it would do the same thing as casting ptr to (char*). The point is (probably) that the value passed to the thread is an integer value, not really a 'void *'. This solution is in accordance with INT18-C. ../lib/odp-util.c:5658:9: note: expanded from macro 'SCAN_END_SINGLE' Where does this (supposedly) Gibson quote come from? For integer casts in specific, using into() signals that . I usually have all automatic conversion warnings effective when developing in C, and I use explicit casting in order to suppress a specific . Whats the grammar of "For those whose stories they are"? Use of Void pointers in C programming language What is the purpose of non-series Shimano components? Using indicator constraint with two variables. Thanks for contributing an answer to Stack Overflow! So,solution #3 works just fine. error: cast from pointer to smaller type 'unsigned int' loses 471,961 Members | 900 Online. This is what the second warning is telling you. Visit Microsoft Q&A to post new questions. Create an account to follow your favorite communities and start taking part in conversations. Therefore, you need to change it to long long instead of long in windows for 64 bits. The only exception is exotic systems with the SILP64 data model, where the size of int is also 64 bits. that any valid pointer to void can be converted to this type, then What video game is Charlie playing in Poker Face S01E07? If this is the data to a thread procedure, then you quite commonly want to pass by value. return ((void **) returnPtr);} /* Matrix() */. Alternatively, if you choose to castthe ptr variableto (size_t) instead, then you don't need to worry about the pointer typeanymore. Functions return bigint only if the parameter expression is a bigint data type. Losing bytes like thisis called 'truncation', and that's what the first warning is telling you. Have a question about this project? Here is my code: I already tried (void*)M_TABLE_SIZE but then I get an error that I cannot use the * operator. Connect and share knowledge within a single location that is structured and easy to search. Just edited. 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. Actions. Casting type void to uint8_t - Arduino Forum 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 Already on GitHub? I think the solution 3> should be the correct one. with ids being an array of ints and touch being a pointer. This allows you to reinterpret the void * as an int. For the second example you can make sure that sizeof(int) <= sizeof(void *) by using a static_assert -- this way at least you'll get a notice about it. What you do here is undefined behavior, and undefined behavior of very practical sort. On all of them int is 32bit, not 16bit. Can Martian regolith be easily melted with microwaves? ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? linux c-pthreads: problem with local variables. @DietrichEpp can you explain what is race condition with using. Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? ^~~~~~~~~~~~~~~~~~~~ To subscribe to this RSS feed, copy and paste this URL into your RSS reader. 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. How to correctly cast a pointer to int in a 64-bit application? This is flat out wrong. But then you need to cast your arguments inside your thread function which is quite unsafe cf. @DavidHeffernan I rephrased that sentence a little. Since all pointers on 64-bit Windows are 64 bits, you are growing the data size from 32 bits backto 64 bits. Bulk update symbol size units from mm to map units in rule-based symbology. what happens when we typecast normal variable to void* or any pointer variable? XCode 5.1 is change all architecture to 64 bit. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? What does casting to void* does when passing arguments to variadic functions? Put your define inside a bracket: #define M_TABLE_SIZE (64*1024) Now, you can do: static const void* M_OFFSET = (void*) M_TABLE_SIZE; without a problem. There is no "correct" way to store a 64-bit pointer in an 32-bit integer. What is "cast from integer to pointer of different size" warning? I guess the other important fact is that the cast operator has higher precedence that the multiplication operator. Casting int to void* : r/C_Programming - reddit So, when you cast a (void*) to (long), you are losing 32 bits of data in the conversion. To learn more, see our tips on writing great answers. For the second example you can make sure that sizeof (int) <= sizeof (void *) by using a static_assert -- this way at least you'll get a notice about it. I get the error: "cast to smaller integer type 'int' from 'string' (aka 'char *')" referencing line of code: while (isalpha(residents[i].name) == 0), How Intuit democratizes AI development across teams through reusability. This is why you got Error 1 C2036, from your post. ^~~~~~~~~~~~~~~~~~~~~ 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)). Please tell me error: cast from 'void*' to 'int' loses precision, How Intuit democratizes AI development across teams through reusability. } SCAN_END_SINGLE(ATTR) this way you won't get any warning. [PATCH] platform/x86: hp-wmi: Fix cast to smaller integer type warning Why is there a voltage on my HDMI and coaxial cables? Thanks for contributing an answer to Stack Overflow! The only alternative is really to take time and fix all 64-bit code issues, of which there may be some non-trivial issues. 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. Euler: A baby on his lap, a cat on his back thats how he wrote his immortal works (origin? Most answers just try to extract 32 useless bits out of the argument. There's no proper way to cast this to int in general case. Implicit conversions - cppreference.com To avoid truncating your pointer, cast it to a type of identical size. But this code pass the normal variable .. Find centralized, trusted content and collaborate around the technologies you use most. How Intuit democratizes AI development across teams through reusability. Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded? 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. 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. Did i have to face to unexpected runtime issues, i guess not, i've found another discussion on this -. The reinterpret_cast makes the int the size of a pointer and the warning will stop. The proper way is to cast it to another pointer type. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. what does it mean to convert int to void* or vice versa? If you preorder a special airline meal (e.g. static_cast conversion - cppreference.com Compile error on Android ARM Issue #163 cisco/ChezScheme Your first example is risky because you have to be very careful about the object lifetimes. Surely the solution is to change the type of ids from int to type that is sufficiently large to hold a pointer. 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. [Solved] Properly casting a `void*` to an integer in C++ If that happens soon after the call to pthread_create() then you have a race condition, because there's a chance that the thread will attempt to read x's value after it's life has ended, which invokes undefined behavior. Mutually exclusive execution using std::atomic? The 32 remaining bits stored inside int are insufficient to reconstruct a pointer to the thread function. That's not a good idea if the original object (that was cast to void*) was an integer. Why are Suriname, Belize, and Guinea-Bissau classified as "Small Island Developing States"? Then i can continue compiling. Is it possible to create a concave light? Projects. Does Counterspell prevent from any further spells being cast on a given turn? 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). to the original pointer: The following type designates an unsigned integer type with the ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ warning C4311: 'type cast': pointer truncation from 'void *' to 'long' in ECPG test files. As with all cast expressions, the result is: Two objects a and b are pointer-interconvertible if: static_cast may also be used to disambiguate function overloads by performing a function-to-pointer conversion to specific type, as in. Any help with this is appreciated. For example, if youwrite ((int*)ptr + 1), it will add 4 bytes to the pointer, because "ints" are 4 bytes each. reinterpret_cast is a type of casting operator used in C++. 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. However even though their types are different, the address is going to be the same. How do I align things in the following tabular environment? Before I update Xcode, my project still can build and run normally with all devices. And, most of these will not even work on gcc4. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Why do academics stay as adjuncts for years rather than move around? error: cast from pointer to smaller type 'unsigned int' loses information. How to correctly cast a pointer to int in a 64-bit application? 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. You are right! - the incident has nothing to do with me; can I use this this way? The main point is: a pointer has a platform dependent size. For the Nozomi from Shinagawa to Osaka, say on a Saturday afternoon, would tickets/seats typically be available - or would you need to book? Returns a value of type new-type. Bulk update symbol size units from mm to map units in rule-based symbology. This is not a conversion at all. "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. 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. ../lib/odp-util.c:5834:5: error: cast to smaller integer type 'unsigned long' from 'void *' [-Werror,-Wvoid-pointer-to-int-cast]
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