cast to 'void *' from smaller integer type 'int' cast to 'void *' from smaller integer type 'int'

value of malloc is bad, like: He also rips off an arm to use as a sword, Two MacBook Pro with same model number (A1286) but different year. Can you still use Commanders Strike if the only attack available to forego is an attack against an ally? ", "!"? equal to the original pointer: First you are using a define, which is not a variable. How to convert a factor to integer\numeric without loss of information? How should a standardized and beautiful flowchart be designed? If you write ((char*)ptr + 1), it will advance the pointer 1 byte, because a "char" is 1 byte. What is the correct method to cast an int to a void*? If the types are from the same inheritance tree, then you should either use dynamic_casts or even better, you should benefit from dynamic dispatching.. dynamic_cast is slightly better, but still should be avoided. how to cascade 2d int array to 2d void pointer array? 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. And in the function you get the value of the pointer by using the dereference operator *: Please read why glib provide macros for this kind of conversions, there's no need to repeat the text here. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Please unaccept the answer you have chosen as it is wrong (as the comments below it say) and will lead to bugs. Casting arguments inside the function is a lot safer. Has the cause of a rocket failure ever been mis-identified, such that another launch failed due to the same problem? For more information, see User-defined conversion operators. Terrible solution. Casting int to void* loses precision, and what is the solution in required cases, c++: cast from "const variable*" to "uint32" loses precision, cast from 'char*' to 'int' loses precision. The error message mentions the diagnostic responsible for error message, e.g. For example, (double) 1/3 will give a double result instead of an int one. i Unfortunately, that hardware is 64-bit and the code contains many instances of pointer arithmetic that expects pointers to be 32-bit, i.e. that any valid pointer to void can be converted to this type, then Was Aristarchus the first to propose heliocentrism? This is not even remotely "the correct answer". Save this piece of code as mycast.hpp and add -include mycast.hpp to your Makefile. You use the address-of operator & to do that. I would like to know the reason. How to get the error message from the error code returned by GetLastError()? To learn more, see our tips on writing great answers. You cannot just cast the 32-bit variable to a pointer, because that pointer on a 64-bit machine is twice as long. Asking for help, clarification, or responding to other answers. @DavidHeffernan I rephrased that sentence a little. 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 saw on a couple of recent posts people saying that casting the return Could a subterranean river or aquifer generate enough continuous momentum to power a waterwheel for the purpose of producing electricity? For example, assigning an int value to a long variable. LLNL's tutorial is bad and they should feel bad. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Or, they are all wrong. To learn more, see our tips on writing great answers. In both cases, converting the pointer to an integer type that's too small to represent all pointer values is a bug. Yes, for the reason you mentioned that's the proper intermediate type. The semantics of numeric casts are: Casting between two integers of the same size (e.g. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Since gcc compiles that you are performing arithmetic between void* and an int (1024). Because C# is statically-typed at compile time, after a variable is declared, it cannot be declared again or assigned a value of another type unless that type is implicitly convertible to the variable's type. But to just truncate the integer value and not having to fix all the wrong uses of uint32_t just yet, you could use static_cast(reinterpret_cast(ptr)). Syntax static_cast< new-type > ( expression ) Returns a value of type new-type . What you do here is undefined behavior, and undefined behavior of very practical sort. It's always a good practice to put your #define's in brackets to avoid such surprise. @jackdoe: It's a waste of human life to write code that "you may need in the future". Solution 1. I am using the UDF of the Ansys Manual Book as a base for what I intended, but I am trying to incorporate a second component to my condensable mixture, being methanol . Just edited. what does it mean to convert int to void* or vice versa? Asking for help, clarification, or responding to other answers. Is there any known 80-bit collision attack? What does it mean to convert int to void* or vice versa? I'm not sure how to tell Clang (it's tools, really) that the platform is a 32-bit platform and to stop complaining. Youll be auto redirected in 1 second. You might want to typedef, You should change your code to handle this. Did the Golden Gate Bridge 'flatten' under the weight of 300,000 people in 1987? But then you need to cast your arguments inside your thread function which is quite unsafe cf. By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use. or, Array with multiple data types? Explicitly call a single-argument constructor or a conversion operator. Widening or Automatic Type Conversion Boolean algebra of the lattice of subspaces of a vector space? How to use Clang static analyzer with a Cortex-M project? 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). /** Dynamically allocate a 2d (x*y) array of elements of size _size_ bytes. I'll edit accordingly. Converting a void* to an int is non-portable way that may work or may not! 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. Where can I find a clear diagram of the SPECK algorithm? Were sorry. And in this context, it is very very very common to see programmers lazily type cast the. I think that's what you want: // Declaration uint8_t *myData; void loop () { myData = "custom string"; } This is an old C callback mechanism so you can't change that. Find centralized, trusted content and collaborate around the technologies you use most. If not, check the pointer size on your platform, define these typedefs accordingly yourself and use them. What does casting to void* does when passing arguments to variadic functions? The C Standard allows any object pointer to be cast to and from void *. If so, is Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. " is pointer to interface, not interface" confusion, Cast from uint8_t pointer to uint32_t integer compilation error. The correct answer is, if one does not mind losing data precision. As a result, it is possible to silently convert from one pointer type to another without the compiler diagnosing the problem by storing or casting a pointer to void * and then storing or casting it to the final type. What is this brick with a round back and a stud on the side used for. Question is, how do I explain this to Clang? it means that myData is a variable of type "pointer to uint8_t", but it doesn't point to anything yet. Typical examples include numeric conversion to a type that has less precision or a smaller range, and conversion of a base-class instance to a derived class. Examples include conversions from smaller to larger integral types, and conversions from derived classes to base classes. Hello, I am currently working on a UDF for the heterogeneous reaction using it to describe a simple equilibrium model using the Antoine equation and vapor pressure. I wish your idea worked. This option of Python is missing in matplotlibcpp within Visual Studio -> works only in b/w ! Why did US v. Assange skip the court of appeal? pointer/reference to a derived class pointer/reference. You need to cast the void* pointer to a char* pointer - and then dereference that char* pointer to give you the char that it points to! A boy can regenerate, so demons eat him for years. What differentiates living as mere roommates from living in a marriage-like relationship? Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey. We have to pass address of the variable to the function because in function definition argument is pointer variable. cwindowccwindowsword[3]={"ab"};_ab charPersondebug, A, A, , "C" ???? This is flat out wrong. I agree that you should bite the bullet and fix the code to use the correct integer type. Integer conversions, both implicit and explicit (using a cast), must be guaranteed not to result in lost or misinterpreted data. How do I force make/GCC to show me the commands? ), For those who are interested. Even though what you say regarding the lifetime of the object is true, integral types are too limited for a generic API. cast to void *' from smaller integer type 'int cast to void *' from smaller integer type 'int. Technically, these casts should therefore be valid. Say I want to make #, Nov 14 '05 This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s). No special syntax is necessary because a derived class always contains all the members of a base class. "jacob navia" wrote: This question has probably been asked a million time, but here it comes There is absolutely not gurantee that sizeof(int) <= sizeof(void*). I can easily imagine a situation where rewriting code using, Disabling "cast from pointer to smaller type uint32_t" error in Clang, https://github.com/llvm-mirror/clang/blob/release_50/include/clang/Basic/DiagnosticSemaKinds.td#L6193, https://github.com/llvm-mirror/clang/blob/release_50/lib/Sema/SemaCast.cpp#L2112, How a top-ranked engineering school reimagined CS curriculum (Ep. What is this brick with a round back and a stud on the side used for? @Artelius: Which, presumably, is exactly what Joshua did: A C++ reinterpret cast will not solve the problem. Can I use my Coinbase address to receive bitcoin? You can insert some debugging/logging logic to Reinterpret_cast if necessary. Therefore, you need to change it to long long instead of long in windows for 64 bits. u8 -> u32) will zero-extend if the source is unsigned sign-extend if the source is signed 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;. I usually have all automatic conversion warnings effective when developing in C, and I use explicit casting in order to suppress a specific . To subscribe to this RSS feed, copy and paste this URL into your RSS reader. This method will not work on 64 bit Big Endian platform, so it unnecessarily breaks portability. I guess the other important fact is that the cast operator has higher precedence that the multiplication operator. How can I control PNP and NPN transistors together from one pin? 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. The error I'm getting is: error: cast from pointer to smaller type 'uint32_t' (aka 'unsigned int') loses information. Instead of using a long cast, you should cast to size_t. To perform a cast, specify the type that you are casting to in parentheses in front of the value or variable to be converted. a cast of which the programmer should be aware of what (s)he is doing. Did the Golden Gate Bridge 'flatten' under the weight of 300,000 people in 1987? To access the object value, use the * dereference operator: int * p; assert (p == null ); p = new int (5); assert (p != null ); assert (*p == 5); (*p)++; assert (*p == 6); If a pointer contains a null value, it is not pointing to a valid object. dynamic_cast safely converts pointers and references to classes up, down and sideways along the inheritance hierarchy - according to CppReference. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Why does setupterm terminate the program? 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. Or you might need to assign a class variable to a variable of an interface type. For example, a variable of type long (64-bit integer) can store any value that an int (32-bit integer) can store. Needless to say, this will still be wrong. Is pthread_join a must when using pthread in linux? If your code has the chance to ever be ported to some platform where this doesn't hold, this won't work. char **array; 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], Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. With that declaration, you can later say: myData = "custom string"; That points the myData pointer to the address of your constant string.