university of mississippi baseball camp 2 seconds ago0 views

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

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)). How can I control PNP and NPN transistors together from one pin? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. I have a question about casting a function pointer. This code is a bit odd (but a void* can certainly host a int on all architectures on which GDAL can be compiled), and certainly unused by anyone, so you could just remove the GetInternalHandle () implementation as well if you prefer. When is casting void pointer needed in C? For built-in numeric types, an implicit conversion can be made when the value to be stored can fit into the variable without being truncated or rounded off. converted back to pointer to void, and the result will compare equal Extracting arguments from a list of function calls. it means that myData is a variable of type "pointer to uint8_t", but it doesn't point to anything yet. In some reference type conversions, the compiler cannot determine whether a cast will be valid. So instead I modified the implementation of malloc to ensure it never allocates memory above the 4GB limit. 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, Short story about swapping bodies as a job; the person who hires the main character misuses his body. Asking for help, clarification, or responding to other answers. If you do this, you have the thread reference a value that (hopefully still) lives in some other thread. 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. Why did US v. Assange skip the court of appeal? To learn more, see our tips on writing great answers. I agree that you should bite the bullet and fix the code to use the correct integer type. This forum has migrated to Microsoft Q&A. Referring to N1570 7.20.1.4/p1 (Integer types capable of holding object pointers): The following type designates a signed integer type with the property 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. Connect and share knowledge within a single location that is structured and easy to search. The high-order 9 bits of the number are used to hold a flag value, and the result is converted back into a pointer. Two MacBook Pro with same model number (A1286) but different year. For reference types, an implicit conversion always exists from a class to any one of its direct or indirect base classes or interfaces. Even though what you say regarding the lifetime of the object is true, integral types are too limited for a generic API. There's no proper way to cast this to int in general case. I am looking to clean up the A good thing in general, but if you want to disable the warning, just do it. Remembering to delete the pointer after use so that we don't leak. is returned by the malloc. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. 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. The only exception is exotic systems with the SILP64 data model, where the size of int is also 64 bits. Casting arguments inside the function is a lot safer. Share Improve this answer Follow answered May 6, 2018 at 7:24 Rahul Convert integers, floating-point values and enum types to enum types. User-defined conversions: User-defined conversions are performed by special methods that you can define to enable explicit and implicit conversions between custom types that do not have a base classderived class relationship. INT36-C. Converting a pointer to integer or integer to pointer error: comparison between pointer and integer ('int' and 'string' (aka 'char *')), CS50 Caesar program is working but check50 says it isn't. 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. [Solved] Disabling "cast from pointer to smaller type | 9to5Answer BUT converting a pointer to void* and back again is well supported (everywhere). This thread has been closed and replies have been disabled. Ubuntu won't accept my choice of password, Adding EV Charger (100A) in secondary panel (100A) fed off main (200A), Passing negative parameters to a wolframscript. Asking for help, clarification, or responding to other answers. While working with Threads in C, I'm facing the warning, "warning: cast to pointer from integer of different size". Is pthread_join a must when using pthread in linux? How a top-ranked engineering school reimagined CS curriculum (Ep. Write values of different data types in sequence in memory? I've always been a little sketchy on the differences between static, value of malloc is bad, like: rev2023.5.1.43405. 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. Thanks for contributing an answer to Stack Overflow! You just need to suppress the warning, and this will do it: This may offend your sensibilities, but it's very short and has no race conditions (as you'd have if you used &i). @ok Since the culprit is probably something like -Wall which enables many warnings you should keep on, you should selectively disable this single warning. "I think what you should do is actually pass the address of the variable to the function" Not necessarily. For example, you might have an integer variable that you need to pass to a method whose parameter is typed as double. Now, what happens when I run it with the thread sanitizer? MIP Model with relaxed integer constraints takes longer to solve than normal model, why? 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 was sent this code and can't figure out why I keep getting "Incomplete Data type Error, Embracing Modern Android Development: A Dive into Java and Kotlin. Most answers just try to extract 32 useless bits out of the argument. Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey, Setting a buffer of char* with intermediate casting to int*. To learn more, see our tips on writing great answers. I saw on a couple of recent posts people saying that casting the return Going through them one by one would be very tedious and since this is an experimental project anyway, I'm happy to settle for a "hackish" workaround. 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). Can I use the spell Immovable Object to create a castle which floats above the clouds? property that any valid pointer to void can be converted to this type, Why does Acts not mention the deaths of Peter and Paul? C++ how to get the address stored in a void pointer? How can I control PNP and NPN transistors together from one pin? Find centralized, trusted content and collaborate around the technologies you use most. Disabling "cast from pointer to smaller type uint32_t" error in Clang 472,096 Members | 2,054 Online. Where can I find a clear diagram of the SPECK algorithm? Converting a void* to an int is non-portable way that may work or may not! No sense in writing a few dozen lines of extra code just to get a bunch of numbered threads. User without create permission can create a custom object from Managed package using Custom Rest API. Conversions with helper classes: To convert between non-compatible types, such as integers and System.DateTime objects, or hexadecimal strings and byte arrays, you can use the System.BitConverter class, the System.Convert class, and the Parse methods of the built-in numeric types, such as Int32.Parse. #, In a 64 bit machine with sizeof(int) == 4. to the original pointer: The following type designates an unsigned integer type with the Please help me with the right way to convert void* to int in c++ Mar 30, 2020 at 10:44am George P (5286) Maybe try reinterpret_cast? The most general answer is in no way. Since all pointers on 64-bit Windows are 64 bits, you are growing the data size from 32 bits backto 64 bits. Which was the first Sci-Fi story to predict obnoxious "robo calls"? 565), Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. If you write ((char*)ptr + 1), it will advance the pointer 1 byte, because a "char" is 1 byte. Or you might need to assign a class variable to a variable of an interface type. 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. this way you won't get any warning. Since gcc compiles that you are performing arithmetic between void* and an int (1024). And you can't pass a pointer to a stack based object from the other thread as it may no longer be valid. I am an entry level C programmer. dynamic_cast safely converts pointers and references to classes up, down and sideways along the inheritance hierarchy - according to CppReference. Did the Golden Gate Bridge 'flatten' under the weight of 300,000 people in 1987? for (i=0, j=0; j should be the correct one. Yes, for the reason you mentioned that's the proper intermediate type. What would you do next year when you need to port it to yet another experimental hardware? Did the drapes in old theatres actually say "ASBESTOS" on them? Types - D Programming Language If the result lies outside the range of representable values by the type, the conversion causes, Otherwise, if the conversion is between numeric types of the same kind (integer-to-integer or floating-to-floating), the conversion is valid, but the value is. I guess the other important fact is that the cast operator has higher precedence that the multiplication operator. pthread passes the argument as a void*. How to force Unity Editor/TestRunner to run at full speed when in background? How to Cast a void* ponter to a char without a warning? Visit Microsoft Q&A to post new questions. Folder's list view has different sized fonts in different folders. . In the following example, the compiler implicitly converts the value of num on the right to a type long before assigning it to bigNum. Thank you all for your feedback. Unfortunately, that hardware is 64-bit and the code contains many instances of pointer arithmetic that expects pointers to be 32-bit, i.e. Both languages have been widely adopted by How to plot text in color? it often does reinterpret_cast<uint32_t> (ptr). Is "I didn't think it was serious" usually a good defence against "duty to rescue"? You can then disable this diagnostic completely by adding -Wno-extra-tokens (again, the "extra tokens" warning is an example), or turn it into a non-fatal warning by means of -Wno-error=extra-tokens. He also rips off an arm to use as a sword, Two MacBook Pro with same model number (A1286) but different year. Find centralized, trusted content and collaborate around the technologies you use most. static_cast conversion - cppreference.com I'll edit accordingly. How to correctly cast a pointer to int in a 64-bit application? If so, is This is an old C callback mechanism so you can't change that. Why does Acts not mention the deaths of Peter and Paul? I'm working on a school project that involves porting a large piece of C++ code on an experimental piece of hardware. Surely the solution is to change the type of ids from int to type that is sufficiently large to hold a pointer. Can you still use Commanders Strike if the only attack available to forego is an attack against an ally? cwindowccwindowsword[3]={"ab"};_ab charPersondebug, A, A, , "C" ???? Instead of using a long cast, you should cast to size_t. The point is (probably) that the value passed to the thread is an integer value, not really a 'void *'. Becase one can always legally cast any Hello, I'm new to coding and am trying to implement a simple program on my own, that prompts the user the number of residents in an apt complex, the prompts the user to enter the names and apt numbers of each resident. Just edited. 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). Needless to say, this will still be wrong. Episode about a group who book passage on a space ship controlled by an AI, who turns out to be a human who can't leave his ship? (i.e. But this code pass the normal variable .. How to cast a void pointer to any other type in C || #C Programming language || Coding is Life 487 03 : 37 Unable to cast object of type 'System DateTime' to type 'System String' SharpCoder 336 10 : 53 Tkinter window geometry to manage height width and zoom out using state and resizable () option plus2net 107 Author by david.brazdil A boy can regenerate, so demons eat him for years. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. 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. I would like to know the reason. And, most of these will not even work on gcc4. Well it does this because you are converting a 64 bits pointer to an 32 bits integer so you loose information. 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. Is "I didn't think it was serious" usually a good defence against "duty to rescue"? Explicitly call a single-argument constructor or a conversion operator. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Find centralized, trusted content and collaborate around the technologies you use most. Youll be auto redirected in 1 second. */void **MatrixIB (unsigned long x, unsigned long y, int size){ void *ptr; void **returnPtr; register unsigned long i, j; I hit this same problem in a project without C++11, and worked around it like this: Thanks for contributing an answer to Stack Overflow! u8 -> u32) will zero-extend if the source is unsigned sign-extend if the source is signed I'm not sure how to tell Clang (it's tools, really) that the platform is a 32-bit platform and to stop complaining. Infact I know several systems where that does not hold. Does a password policy with a restriction of repeated characters increase security? Find centralized, trusted content and collaborate around the technologies you use most. What is this brick with a round back and a stud on the side used for? I agree passing a dynamically allocated pointer is fine (and I think the best way). You are right! Does it effect my blogs SEO rankings? Find centralized, trusted content and collaborate around the technologies you use most. 565), Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. @Artelius: Which, presumably, is exactly what Joshua did: A C++ reinterpret cast will not solve the problem. If you convert (void*) to (long) no precision is lost, then by assigning the (long) to an (int), it properly truncates the number to fit. Interpreting non-statistically significant results: Do we have "no evidence" or "insufficient evidence" to reject the null? rev2023.5.1.43405. c - type casting integer to void* - Stack Overflow What does casting to void* does when passing arguments to variadic functions? He also rips off an arm to use as a sword. Solution 1. But then you need to cast your arguments inside your thread function which is quite unsafe cf. It does not because. Why is it shorter than a normal address? Why don't we use the 7805 for car phone chargers? If the function had the correct signature you would not need to cast it explicitly. A. if(x%2=1)y=x;B. if(sqrt(x)%2)y=x;C. if(x==1)y=x;D. if(x==1)y=&x; Cerror: cast to 'void *' from smaller integer type 'int'. If your standard library (even if it is not C99) happens to provide these types - use them. Thanks in A colleague asked me something along the lines of the following today. For example, (double) 1/3 will give a double result instead of an int one. How can I control PNP and NPN transistors together from one pin? Storage management is an important module of database, which can be subdivided into memory management and external memory management. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. [Solved] Error "Cast from pointer to smaller type 'int' loses To subscribe to this RSS feed, copy and paste this URL into your RSS reader. does lazarbeam have a wife; Books. However, you are also casting the result of this operation to (void*). 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! cast to void *' from smaller integer type 'int The following program casts a double to an int. This is memory reinterpretation - a completely unacceptable way to do what the OP is trying to do. Connect and share knowledge within a single location that is structured and easy to search. It is commonly called a pointer to T and its type is T*. Why don't we use the 7805 for car phone chargers? To perform a cast, specify the type that you are casting to in parentheses in front of the value or variable to be converted. Not the answer you're looking for? To learn more, see our tips on writing great answers. C / C++ Forums on Bytes. Thanks for contributing an answer to Stack Overflow! If this is the data to a thread procedure, then you quite commonly want to pass by value. Don't do that. drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c:415:10: warning: cast @Xax: Here's a fixed version, without the race condition: gist.github.com/depp/241d6f839b799042c409, gist.github.com/depp/3f04508a88a114734195, How a top-ranked engineering school reimagined CS curriculum (Ep. Your strategy will not work for stack-allocated objects, be careful!! The proper way is to cast it to another pointer type. return ((void **) returnPtr);} /* Matrix() */. In this case, casting the pointer back to an integer is meaningless, because . The -fms-extensions flag resolved the issue. Thanks for pointing that out. @DietrichEpp can you explain what is race condition with using. 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; Unless you have a valid address at that value, you are going to invoke undefined behaviour when try to use that pointer.