../lib/odp-util.c:5603:13: note: expanded from macro 'SCAN_PUT' . Types - D Programming Language If pointers are 64 bits and ints are 32 bits, an int is too small to hold a pointer value. Thanks for contributing an answer to Stack Overflow! My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? To be honest, I think, clang is too restrictive here. Java Type Casting - W3Schools I usually have all automatic conversion warnings effective when developing in C, and I use explicit casting in order to suppress a specific . In C (int)b is called an explicit conversion, i.e. 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 What is "cast from integer to pointer of different size" warning? 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. (int) pthread_self() 64int48intuintptr_t (unsigned int) In both cases, converting the pointer to an integer type that's too small to represent all pointer values is a bug. Even though what you say regarding the lifetime of the object is true, integral types are too limited for a generic API. The preprocessor will replace your code by this: This is unlikely what you are trying to do. How create a simple program using threads in C? This is what the second warning is telling you. 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. Then i can continue compiling. 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 vegan) just to try it, does this inconvenience the caterers and staff? Asking for help, clarification, or responding to other answers. vegan) just to try it, does this inconvenience the caterers and staff? This forum has migrated to Microsoft Q&A. To learn more, see our tips on writing great answers. windows meson: cast to smaller integer type 'unsigned long' from 'void If your standard library (even if it is not C99) happens to provide these types - use them. The main point is: a pointer has a platform dependent size. Narrowing Casting (manually) - converting a larger type to a . The correct answer is, if one does not mind losing data precision. Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? When is casting void pointer needed in C? pthread passes the argument as a void*. Why is this sentence from The Great Gatsby grammatical? On all of them int is 32bit, not 16bit. If the function had the correct signature you would not need to cast it explicitly. c - How to cast an integer to void pointer? - Stack Overflow I am an entry level C programmer. to your account, [87/252] Compiling C object lib/libopenvswitch.a.p/odp-util.c.obj should we also have a diagnostic for the (presumed) user error? The result is the same as implicit conversion from the enum's underlying type to the destination type. It solved my problem too. "After the incident", I started to be more careful not to trip over things. I'm unfamiliar with XCode, but the solution should be something like follows: Most of the "solutions" above can lose part of the pointer address when casting to a smaller type. SCAN_PUT(ATTR, NULL); The high-order 9 bits of the number are used to hold a flag value, and the result is converted back into a pointer. But I don't want to edit code in "EAGLView.mm" because it's a "library file". Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? Already on GitHub? This is flat out wrong. Java Type Casting (With Examples) - Programiz However, you are also casting the result of this operation to (void*). There's no proper way to cast this to int in general case. For example, if youwrite ((int*)ptr + 1), it will add 4 bytes to the pointer, because "ints" are 4 bytes each. ../lib/odp-util.c:5665:7: note: expanded from macro 'SCAN_SINGLE' For example, the main thread could wait for all of the other threads to end before terminating. If you are going to pass the address you typically need to exert some more control over the lifetime of the object. For the Nozomi from Shinagawa to Osaka, say on a Saturday afternoon, would tickets/seats typically be available - or would you need to book? 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. How to tell which packages are held back due to phased updates, Identify those arcade games from a 1983 Brazilian music video. Can I tell police to wait and call a lawyer when served with a search warrant? Floating-point conversions However the actual code in question contains an explicit c-style cast to int. Are there tables of wastage rates for different fruit and veg? Any help with this is appreciated. Remarks. "-I.." "-Iinclude\openflow" "-I..\include\openflow" "-Iinclude\openvswitch" "-I..\include\openvsw ", "!"? Mutually exclusive execution using std::atomic? 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. Making statements based on opinion; back them up with references or personal experience. Why are Suriname, Belize, and Guinea-Bissau classified as "Small Island Developing States"? Fork 63. linux c-pthreads: problem with local variables. What is the point of Thrower's Bandolier? 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. Yeah, the tutorial is doing it wrong. While working with Threads in C, I'm facing the warning, "warning: cast to pointer from integer of different size". a cast of which the programmer should be aware of what (s)he is doing. This is an old C callback mechanism so you can't change that. The following behavior-changing defect reports were applied retroactively to previously published C++ standards. Visit Microsoft Q&A to post new questions. Safe downcast may be done with dynamic_cast. Euler: A baby on his lap, a cat on his back thats how he wrote his immortal works (origin?). And when assigning to a void pointer, all type information is lost. 471,961 Members | 900 Online. XCode 5.1 is change all architecture to 64 bit. 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. eg. In Java, there are two types of casting: Widening Casting (automatically) - converting a smaller type to a larger type size. Why does Mister Mxyzptlk need to have a weakness in the comics? Why do academics stay as adjuncts for years rather than move around? Basically its a better version of (void *)i. If you do this, you have the thread reference a value that (hopefully still) lives in some other thread. I assumed that gcc makes a 65536 out of my define, but I was wrong. rev2023.3.3.43278. To avoid truncating your pointer, cast it to a type of identical size. whether it was an actual problem is a different matter though. Apparently the clang version in Xcode 5.1 and above is more strict about potential 32bit vs. 64 bit incompatibilities in source code than older clang versions have been. [Solved] Properly casting a `void*` to an integer in C++ This will get you a pointer from a 32 bit offset: A function pointer is incompatible to void* (and any other non function pointer). ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ C++ how to get the address stored in a void pointer? Thanks for contributing an answer to Stack Overflow! So make sure you understand what you are doing! I personally upvoted this answer because by it's first line of text it helped me to understand the reason of this strange error message and what am I, poor idiot, doing :D. Not valid on Windows 64 - long is still 32-bit but pointers are 64-bit. 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. How to correctly cast a pointer to int in a 64-bit application? Casting type void to uint8_t - Arduino Forum static_cast on the other hand should deny your stripping away the const qualifier. you can just change architecture to support 32 bit compilation by all below in in Build Settings. The proper way is to cast it to another pointer type. In this case, casting the pointer back to an integer is meaningless, because . Casting and type conversions - C# Programming Guide And you can't pass a pointer to a stack based object from the other thread as it may no longer be valid. How to Cast a void* ponter to a char without a warning? So you could do this: Note: As sbi points out this would require a change on the OP call to create the thread. Next, when doing pointer arithmetic, the addition operation will use the pointer's type to determine how many bytes to add to it when incrementing it. How to correctly cast a pointer to int in a 64-bit application? C/C++ , Cerror: cast to 'void *' from smaller integer type 'int'. If your code has the chance to ever be ported to some platform where this doesn't hold, this won't work. You should perform type conversion based on 64bit build system because the type "int" supports only -32768 ~ 32768. SCAN_PUT(ATTR, NULL); What is the point of Thrower's Bandolier? You can use any other pointer, or you can use (size_t), which is 64 bits. Functions return bigint only if the parameter expression is a bigint data type. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? Share Improve this answer Follow answered May 6, 2018 at 7:24 Rahul 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. 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. ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~. 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. Note the difference between the type casting of a variable and type casting of a pointer. "clang" "-Ilib\libopenvswitch.a.p" "-Ilib" "-I..\lib" "-I." And in this context, it is very very very common to see programmers lazily type cast the. Making statements based on opinion; back them up with references or personal experience. @LearnCocos2D: so, how can i "overcome" the error without editing any not-my-code or in-library-file lines? The point is (probably) that the value passed to the thread is an integer value, not really a 'void *'. Disconnect between goals and daily tasksIs it me, or the industry? what happens when we typecast normal variable to void* or any pointer variable? Recovering from a blunder I made while emailing a professor. cast to void *' from smaller integer type 'int rev2023.3.3.43278. int, bigint, smallint, and tinyint (Transact-SQL) - SQL Server Asking for help, clarification, or responding to other answers. 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. B language was designed to develop . [that could be a TODO - not to delay solving the ICE]. ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ // OK: lvalue denoting the original d object, // UB: the b subobject is not a base class subobject, // 6. array-to-pointer followed by upcast, https://en.cppreference.com/mwiki/index.php?title=cpp/language/static_cast&oldid=147983, when converting a 'pointer to object' to 'pointer to, the conversion from floating-point values, the conversion from bit-fields to rvalue references, the conversion from integral or enumeration values to enumeration, the conversion from integral or enumeration values to, the conversion from a member of base class type to, a standard-layout class object with no data members, a non-standard-layout union object and a non-static data, for base-to-derived pointer conversions and, the conversion to enumeration types with fixed underlying type, a standard-layout class might have a non-pointer-interconvertible, If the underlying type is not fixed, the behavior is undefined if the value of, If the underlying type is fixed, the result is the same as, one is a union object and the other is a non-static data member of that object, or. If you really need such trickery, then consider one of dedicated types, which are intptr_t and uintptr_t. Not the answer you're looking for? Use of Void pointers in C programming language To subscribe to this RSS feed, copy and paste this URL into your RSS reader. *sound/soc/codecs/tlv320aic32x4.c:1202:18: warning: cast to smaller integer type 'enum aic32x4_type' from 'void *' @ 2022-04-22 9:48 kernel test robot 0 siblings, 0 . 4. Type Conversions - C in a Nutshell [Book] - O'Reilly Online Learning Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? If the sizes are different then endianess comes into play. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. In the best case this will give the same results as the original code, with no advantages, but in the worst case it will fail in multiple catastrophic ways (type punning, endianness, less efficient, etc. You use the address-of operator & to do that. Connect and share knowledge within a single location that is structured and easy to search. Using indicator constraint with two variables. Converting one datatype into another is known as type casting or, type-conversion.
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