cast to void *' from smaller integer type 'int

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. Asking for help, clarification, or responding to other answers. Thanks for contributing an answer to Stack Overflow! In the first example, the variable c1 of the char type is converted to a temporary variable of the int type, because the second operand in the division operation, the constant 2, is of the higher type int. Don't pass your int as a void*, pass a int* to your int, so you can cast the void* to an int* and copy the dereferenced pointer to your int. c - How to cast an integer to void pointer? - Stack Overflow If the value in a pointer is cast to a different type and it does not have the correct alignment for the new type, the behavior is undefined. clang11 report error: cast to smaller integer type #82 - GitHub Why do small African island nations perform better than African continental nations, considering democracy and human development? Whats the grammar of "For those whose stories they are"? ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ If you really need such trickery, then consider one of dedicated types, which are intptr_t and uintptr_t. ncdu: What's going on with this second size column? As a result of the integer division 3/2 we get the value 1, which is of the int type. For example, if you want to store a 'long' value into a simple integer then you can type cast 'long' to 'int'. Casting a pointer to void* and back is valid use of reinterpret_cast<>. But then you need to cast your arguments inside your thread function which is quite unsafe cf. The most general answer is - in no way. 7.1 New Cast Operations The C++ standard defines new cast operations that provide finer control than previous cast operations. The following program casts a double to an int. The preprocesor absolutely will not perform arithmetic. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. "-I.." "-Iinclude\openflow" "-I..\include\openflow" "-Iinclude\openvswitch" "-I..\include\openvsw Floating-point conversions Can I tell police to wait and call a lawyer when served with a search warrant? In the case of Widening Type Casting, the lower data type (having smaller size) is converted into the higher data type (having larger size). } SCAN_END_SINGLE(ATTR) Yeah, the tutorial is doing it wrong. Find centralized, trusted content and collaborate around the technologies you use most. to your account, [87/252] Compiling C object lib/libopenvswitch.a.p/odp-util.c.obj This solution is in accordance with INT18-C. 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 an int type guaranteed to be big enough to contain a pointer. (void *)i Error: cast to 'void *' from smaller integer type 'int'. 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)). On a 64-bit Windows computer, 'long' is a 32-bit type, and all pointers are 64-bit types. ^~~~~~~~~~~~~~~~~~~~~ So make sure you understand what you are doing! void* -> integer -> void* rather than integer -> void* -> integer. How do I work around the GCC "error: cast from SourceLocation* to int loses precision" error when compiling cmockery.c? Why is there a voltage on my HDMI and coaxial cables? Wrong. How create a simple program using threads in C? Most answers just try to extract 32 useless bits out of the argument. Making statements based on opinion; back them up with references or personal experience. Sign up for a free GitHub account to open an issue and contact its maintainers and the community. Disconnect between goals and daily tasksIs it me, or the industry? I'm using cocos2d-x-2.2.2. Maybe you can try this too. ../lib/odp-util.c:5601:9: note: expanded from macro 'SCAN_PUT' And in this context, it is very very very common to see programmers lazily type cast the. It is commonly called a pointer to T and its type is T*. ../lib/odp-util.c:5834:5: error: cast to smaller integer type 'unsigned long' from 'void *' [-Werror,-Wvoid-pointer-to-int-cast] error: cast from 'void*' to 'int' loses precision - Stack Overflow If you write ((char*)ptr + 1), it will advance the pointer 1 byte, because a "char" is 1 byte. To learn more, see our tips on writing great answers. 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. How to get the error message from the error code returned by GetLastError()? Asking for help, clarification, or responding to other answers. The result is implementation-defined and typically yields the numeric address of the byte in memory that the pointer pointers to. XCode 5.1 is change all architecture to 64 bit. vegan) just to try it, does this inconvenience the caterers and staff? "I think what you should do is actually pass the address of the variable to the function" Not necessarily. Not the answer you're looking for? 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. Types - D Programming Language Connect and share knowledge within a single location that is structured and easy to search. this way you won't get any warning. Cast Operations - Oracle However, I believe that even if the define was for the "65536", it would not be what @kaetzacoatl wanted. The only exception is exotic systems with the SILP64 data model, where the size of int is also 64 bits. 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. windows meson: cast to smaller integer type 'unsigned long' from 'void *'. @Artelius: Which, presumably, is exactly what Joshua did: A C++ reinterpret cast will not solve the problem. Any expression can be cast to type void (which means that the result of the expression is ignored), but it's not legal to cast an expression of type void to type int not least because the result of such a cast wouldn't make any sense. int, bigint, smallint, and tinyint (Transact-SQL) - SQL Server Implementation-dependent. ), Styling contours by colour and by line thickness in QGIS. What is "cast from integer to pointer of different size" warning? C++ Tutorial => Conversion between pointer and integer You can convert the values from one type to another explicitly using the cast operator as follows (type_name) expression Get the address of a callback function to call dynamically in C++, error: call of overloaded function ambiguous, error: cast from to unsigned int loses precision [-fpermissive]. C - Type Casting - tutorialspoint.com Usually that means the pointer is allocated with. 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. and how to print the thread id of 2d array argument? To be honest, I think, clang is too restrictive here. Don't do that. What I am trying to do in that line of code is check to make sure each character in my string is alphabetical. Connect and share knowledge within a single location that is structured and easy to search. So you could do this: Note: As sbi points out this would require a change on the OP call to create the thread. Keep in mind that thrArg should exist till the myFcn() uses it. Euler: A baby on his lap, a cat on his back thats how he wrote his immortal works (origin?). If not, check the pointer size on your platform, define these typedefs accordingly yourself and use them. Put your define inside a bracket: without a problem. Create an account to follow your favorite communities and start taking part in conversations. My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? Or, they are all wrong. iphone - Error "Cast from pointer to smaller type 'int' loses Losing bytes like thisis called 'truncation', and that's what the first warning is telling you. 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; ../lib/odp-util.c:5489:33: note: expanded from macro 'SCAN_PUT_ATTR' I assumed that gcc makes a 65536 out of my define, but I was wrong. On a 64-bit Windows computer, 'long' is a 32-bit type, and all pointers are 64-bit types. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Click to see the query in the CodeQL repository. What is the point of Thrower's Bandolier? arrays - I get the error: "cast to smaller integer type 'int' from Thank you all for your feedback. SCAN_SINGLE("skb_priority(", uint32_t, u32, OVS_KEY_ATTR_PRIORITY); Type Casting in C Language with Examples - Dot Net Tutorials Getting Command /bin/sh failed with exit code 65 Error with Xcode 5.1 . If you need to keep the returned address, just keep it as void*. Replacing broken pins/legs on a DIP IC package, How to handle a hobby that makes income in US. ^~~~~~~~~~~~~~~~~~~ Alternatively, if you choose to castthe ptr variableto (size_t) instead, then you don't need to worry about the pointer typeanymore. Java Type Casting (With Examples) - Programiz What is the purpose of non-series Shimano components? 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. Again, all of the answers above missed the point badly. (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 If the function had the correct signature you would not need to cast it explicitly. [PATCH] platform/x86: hp-wmi: Fix cast to smaller integer type warning // 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. I have a function with prototype void* myFcn(void* arg) which is used as the starting point for a pthread. then converted back to pointer to void, and the result will compare If your standard library (even if it is not C99) happens to provide these types - use them. 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. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. B language was designed to develop . This will only compile if the destination type is long enough. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Star 675. But this code pass the normal variable .. Bulk update symbol size units from mm to map units in rule-based symbology. 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? Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? If any, how can the original function works without errors if we just ignore the warning. A nit: in your version, the cast to void * is unnecessary. You are correct, but cocos actually only uses that address as a unique id. error: cast from pointer to smaller type 'unsigned int' loses 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.. Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, "what happen when typcating normal variable to void* or any pointer variable?" What you do here is undefined behavior, and undefined behavior of very practical sort. Mutually exclusive execution using std::atomic? If this is the data to a thread procedure, then you quite commonly want to pass by value. This forum has migrated to Microsoft Q&A. actually no, as int my be a smaller type than a pointer ;-) But, of course with int64_t it works fine. The cast back to int * is not, though. I have the following function and when I compile it under VS.NET 2005, the following compile warnings show up: Warning1warning C4311: 'type cast' : pointer truncation from 'void *' to 'long'c:\temp\testone\lib\utils.c56Warning2warning C4312: 'type cast' : conversion from 'unsigned long' to 'void *' of greater sizec:\temp\testone\lib\utils.c56, Code Snippet 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. Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, @Dinesh: could you please 1) show us those. Did i have to face to unexpected runtime issues, i guess not, i've found another discussion on this -. 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. Does Counterspell prevent from any further spells being cast on a given turn? 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. returnPtr = (void **) malloc (x * sizeof(void *)); ptr = (void *) malloc (x * y * size); Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. what does it mean to convert int to void* or vice versa? 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. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? I agree passing a dynamically allocated pointer is fine (and I think the best way). Casting type void to uint8_t - Arduino Forum what does it mean to convert int to void* or vice versa? Why is there a voltage on my HDMI and coaxial cables? The difference between the phonemes /p/ and /b/ in Japanese, Styling contours by colour and by line thickness in QGIS. Using an integer address (like &x) is probably wrong, indeed each modification you will execute on x will affect the pass behaviour. this way you won't get any warning. He should pass the address of the integer, the thread should get that address, Note: This is only appropriate is you cast the. Here, the Java first converts the int type data into the double type. ../lib/odp-util.c:5665:7: note: expanded from macro 'SCAN_SINGLE' How do I set, clear, and toggle a single bit? There is no "correct" way to store a 64-bit pointer in an 32-bit integer. That's probably going to be true for most platforms you will ever encounter, but it's not a guarantee; it's implementation-dependent. How to use Slater Type Orbitals as a basis functions in matrix method correctly? But I'm nitpicking .. for (i=0, j=0; jINT36-C. Converting a pointer to integer or integer to pointer 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. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? Typecasting - Data Types - Language Basics - MQL4 Reference 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 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. ", "? What does casting to void* does when passing arguments to variadic functions? Thanks. 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. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. What happens if you typecast as unsigned first? In such a case the programmer can use a void pointer to point to the location of the unknown data type. I am compiling this program in linux gcc compiler.. You can use a 64 bits integer instead howerver I usually use a function with the right prototype and I cast the function type : The point is (probably) that the value passed to the thread is an integer value, not really a 'void *'. From the question I presume the OP does. Since gcc compiles that you are performing arithmetic between void* and an int (1024). If the original type is a void *, converting to an int may lose date on platforms where sizeof(void *) != sizeof(int) (which is true of LP64 programming model). In C (int)b is called an explicit conversion, i.e. It's always a good practice to put your #define's in brackets to avoid such surprise. Java Type Casting - W3Schools Well it does this because you are converting a 64 bits pointer to an 32 bits integer so you loose information. How do I check if a string represents a number (float or int)? Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. If int is no larger than pointer to void then one way to store the value is by simply copying the bytes: int i . Mutually exclusive execution using std::atomic? Connect and share knowledge within a single location that is structured and easy to search. Cast a smaller integer to a larger integer - community - The Rust Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? The difference between a and &a is the type. This is known as implicit type casting or type promotion, compiler automatically converts smaller data type to larger data type. 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. */ >> -bool >> +enum conversion_safety >> unsafe_conversion_p (tree type, tree expr, bool . a is of type int[4], which can be implicitly cast to int* (ie, a pointer to an int) &a is of type int(*)[4] (ie: a pointer to an array of 4 ints). [that could be a TODO - not to delay solving the ICE]. rev2023.3.3.43278. The difference between the phonemes /p/ and /b/ in Japanese, Styling contours by colour and by line thickness in QGIS, AC Op-amp integrator with DC Gain Control in LTspice, Identify those arcade games from a 1983 Brazilian music video. But gcc always give me a warning, that i cannot cast an int to a void*. If you preorder a special airline meal (e.g. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. p-util.c.obj "-c" ../lib/odp-util.c Use of Void pointers in C programming language On most platforms pointers and longs are the same size, but ints and pointers often are not the same size on 64bit platforms. *PATCH] platform/x86: hp-wmi: Fix cast to smaller integer type warning @ 2023-01-23 13:28 Hans de Goede 2023-01-23 13:56 ` Hans de Goede 0 siblings, 1 reply; 2+ messages in thread From: Hans de Goede @ 2023-01-23 13:28 UTC (permalink / raw) To: Mark Gross Cc: Hans de Goede, Andy Shevchenko, platform-driver-x86, kernel test robot Fix the following .

cast to void *' from smaller integer type 'int 2023