I had the same problem and after doing a bit of research, here is my conclusion about this issue: The compiler warns you about a @property that you declared as atomic (i.e. by omitting the nonatomic keyword), yet you provide an incomplete implementation of how to synchronize access to that property. To make that warning … Read more
To be pedantic, there are 8 different valid -O options you can give to gcc, though there are some that mean the same thing. The original version of this answer stated there were 7 options. GCC has since added -Og to bring the total to 8. From the man page: -O (Same as -O1) -O0 … Read more
You can use GCC on Windows by downloading MingW (discontinued) or its successor Mingw-w64.
It tells NGen that it is OK to inline the method it’s applied to even in a different assembly. For example: String.Equals has [TargetedPatchingOptOut] You write a program that calls String.Equals You run NGen on this program for maximum performance NGen will inline the String.Equals call, replacing the method call instruction with the actual code … Read more
This flag causes the linker to load every object file in the library that defines an Objective-C class or category. While this option will typically result in a larger executable (due to additional object code loaded into the application), it will allow the successful creation of effective Objective-C static libraries that contain categories on existing … Read more
It’s not magic. The behavior of this code in C is described in section 6.7.8.21 of the C specification (online draft of C spec): for the elements that don’t have a specified value, the compiler initializes pointers to NULL and arithmetic types to zero (and recursively applies this to aggregates). The behavior of this code … Read more
Here are some up-to-date albeit narrow findings of mine with GCC 4.7.2 and Clang 3.2 for C++. UPDATE: GCC 4.8.1 v clang 3.3 comparison appended below. UPDATE: GCC 4.8.2 v clang 3.4 comparison is appended to that. I maintain an OSS tool that is built for Linux with both GCC and Clang, and with Microsoft’s … Read more
First, the inline specification on a function is just a hint. The compiler can (and often does) completely ignore the presence or absence of an inline qualifier. With that said, a compiler can inline a recursive function, much as it can unroll an infinite loop. It simply has to place a limit on the level … Read more
The reason is to reduce program size. Imagine that your C program runs on an embedded system, where the code and all constants are saved in true ROM (flash memory). In such systems, an initial “copy-down” must be executed to set all static storage duration objects, before main() is called. It will typically go like … Read more
The original C# compiler wasn’t written in C#, it was in C and C++. The new Roslyn compiler was written in C#, but was initially compiled with the old compiler. Once the new compiler was done, it was able to compile its own source code: this is called bootstrapping.