Define preprocessor macro through CMake?
How do I define a preprocessor variable through CMake? The equivalent code would be #define foo. 6 Answers 6
How do I define a preprocessor variable through CMake? The equivalent code would be #define foo. 6 Answers 6
I’m working on a project that has a lot of legacy C code. We’ve started writing in C++, with the intent to eventually convert the legacy code, as well. I’m a little confused about how the C and C++ interact. I understand that by wrapping the C code with extern “C” the C++ compiler will … Read more
Where are MIN and MAX defined in C, if at all? What is the best way to implement these, as generically and type safely as possible? (Compiler extensions/builtins for mainstream compilers preferred.) 15 Answers 15
I’m going through some C course notes, and every C program source file begins with a single # on the first line of the program. Then there are blank lines, and following that other stuff followed by the main function. What is the reason for the #? (It’s out of term now and I can’t … Read more
I have been seeing code like this usually in the start of header files: #ifndef HEADERFILE_H #define HEADERFILE_H And at the end of the file is #endif What is the purpose of this? 4 s 4
In many C/C++ macros I’m seeing the code of the macro wrapped in what seems like a meaningless do while loop. Here are examples. #define FOO(X) do { f(X); g(X); } while (0) #define FOO(X) if (1) { f(X); g(X); } else I can’t see what the do while is doing. Why not just write … Read more
Why does the C preprocessor in GCC interpret the word linux (small letters) as the constant 1? test.c: #include <stdio.h> int main(void) { int linux = 5; return 0; } Result of $ gcc -E test.c (stop after the preprocessing stage): …. int main(void) { int 1 = 5; return 0; } Which of course … Read more
In the C and C++ programming languages, what is the difference between using angle brackets and using quotes in an include statement, as follows? #include <filename> #include “filename” 3 31