gcc -E file.c or g++ -E file.cpp will do this for you. The -E switch forces the compiler to stop after the preprocessing phase, spitting all it’s got at the moment to standard output. Note: Surely you must have some #include directives. The included files get preprocessed, too, so you might get lots of output. … Read more
It depends on the order of data member declarations in the class. So a_ will be the first one, then b_ will be the second one in your example.
If you don’t declare a function and it only appears after being called, it is automatically assumed to be int, so in your case, you didn’t declare void my_print (char *); void my_print2 (char *); before you call it in main, so the compiler assume there are functions which their prototypes are int my_print2 (char … Read more
In x86-64, 32-bit instructions implicitly zero-extend: bits 32-63 are cleared (to avoid false dependencies). So sometimes that’s why you’ll see odd-looking instructions. (Is mov %esi, %esi a no-op or not on x86-64?) However, in this case the previous mov-load is also 32-bit so the high half of %rax is already cleared. The mov %eax, %eax … Read more
GCC: pure/const function attributes llvm-gcc: supports the GCC pure/const attributes Clang: seems to support it (I tried on a simple example with the GCC style attributes and it worked.) ICC: seems to adopt the GCC attributes (Sorry, only a forum post.) MSVC: Seems not to support it. (discussion) In general, it seems that almost all … Read more
The page “Notes on Multiple Inheritance in GCC C++ Compiler v4.0.1” is offline now, and http://web.archive.org didn’t archive it. So, I have found a copy of the text at tinydrblog which is archived at the web archive. There is full text of the original Notes, published online as part of “Doctoral Programming Language Seminar: GCC … Read more
There’s no single definitive answer to your question. Firstly, the external behavior of a freed block will depend on whether it was released to the system or stored as a free block in the internal memory pool of the process or C runtime library. In modern OSes the memory “returned to the system” will become … Read more
Currently, there exists a standard feature, as mentioned in C11, chapter §6.7.2.1, called flexible array member. Quoting the standard, As a special case, the last element of a structure with more than one named member may have an incomplete array type; this is called a flexible array member. In most situations, the flexible array member … Read more
Refer “How to install multiple versions of GCC” here in the GNU GCC FAQ. There’s also a white paper here.
In a typical implementation the destructor usually has two branches: one for non-dynamic object destruction, another for dynamic object destruction. The selection of a specific branch is performed through a hidden boolean parameter passed to the destructor by the caller. It is usually passed through a register as either 0 or 1. I would guess … Read more