Next, we can download and extract the latest stable version of GCC: 1 curl -L | tar xf. Let’s start by creating a working folder: 1 cd ~ 2 mkdir gcc_all & cd gcc_all Which will guide you through the installation process. If you don’t have the Command Line Tools installed, open a Terminal and write: 1 xcode-select -install At the time of this writing Apple’s Command Line Tools maps the gcc and g++ to clang and clang++. In the remaining of this article I will assume that you have installed the Command Line Tools for Xcode. In order to compile GCC from sources you will need a working C++ compiler.
Testing your code with two different compilers is always a good idea.īuilding GCC 10 from sources could take some time, in my case it took about two hours on a MacBook Air with a 16GB of RAM.
Another reason to have the latest stable version of GCC on your macOS is that it provides you with an alternative C and C++ compiler. you will need gfortran that comes with GCC. If you are interested in a modern Fortran compiler, e.g. The instructions from this tutorial were tested on Catalina (macOS 10.15).Ĭlang, the default compiler for macOS, supports only C, C++, Objective-C and Objective-C++.
In this tutorial, I will show you how to compile from source and install the current stable version of GCC on your macOS computer. Just for fun, you could say: printf("%p\n",free) and compare this against the link map of your program.Solarian Programmer My programming ramblings Home Archives Contact Privacy Compiling GCC 10 on macOS Catalina Posted on Octoby Paul set pointer to function from previous pointer to function this allows a pointer to function to behave syntactically like a
invoke the free function via indirect pointer set pointer to function from the address of the free function Here is a snippet that will invoke the free function and illustrates the usage of just free without parens: #include &free) is not required for a function as it would be for a scalar like intįree and &free generate the same code but leaving off the & is more idiomatic. To invoke it, you'd do something like: free(my_pointer)īut, when you just specify free without any parentheses, this means you want the address of the free function/symbol itself. Usually free is the function for freeing memory from allocated from the heap via malloc et. (Also, you can produce a similar spellcheck suggestion with gcc-8, if you happen to have it kicking around. :4:9: note: prefix with the address-of operator to silence this warning :4:9: warning: address of function 'free' will always evaluate to 'true' usr/include/stdlib.h:563:13: note: 'free' declared here So here is the warning in all its glory (accompanied by another useful warning because I compiled with -Wall: :4:9: error: use of undeclared identifier 'true' did you mean 'free'? People trying to reproduce this odd warning would be well-advised to recall that OP is using a Mac, and the default development environment on Macs uses Clang as its C/C++ compiler, and also aliases gcc to clang, presumably because so many people think that you use the gcc command to compile. So it's plausible that a spell-checker would guess that true was a misspelling of free. If you look at free and true carefully, you will note their similarity: they both have vowels and consonants in the same place, and two of the four letters are identical moreover, f looks a lot like a t (and, as noted in a comment, is nearby on the keyboard). So you can definitely use a function name in a boolean expression, where it will be converted to a true value. The standard conversions of C mean that a function will automatically be converted to a pointer to function, and a pointer to function can be automatically converted to boolean. On the other hand, if you do #include then free will be declared as a function.
If you do not #include then true will not be defined. As with most spellcheckers, this occasionally has hilarious results, and this is one of those times. Many C compilers trying to use something akin to a spellchecker to help guess an appropriate replacement for undeclared identifiers.