Can't compile a C program on a Mac after upgrading to Catalina 10.15

Can't compile a C program on a Mac after upgrading to Catalina 10.15

c xcode macos gcc macos-catalina

xcode

Xcode - Warning: Implicit declaration of function is invalid in C99

c xcode

xcode

Giving Command line arguments in Xcode in C program

c xcode command-line

xcode

How to set include path in xcode project

c xcode include environment-variables

xcode

Combine static libraries on Apple

objective-c c xcode static-libraries

xcode

Which macro to wrap Mac OS X specific code in C/C++

c++ c xcode macos macros

xcode

Getting warning in C for 'atoi' function

c xcode atoi

xcode

How can I avoid "duplicate symbol" errors in xcode with shared static libraries?

c objective-c xcode duplicate-symbol

xcode

Swift Compiler error: 'Double' is not convertible to CGFloat

ios c xcode swift

xcode

GCC memory leak detection equivalent to Microsoft crtdbg.h?

c++ c xcode gcc memory-leaks

xcode

implicit declaration of function free is invalid in c99

c xcode

xcode

How to tell Xcode how to include a library specified with angle brackets?

ios objective-c c xcode

xcode

How can I add an #ifdef DEBUG to Xcode?

objective-c c ios xcode debugging

xcode

How use Instruments and display the console in Command Lines applications

c xcode debugging macos instruments

xcode

A Guide for Creating your own Library for Cocoa(touch) development

c xcode oop frameworks

xcode