Developer Guide and Reference

Contents

fcommon

Determines whether the compiler treats common symbols as global definitions.

Syntax

Linux:
-fcommon
-fno-common
macOS:
-fcommon
-fno-common
Windows:
None
Arguments
None
Default
-fcommon
The compiler does not treat common symbols as global definitions.
Description
This option determines whether the compiler treats common symbols as global definitions and to allocate memory for each symbol at compile time.
Option
-fno-common
tells the compiler to treat common symbols as global definitions. When using this option, you can only have a common variable declared in one module; otherwise, a link time error will occur for multiple defined symbols.
Normally, a file-scope declaration with no initializer and without the
extern
or
static
keyword "int i;" is represented as a common symbol. Such a symbol is treated as an external reference. However, if no other compilation unit has a global definition for the name, the linker allocates memory for it.
Alternate Options
None