Empty Statements (GNU Compiler Collection (GCC) Internals)

#### 11.7.4 Empty Statements ¶

Whenever possible, statements with no effect are discarded. But if they are nested within another construct which cannot be discarded for some reason, they are instead replaced with an empty statement, generated by `build_empty_stmt`. Initially, all empty statements were shared, after the pattern of the Java front end, but this caused a lot of trouble in practice.

An empty statement is represented as `(void)0`.