5.4.7 Example: Using a Pragma

Consider the following example source code:

struct foo;
struct bar;
#pragma alias (struct foo, struct bar)

struct foo {
        int f1;
        int f2;
} *fp;

struct bar {
        short b1;
        short b2;
        int   b3;
} *bp;

The pragma in this example tells the compiler that foo and bar are allowed to alias each other. The compiler makes the following assumptions about alias information:

• fp->f1 can alias with bp->b1, bp->b2, and bp->b3

• fp->f2 can alias with bp->b1, bp->b2, and bp->b3