alloca

Allocates memory and returns a pointer.

void alloca(size_t size)

The alloca function allocates size bytes out of scratch memory, and returns a pointer to the allocated memory. The returned pointer is guaranteed to have 8–byte alignment. Scratch memory is only valid during the processing of a clause. Memory that's allocated with alloca is deallocated when processing of the clause completes. If insufficient scratch memory is available, no memory is allocated and an error is generated.

Example 8-1 How to use alloca to assign a string to an allocated memory region and then to read it out again by using the pointer

BEGIN
{
        x = (string *)alloca(sizeof(string) + 1);
        *x = "abc";
        trace(*x);
        exit(0);
}