5.10.2 Generic Compiler Characteristics

Macro: AC_CHECK_SIZEOF (type, [unused], [includes = `default-includes'])

Define SIZEOF_type (see section 5.1.1 Standard Symbols) to be the size in bytes of type. If `type' is unknown, it gets a size of 0. If no includes are specified, the default includes are used (see section 5.1.2 Default Includes). If you provide include, be sure to include `stdio.h' which is required for this macro to run.

This macro now works even when cross-compiling. The unused argument was used when cross-compiling.

For example, the call

AC_CHECK_SIZEOF(int *)

defines SIZEOF_INT_P to be 8 on DEC Alpha AXP systems.