64位机器上要编译32为的扩展

When compiling an extension for a stack which is 64 bits (for example) and your compiler is configured to compile in 32 bits, you can manually compile your extensions using C flags before your configure.

Example: my system compiler is 32 bits and my stack is 64 bits. To compile my xdebug:

# phpize
# CFLAGS=-m64 CPPFLAGS=-m64 CCASFLAGS=-m64 ./configure --enable-xdebug
# gmake
# file modules/xdebug.so

modules/xdebug.so:      ELF 64-bit LSB dynamic lib AMD64 Version 1, dynamically linked, not stripped, no debugging information available

那么反过来，如果是32位机器要编译64的扩展呢？

CFLAGS=-m32 CPPFLAGS=-m32 CCASFLAGS=-m32