cc-defines

#!/bin/sh

# Show C/C++ macros pre-defined by the compiler:
# 
# $ cc-defines | head 
# #define __amd64 1
# #define __amd64__ 1
# <...>
#
# $ CC=arm-none-eabi-gcc cc-defines  | head
# #define __ACCUM_EPSILON__ 0x1P-15K
# <...>
# #define __arm__ 1
# <...>

# See also:
# GCC Manual: Common Predefined Macros: http://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html
# Pre-defined C/C++ Compiler Macros Wiki: http://sourceforge.net/p/predef/wiki/Home/
# C/C++ tip: How to list compiler predefined macros: http://nadeausoftware.com/articles/2011/12/c_c_tip_how_list_compiler_predefined_macros

# See also:
# http://www.commandlinefu.com/commands/view/3917/display-gcc-predefined-macros#comment
# 1: gcc -dM -E - <<<''
# 2: echo | gcc -dM -E -
# 3: cpp -dM /dev/null

if [ "$CC" = "" ]; then
	CC=gcc
fi
$CC "$@" -dM -E -x c - < /dev/null | sort