GCC, How do I show what the default include path is.

[Sergei Organov]

Kai Ruottu <karuottu@mbnet.fi> writes:

> G-Mail wrote:
>> I like to know the default include path gcc use. GCC start including
>> files in a defined order of directories
>> starting with directories defined during build of gcc. I think there
>> is an command-line option which list
>> each include directory but I can't remember the option.
>>
>> I know gcc -v .....
> The preprocessor part, 'cpp',  uses the headers, not  'gcc', so  quite
> logically you should try 'cpp -v' and
> not 'gcc -v' !

Sorry, what's the problem with gcc -v ? Consider:

$ echo | gcc -v -x c -E -
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v --enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --program-suffix=-4.1 --enable-__cxa_atexit --enable-clocale=gnu --enable-libstdcxx-debug --enable-mpfr --with-tune=i686 --enable-checking=release i486-linux-gnu
Thread model: posix
gcc version 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)
 /usr/lib/gcc/i486-linux-gnu/4.1.2/cc1 -E -quiet -v - -mtune=i686
ignoring nonexistent directory "/usr/local/include/i486-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../i486-linux-gnu/include"
ignoring nonexistent directory "/usr/include/i486-linux-gnu"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /usr/lib/gcc/i486-linux-gnu/4.1.2/include
 /usr/include
End of search list.
# 1 "<stdin>"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "<stdin>"
$ echo | gcc -v -x c++ -E -
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v --enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --program-suffix=-4.1 --enable-__cxa_atexit --enable-clocale=gnu --enable-libstdcxx-debug --enable-mpfr --with-tune=i686 --enable-checking=release i486-linux-gnu
Thread model: posix
gcc version 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)
 /usr/lib/gcc/i486-linux-gnu/4.1.2/cc1plus -E -quiet -v -D_GNU_SOURCE - -mtune=i686
ignoring nonexistent directory "/usr/local/include/i486-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../i486-linux-gnu/include"
ignoring nonexistent directory "/usr/include/i486-linux-gnu"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2
 /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/i486-linux-gnu
 /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/backward
 /usr/local/include
 /usr/lib/gcc/i486-linux-gnu/4.1.2/include
 /usr/include
End of search list.
# 1 "<stdin>"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "<stdin>"
$ 

-- Sergei.