Re: Does Debian supports backticks in the Makefile?

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

how about this theory:

  https://gcc.gnu.org/onlinedocs/cpp/Invocation.html#Invocation
says

  "-I dir
     Add the directory dir to the list of directories to be searched
     for header files during preprocessing."

Note the the singular "dir", not "dirs".

In Igor Korot's Makefile.am we see

  libpostgres_la_CXXFLAGS = -D__WXGTK__ \
      -I../../dbinterface \
      `pg_config \
      --includedir`

which is supposed to a set the variable libpostgres_la_CXXFLAGS to

  -D__WXGTK__ -I../../dbinterface /usr/include/postgresql

It appears that an argument -I is missing before /usr/include/postgresql.

--------------------------------------------------------------------

I tested with a small dummy program which does:
  #include "test1.h"
  #include "test2.h"
There are dummy header files:
  test/include/test_2_dir/test1.h
  test/include/test_2_dir/test2.h

Then i try
  cc -g -Itest/include/test_1_dir test/include/test_2_dir -o t t.c
which complains
  t.c:19:19: fatal error: test2.h: No such file or directory
   #include "test2.h"
                     ^
  compilation terminated.
I.e. it does not mention the surplus argument test/include/test_2_dir
before it ends.

This run succeeds:
  cc -g -Itest/include/test_1_dir -Itest/include/test_2_dir -o t t.c

--------------------------------------------------------------------

If my theory is right, then the question arises why it works with
Igor Korot's Gentoo installation.
man gcc proposes as suspects:

       CPATH
       C_INCLUDE_PATH
       CPLUS_INCLUDE_PATH
       OBJC_INCLUDE_PATH
           Each variable's value is a list of directories separated by a
           special character, much like PATH, in which to look for header
           files.


Have a nice day :)

Thomas