Library/header path for ./configure

Applications Programming
1

Hello,
I am always confused about adding library path for ./configure when compiling software under Linux Debian based OS. For example the README of the software tells

  --with-boost=PATH       specify directory for the boost header files
  --with-mpi=PATH         specify prefix directory for the installed MPI parallel computing library
  --with-gtest=PATH       specify prefix directory for the installed gtest library
  --google sparsehash is also recommended

What I did is like:

./configure --with-boost=/usr/local/include --with-mpi=/usr/lib/openmpi

And sparsehash is installed at /usr/include/google/sparsehash

Under directory

/usr/include/google

there are many header files including the subdirectory

/usr/include/google/sparsehash

which also has many header files.
My question is how to correctly set the PATHs for sparsehash:

/usr/include    #which is one of the default searching PATHs and no need to assign explicitly??
/usr/include/google 
or
/usr/include/google/sparsehash

What is the rule for those cutomized library PATHs setting on top of the environment variable LD_LIBRARY_PATH, especially it is not clear to use the headers or libraries?
Thanks a lot!

2

Depends what the code's including.

If they are doing #include <sparesehash-header.h> and you find it in /usr/include/sparsehash/sparsehash-header.h then you need to add that to the include path.

If they are doing #include <sparesehash/sparesehash-header.h> then you don't need to add it to the include path.

etc.

How to add it depends on the ./configure script as well. See ./configure --help.

3

Thanks Corona688!
The sparsehash part is clear now!
I came to openmpi for which there are many folders containing the header mpi.h The ./configure --help tells to use the prefix directory of the library which seems quite vague to me.

/usr/lib/openmpi
/usr/lib64/openmpi
/usr/include/openmpi-x86_64
/usr/lib64/compat-openmpi-psm
/usr/lib64/compat-openmpi
/usr/lib64/compat-openmpi-psm

I take openmpi as blackbox for granted as I am not familiar with it at all. How do I choose the correct path for similar situation? Thanks again!

4

Take a look at what those folders are with ls -l. A lot of them are probably symlinks to the final location -- i.e. there could be more than one right answer. I would assume the most generic one, /usr/lib/openmpi, would be the one to stick with, but that's only a guess.

5

Thanks!
Most of them are symlinks.
You are right the path is /usr/lib/openmpi where mpi.h is located under the sub-folder /include Thanks again!