adding support for clang compilation in compile.sh

[jmrenouard]

compile.sh support also clang compilation.

Clang compilation works perfectly.

Howto compile with gcc
./compile.sh or ./compile.sh gcc

Howto compile with clang
./compile.sh clang

[jmrenouard]

I have update Install.txt.

Clang is a very good compiler (fast and clean code generated).
MacOs is using CLANG as OS Compiler so whitedb can also be used for Whitedb.

compiler.sh parameter is optionnal. The script version allows to detect earlier missing gcc or clang executable before trying to use it.

[necrophcodr]

I'd like to add that testing this results in the library being built using gcc regardless of parameters, and regardless of gcc being installed.
The problem is here: https://github.com/priitj/whitedb/blob/master/compile.sh#L11

That line is not changed in this commit, and due to the lack of ${COMPILER} variable there, gcc will always be used.

Additionally, the COMPILER variable should have a default value, so as to not result in NO compiler being used (the consequence which can be seen here https://github.com/jmrenouard/whitedb/commit/14d65ee92bf12fdeb0e14da8ff7e4307639730cc#diff-0f8ed536b6067bbcef0adc6e88ab88d5R21 is probably not very useful)

[jmrenouard]

Hello,

The last pull request with additional PR from necrophcodr.

It fixes unset COMPILER var issue.

Br.
Jean-Marie RENOUARD

[priitj]

IMHO 'compile.sh' will never be portable. It was not meant to, rather the user was meant to edit it to their needs. Still, I'll merge this if you guys feel it makes things more convinient for clang users :-)

Thanks.

[priitj]

I've noticed that this shell script syntax is rather fragile. It seems to break on a system I'd expect to be quite common, 12.04 Ubuntu LTS.

Rather than attempt to fix this, I'd propose this:

How would you feel about running

CC=clang ./compile.sh

instead? I should have proposed this from the start but was preoccupied with other things and didn't divert much attention here. You can then also export CC=clang and I can add support for this to other shell scripts as well (such as Python/compile.sh, the examples etc).