deps: copy all openssl header files to include dir

[shigeki]

On upgrading openssl, all symlinks in pulic header files are replaced with nested include files. The issue was raised that installing them leads to lost its references to real header files.
To avoid this, all public header files are copied into the deps/openssl/openssl/include/openssl/ directory.
As a result, we have duplicated header files under deps/openssl/openssl/ but copied files are refereed in build as specified to include path in openssl.gyp.

Fixes: #9269

I made a test to install node in my Linux server and confirmed that all real headers of openssl exist in /usr/local/include/node/openssl/

[misterdjules]

@shigeki Why not removing the openssl header files that are the target of the symlinks (or targets of the #include directives in node's codebase) and keep only deps/openssl/openssl/include/openssl/*?

[shigeki]

@misterdjules The current master of openssl has already remove them in openssl/openssl@dee502b. You can see that it also needs to change Configure, Makefile and related scripts. Although these files are not used in building with gyp, I think it is better to keep library sources healthy.
Note that iojs uses Configure to generate opensslconf.h for various platforms as https://github.com/nodejs/io.js/blob/master/deps/openssl/config/Makefile#L25.

[misterdjules]

@shigeki I see what you mean, thank you for the clarification 👍

My concern is more that by keeping both set of files in our repository, if the OpenSSL project makes changes to the files that are symlink targets, we won't pickup these changes unless we explicitly watch for that. Is there a chance that openssl/openssl@dee502b make it to the 1.0.1 branch at some point?

[shigeki]

@misterdjules I wouldn't bet on it. In order to avoid missing changes of header files in the future, I revised the upgrading docs of https://github.com/nodejs/io.js/blob/master/deps/openssl/doc/UPGRADING.md#3-replace-openssl-header-files-in-depsopensslopensslincludeopenssl.
I made it with a small bash script as

#!/bin/bash
for h  in *.h
do
  a=`readlink $h`
  echo $a
  mv $h ${h}.org
  cp $a .
done

[misterdjules]

@shigeki Would it be better to add in tools/install.py something that automatically copies the actual header files to include/node/openssl at the install step (and thus when building the binary tarball too) instead of doing it manually when upgrading OpenSSL?

That way we do not float another patch on OpenSSL, and we do not run the risk of forgetting to run this step manually during future upgrades of OpenSSL.

That's just a suggestion, you know the OpenSSL code base and the way we integrate it in this repository much better than I do.

[shigeki]

@misterdjules Replacing all symlink of header files with real header files is necessary with/without executing tool/install.py since symlinks cause issues in extracting source files on Windows.
We should rather make tools/openssl_upgrade.py but it's a long way to go :-)

[misterdjules]

@shigeki Right, I'm not questioning removing symlinks, I understand we need that on Windows. What I'm suggesting is that we could replace a manual, error prone, process to copy header files with an automated one in tools/install.py.

If that's not an option, then we'll need to mention the additional step of copying header files in the one bundled in official releases in the OpenSSL upgrade guide.

[misterdjules]

This has landed in v0.10 with 8277822.