A direct dependent of this project should also use the x64 version of

openssl.gyp

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'targets': [
     {
       'target_name': 'openssl',
       'type': '<(component)',
       'includes': [
         # Include the auto-generated gypi file.
         'openssl.gypi'
       ],
       'variables': {
         'openssl_include_dirs': [
           '.',
           'openssl',
           'openssl/crypto',
           'openssl/crypto/asn1',
           'openssl/crypto/evp',
           'openssl/crypto/modes',
           'openssl/include',
         ],
+        'openssl_public_include_dirs': [
+          'openssl/include',
+        ],
       },
       'sources': [
         '<@(openssl_common_sources)',
       ],
       'defines': [
         '<@(openssl_common_defines)',
         'PURIFY',
         'MONOLITH',
         'OPENSSL_NO_ASM',
       ],
@@ skipping 42 matching lines @@
                 ['include', 'openssl/crypto/rc4/rc4_enc\\.c' ],
                 ['include', 'openssl/crypto/rc4/rc4_skey\\.c' ],
               ],
             }]
           ],
           'defines': [ '<@(openssl_x86_64_defines)' ],
           'defines!': [ 'OPENSSL_NO_ASM' ],
           'variables': {
             # Ensure the 64-bit opensslconf.h header is used.
             'openssl_include_dirs+': [ 'config/x64' ],
+            'openssl_public_include_dirs+': [ 'config/x64' ],

[Ryan Sleevi, 2014/02/05 02:13:03]

Is the public API affected by this (eg: including opensslconf.h)?

The way we've dealt with this in other third-party projects is to ensure the
#defines are included within the .gyp file, not the config.h file - or that the
config.h is only used internally when generating the library.

[wtc, 2014/02/05 17:14:32]

opensslconf.h is the only header under the config/x64 directory. (It's in an
"openssl" subdirectory.) So this change won't make other headers available to a
direct dependent.

opensslconf.h is a public header. (For example, on a Ubuntu Linux computer,
opensslconf.h is in /usr/include/openssl.) I don't think it is usually included
directly, but several public headers include it.

           },
         }],
         ['component == "shared_library"', {
           'cflags!': ['-fvisibility=hidden'],
         }],
         ['clang==1', {
           'cflags': [
             # OpenSSL has a few |if ((foo == NULL))| checks.
             '-Wno-parentheses-equality',
             # OpenSSL uses several function-style macros and then ignores the
             # returned value.
             '-Wno-unused-value',
           ],
         }, { # Not clang. Disable all warnings.
           'cflags': [
             '-w',
           ],
         }]
       ],
       'include_dirs': [
         '<@(openssl_include_dirs)',
       ],
       'direct_dependent_settings': {
         'include_dirs': [
-          'openssl/include',
+          '<@(openssl_public_include_dirs)',
         ],
       },
     },
   ],
 }
 
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