Use the ARM assembly code in mpi_arm.c for iOS.

nss/nss.gyp

Index: nss/nss.gyp
===================================================================
--- nss/nss.gyp	(revision 179275)
+++ nss/nss.gyp	(working copy)
@@ -12,6 +12,9 @@
         'exclude_nss_root_certs%': 1,
         'exclude_nss_libpkix%': 1,
       }],
+      ['OS=="mac" or OS=="ios"', {
+        'forced_include_file%': '<(DEPTH)/third_party/nss/mozilla/security/nss/lib/freebl/build_config_mac.h',

[Mark Mentovai, 2013/01/30 20:37:54]

You shouldn’t need a <(DEPTH)-rooted path. You should be able to specify this
ias mozilla/security/…, relative to the directory of the .gyp file.

[wtc, 2013/01/30 23:11:09]

Both you and Ryan suggested this, but my experiments showed
this only works with the xcode GYP generator, but not with
the ninja and make GYP generators. Please se the ninja and
make compile error messages in my comment at

https://codereview.chromium.org/10828060/diff/20001/nss/nss.gyp#newcode16

I wonder if I made a mistake. Could it be that I define
this variable outside the target that uses the variable?

[Mark Mentovai, 2013/01/30 23:20:32]

Hmm. Looks like maybe ninja isn’t changing to the right directory before
starting the compiler.

[wtc, 2013/01/31 00:00:15]

I run ninja inside the src directory, with this command:

    ninja -C out/Debug nss_static

The clang command line issued by ninja shows that ninja
is inside the out/Debug directory. ninja refers to the source
file using a path like
../../third_party/nss/mozilla/security/nss/lib/certhigh/ocsp.c
and specifies the output .o file using a path like
-o obj/third_party/nss/mozilla/security/nss/lib/certhigh/nss_static.ocsp.o

Therefore, if the current directory is out/Debug,
-include mozilla/security/nss/lib/freebl/build_config_mac.h
won't work.

+      }],
     ],
   },
   'target_defaults': {
@@ -582,6 +585,8 @@
         'mozilla/security/nss/lib/freebl/mpi/mpi.c',
         'mozilla/security/nss/lib/freebl/mpi/mpi.h',
         'mozilla/security/nss/lib/freebl/mpi/mpi_amd64.c',
+        'mozilla/security/nss/lib/freebl/mpi/mpi_arm.c',
+        'mozilla/security/nss/lib/freebl/mpi/mpi_arm_mac.c',
         'mozilla/security/nss/lib/freebl/mpi/mpi_x86_asm.c',
         'mozilla/security/nss/lib/freebl/mpi/mplogic.c',
         'mozilla/security/nss/lib/freebl/mpi/mplogic.h',
@@ -1056,8 +1061,8 @@
           ],
         }],
         ['target_arch=="ia32"', {
-          'sources/': [
-            ['exclude', 'amd64'],
+          'sources!': [
+            'mozilla/security/nss/lib/freebl/mpi/mpi_amd64.c',
           ],
         }],
         ['OS=="mac" or OS=="ios"', {
@@ -1072,6 +1077,9 @@
           ],
           'sources!': [
             'mozilla/security/nss/lib/freebl/mpi/mpi_amd64.c',
+            # mpi_arm.c is included by mpi_arm_mac.c.
+            'mozilla/security/nss/lib/freebl/mpi/mpi_arm.c',

[Mark Mentovai, 2013/01/30 20:37:54]

You said that mpi_arm_mac.c existed to avoid a more complicated change in the
.gyp file, but now that you’re excluding mpi_arm.c (to avoid compiling it twice,
once on its own and once as part of mpi_arm_mac.c), you’ve got a freaky thing
going on in the .gyp file. I think it would be better to get rid of
mpi_arm_mac.cc and add the necessary GYP bits to build mpi_arm.cc only on iOS
(or other ARM platforms?)

[wtc, 2013/01/30 23:11:09]

1. A wrapper file for mpi_arm.c is still necessary for iOS
because only the device (arm) target (but not the simulator
target) can use mpi_arm.c. I assume it is still not possible
to specify arch specific source files in Xcode.

2. Strictly speaking I just need to use the wrapper file
for OS=="ios". But it is convenient to treat mac and ios
in the same way in this GYP file. If I name the wrapper
file mpi_arm_ios.c and only use it for iOS, the changes
to this GYP file will be larger. That's what I wanted to
avoid.

+            # mpi_x86_asm.c contains MSVC inline assembly code.
             'mozilla/security/nss/lib/freebl/mpi/mpi_x86_asm.c',
           ],
           'xcode_settings': {
@@ -1080,20 +1088,11 @@
                 'GCC_SYMBOLS_PRIVATE_EXTERN': 'NO',  # no -fvisibility=hidden
               }],
             ],
-            # Can't use 'target_arch=="ia32"' conditional because that is
-            # only checked at GYP file generation time.
-            'GCC_PREPROCESSOR_DEFINITIONS[arch=i386]': [
-              '$(inherited)',
-              'NSS_X86_OR_X64',
-              'NSS_X86',
-              'i386',
+            # Define processor architecture specific macros in
+            # <(forced_include_file).
+            'OTHER_CFLAGS': [
+              '-include', '<(forced_include_file)',
             ],
-            'GCC_PREPROCESSOR_DEFINITIONS[arch=x86_64]': [
-              '$(inherited)',
-              'NSS_USE_64',
-              'NSS_X86_OR_X64',
-              'NSS_X64',
-            ],
           },
         }],
         ['OS=="win"', {
@@ -1106,6 +1105,11 @@
             'WIN95',
             '_WINDOWS',
           ],
+          'sources!': [
+            # mpi_arm.c contains GCC inline assembly code.

[Mark Mentovai, 2013/01/30 20:37:54]

Don’t you really want to do this whenever OS!="mac" or OS!="ios", not just when
OS=="win"? In conjunction with the other suggestion, this will probably all
change.

+            'mozilla/security/nss/lib/freebl/mpi/mpi_arm.c',
+            'mozilla/security/nss/lib/freebl/mpi/mpi_arm_mac.c',
+          ],
           'direct_dependent_settings': {
             'defines': [
               '_WINDOWS',