[GN]: BUILD file housecleaning

[GN]: BUILD file housecleaning

+ Turn on precompiled headers on Mac.
+ Change the toolchains to use asmflags instead of cflags and cflags_c.
+ Remove a TODO to hardcode the Mac SDK since the location of the SDK is not always guaranteed (on bots, for example).
+ GN: .S or .asm files no longer trigger cflags or cflags_c to be written to the ninja file.

BUG=none

Committed: https://crrev.com/7a73be6eb4963662a1e9455dcdab0d5130324901
Cr-Commit-Position: refs/heads/master@{#351202}

[Bons, 2015-09-27 05:24:41]

The CQ bit was checked by andybons@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-09-27 05:24:51]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1368223002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1368223002/1

[commit-bot: I haz the power, 2015-09-27 05:28:11]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-09-27 05:28:11]

Dry run: Try jobs failed on following builders:
  mac_chromium_gn_rel on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_gn_r...)

[Bons, 2015-09-27 05:31:08]

The CQ bit was checked by andybons@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-09-27 05:31:14]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1368223002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1368223002/20001

[commit-bot: I haz the power, 2015-09-27 05:44:04]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-09-27 05:44:04]

Dry run: Try jobs failed on following builders:
  android_chromium_gn_compile_rel on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/android_chromiu...)

[Bons, 2015-09-28 02:53:37]

The CQ bit was checked by andybons@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-09-28 02:53:44]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1368223002/80001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1368223002/80001

[Bons, 2015-09-28 02:54:22]

andybons@chromium.org changed reviewers:
+ brettw@chromium.org

[commit-bot: I haz the power, 2015-09-28 03:08:32]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-09-28 03:08:32]

Dry run: Try jobs failed on following builders:
  android_chromium_gn_compile_rel on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/android_chromiu...)

[brettw, 2015-09-28 19:44:52]

https://codereview.chromium.org/1368223002/diff/80001/build/config/android/BU...
File build/config/android/BUILD.gn (right):

https://codereview.chromium.org/1368223002/diff/80001/build/config/android/BU...
build/config/android/BUILD.gn:119: asmflags = cflags
A comment here might be helpful for future generations, even if it's stupid, so
it's obvious we're doing this on purpose.

https://codereview.chromium.org/1368223002/diff/80001/build/config/compiler/B...
File build/config/compiler/BUILD.gn (right):

https://codereview.chromium.org/1368223002/diff/80001/build/config/compiler/B...
build/config/compiler/BUILD.gn:558: if (is_posix) {
Ditto. Also, it's probably worth mentioning that the Windows assembler takes
different types of flags which is why we don't use it there.

https://codereview.chromium.org/1368223002/diff/80001/build/config/compiler/B...
build/config/compiler/BUILD.gn:1194: asmflags = cflags
I think these are OK and don't need comments since the configs are very focused
and it's obvious that this stuff should also apply to the assembler.

https://codereview.chromium.org/1368223002/diff/80001/build/config/win/BUILD.gn
File build/config/win/BUILD.gn (right):

https://codereview.chromium.org/1368223002/diff/80001/build/config/win/BUILD....
build/config/win/BUILD.gn:138: "/SAFESEH",
This didn't seem to come from anywhere else. I'm assuming you noticed this was
needed for some reason? Can this reason be added to the commit message?

Also, should this go on the compiler config above instead?

[Bons, 2015-09-28 20:15:39]

https://codereview.chromium.org/1368223002/diff/80001/build/config/android/BU...
File build/config/android/BUILD.gn (right):

https://codereview.chromium.org/1368223002/diff/80001/build/config/android/BU...
build/config/android/BUILD.gn:119: asmflags = cflags
On 2015/09/28 19:44:52, brettw wrote:
> A comment here might be helpful for future generations, even if it's stupid,
so
> it's obvious we're doing this on purpose.

Done.

https://codereview.chromium.org/1368223002/diff/80001/build/config/compiler/B...
File build/config/compiler/BUILD.gn (right):

https://codereview.chromium.org/1368223002/diff/80001/build/config/compiler/B...
build/config/compiler/BUILD.gn:558: if (is_posix) {
On 2015/09/28 19:44:52, brettw wrote:
> Ditto. Also, it's probably worth mentioning that the Windows assembler takes
> different types of flags which is why we don't use it there.

Done.

https://codereview.chromium.org/1368223002/diff/80001/build/config/compiler/B...
build/config/compiler/BUILD.gn:1194: asmflags = cflags
On 2015/09/28 19:44:52, brettw wrote:
> I think these are OK and don't need comments since the configs are very
focused
> and it's obvious that this stuff should also apply to the assembler.

Acknowledged.

https://codereview.chromium.org/1368223002/diff/80001/build/config/win/BUILD.gn
File build/config/win/BUILD.gn (right):

https://codereview.chromium.org/1368223002/diff/80001/build/config/win/BUILD....
build/config/win/BUILD.gn:138: "/SAFESEH",
On 2015/09/28 19:44:52, brettw wrote:
> This didn't seem to come from anywhere else. I'm assuming you noticed this was
> needed for some reason? Can this reason be added to the commit message?
It came from the windows toolchain config where it was hardcoded.

> Also, should this go on the compiler config above instead?
Done.

[brettw, 2015-09-28 20:22:55]

lgtm

[Bons, 2015-09-28 22:52:36]

The CQ bit was checked by andybons@chromium.org

[commit-bot: I haz the power, 2015-09-28 22:54:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1368223002/120001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1368223002/120001

[commit-bot: I haz the power, 2015-09-28 23:35:25]

Committed patchset #7 (id:120001)

[commit-bot: I haz the power, 2015-09-28 23:36:10]

Patchset 7 (id:??) landed as
https://crrev.com/7a73be6eb4963662a1e9455dcdab0d5130324901
Cr-Commit-Position: refs/heads/master@{#351202}

[agrieve, 2015-09-30 14:12:50]

A revert of this CL (patchset #7 id:120001) has been created in
https://codereview.chromium.org/1381473003/ by agrieve@chromium.org.

The reason for reverting is: [721/14633] ASM
obj/third_party/openmax_dl/dl/openmax_dl_armv7/omxSP_FFTInv_CCSToR_F32_Sfs_s.o
FAILED: /usr/local/google/home/agrieve/goma/gomacc
../../third_party/llvm-build/Release+Asserts/bin/clang -MMD -MF
obj/third_party/openmax_dl/dl/openmax_dl_armv7/omxSP_FFTInv_CCSToR_F32_Sfs_s.o.d
-DV8_DEPRECATION_WARNINGS -DCLD_VERSION=2 -DENABLE_NOTIFICATIONS
-DENABLE_BROWSER_CDMS -DENABLE_PRINTING=1 -DENABLE_BASIC_PRINTING=1
-DENABLE_SPELLCHECK=1 -DUSE_BROWSER_SPELLCHECKER=1 -DDONT_EMBED_BUILD_METADATA
-DUSE_OPENSSL=1 -DUSE_OPENSSL_CERTS=1 -DNO_TCMALLOC -DDISABLE_NACL
-DENABLE_CONFIGURATION_POLICY -DENABLE_SUPERVISED_USERS=1
-DENABLE_AUTOFILL_DIALOG=1 -DUSE_PROPRIETARY_CODECS
-DV8_USE_EXTERNAL_STARTUP_DATA -DVIDEO_HOLE=1 -DMOBILE_SAFE_BROWSING
-DSAFE_BROWSING_DB_REMOTE -DSAFE_BROWSING_SERVICE -DCHROMIUM_BUILD
-DENABLE_MEDIA_ROUTER=1 -DENABLE_WEBVR -DFIELDTRIAL_TESTING_ENABLED
-DCR_CLANG_REVISION=247874-1 -D_FILE_OFFSET_BITS=64 -DANDROID -DHAVE_SYS_UIO_H
-D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DCOMPONENT_BUILD
-D__GNU_SOURCE=1 -D__compiler_offsetof=__builtin_offsetof -Dnan=__builtin_nan
-D_DEBUG -DDYNAMIC_ANNOTATIONS_ENABLED=1 -DWTF_USE_DYNAMIC_ANNOTATIONS=1
-DDL_ARM_NEON_OPTIONAL -I../.. -Igen -I../../third_party/openmax_dl
-I../../third_party/android_tools/ndk/sources/android/cpufeatures
-fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -march=armv7-a
-mfloat-abi=softfp -mthumb -mtune=generic-armv7-a -funwind-tables -fPIC -pipe
-fcolor-diagnostics -mfpu=vfpv3-d16
--sysroot=/usr/local/google/home/agrieve/ssd/git/clankium1/src/third_party/android_tools/ndk/platforms/android-16/arch-arm
-c
../../third_party/openmax_dl/dl/sp/src/arm/armv7/omxSP_FFTInv_CCSToR_F32_Sfs_s.S
-o
obj/third_party/openmax_dl/dl/openmax_dl_armv7/omxSP_FFTInv_CCSToR_F32_Sfs_s.o
clang: warning: argument unused during compilation: '-mfloat-abi=softfp'
clang: warning: argument unused during compilation: '-mthumb'
clang: warning: argument unused during compilation: '-mfpu=vfpv3-d16'
error: unknown target CPU 'armv7-a'.

[agrieve, 2015-09-30 14:31:04]

On 2015/09/30 14:12:50, agrieve wrote:
> A revert of this CL (patchset #7 id:120001) has been created in
> https://codereview.chromium.org/1381473003/ by mailto:agrieve@chromium.org.
> 
> The reason for reverting is: [721/14633] ASM
> obj/third_party/openmax_dl/dl/openmax_dl_armv7/omxSP_FFTInv_CCSToR_F32_Sfs_s.o
> FAILED: /usr/local/google/home/agrieve/goma/gomacc
> ../../third_party/llvm-build/Release+Asserts/bin/clang -MMD -MF
>
obj/third_party/openmax_dl/dl/openmax_dl_armv7/omxSP_FFTInv_CCSToR_F32_Sfs_s.o.d
> -DV8_DEPRECATION_WARNINGS -DCLD_VERSION=2 -DENABLE_NOTIFICATIONS
> -DENABLE_BROWSER_CDMS -DENABLE_PRINTING=1 -DENABLE_BASIC_PRINTING=1
> -DENABLE_SPELLCHECK=1 -DUSE_BROWSER_SPELLCHECKER=1 -DDONT_EMBED_BUILD_METADATA
> -DUSE_OPENSSL=1 -DUSE_OPENSSL_CERTS=1 -DNO_TCMALLOC -DDISABLE_NACL
> -DENABLE_CONFIGURATION_POLICY -DENABLE_SUPERVISED_USERS=1
> -DENABLE_AUTOFILL_DIALOG=1 -DUSE_PROPRIETARY_CODECS
> -DV8_USE_EXTERNAL_STARTUP_DATA -DVIDEO_HOLE=1 -DMOBILE_SAFE_BROWSING
> -DSAFE_BROWSING_DB_REMOTE -DSAFE_BROWSING_SERVICE -DCHROMIUM_BUILD
> -DENABLE_MEDIA_ROUTER=1 -DENABLE_WEBVR -DFIELDTRIAL_TESTING_ENABLED
> -DCR_CLANG_REVISION=247874-1 -D_FILE_OFFSET_BITS=64 -DANDROID -DHAVE_SYS_UIO_H
> -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DCOMPONENT_BUILD
> -D__GNU_SOURCE=1 -D__compiler_offsetof=__builtin_offsetof -Dnan=__builtin_nan
> -D_DEBUG -DDYNAMIC_ANNOTATIONS_ENABLED=1 -DWTF_USE_DYNAMIC_ANNOTATIONS=1
> -DDL_ARM_NEON_OPTIONAL -I../.. -Igen -I../../third_party/openmax_dl
> -I../../third_party/android_tools/ndk/sources/android/cpufeatures
> -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector
-march=armv7-a
> -mfloat-abi=softfp -mthumb -mtune=generic-armv7-a -funwind-tables -fPIC -pipe
> -fcolor-diagnostics -mfpu=vfpv3-d16
>
--sysroot=/usr/local/google/home/agrieve/ssd/git/clankium1/src/third_party/android_tools/ndk/platforms/android-16/arch-arm
> -c
>
../../third_party/openmax_dl/dl/sp/src/arm/armv7/omxSP_FFTInv_CCSToR_F32_Sfs_s.S
> -o
> obj/third_party/openmax_dl/dl/openmax_dl_armv7/omxSP_FFTInv_CCSToR_F32_Sfs_s.o
> clang: warning: argument unused during compilation: '-mfloat-abi=softfp'
> clang: warning: argument unused during compilation: '-mthumb'
> clang: warning: argument unused during compilation: '-mfpu=vfpv3-d16'
> error: unknown target CPU 'armv7-a'.

Andy's going to look into fixing this, so let's hold off a revert for now. For
anyone hitting this locally you can work around it by by patching in
https://codereview.chromium.org/1381473003/