Enable noexcept on Windows, use for a few move constructors.

Enable noexcept on Windows, use for a few move constructors.

MSVC complains if you use noexcept with no exception handling mode specified (as we do).
This code disables the warning. noexcept on move constructors allows better optimizations
in some cases.
http://en.cppreference.com/w/cpp/language/noexcept_spec

Updates a few common classes' move constructors to use this.

Review-Url: https://codereview.chromium.org/2771643002
Cr-Commit-Position: refs/heads/master@{#458956}
Committed: https://chromium.googlesource.com/chromium/src/+/76aac97386e2788241161420c5e7e0bfee16f88c

[brettw, 2017-03-22 21:30:17]

jni

[brettw, 2017-03-22 21:30:18]

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

[brettw, 2017-03-22 21:30:31]

Description was changed from

==========
Enable noexcept on Windows, use for a few move constructors.

MSVC complains if you use noexcept with no exception handling mode specified (as
we do).
This code disables the warning. noexcept on move constructors allows better
optimizations
in some cases.

BUG=
==========

to

==========
Enable noexcept on Windows, use for a few move constructors.

MSVC complains if you use noexcept with no exception handling mode specified (as
we do).
This code disables the warning. noexcept on move constructors allows better
optimizations
in some cases.

Updates a few common classes' move constructors to use this.
==========

[brettw, 2017-03-22 21:30:31]

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

[commit-bot: I haz the power, 2017-03-22 21:30:57]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[brucedawson, 2017-03-22 21:39:05]

lgtm.

Maybe include a link to this:
http://en.cppreference.com/w/cpp/language/noexcept_spec

and maybe this quote:
"For example, containers such as std::vector will move their elements if the
elements' move constructor is noexcept, and copy otherwise..."

I knew there was some sordid history about annotating functions as not throwing
actually making things worse, but that was throw(), and even that is fixed in
C++ 17.

https://codereview.chromium.org/2771643002/diff/20001/base/containers/flat_map.h
File base/containers/flat_map.h (right):

https://codereview.chromium.org/2771643002/diff/20001/base/containers/flat_ma...
base/containers/flat_map.h:207: flat_map<Key, Mapped,
Compare>::flat_map(flat_map&&) noexcept = default;
That reads weird, as if you are setting noexcept to the default. But, such is
this crazy language we use.

[commit-bot: I haz the power, 2017-03-22 21:43:31]

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

[commit-bot: I haz the power, 2017-03-22 21:43:32]

Dry run: Try jobs failed on following builders:
  ios-device on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device/builds...)
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[brettw, 2017-03-22 22:17:23]

No flat_map

[brettw, 2017-03-22 22:17:43]

Description was changed from

==========
Enable noexcept on Windows, use for a few move constructors.

MSVC complains if you use noexcept with no exception handling mode specified (as
we do).
This code disables the warning. noexcept on move constructors allows better
optimizations
in some cases.

Updates a few common classes' move constructors to use this.
==========

to

==========
Enable noexcept on Windows, use for a few move constructors.

MSVC complains if you use noexcept with no exception handling mode specified (as
we do).
This code disables the warning. noexcept on move constructors allows better
optimizations
in some cases.
http://en.cppreference.com/w/cpp/language/noexcept_spec

Updates a few common classes' move constructors to use this.
==========

[brettw, 2017-03-22 22:17:54]

The CQ bit was checked by brettw@chromium.org

[brettw, 2017-03-22 22:17:54]

The patchset sent to the CQ was uploaded after l-g-t-m from
brucedawson@chromium.org
Link to the patchset: https://codereview.chromium.org/2771643002/#ps40001
(title: "No flat_map")

[commit-bot: I haz the power, 2017-03-22 22:18:32]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-22 23:34:02]

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

[commit-bot: I haz the power, 2017-03-22 23:34:04]

Try jobs failed on following builders:
  linux_chromium_chromeos_ozone_rel_ng on master.tryserver.chromium.linux
(JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[brettw, 2017-03-22 23:52:32]

The CQ bit was checked by brettw@chromium.org

[commit-bot: I haz the power, 2017-03-22 23:53:32]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-23 00:37:43]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1490226752669420,
"parent_rev": "d741d25d04cbff8e7647d204a43dc4dfa76093ca", "commit_rev":
"76aac97386e2788241161420c5e7e0bfee16f88c"}

[commit-bot: I haz the power, 2017-03-23 00:39:02]

Description was changed from

==========
Enable noexcept on Windows, use for a few move constructors.

MSVC complains if you use noexcept with no exception handling mode specified (as
we do).
This code disables the warning. noexcept on move constructors allows better
optimizations
in some cases.
http://en.cppreference.com/w/cpp/language/noexcept_spec

Updates a few common classes' move constructors to use this.
==========

to

==========
Enable noexcept on Windows, use for a few move constructors.

MSVC complains if you use noexcept with no exception handling mode specified (as
we do).
This code disables the warning. noexcept on move constructors allows better
optimizations
in some cases.
http://en.cppreference.com/w/cpp/language/noexcept_spec

Updates a few common classes' move constructors to use this.

Review-Url: https://codereview.chromium.org/2771643002
Cr-Commit-Position: refs/heads/master@{#458956}
Committed:
https://chromium.googlesource.com/chromium/src/+/76aac97386e2788241161420c5e7...
==========

[commit-bot: I haz the power, 2017-03-23 00:39:05]

Committed patchset #3 (id:40001) as
https://chromium.googlesource.com/chromium/src/+/76aac97386e2788241161420c5e7...

[scottmg, 2017-03-23 15:38:28]

scottmg@chromium.org changed reviewers:
+ lfg@chromium.org, scottmg@chromium.org

[scottmg, 2017-03-23 15:38:29]

Seeing this at head, could it be due to this change?

[0->353/353 ~1] CXX obj/storage/browser/browser/quota_reservation_manager.obj
FAILED: obj/storage/browser/browser/quota_reservation_manager.obj
ninja -t msvc -e environment.x86 --
"c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\VC\bin\amd64_x86/cl.exe"
/nologo /showIncludes /FC
@obj/storage/browser/browser/quota_reservation_manager.obj.rsp /c
../../storage/browser/fileapi/quota/quota_reservation_manager.cc
/Foobj/storage/browser/browser/quota_reservation_manager.obj
/Fd"obj/storage/browser/browser_cc.pdb"
c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\vc\include\utility(113):
error C2220: warning treated as error - no 'object' file generated
c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\vc\include\utility(113):
warning C4577: 'noexcept' used with no exception handling mode specified;
termination on exception is not guaranteed. Specify /EHsc
c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\vc\include\utility(113):
note: to simplify migration, consider the
temporary use of /Wv:18 flag with the version of the compiler with which you
used to build without warnings
ninja: build stopped: subcommand failed.

[scottmg, 2017-03-23 15:47:16]

On 2017/03/23 15:38:29, scottmg wrote:
> Seeing this at head, could it be due to this change?
> 
> [0->353/353 ~1] CXX obj/storage/browser/browser/quota_reservation_manager.obj
> FAILED: obj/storage/browser/browser/quota_reservation_manager.obj
> ninja -t msvc -e environment.x86 --
>
"c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\VC\bin\amd64_x86/cl.exe"
> /nologo /showIncludes /FC
> @obj/storage/browser/browser/quota_reservation_manager.obj.rsp /c
> ../../storage/browser/fileapi/quota/quota_reservation_manager.cc
> /Foobj/storage/browser/browser/quota_reservation_manager.obj
> /Fd"obj/storage/browser/browser_cc.pdb"
>
c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\vc\include\utility(113):
> error C2220: warning treated as error - no 'object' file generated
>
c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\vc\include\utility(113):
> warning C4577: 'noexcept' used with no exception handling mode specified;
> termination on exception is not guaranteed. Specify /EHsc
>
c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\vc\include\utility(113):
> note: to simplify migration, consider the
> temporary use of /Wv:18 flag with the version of the compiler with which you
> used to build without warnings
> ninja: build stopped: subcommand failed.

[[ bisecting now to confirm... my gn args aren't too odd?

c:\src\cr\src>type out\debug\args.gn
is_debug = true
is_component_build = true
enable_nacl = false
is_chrome_branded = true
symbol_level = 2
target_cpu = "x86"
is_win_fastlink = true
is_clang = false
win_console_app = true
win_linker_timing = true

]]

[scottmg, 2017-03-23 15:56:29]

On 2017/03/23 15:47:16, scottmg wrote:
> On 2017/03/23 15:38:29, scottmg wrote:
> > Seeing this at head, could it be due to this change?
> > 
> > [0->353/353 ~1] CXX
obj/storage/browser/browser/quota_reservation_manager.obj
> > FAILED: obj/storage/browser/browser/quota_reservation_manager.obj
> > ninja -t msvc -e environment.x86 --
> >
>
"c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\VC\bin\amd64_x86/cl.exe"
> > /nologo /showIncludes /FC
> > @obj/storage/browser/browser/quota_reservation_manager.obj.rsp /c
> > ../../storage/browser/fileapi/quota/quota_reservation_manager.cc
> > /Foobj/storage/browser/browser/quota_reservation_manager.obj
> > /Fd"obj/storage/browser/browser_cc.pdb"
> >
>
c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\vc\include\utility(113):
> > error C2220: warning treated as error - no 'object' file generated
> >
>
c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\vc\include\utility(113):
> > warning C4577: 'noexcept' used with no exception handling mode specified;
> > termination on exception is not guaranteed. Specify /EHsc
> >
>
c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\vc\include\utility(113):
> > note: to simplify migration, consider the
> > temporary use of /Wv:18 flag with the version of the compiler with which you
> > used to build without warnings
> > ninja: build stopped: subcommand failed.
> 
> [[ bisecting now to confirm... my gn args aren't too odd?
> 
> c:\src\cr\src>type out\debug\args.gn
> is_debug = true
> is_component_build = true
> enable_nacl = false
> is_chrome_branded = true
> symbol_level = 2
> target_cpu = "x86"
> is_win_fastlink = true
> is_clang = false
> win_console_app = true
> win_linker_timing = true
> 
> ]]

76aac97386e2788241161420c5e7e0bfee16f88c is the first bad commit
commit 76aac97386e2788241161420c5e7e0bfee16f88c
Author: brettw <brettw@chromium.org>
Date:   Wed Mar 22 17:37:36 2017 -0700

    Enable noexcept on Windows, use for a few move constructors.

    MSVC complains if you use noexcept with no exception handling mode specified
(as we do).
    This code disables the warning. noexcept on move constructors allows better
optimizations
    in some cases.
    http://en.cppreference.com/w/cpp/language/noexcept_spec

    Updates a few common classes' move constructors to use this.

    Review-Url: https://codereview.chromium.org/2771643002
    Cr-Commit-Position: refs/heads/master@{#458956}

I know the bots are green, but since I can't build at head I'm going to revert
for now. Sorry. :(

[scottmg, 2017-03-23 15:57:15]

A revert of this CL (patchset #3 id:40001) has been created in
https://codereview.chromium.org/2769703007/ by scottmg@chromium.org.

The reason for reverting is: Seems to have broken Windows build with args.gn as:

> is_debug = true
> is_component_build = true
> enable_nacl = false
> is_chrome_branded = true
> symbol_level = 2
> target_cpu = "x86"
> is_win_fastlink = true
> is_clang = false
> win_console_app = true
> win_linker_timing = true.

[lfg, 2017-03-23 16:06:46]

Same as scottmg@, I can't build after this change. Reverting this fixes my
build.

[scottmg, 2017-03-23 18:32:11]

Brett and I narrowed this down to a pch dependency problem (i.e. the pch isn't
necessarily rebuilt when this warning flag is changed.)

Here's a log for posterity:

[d47446e...]c:\src\cr\src>ninja -C out\Debug
obj/storage/browser/browser/quota_reservation_manager.obj
ninja: Entering directory `out\Debug'
[0->1/1 ~1] Regenerating ninja files
[0->1/1 ~1] CXX obj/storage/browser/browser/quota_reservation_manager.obj
FAILED: obj/storage/browser/browser/quota_reservation_manager.obj
ninja -t msvc -e environment.x86 --
"c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\VC\bin\amd64_x86/cl.exe"
/nologo /showIncludes /FC
@obj/storage/browser/browser/quota_reservation_manager.obj.rsp /c
../../storage/browser/fileapi/quota/quota_reservation_manager.cc
/Foobj/storage/browser/browser/quota_reservation_manager.obj
/Fd"obj/storage/browser/browser_cc.pdb"
c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\vc\include\utility(113):
error C2220: warning treated as error - no 'object' file generated
c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\vc\include\utility(113):
warning C4577: 'noexcept' used with no exception handling mode specified;
termination on exception is not guaranteed. Specify /EHsc
c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\vc\include\utility(113):
note: to simplify migration, consider the
temporary use of /Wv:18 flag with the version of the compiler with which you
used to build without warnings
ninja: build stopped: subcommand failed.

[d47446e...]c:\src\cr\src>type out\debug\args.gn
is_debug = true
is_component_build = true
enable_nacl = false
is_chrome_branded = true
symbol_level = 2
target_cpu = "x86"
is_win_fastlink = true
is_clang = false
win_console_app = true
win_linker_timing = true

[d47446e...]c:\src\cr\src>type
out\debug\obj\storage\browser\browser\quota_reservation_manager.obj.rsp
-DSTORAGE_BROWSER_IMPLEMENTATION -DV8_DEPRECATION_WARNINGS -DUSE_AURA=1
-DNO_TCMALLOC -DDISABLE_NACL -DFULL_SAFE_BROWSING -DSAFE_BROWSING_CSD
-DSAFE_BROWSING_DB_LOCAL -DGOOGLE_CHROME_BUILD -DENABLE_MEDIA_ROUTER=1
-DCOMPONENT_BUILD -D__STD_C -D_CRT_RAND_S -D_CRT_SECURE_NO_DEPRECATE
-D_HAS_EXCEPTIONS=0 -D_SCL_SECURE_NO_DEPRECATE -D_ATL_NO_OPENGL -D_WINDOWS
-DCERT_CHAIN_PARA_HAS_EXTRA_FIELDS -DPSAPI_VERSION=1 -DWIN32 -D_SECURE_ATL
-D_USING_V110_SDK71_ -DWIN32_LEAN_AND_MEAN -DNOMINMAX -D_UNICODE -DUNICODE
-DNTDDI_VERSION=0x0A000000 -D_WIN32_WINNT=0x0A00 -DWINVER=0x0A00 -D_DEBUG
-DDYNAMIC_ANNOTATIONS_ENABLED=1 -DWTF_USE_DYNAMIC_ANNOTATIONS=1
-DU_USING_ICU_NAMESPACE=0 -DU_ENABLE_DYLOAD=0
-DICU_UTIL_DATA_IMPL=ICU_UTIL_DATA_FILE -DGOOGLE_PROTOBUF_NO_RTTI
-DGOOGLE_PROTOBUF_NO_STATIC_INITIALIZER -DPROTOBUF_USE_DLLS
-DBORINGSSL_SHARED_LIBRARY -DLEVELDB_PLATFORM_CHROMIUM=1
-DSQLITE_API=__declspec(dllimport) -I../.. -Igen -I../../third_party/ced/src
-I../../third_party/icu/source/common -I../../third_party/icu/source/i18n
-I../../third_party/protobuf/src -Igen/protoc_out
-I../../third_party/protobuf/src -I../../third_party/boringssl/src/include
-I../../third_party/leveldatabase -I../../third_party/leveldatabase/src
-I../../third_party/leveldatabase/src/include /wd4117 /D__DATE__= /D__TIME__=
/D__TIMESTAMP__= /Gy /FS /bigobj /d2FastFail /Zc:sizedDealloc- /W4 /WX /utf-8
/wd4091 /wd4127 /wd4251 /wd4312 /wd4351 /wd4355 /wd4503 /wd4589 /wd4611 /wd4100
/wd4121 /wd4244 /wd4505 /wd4510 /wd4512 /wd4610 /wd4838 /wd4995 /wd4996 /wd4456
/wd4457 /wd4458 /wd4459 /wd4577 /wd4267 /Od /Ob0 /GF /Zi /MDd
/FIbuild/precompile.h /Fpobj/storage/browser/browser_cc.pch
/Yubuild/precompile.h /TP /GR-

[d47446e...]c:\src\cr\src>del out\debug\obj\storage\browser\browser_cc.pch

[d47446e...]c:\src\cr\src>ninja -C out\Debug
obj/storage/browser/browser/quota_reservation_manager.obj
ninja: Entering directory `out\Debug'
[0->1/1 ~1] CXX obj/storage/browser/browser/quota_reservation_manager.obj
FAILED: obj/storage/browser/browser/quota_reservation_manager.obj
ninja -t msvc -e environment.x86 --
"c:\src\depot_tools\win_toolchain\vs_files\d3cb0e37bdd120ad0ac4650b674b09e81be45616\VC\bin\amd64_x86/cl.exe"
/nologo /showIncludes /FC
@obj/storage/browser/browser/quota_reservation_manager.obj.rsp /c
../../storage/browser/fileapi/quota/quota_reservation_manager.cc
/Foobj/storage/browser/browser/quota_reservation_manager.obj
/Fd"obj/storage/browser/browser_cc.pdb"
c:\src\cr\src\storage\browser\fileapi\quota\quota_reservation_manager.cc: fatal
error C1083: Cannot open precompiled header file:
'obj/storage/browser/browser_cc.pch': No such file or directory
ninja: build stopped: subcommand failed.

[d47446e...]c:\src\cr\src>ninja -C out\Debug obj/storage/browser/browser_cc.pch
ninja: Entering directory `out\Debug'
ninja: error: unknown target 'obj/storage/browser/browser_cc.pch'

[d47446e...]c:\src\cr\src>ninja -C out\Debug
obj/storage/browser/browser/precompile.cc.obj
ninja: Entering directory `out\Debug'
ninja: no work to do.

[d47446e...]c:\src\cr\src>del
out\debug\obj\storage\browser\browser\precompile.cc.obj

[d47446e...]c:\src\cr\src>ninja -C out\Debug
obj/storage/browser/browser/precompile.cc.obj
ninja: Entering directory `out\Debug'
[0->1/1 ~1] CXX obj/storage/browser/browser/precompile.cc.obj

[d47446e...]c:\src\cr\src>ninja -C out\Debug
obj/storage/browser/browser/quota_reservation_manager.obj
ninja: Entering directory `out\Debug'
[0->1/1 ~1] CXX obj/storage/browser/browser/quota_reservation_manager.obj

[dyaroshev, 2017-03-24 09:29:11]

Small notes on noexcept and default.

https://godbolt.org/g/Aji72L

if you have compilation problems I suggest just to do, in particular for flat_*
containers/trees etc.

class X {
  X(X&&) = default;
  X& operator=(X&&) = default
};