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chromium / chromium / src.git / 65eb2ba3425e18bb3b101299f11358786e0dacae
commit65eb2ba3425e18bb3b101299f11358786e0dacae[log] [tgz]
authorFyodor Gayokho <[email protected]>Thu Mar 22 18:09:21 2018
committerCommit Bot <[email protected]>Thu Mar 22 18:09:21 2018
treee920d870dd99cf9ecb946860ba2004bf336dd2ce
parentd927492b95bcfae183359241e02a39c3afd7a941 [diff]
Fix move constructors' noexcept propagation

By spec, if a member (OptionalStorage) has potentially-throwing move
constructor (when T is not trivially move constructible), the implicit
move constructor is also potentially-throwing (OptionalBase and
Optional).
However, if T is nothrow move constructible, noexcept is explicitly
specified to the Optional's move constructor. This hits the following
statement in the spec (11.4.2 [dcl.fct.def.default])

If a function that is explicitly defaulted has an explicit
exception-specification that is not compatible (18.4 [except.spec])
with the exception-specification on the implicit declaration, then
- if the function is explicitly defaulted on its first declaration,
it is defined as deleted;

So, move constructor would be deleted.
Note that, practically, with -fno-exceptions as we build Chrome,
clang outputs is_nothrow_move_constructible<Optional<T>>::value will
be false, although move ctor itself looks generated. This is the fix
for that case.

Also note that, without -fno-exceptions, clang would report
"error: exception specification of explicitly defaulted move
constructor does not match the calculated one".
This is a clang bug (https://bugs.llvm.org/show_bug.cgi?id=22325).

Change-Id: I7c5775084e2c75157b337c97b04a84e9d2879e11
Reviewed-on: https://chromium-review.googlesource.com/964961
Reviewed-by: danakj <[email protected]>
Reviewed-by: Hidehiko Abe <[email protected]>
Commit-Queue: danakj <[email protected]>
Cr-Commit-Position: refs/heads/master@{#545156}
2 files changed
tree: e920d870dd99cf9ecb946860ba2004bf336dd2ce
  1. android_webview/
  2. apps/
  3. ash/
  4. base/
  5. blink/
  6. build/
  7. build_overrides/
  8. cc/
  9. chrome/
  10. chrome_cleaner/
  11. chrome_elf/
  12. chromecast/
  13. chromeos/
  14. cloud_print/
  15. components/
  16. content/
  17. courgette/
  18. crypto/
  19. dbus/
  20. device/
  21. docs/
  22. extensions/
  23. gin/
  24. google_apis/
  25. google_update/
  26. gpu/
  27. headless/
  28. infra/
  29. ios/
  30. ipc/
  31. jingle/
  32. mash/
  33. media/
  34. mojo/
  35. native_client_sdk/
  36. net/
  37. notification_helper/
  38. pdf/
  39. ppapi/
  40. printing/
  41. remoting/
  42. rlz/
  43. sandbox/
  44. services/
  45. skia/
  46. sql/
  47. storage/
  48. styleguide/
  49. testing/
  50. third_party/
  51. tools/
  52. ui/
  53. url/
  54. .clang-format
  55. .eslintrc.js
  56. .git-blame-ignore-revs
  57. .gitattributes
  58. .gitignore
  59. .gn
  60. .vpython
  61. AUTHORS
  62. BUILD.gn
  63. CODE_OF_CONDUCT.md
  64. codereview.settings
  65. DEPS
  66. ENG_REVIEW_OWNERS
  67. LICENSE
  68. LICENSE.chromium_os
  69. OWNERS
  70. PRESUBMIT.py
  71. PRESUBMIT_test.py
  72. PRESUBMIT_test_mocks.py
  73. README.md
  74. WATCHLISTS
README.md

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