This is an archive of the discontinued LLVM Phabricator instance.

Differential D28727

Add -fstrict-vtable-pointers to UserManual
ClosedPublic

Authored by Prazek on Jan 14 2017, 2:10 AM.

Details

Reviewers
hans
rsmith
Commits
rGeb9dd5aec883: Add -fstrict-vtable-pointers to UsersManual
rC292112: Add -fstrict-vtable-pointers to UsersManual
rL292112: Add -fstrict-vtable-pointers to UsersManual
Summary

It would be good to merge it to 4.0 branch.

Diff Detail

Event Timeline

Prazek updated this revision to Diff 84442.Jan 14 2017, 2:10 AM
Prazek retitled this revision from to Add -fstrict-vtable-pointers to UserManual.
Prazek updated this object.
Prazek added a reviewer: hans.
Prazek added a subscriber: cfe-commits.
Prazek added a child revision: D28606: Mention devirtualization in release notes.Jan 14 2017, 5:34 AM
hans edited edge metadata.Jan 14 2017, 1:20 PM

Would it be possible to expand on, or give some kind of pointer to, what "strict rules for overwriting polymorphic C++ objects" means?

Prazek updated this revision to Diff 84489.Jan 15 2017, 6:14 AM
Prazek edited edge metadata.

suggested fix

Prazek updated this revision to Diff 84492.Jan 15 2017, 6:26 AM

Removed [no-] so hyperlink would work

Prazek added a reviewer: rsmith.Jan 15 2017, 2:37 PM
hans accepted this revision.Jan 15 2017, 4:22 PM
hans edited edge metadata.

lgtm with comment

docs/UsersManual.rst
1103

e.g should be i.e. (or you could even spell it out: "that is")

I think it should also be "*the* vptr" and "*the* object* or "during an object's lifetime".

This revision is now accepted and ready to land.Jan 15 2017, 4:22 PM
Closed by commit rL292112: Add -fstrict-vtable-pointers to UsersManual (authored by Prazek). · Explain WhyJan 16 2017, 5:31 AM
This revision was automatically updated to reflect the committed changes.
Prazek marked an inline comment as done.
Prazek added a comment.Jan 16 2017, 5:37 AM

I also have sent it on the branch

Revision Contents

PathSize
docs/
6 lines

Diff 84489

docs/UsersManual.rst

Show First 20 Lines • Show All 1,091 Lines • ▼ Show 20 Lines.. option:: -fsanitize-undefined-trap-on-error
Deprecated alias for ``-fsanitize-trap=undefined``. Deprecated alias for ``-fsanitize-trap=undefined``.
.. option:: -fsanitize-cfi-cross-dso .. option:: -fsanitize-cfi-cross-dso
Enable cross-DSO control flow integrity checks. This flag modifies Enable cross-DSO control flow integrity checks. This flag modifies
the behavior of sanitizers in the ``cfi`` group to allow checking the behavior of sanitizers in the ``cfi`` group to allow checking
of cross-DSO virtual and indirect calls. of cross-DSO virtual and indirect calls.
.. option:: -f[no-]strict-vtable-pointers
Enable optimizations based on the strict rules for overwriting polymorphic
C++ objects, e.g. vptr is invariant during the lifetime of object.
hansUnsubmitted
Done
ReplyInline Actions

e.g should be i.e. (or you could even spell it out: "that is")

I think it should also be "*the* vptr" and "*the* object* or "during an object's lifetime".

hans: e.g should be i.e. (or you could even spell it out: "that is") I think it should also be…
This enables better devirtualization. Turned off by default.
.. option:: -ffast-math .. option:: -ffast-math
Enable fast-math mode. This defines the ``__FAST_MATH__`` preprocessor Enable fast-math mode. This defines the ``__FAST_MATH__`` preprocessor
macro, and lets the compiler make aggressive, potentially-lossy assumptions macro, and lets the compiler make aggressive, potentially-lossy assumptions
about floating-point math. These include: about floating-point math. These include:
* Floating-point math obeys regular algebraic rules for real numbers (e.g. * Floating-point math obeys regular algebraic rules for real numbers (e.g.
``+`` and ``*`` are associative, ``x/y == x * (1/y)``, and ``+`` and ``*`` are associative, ``x/y == x * (1/y)``, and
▲ Show 20 Lines • Show All 1,575 Lines • Show Last 20 Lines