Commit Graph

6 Commits

Author SHA1 Message Date
Leonard Chan cf8ff75bad [clang][RelativeVTablesABI] Use dso_local_equivalent rather than emitting stubs
Thanks to D77248, we can bypass the use of stubs altogether and use PLT
relocations if they are available for the target. LLVM and LLD support the
R_AARCH64_PLT32 relocation, so we can also guarantee a static PLT relocation on AArch64.
Not emitting these stubs saves a lot of extra binary size.

Differential Revision: https://reviews.llvm.org/D83812
2020-11-30 16:02:35 -08:00
CJ Johnson 69cd776e1e [CodeGen] Apply 'nonnull' and 'dereferenceable(N)' to 'this' pointer
arguments.

* Adds 'nonnull' and 'dereferenceable(N)' to 'this' pointer arguments
* Gates 'nonnull' on -f(no-)delete-null-pointer-checks
* Introduces this-nonnull.cpp and microsoft-abi-this-nullable.cpp tests to
  explicitly test the behavior of this change
* Refactors hundreds of over-constrained clang tests to permit these
  attributes, where needed
* Updates Clang12 patch notes mentioning this change

Reviewed-by: rsmith, jdoerfert

Differential Revision: https://reviews.llvm.org/D17993
2020-11-16 17:39:17 -08:00
Leonard Chan de172dd17f [clang][RelativeVTablesABI] Update CodeGenCXX/RelativeVTablesABI/dynamic-cast.cpp
After c7bcd431d9, this test started failing when
running with the new pass manager. One of the CHECKs in this file checks how the
vtable is loaded for a void cast, which involves taking 2 bitcasts from the pointer
to the original object. The order of these bitcasts changes under the new PM.
The order doesn't matter, so this relaxes the CHECKs.

Differential Revision: https://reviews.llvm.org/D82802
2020-06-29 13:06:42 -07:00
Leonard Chan 71568a9e28 [clang] Frontend components for the relative vtables ABI (round 2)
This patch contains all of the clang changes from D72959.

- Generalize the relative vtables ABI such that it can be used by other targets.
- Add an enum VTableComponentLayout which controls whether components in the
  vtable should be pointers to other structs or relative offsets to those structs.
  Other ABIs can change this enum to restructure how components in the vtable
  are laid out/accessed.
- Add methods to ConstantInitBuilder for inserting relative offsets to a
  specified position in the aggregate being constructed.
- Fix failing tests under new PM and ASan and MSan issues.

See D72959 for background info.

Differential Revision: https://reviews.llvm.org/D77592
2020-06-11 11:17:08 -07:00
Leonard Chan 7201272d4c Revert "[clang] Frontend components for the relative vtables ABI"
This reverts commit 2e009dbcb3.

Reverting since there were some test failures on buildbots that used the
new pass manager. ASan and MSan are also finding some bugs in this that
I'll need to address.
2020-06-10 13:50:05 -07:00
Leonard Chan 2e009dbcb3 [clang] Frontend components for the relative vtables ABI
This patch contains all of the clang changes from D72959.

- Generalize the relative vtables ABI such that it can be used by other targets.
- Add an enum VTableComponentLayout which controls whether components in the
  vtable should be pointers to other structs or relative offsets to those structs.
  Other ABIs can change this enum to restructure how components in the vtable
  are laid out/accessed.
- Add methods to ConstantInitBuilder for inserting relative offsets to a
  specified position in the aggregate being constructed.

See D72959 for background info.

Differential Revision: https://reviews.llvm.org/D77592
2020-06-10 12:48:10 -07:00