diff options
| author | Eric Fiselier <eric@efcs.ca> | 2018-03-21 19:19:48 +0000 |
|---|---|---|
| committer | Eric Fiselier <eric@efcs.ca> | 2018-03-21 19:19:48 +0000 |
| commit | f353d86deb3ea8299f37c5477dcbb9ea30558fb1 (patch) | |
| tree | 277f0ceefb2c06a7a36f8c0f221d7fb992571def /include/clang/Basic/Builtins.def | |
| parent | 440ae10990a4c227674ec4f21f3e002baa0e7c95 (diff) | |
[Builtins] Overload __builtin_operator_new/delete to allow forwarding to usual allocation/deallocation functions.
Summary:
Libc++'s default allocator uses `__builtin_operator_new` and `__builtin_operator_delete` in order to allow the calls to new/delete to be ellided. However, libc++ now needs to support over-aligned types in the default allocator. In order to support this without disabling the existing optimization Clang needs to support calling the aligned new overloads from the builtins.
See llvm.org/PR22634 for more information about the libc++ bug.
This patch changes `__builtin_operator_new`/`__builtin_operator_delete` to call any usual `operator new`/`operator delete` function. It does this by performing overload resolution with the arguments passed to the builtin to determine which allocation function to call. If the selected function is not a usual allocation function a diagnostic is issued.
One open issue is if the `align_val_t` overloads should be considered "usual" when `LangOpts::AlignedAllocation` is disabled.
In order to allow libc++ to detect this new behavior the value for `__has_builtin(__builtin_operator_new)` has been updated to `201802`.
Reviewers: rsmith, majnemer, aaron.ballman, erik.pilkington, bogner, ahatanak
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D43047
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@328134 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include/clang/Basic/Builtins.def')
| -rw-r--r-- | include/clang/Basic/Builtins.def | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/clang/Basic/Builtins.def b/include/clang/Basic/Builtins.def index 9b7e09a75b..36b72ba385 100644 --- a/include/clang/Basic/Builtins.def +++ b/include/clang/Basic/Builtins.def @@ -1371,8 +1371,8 @@ BUILTIN(__builtin_smulll_overflow, "bSLLiCSLLiCSLLi*", "n") // Clang builtins (not available in GCC). BUILTIN(__builtin_addressof, "v*v&", "nct") -BUILTIN(__builtin_operator_new, "v*z", "c") -BUILTIN(__builtin_operator_delete, "vv*", "n") +BUILTIN(__builtin_operator_new, "v*z", "tc") +BUILTIN(__builtin_operator_delete, "vv*", "tn") BUILTIN(__builtin_char_memchr, "c*cC*iz", "n") // Safestack builtins |