Close https://github.com/llvm/llvm-project/issues/71034
See
https://discourse.llvm.org/t/rfc-c-20-modules-introduce-thin-bmi-and-decls-hash/74755
This patch introduces reduced BMI, which doesn't contain the definitions
of functions and variables if its definitions won't contribute to the
ABI.
Testing is a big part of the patch. We want to make sure the reduced BMI
contains the same behavior with the existing and relatively stable
fatBMI. This is pretty helpful for further reduction.
The user interfaces part it left to following patches to ease the
reviewing.
This reverts commit 67b298f6d82e0b4bb648ac0dabe895e816a77ef1.
We got linker errors with undefined symbols during a compiler release
and tracked it down to this change. I am in the process of understanding
what is happening and getting a reproducer.
Sorry for reverting this again.
I will reopen#61065 until we fix this.
Fixes#61065.
This reverts commit 363c98b2d67986b9766bb1426739970ce6d9a6f3 and relands
db987b9589be1eb604fcb74c85b410469e31485f with fixes from
bc95f27337c7ed77c28e713c855272848f01802a.
The module-related issues surfaced there are fixed in the
previous commit.
This reverts commit bc95f27337c7ed77c28e713c855272848f01802a, originally db987b9589be1eb604fcb74c85b410469e31485f.
clang/test/Modules/pr61065.cppm is retained to make relands show less diff.
There are other module-related issues that were not caught, related to
false positive errors like
"error: no matching constructor for initialization of 'union (anonymous union at ..."
Reopen#61065
This re-lands commit db987b9589be1eb604fcb74c85b410469e31485f,
previously reverted in commit 1e0709167f5edd330889f51bb203c458bdb5e359,
with a fix for a pre-existing bug in how we write constructor names into
lookup tables that was exposed by that change.
As yet, we've been unable to produce a reduced testcase for this bug,
but we understand the problem: if we write out a lookup table for a
class which has two constructor names, and we only have local lookup
results for one of those constructor names, then we will write out a
lookup table where the "all the constructors" lookup result contains
results for only one of the constructor names.
Close https://github.com/llvm/llvm-project/issues/61065.
We will avoid writing the names from external AST naturally. But
currently its check is often false positive since we may have already
marked the declarations as external but
DeclContext::hasNeedToReconcileExternalVisibleStorage would be false
after reconciling.
Tested with libcxx's modular build.
This patch can improve 8% compilation time in an internal workloads.
See the discussion in
https://reviews.llvm.org/rG1e0709167f5edd330889f51bb203c458bdb5e359
to see the information for recommitting.
This reverts commit db987b9589be1eb604fcb74c85b410469e31485f.
We're seeing failures in modules-enabled builds from within stdlib after
this commit. Errors look like:
In module '...stl_cc_library':
...optional:560:38: error: 'std::__optional_copy_assign_base<unsigned
long>::__optional_copy_assign_base' from module '...optional' is not
present in definition of 'std::__optional_copy_assign_base<unsigned
long>' in module '...optional'
using __optional_move_base<_Tp>::__optional_move_base;
In module '...stl_cc_library':
...optional:771:11: error: no matching constructor for initialization of '__optional_move_assign_base<unsigned long>'
: __base(in_place, _VSTD::forward<_Up>(__v)) {}
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
llvm-project/clang/include/clang/Basic/CodeGenOptions.h:448:57: note: in instantiation of function template specialization 'std::optional<unsigned long>::optional<int, 0>' requested here
std::optional<uint64_t> DiagnosticsHotnessThreshold = 0;
I don't have a self-contained reproducer at this point. I'm hoping that
we may be able to share more information about these issues later, if
necessary.
Close https://github.com/llvm/llvm-project/issues/61065.
We will avoid writing the names from external AST naturally. But
currently its check is often false positive since we may have already
marked the declarations as external but
DeclContext::hasNeedToReconcileExternalVisibleStorage would be false
after reconciling.
Tested with libcxx's modular build.
This patch can improve 8% compilation time in an internal workloads.
