For a definition (of most linkage types), dso_local is set for ELF -fno-pic/-fpie
and COFF, but not for Mach-O. This nuance causes unneeded binary format differences.
This patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `
if there is an explicit linkage.
* Clang will set dso_local for Mach-O, which is currently implied by TargetMachine.cpp. This will make COFF/Mach-O and executable ELF similar.
* Eventually I hope we can make dso_local the textual LLVM IR default (write explicit "dso_preemptable" when applicable) and -fpic ELF will be similar to everything else. This patch helps move toward that goal.
r235815 changed CGRecordLowering::accumulateBases to ignore non-virtual
bases of size 0, which prevented adding those non-virtual bases to
CGRecordLayout's NonVirtualBases. This caused clang to assert when
CGRecordLayout::getNonVirtualBaseLLVMFieldNo was called in
EmitNullConstant. This commit fixes the bug by ignoring zero-sized
non-virtual bases in EmitNullConstant.
rdar://problem/28100139
Differential Revision: https://reviews.llvm.org/D24312
llvm-svn: 281405
Fixes rdar://20621065.
A more elegant fix would preclude this case by defining the
rules such that zero-size classes are always formally empty.
I believe the only extensions which create zero-size classes
right now are flexible arrays and zero-length arrays; it's
not abstractly unreasonable to say that those don't count
as members for the purposes of emptiness, just as zero-width
bitfields don't count. But that's an ABI-affecting change
and requires further discussion; in the meantime, let's not
assert / miscompile.
llvm-svn: 235815
The problem was that we were asserting the we never added an empty class
to the same offset twice. This is not true for unions, where two members, empty
or not, can have the some offset.
llvm-svn: 122633
Fangrui Song