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.
virtual table offset in a member function pointer.
We are reserving this space for future ABI use relating to alternative
v-table configurations. In the meantime, continue to zero-initialize
this space when actually emitting a member pointer literal.
This will successfully interoperate with existing compilers.
Future versions of the compiler may place additional data in
this location, and at that point, code emitted by compilers
prior to this patch will fail if exposed to such a member pointer.
This is therefore a somewhat hard ABI break. However, because
it is limited to an uncommon case of an uncommon language feature,
and especially because interoperation with the standard library
does not depend on member pointers, we believe that with a
sufficiently advance compiler change the impact of this break
will be minimal in practice.
llvm-svn: 281693
dynamic classes in the translation unit and check whether each one's key
function is defined when we got to the end of the TU (and when we got to the
end of each module). This is really terrible for modules performance, since it
causes unnecessary deserialization of every dynamic class in every compilation.
We now use a much simpler (and, in a modules build, vastly more efficient)
system: when we see an out-of-line definition of a virtual function, we check
whether that function was in fact its class's key function. (If so, we need to
emit the vtable.)
llvm-svn: 230830
This adds Clang support for the ARM64 backend. There are definitely
still some rough edges, so please bring up any issues you see with
this patch.
As with the LLVM commit though, we think it'll be more useful for
merging with AArch64 from within the tree.
llvm-svn: 205100
Fangrui Song