devirtualized.
The code to detect devirtualized calls is already in IRGen, so move the
code to lib/AST and make it a shared utility between Sema and IRGen.
This commit fixes a linkage error I was seeing when compiling the
following code:
$ cat test1.cpp
struct Base {
virtual void operator()() {}
};
template<class T>
struct Derived final : Base {
void operator()() override {}
};
Derived<int> *d;
int main() {
if (d)
(*d)();
return 0;
}
rdar://problem/33195657
Differential Revision: https://reviews.llvm.org/D34301
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@307883 91177308-0d34-0410-b5e6-96231b3b80d8
If we see a virtual method call to Base::foo() but can infer that the
object is an instance of Derived, and that 'foo' is marked 'final' in
Derived, we can devirtualize the call to Derived::foo().
Differential Revision: https://reviews.llvm.org/D25813
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@284766 91177308-0d34-0410-b5e6-96231b3b80d8
Consider this program:
struct A {
virtual void operator-() { printf("base\n"); }
};
struct B final : public A {
virtual void operator-() override { printf("derived\n"); }
};
int main() {
B* b = new B;
-static_cast<A&>(*b);
}
Before this patch, clang saw the virtual call to A::operator-(), figured out
that it can be devirtualized, and then just called A::operator-() directly,
without going through the vtable. Instead, it should've looked up which
operator-() the call devirtualizes to and should've called that.
For regular virtual member calls, clang gets all this right already. So
instead of giving EmitCXXOperatorMemberCallee() all the logic that
EmitCXXMemberCallExpr() already has, cut the latter function into two pieces,
call the second piece EmitCXXMemberOrOperatorMemberCallExpr(), and use it also
to generate code for calls to virtual member operators.
This way, virtual overloaded operators automatically don't get devirtualized
if they have covariant returns (like it was done for regular calls in r218602),
etc.
This also happens to fix (or at least improve) codegen for explicit constructor
calls (`A a; a.A::A()`) in MS mode with -fsanitize-address-field-padding=1.
(This adjustment for virtual operator calls seems still wrong with the MS ABI.)
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@223185 91177308-0d34-0410-b5e6-96231b3b80d8
Reported in the thread "devirtualisation appears to crash clang on covariant functions on ARM" on cfe-dev.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@166651 91177308-0d34-0410-b5e6-96231b3b80d8
will be represented in the IR as a plain "i32" type. This causes the
tests to spuriously fail on platforms where int is not a 32-bit type,
or where the ABI requires attributes like "signext" or "zeroext" to
be used.
This patch adds -triple or -target parameters to force those tests
to use the i386-unknown-unknown target.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@166551 91177308-0d34-0410-b5e6-96231b3b80d8
handy. It can be done, but we would have to build a derived-to-base cast
during codegen to compute the correct this pointer.
I will handle covariant returns next.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159350 91177308-0d34-0410-b5e6-96231b3b80d8
the correct this pointer. There is some potential for sharing a bit more
code with canDevirtualizeMemberFunctionCalls, but that can be done in an
independent patch.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159326 91177308-0d34-0410-b5e6-96231b3b80d8
to see if we had an underlying final class or method, but we would then
use the cast type to do the call, resulting in a direct call to the wrong
method.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159212 91177308-0d34-0410-b5e6-96231b3b80d8
Akira Hatanaka