The PR reapply https://github.com/llvm/llvm-project/pull/97308.
- Implement [CWG1815](https://wg21.link/CWG1815): Support lifetime
extension of temporary created by aggregate initialization using a
default member initializer.
- Fix crash that introduced in
https://github.com/llvm/llvm-project/pull/97308. In
`InitListChecker::FillInEmptyInitForField`, when we enter
rebuild-default-init context, we copy all the contents of the parent
context to the current context, which will cause the `MaybeODRUseExprs`
to be lost. But we don't need to copy the entire context, only the
`DelayedDefaultInitializationContext` was required, which is used to
build `SourceLocExpr`, etc.
---------
Signed-off-by: yronglin <yronglin777@gmail.com>
This reverts commit 45c8766973bb3bb73dd8d996231e114dcf45df9f
and 049512e39d96995cb373a76cf2d009a86eaf3aab.
This change triggers failed asserts on inputs like this:
struct a {
} constexpr b;
class c {
public:
c(a);
};
class B {
public:
using d = int;
struct e {
enum { f } g;
int h;
c i;
d j{};
};
};
B::e k{B::e::f, int(), b};
Compiled like this:
clang -target x86_64-linux-gnu -c repro.cpp
clang: ../../clang/lib/CodeGen/CGExpr.cpp:3105: clang::CodeGen::LValue
clang::CodeGen::CodeGenFunction::EmitDeclRefLValue(const clang::DeclRefExpr*):
Assertion `(ND->isUsed(false) || !isa<VarDecl>(ND) || E->isNonOdrUse() ||
!E->getLocation().isValid()) && "Should not use decl without marking it used!"' failed.
This reverts commit 17daa204feadf9c28fc13b7daa69c3cbe865b238.
Multiple examples on the PR
https://github.com/llvm/llvm-project/pull/87933
show regressions, so reverting until they can be fixed in the followup.
This PR complete [DR1815](https://wg21.link/CWG1815) under the guidance
of `FIXME` comments. And reuse `CXXDefaultInitExpr` rewrite machinery to
clone the initializer expression on each use that would lifetime extend
its temporaries.
---------
Signed-off-by: yronglin <yronglin777@gmail.com>
