ahatanak marked an inline comment as done.
ahatanak added inline comments.
================
Comment at: clang/lib/Sema/SemaExpr.cpp:677
+ E->getType().isDestructedType() == QualType::DK_nontrivial_c_struct)
+ Cleanup.setExprNeedsCleanups(true);
+
----------------
rjmccall wrote:
> ahatanak wrote:
> > rjmccall wrote:
> > > Why only when the l-value is volatile?
> > I was trying to avoid emitting `ExprWithCleanups` when it wasn't needed and
> > it seemed that it wasn't needed for non-volatile types. I'm not sure it's
> > important, so I've removed the check for volatile. Also, `ExprWithCleanups`
> > shouldn't' be emitted when this is in file scope, so I fixed that too.
> Hmm, not sure about this file-scope thing, since the combination of C++
> dynamic initializers and statement-expressions means we can have pretty
> unrestricted code there.
I should have explained why this was needed, but I wanted to prevent emitting
`ExprWithCleanups` in the following example:
```
struct A {
id f0;
};
typedef struct A A;
A g = (A){ .f0 = 0 };
```
The l-value to r-value conversion happens here because compound literals are
l-values. Since `g` is a global of a non-trivial C struct type, we shouldn't
try to push a cleanup and destruct the object.
We don't have to think about the C++ case since the line below checks the type
is a non-trivial C type. I didn't think about statement expressions, but they
aren't allowed in file scope, so I guess that's not a problem either.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D66094/new/
https://reviews.llvm.org/D66094
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