shuaiwang added a comment.
In https://reviews.llvm.org/D52219#1238423, @JonasToth wrote:
> Do you think it would be possible to the analysis for `>const?< int
> ***`-cases? (recursively checking through the pointer levels)
I think that should be possible, will do after single-layer pointee analysis is
done. I believe we can build multi-layer analysis based on much of the
single-layer analysis.
================
Comment at: lib/Analysis/ExprMutationAnalyzer.cpp:198
const Stmt *ExprMutationAnalyzer::findDirectMutation(const Expr *Exp) {
+ // `Exp` can be *directly* mutated if the type of `Exp` is not const.
+ // Bail out early otherwise.
----------------
JonasToth wrote:
> Just to be sure that i understand:
> the changes here are more performance optimizations then directly related to
> detect pointee mutations?
Yes :)
================
Comment at: lib/Analysis/ExprMutationAnalyzer.cpp:481
+ const auto AsArg =
+ anyOf(callExpr(hasAnyArgument(equalsNode(Exp))),
+ cxxConstructExpr(hasAnyArgument(equalsNode(Exp))),
----------------
JonasToth wrote:
> shouldn't be the constness of the argument considered here?
We need that for non-pointee version, but not for pointee version, for example:
```
void g1(int * const);
void f1() {
int *x;
g1(x); // <-- x is passed to `g1`, we consider that as a mutation, the
argument type do have a top-level const
}
void g2(const int *);
void f2() {
int *x;
g2(x); // <-- declRefExp(to(x)) is NOT directly passed to `g2`, there's a
layer a ImplicitCastExpr<NoOp> in between, and after the implicit cast, the
type of the expression becomes "const int *" instead of just "int*", so it'll
fail the `isPointeeMutable` check at the beginning of
`findPointeeDirectMutation`
}
```
In summary, we rely on:
- Checking whether pointee is actually mutable at the beginning
- Carefully handling casts by not trivially ignoring them unless absolutely safe
Repository:
rC Clang
https://reviews.llvm.org/D52219
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