steakhal added a comment.
In D85528#2205094 <https://reviews.llvm.org/D85528#2205094>, @xazax.hun wrote:
> Looks reasonable to me, but I am not very familiar with the impacts of the
> additional casts. Do we lose some modeling power when we are using the
> regular constraint solver?
>
> For example, when we have constraints both on the original and the cased
> symbol can the analyzer "merge" them?
>
> Something like:
>
> ScopedPrimitive sym = conjure<ScopedPrimitive>();
> if (sym == ScopedPrimitive::Max)
> return;
> int sym2 = static_cast<unsigned char>(sym);
> if (sym2 == 0)
> return;
> // Do we know here that both sym and sym2 has the same range?
> // Is there a change in the behavior compared to before the patch?
Huh, it's a really interesting question.
Here is the result:
---
Here is the test code:
enum class ScopedPrimitive : unsigned char { Min = 2, Max = 8 };
void foo() {
auto sym = conjure<ScopedPrimitive>();
if (sym == ScopedPrimitive::Max)
return;
int sym2 = static_cast<unsigned char>(sym);
if (sym2 == 0)
return;
// Do we know here that both sym and sym2 has the same range?
// Is there a change in the behavior compared to before the patch?
clang_analyzer_printState();
(void)sym;
(void)sym2;
}
Before the patch:
"constraints": [
{ "symbol": "conj_$2{enum ScopedPrimitive, LC1, S1083, #1}", "range": "{
[1, 7], [9, 255] }" }
]
After the patch:
"constraints": [
{ "symbol": "conj_$2{enum ScopedPrimitive, LC1, S1881, #1}", "range": "{
[0, 7], [9, 255] }" },
{ "symbol": "(unsigned char) (conj_$2{enum ScopedPrimitive, LC1, S1881,
#1})", "range": "{ [1, 255] }" }
]
---
> For example, when we have constraints both on the original and the cased
> symbol can the analyzer "merge" them?
Apparently, not xD.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D85528/new/
https://reviews.llvm.org/D85528
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