[PATCH] D33672: [analyzer] INT50-CPP. Do not cast to an out-of-range enumeration checker

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman added a comment.

In https://reviews.llvm.org/D33672#830492, @gamesh411 wrote:

> As for the the loss of precision problem, in the special case of char the size of char is known. However does the analysis have the necessary information in this stage to know the size of an int for example? I found bit-width specifying information in the llvm::Type class which is used in the code generation phase. It could be done by checking on a per type basis, but then again, it could possibly lead to false positives. Correct me if I am wrong.


The frontend has this information available to it as well, through the `ASTContext`. See `getTypeSize()`, `getTypeSizeInChars()`, etc.



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Comment at: lib/StaticAnalyzer/Checkers/EnumCastOutOfRangeChecker.cpp:74-75
+  EnumValueVector DeclValues;
+  for (const auto *D : ED->decls()) {
+    const auto ECD = dyn_cast<EnumConstantDecl>(D);
+    DeclValues.push_back(ECD->getInitVal());
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aaron.ballman wrote:
> Instead of enumerating over `decls()` and then casting, just enumerate over `enumerators()` and  the cast isn't needed. Or, even better:
> ```
> EnumValueVector DeclValues(ED->enumerator_end() - ED->enumerator_begin());
> std::transform(ED->enumerator_begin(), ED->enumerator_end(), DeclValues.begin(),
>                        [](const EnumConstantDecl *D) { return D->getInitVal(); });
> ```
I think my suggestion was a bit more efficient than your implementation, was there a reason you avoided `std::transform()`?


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Comment at: lib/StaticAnalyzer/Checkers/EnumCastOutOfRangeChecker.cpp:35
+  const DefinedOrUnknownSVal CompareValue;
+
+  const ProgramStateRef PS;
----------------
You can remove the newline.


https://reviews.llvm.org/D33672