martong added inline comments.
================
Comment at: clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp:504
+
+ OrigStdin = findStdStream("stdin", C);
+ OrigStdout = findStdStream("stdout", C);
----------------
steakhal wrote:
> balazske wrote:
> > steakhal wrote:
> > > balazske wrote:
> > > > steakhal wrote:
> > > > > martong wrote:
> > > > > > We should be careful, to cache the results (either here, or deeper
> > > > > > in the call stack).
> > > > > > I mean, we certainly don't want to do a lookup of "stdin" every
> > > > > > time a function is evaluated. We should do this lazily, only once.
> > > > > I agree. We should do this only for the first top-level function,
> > > > > instead of doing this for every top-level function.
> > > > I am not sure if the `SymbolRef` values are safe to store between
> > > > top-level function analyses. The `FILE` type and std stream
> > > > declarations are safe to cache, but the SymbolRef values of these
> > > > variables probably not.
> > > I think it should be safe. But place there an assert and run the test
> > > suite. If it won't trigger, that means that we have high confidentiality
> > > that this is safe. I know it's not 100%, but pretty close.
> > I tried to check if these `SymbolRef`'s are the same at
> > `checkBeginFunction` after initialized once. The assertion for equality
> > failed sometimes, or other crash happened when `dump` was called on the
> > value. So it looks not safe to cache these. And should we add assumptions
> > about that these `StdinSym`, `StdoutSym`, `StderrSym` are not equal to each
> > other?
> Good to know. I don't think it's necessary to add assertions.
Okay, so we should not cache the SymbolRefs then. But we must cache the
VarDecls. I mean, we should avoid calling
```
StdinDecl = findStdStreamDecl("stdin", C);
```
more than once for each TU.
I think you could use and Optional for StdinDecl (and the others) to achieve
this.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D106644/new/
https://reviews.llvm.org/D106644
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
