[PATCH] D83717: [clang-tidy] Add check fo SEI CERT item ENV32-C

[Whisperity via Phabricator via cfe-commits]

whisperity added inline comments.


================
Comment at: clang-tools-extra/clang-tidy/cert/ExitHandlerCheck.cpp:33
+bool isExitFunction(StringRef FnName) {
+  return FnName == "_Exit" || FnName == "exit" || FnName == "quick_exit";
+}
----------------
aaron.ballman wrote:
> Because this rule applies in C++ as well as C, you should protect these names so that calling something like this doesn't trigger the check:
> ```
> namespace menu_items {
> void exit(int);
> }
> ```
> I think we want `::_Exit` and `::std::_Exit` to check the fully qualified names (I believe this will still work in C, but should be tested). The same goes for the other names (including `atexit` and `at_quick_exit` above).
> I think we want `::_Exit` and `::std::_Exit` to check the fully qualified names (I believe this will still work in C, but should be tested).

Tested with Clang-Query:

```
clang-query> m functionDecl(hasName("::atexit"))

Match #1:

/home/whisperity/LLVM/Build/foo.c:1:1: note: "root" binds here
int atexit(int) {}
^~~~~~~~~~~~~~~~~~
1 match.
```


================
Comment at: clang-tools-extra/clang-tidy/cert/ExitHandlerCheck.cpp:64
+/// argument.
+void ExitHandlerCheck::registerMatchers(MatchFinder *Finder) {
+  const auto IsRegisterFunction =
----------------
aaron.ballman wrote:
> whisperity wrote:
> > What happens if this test is run on C++ code calling the same functions? I see the rule is only applicable to C, for some reason... Should it be disabled from registering if by accident the check is enabled on a C++ source file?
> The CERT C++ rules inherit many of the C rules, including this one. It's listed towards the bottom of the set of inherited rules here: https://wiki.sei.cmu.edu/confluence/pages/viewpage.action?pageId=88046336
Right, thanks for the heads-up. This should be somewhat more indicative on the Wiki on the page for the rule (especially because people won't immediately understand why a `-c` check reports on their cpp code, assuming they understand `-c` means C.)


================
Comment at: clang-tools-extra/clang-tidy/cert/ExitHandlerCheck.cpp:124-125
+      diag(RegisterCall->getSourceRange().getBegin(),
+           "exit-handler potentially calls a jump function. Handlers should "
+           "terminate by returning");
+      diag(HandlerDecl->getBeginLoc(), "handler function declared here",
----------------
aaron.ballman wrote:
> whisperity wrote:
> > This semi-sentence structure of starting with lowercase but also terminating the sentence and leaving in another but unterminated sentences looks really odd.
> > 
> > Suggestion: "exit handler potentially jumps instead of terminating normally with a return"
> Slight tweak here as well. I don't think we'll ever see a jump function other than longjmp for this rule, so what about writing `potentially calls 'longjmp'` instead of `potentially jumps`?
😉 Agree. And if we see, we will have to update the code anyways. One could in theory whip up some inline assembly black magic, but that's a whole other can of worms.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D83717/new/

https://reviews.llvm.org/D83717