[PATCH] D154287: [clang-tidy] Add modernize-use-std-format check

[Mike Crowe via Phabricator via cfe-commits]

mikecrowe added inline comments.


================
Comment at: clang-tools-extra/clang-tidy/modernize/UseStdFormatCheck.cpp:46
+void UseStdFormatCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(
+      callExpr(argumentCountAtLeast(1), hasArgument(0, stringLiteral()),
----------------
PiotrZSL wrote:
> mikecrowe wrote:
> > This matcher also matches the `operator+` call in:
> > ```
> > std::string A(const std::string &in)                                                                                                                                            
> > {                                                                                                                                                                               
> >     return "_" + in;                                                                                                                                                            
> > }                                                                                                                                                                               
> > ```
> > which causes an assertion failure:
> > ```
> > clang-tidy: /home/mac/git/llvm-project/clang/include/clang/AST/Decl.h:275: llvm::StringRef clang::NamedDecl::getName() const: Assertion `Name.isIdentifier() && "Name is not a simple identifier"' failed.
> > ```
> > when the `StrFormatLikeFunctions` option is set to an unqualified name:
> > ```
> > -config="{CheckOptions: [{key: modernize-use-std-format.StrictMode, value: false}, {key: modernize-use-std-format.StrFormatLikeFunctions, value: 'strprintf'}]}"
> > ```
> > 
> > `MatchesAnyListedNameMatcher::NameMatcher::match` calls `NamedDecl.getName()` which presumably raises the assertion due to the `operator+` not having a name (that's mentioned in the source anyway.)
> > 
> > I'm unsure whether I should be narrowing the matcher here so that it guaranteed to not try calling `matchesAnyListedName` on something that lacks a name, or whether `MatchesAnyListedNameMatcher` ought to be more tolerant of being called in such situations.
> > 
> > I note that `HasNameMatcher` has rather more elaborate code for generating the name than `MatchesAnyListedNameMatcher` does.
> > 
> > This problem also affects `modernize-use-std-print`, but due to the need for there to be no return value in that check it requires somewhat-unlikely code like:
> > ```
> > void A(const std::string &in)
> > {
> >   "_" + in;
> > }
> > ```
> > 
> > Do you have any advice? Given that this problem affects a check that has already landed should I open a bug?
> `unless(hasName(""))` could do a trick, or create own matcher to verify first if function got name.
> Probably similar issues can be with cxxConversionDecl.
> 
> Other best option would be to change MatchesAnyListedNameMatcher::NameMatcher::match to verify if NamedDecl got name before calling it.
> `unless(hasName(""))` could do a trick, or create own matcher to verify first if function got name.

That fails with a similar assertion failure.

> Probably similar issues can be with cxxConversionDecl.

I didn't really understand that one.

> Other best option would be to change MatchesAnyListedNameMatcher::NameMatcher::match to verify if NamedDecl got name before calling it.

That's easy and I think it's the best solution since it saves every check having to defend against this. I've done that in [[ https://reviews.llvm.org/D154884 | D154884 ]] .


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D154287/new/

https://reviews.llvm.org/D154287