[clang-tidy] Fix `readability-suspicious-call-argument` crash for arguments without name-like identifier

[whisperity]

Summary

As originally reported by @steakhal in #54074, the name extraction logic in readability-suspicious-call-argument crashes if the argument passed to a function was a function call to a non-trivially named entity (e.g. an operator).

Fixed this crash case by ignoring such constructs and considering them as having no name.

[steakhal]

Reasonable to me.

[aaron.ballman]

LGTM, please add a release note for the fix.

[steakhal]

In D120555#3345471, @aaron.ballman wrote:

LGTM, please add a release note for the fix.

That being said, should backport this to clang-14? @aaron.ballman

[aaron.ballman]

In D120555#3345603, @steakhal wrote:

In D120555#3345471, @aaron.ballman wrote:

LGTM, please add a release note for the fix.

That being said, should backport this to clang-14? @aaron.ballman

I think it's safe enough for that.

[whisperity]

Added Release notes entry.

[whisperity]

Thanks! I'll re-run the tests on top of 14.0 and do the backport too, soon. 🙂

[njames93]

In D120555#3345664, @whisperity wrote:

Thanks! I'll re-run the tests on top of 14.0 and do the backport too, soon. 🙂

If you backport, the release notes change on trunk should then be reverted.

[whisperity]

In D120555#3345707, @njames93 wrote:

If you backport, the release notes change on trunk should then be reverted.

Indeed, this is not the first time I mess this up... Ugh.
I'll wait a little bit for that to make sure the backport is stable, and then I will revert that part of the change.

[whisperity]

In D120555#3345707, @njames93 wrote:

If you backport, the release notes change on trunk should then be reverted.

Release Notes entry of current development tree reverted in rG94850918274c20c15c6071dc52314df51ed2a357.

clang-tools-extra/clang-tidy/readability/SuspiciousCallArgumentCheck.cpp

void SuspiciousCallArgumentCheck::setArgNamesAndTypes(
     const CallExpr *MatchedCallExpr, std::size_t InitialArgIndex) {
   // Reset vectors, and fill them with the currently checked function's
   // arguments' data.
   ArgNames.clear();
   ArgTypes.clear();
 
   for (std::size_t I = InitialArgIndex, J = MatchedCallExpr->getNumArgs();
        I < J; ++I) {
+    assert(ArgTypes.size() == I - InitialArgIndex &&
+           ArgNames.size() == ArgTypes.size() &&
+           "Every iteration must put an element into the vectors!");
+
     if (const auto *ArgExpr = dyn_cast<DeclRefExpr>(
             MatchedCallExpr->getArg(I)->IgnoreUnlessSpelledInSource())) {
       if (const auto *Var = dyn_cast<VarDecl>(ArgExpr->getDecl())) {
         ArgTypes.push_back(Var->getType());
         ArgNames.push_back(Var->getName());
-      } else if (const auto *FCall =
-                     dyn_cast<FunctionDecl>(ArgExpr->getDecl())) {
+        continue;
+      }
+      if (const auto *FCall = dyn_cast<FunctionDecl>(ArgExpr->getDecl())) {
+        if (FCall->getNameInfo().getName().isIdentifier()) {
           ArgTypes.push_back(FCall->getType());
           ArgNames.push_back(FCall->getName());
-      } else {
-        ArgTypes.push_back(QualType());
-        ArgNames.push_back(StringRef());
-      }
-    } else {
-      ArgTypes.push_back(QualType());
-      ArgNames.push_back(StringRef());
-    }
-  }
-}
+          continue;
+        }
+      }
+
 
 bool SuspiciousCallArgumentCheck::areParamAndArgComparable(
     std::size_t Position1, std::size_t Position2, const ASTContext &Ctx) const {
   if (Position1 >= ArgNames.size() || Position2 >= ArgNames.size())
     return false;
 
   // Do not report for too short strings.
   if (ArgNames[Position1].size() < MinimumIdentifierNameLength ||

clang-tools-extra/docs/ReleaseNotes.rst

 ^^^^^^^^^^^^^^^^^
 
 Changes in existing checks
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 - Fixed a false positive in :doc:`readability-non-const-parameter
   <clang-tidy/checks/readability-non-const-parameter>` when the parameter is referenced by an lvalue
 
+- Fixed a crash in :doc:`readability-suspicious-call-argument
+  <clang-tidy/checks/readability-suspicious-call-argument>` related to passing
+  arguments that refer to program elements without a trivial identifier.
 
 Removed checks
 ^^^^^^^^^^^^^^
 
 Improvements to include-fixer
 -----------------------------
 
 The improvements are...

clang-tools-extra/test/clang-tidy/checkers/readability-suspicious-call-argument.cpp

int main() {
   TestClass test;
   int integ, thisIsAnArg = 0;
   test.thisFunction(integ, thisIsAnArg); // Should pass.
 
   has_unnamed(1, bbbbbb);
 
   return 0;
 }
+
+namespace Issue_54074 {
+
+class T {};
+using OperatorTy = int(const T &, const T &);
+int operator-(const T &, const T &);
+
+template <typename U>
+struct Wrap {
+  Wrap(U);
+};
+
+template <typename V>
+void wrapTaker(V, Wrap<OperatorTy>);
+
+template <typename V>
+void wrapTaker(V aaaaa, V bbbbb, Wrap<OperatorTy>);
+
+void test() {
+  wrapTaker(0, operator-);
+  // NO-WARN. No crash!
+
+  int aaaaa = 4, bbbbb = 8;
+  wrapTaker(bbbbb, aaaaa, operator-);
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: 1st argument 'bbbbb' (passed to 'aaaaa') looks like it might be swapped with the 2nd, 'aaaaa' (passed to 'bbbbb')
+  // CHECK-MESSAGES: :[[@LINE-9]]:6: note: in the call to 'wrapTaker<int>', declared here
+}
+
+} // namespace Issue_54074