[clang-tidy] `bugprone-use-after-move`: Fix handling of moves in lambda captures

[mboehme]

Summary

Previously, we were treating a move in the lambda capture as if it happened
within the body of the lambda, not within the function that defines the lambda.

This fixes the same bug as https://reviews.llvm.org/D119165 (which it appears
may have been abandoned by the author?) but does so more simply.

[njames93]

LGTM, But please add a note to ReleaseNotes before landing.

[mboehme]

Added release notes.

[mboehme]

In D126780#3552999, @njames93 wrote:

LGTM, But please add a note to ReleaseNotes before landing.

Thanks for reminding me! Done.

clang-tools-extra/clang-tidy/bugprone/UseAfterMoveCheck.cpp

Check->diag(UseLoc,
                 DiagnosticIDs::Note);
   }
 }
 
 void UseAfterMoveCheck::registerMatchers(MatchFinder *Finder) {
   auto CallMoveMatcher =
       callExpr(callee(functionDecl(hasName("::std::move"))), argumentCountIs(1),
                hasArgument(0, declRefExpr().bind("arg")),
-               anyOf(hasAncestor(lambdaExpr().bind("containing-lambda")),
+               anyOf(hasAncestor(compoundStmt(
+                         hasParent(lambdaExpr().bind("containing-lambda")))),
                      hasAncestor(functionDecl().bind("containing-func"))),
                unless(inDecltypeOrTemplateArg()),
                // try_emplace is a common maybe-moving function that returns a
                // bool to tell callers whether it moved. Ignore std::move inside
                // try_emplace to avoid false positives as we don't track uses of
                // the bool.
                unless(hasParent(cxxMemberCallExpr(
                    callee(cxxMethodDecl(hasName("try_emplace")))))))

clang-tools-extra/docs/ReleaseNotes.rst

 - Expanded :doc:`readability-simplify-boolean-expr
   <clang-tidy/checks/readability-simplify-boolean-expr>` to simplify expressions
   using DeMorgan's Theorem.
 
 - Fixed a crash in :doc:`performance-unnecessary-value-param
   <clang-tidy/checks/readability-suspicious-call-argument>` when the specialization
   template has an unnecessary value paramter. Removed the fix for a template.
 
+- Fixed a bug in :doc:`bugprone-use-after-move
+  <clang-tidy/checks/bugprone-use-after-move> where a move in a lambda capture
+  was treated as if it happened within the body of the lambda, not within the
+  function that defines the lambda.
+
 Removed checks
 ^^^^^^^^^^^^^^
 
 Improvements to include-fixer
 -----------------------------
 
 The improvements are...
 

clang-tools-extra/test/clang-tidy/checkers/bugprone-use-after-move.cpp

// Same tests but for capture by reference.
     auto lambda = [&a]() { a.foo(); };
     std::move(a);
   }
   {
     A a;
     auto lambda = [&]() { a.foo(); };
     std::move(a);
   }
+  {
+    A a;
+    auto lambda = [a = std::move(a)] { a.foo(); };
+    a.foo();
+    // CHECK-NOTES: [[@LINE-1]]:5: warning: 'a' used after it was moved
+    // CHECK-NOTES: [[@LINE-3]]:24: note: move occurred here
+  }
 }
 
 // Use-after-moves are detected in uninstantiated templates if the moved type
 // is not a dependent type.
 template <class T>
 void movedTypeIsNotDependentType() {
   T t;
   A a;