[clang-format] Extra spaces surrounding arrow in templated member call in variable decl

[MyDeveloperDay]

Summary

https://github.com/llvm/llvm-project/issues/43196

Fixes #43196

-> is incorrectly interpreted as a TrailingReturnArrow if we've seen an auto

auto p = new A;
auto x = p -> foo<1>();

[curdeius]

clang/lib/Format/TokenAnnotator.cpp

1682

Won't it break lambdas with an identifier (e.g. macro) before the arrow? E.g.:

auto lmbd = [] NOEXCEPT -> int {
  return 0;
};

[MyDeveloperDay]

clang/lib/Format/TokenAnnotator.cpp

1682

it doesn't seem so, maybe one of the other rules is catching that

auto lmbd = [] NOEXCEPT -> int { return 0; };

[curdeius]

LGTM.

clang/lib/Format/TokenAnnotator.cpp

1682

Ok, but I'd like to see it as a test case if we don't have something similar already.

[MyDeveloperDay]

clang/lib/Format/TokenAnnotator.cpp

1682

let me add that for completeness before I commit

[MyDeveloperDay]

Add additional test to show lambda's should be ok

clang/lib/Format/TokenAnnotator.cpp

if (Current.is(Keywords.kw_instanceof)) {
       Contexts.back().FirstStartOfName = nullptr;
     } else if (Current.isOneOf(tok::kw_auto, tok::kw___auto_type)) {
       AutoFound = true;
     } else if (Current.is(tok::arrow) &&
                Style.Language == FormatStyle::LK_Java) {
       Current.setType(TT_LambdaArrow);
     } else if (Current.is(tok::arrow) && AutoFound && Line.MustBeDeclaration &&
                Current.NestingLevel == 0 &&
-               !Current.Previous->is(tok::kw_operator)) {
+               !Current.Previous->isOneOf(tok::kw_operator, tok::identifier)) {
       // not auto operator->() -> xxx;
       Current.setType(TT_TrailingReturnArrow);
     } else if (Current.is(tok::arrow) && Current.Previous &&
                Current.Previous->is(tok::r_brace)) {
       // Concept implicit conversion constraint needs to be treated like
       // a trailing return type  ... } -> <type>.
       Current.setType(TT_TrailingReturnArrow);
     } else if (isDeductionGuide(Current)) {

clang/unittests/Format/FormatTest.cpp

verifyFormat("auto SomeFunction(A aaaaaaaaaaaaaaaaaaaaa) const\n"
                "    -> decltype(f(aaaaaaaaaaaaaaaaaaaaa)) {}");
   verifyFormat("auto doSomething(Aaaaaa *aaaaaa) -> decltype(aaaaaa->f()) {}");
   verifyFormat("template <typename T>\n"
                "auto aaaaaaaaaaaaaaaaaaaaaa(T t)\n"
                "    -> decltype(eaaaaaaaaaaaaaaa<T>(t.a).aaaaaaaa());");
 
   // Not trailing return types.
   verifyFormat("void f() { auto a = b->c(); }");
+  verifyFormat("auto a = p->foo();");
+  verifyFormat("int a = p->foo();");
+  verifyFormat("auto lmbd = [] NOEXCEPT -> int { return 0; };");
 }
 
 TEST_F(FormatTest, DeductionGuides) {
   verifyFormat("template <class T> A(const T &, const T &) -> A<T &>;");
   verifyFormat("template <class T> explicit A(T &, T &&) -> A<T>;");
   verifyFormat("template <class... Ts> S(Ts...) -> S<Ts...>;");
   verifyFormat(
       "template <class... T>\n"