[PATCH] D141811: [clang-format] Allow trailing return types in macros

[Emilia Dreamer via Phabricator via cfe-commits]

rymiel created this revision.
rymiel added reviewers: HazardyKnusperkeks, owenpan, MyDeveloperDay.
rymiel added a project: clang-format.
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The trailing return type arrow checker verifies that a declaration is
being parsed, however, this isn't true when inside of macros.

It turns out the existence of the auto keyword is enough to make
sure that we're dealing with a trailing return type, and whether we're
in a declaration doesn't matter.

Fixes https://github.com/llvm/llvm-project/issues/47664


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D141811

Files:
  clang/lib/Format/TokenAnnotator.cpp
  clang/unittests/Format/FormatTest.cpp


Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -7986,6 +7986,10 @@
                "auto aaaaaaaaaaaaaaaaaaaaaa(T t)\n"
                "    -> decltype(eaaaaaaaaaaaaaaa<T>(t.a).aaaaaaaa());");
 
+  verifyFormat("#define MAKE_DEF(NAME)                                         "
+               "                \\\n"
+               "  auto NAME() -> int { return 42; }");
+
   // Not trailing return types.
   verifyFormat("void f() { auto a = b->c(); }");
   verifyFormat("auto a = p->foo();");
Index: clang/lib/Format/TokenAnnotator.cpp
===================================================================
--- clang/lib/Format/TokenAnnotator.cpp
+++ clang/lib/Format/TokenAnnotator.cpp
@@ -1880,7 +1880,8 @@
     } else if (Current.is(tok::arrow) &&
                Style.Language == FormatStyle::LK_Java) {
       Current.setType(TT_LambdaArrow);
-    } else if (Current.is(tok::arrow) && AutoFound && Line.MustBeDeclaration &&
+    } else if (Current.is(tok::arrow) && AutoFound &&
+               (Line.MustBeDeclaration || Line.InPPDirective) &&
                Current.NestingLevel == 0 &&
                !Current.Previous->isOneOf(tok::kw_operator, tok::identifier)) {
       // not auto operator->() -> xxx;


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