[PATCH] D134052: [clang-format] Disallow requires clauses to become function declarations

[Emilia Dreamer via Phabricator via cfe-commits]

rymiel created this revision.
rymiel added reviewers: HazardyKnusperkeks, owenpan, MyDeveloperDay, curdeius.
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There already exists logic to disallow requires *expressions* to be
treated as function declarations, but this expands it to include
requires *clauses*, when they happen to also be parenthesized.

Previously, in the following case:

  template <typename T>
    requires(Foo<T>)
  T foo();

The line with the requires clause was actually being considered as the
line with the function declaration due to the parentheses, and the
*real* function declaration on the next line became a trailing
annotation

(Together with https://reviews.llvm.org/D134049) Fixes https://github.com/llvm/llvm-project/issues/56213


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D134052

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


Index: clang/unittests/Format/TokenAnnotatorTest.cpp
===================================================================
--- clang/unittests/Format/TokenAnnotatorTest.cpp
+++ clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -728,6 +728,16 @@
   BaseTokenCount = 26;
   TestRequires(__LINE__);
 
+  BaseCode = "template<typename T>\n"
+             "T foo();";
+  ConstrainedCode = "template<typename T>\n"
+                    "  requires(Foo<T>)\n"
+                    "T foo();";
+  BaseTokenCount = 11;
+  RequiresTokenCount = 7;
+  PrefixTokenCount = 5;
+  TestRequires(__LINE__);
+
   BaseCode = "template<typename T>\n"
              "Bar(T) -> Bar<typename T::I>;";
   ConstrainedCode = "template<typename T>\n"
Index: clang/lib/Format/TokenAnnotator.cpp
===================================================================
--- clang/lib/Format/TokenAnnotator.cpp
+++ clang/lib/Format/TokenAnnotator.cpp
@@ -1110,7 +1110,7 @@
           !Contexts.back().IsExpression && !Line.startsWith(TT_ObjCProperty) &&
           !Tok->isOneOf(TT_TypeDeclarationParen, TT_RequiresExpressionLParen) &&
           (!Tok->Previous ||
-           !Tok->Previous->isOneOf(tok::kw___attribute,
+           !Tok->Previous->isOneOf(tok::kw___attribute, TT_RequiresClause,
                                    TT_LeadingJavaAnnotation))) {
         Line.MightBeFunctionDecl = true;
       }


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