[clang] 8dab452 - [clang-format] Disallow requires clauses to become function declarations

[Emilia Dreamer via cfe-commits]

Author: Emilia Dreamer
Date: 2022-09-19T04:04:31+03:00
New Revision: 8dab452740007e03c963b349e716068eac2b25a0

URL: https://github.com/llvm/llvm-project/commit/8dab452740007e03c963b349e716068eac2b25a0
DIFF: https://github.com/llvm/llvm-project/commit/8dab452740007e03c963b349e716068eac2b25a0.diff

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

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

Reviewed By: HazardyKnusperkeks, owenpan

Differential Revision: https://reviews.llvm.org/D134052

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index a81bbb99f5d9e..e530120fa4454 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -1110,7 +1110,7 @@ class AnnotatingParser {
           !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;
       }

diff  --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index f3007f85e91b0..d27c176415c83 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -737,6 +737,16 @@ TEST_F(TokenAnnotatorTest, RequiresDoesNotChangeParsingOfTheRest) {
   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"