[clang-format] [PR43531] clang-format damages "alternative representations" for operators

Summary:
https://bugs.llvm.org/show_bug.cgi?id=43531

Fix for clang-format incorrectly handles "alternative operators" as described by https://en.cppreference.com/w/cpp/language/operator_alternative

compl = ~
not = !

these are unary operators, and clang-format will remove the space between them and a numeric constant

this incorrectly formats the following code

```
int a compl 5;
int a not 5;
```

into:

```
int a compl5;
int a not5;
```

The code adds FIXME unit tests for "alternative token" representations for {} [] and # as defined by the same link, which would require a more detailed change to the FormatTokenLexer

Reviewers: klimek, reuk, owenpan, mitchell-stellar, STL_MSFT

Reviewed By: mitchell-stellar

Subscribers: cfe-commits

Tags: #clang-format, #clang-tools-extra, #clang

Differential Revision: https://reviews.llvm.org/D68332

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@373750 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 42 insertions, 0 deletions

diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index b770d0f26f..14ac6f9137 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -14609,6 +14609,48 @@ TEST_F(FormatTest, AmbersandInLamda) {
   verifyFormat("auto lambda = [&a = a]() { a = 2; };", AlignStyle);
 }
 
+TEST_F(FormatTest, AlternativeOperators) {
+  // Test case for ensuring alternate operators are not
+  // combined with their right most neighbour.
+  verifyFormat("int a and b;");
+  verifyFormat("int a and_eq b;");
+  verifyFormat("int a bitand b;");
+  verifyFormat("int a bitor b;");
+  verifyFormat("int a compl b;");
+  verifyFormat("int a not b;");
+  verifyFormat("int a not_eq b;");
+  verifyFormat("int a or b;");
+  verifyFormat("int a xor b;");
+  verifyFormat("int a xor_eq b;");
+  verifyFormat("return this not_eq bitand other;");
+  verifyFormat("bool operator not_eq(const X bitand other)");
+
+  verifyFormat("int a and 5;");
+  verifyFormat("int a and_eq 5;");
+  verifyFormat("int a bitand 5;");
+  verifyFormat("int a bitor 5;");
+  verifyFormat("int a compl 5;");
+  verifyFormat("int a not 5;");
+  verifyFormat("int a not_eq 5;");
+  verifyFormat("int a or 5;");
+  verifyFormat("int a xor 5;");
+  verifyFormat("int a xor_eq 5;");
+
+  verifyFormat("int a compl(5);");
+  verifyFormat("int a not(5);");
+
+  /* FIXME handle alternate tokens
+   * https://en.cppreference.com/w/cpp/language/operator_alternative
+  // alternative tokens
+  verifyFormat("compl foo();");     //  ~foo();
+  verifyFormat("foo() <%%>;");      // foo();
+  verifyFormat("void foo() <%%>;"); // void foo(){}
+  verifyFormat("int a <:1:>;");     // int a[1];[
+  verifyFormat("%:define ABC abc"); // #define ABC abc
+  verifyFormat("%:%:");             // ##
+  */
+}
+
 } // end namespace
 } // end namespace format
 } // end namespace clang