[PATCH] D68332: [clang-format] [PR43531] clang-format damages "alternative representations" for operators

[MyDeveloperDay via Phabricator via cfe-commits]

MyDeveloperDay created this revision.
MyDeveloperDay added reviewers: klimek, reuk, owenpan, mitchell-stellar, STL_MSFT.
MyDeveloperDay added projects: clang-format, clang-tools-extra.
Herald added a project: clang.

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


Repository:
  rC Clang

https://reviews.llvm.org/D68332

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
@@ -14441,6 +14441,44 @@
   verifyFormat("auto lambda = [&a = a]() { a = 2; };", AlignStyle);
 }
 
+TEST_F(FormatTest, AlternativeOperators) {
+  // Test case for bug https://bugs.llvm.org/show_bug.cgi?id=43531
+  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;");
+
+  /* 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
Index: clang/lib/Format/TokenAnnotator.cpp
===================================================================
--- clang/lib/Format/TokenAnnotator.cpp
+++ clang/lib/Format/TokenAnnotator.cpp
@@ -2888,9 +2888,19 @@
       return false;
     return true;
   }
-  if (Left.is(TT_UnaryOperator))
+  if (Left.is(TT_UnaryOperator)) {
+    // Don't combine the unary operators !~ into "compl5" and "not5"
+    // when using alternative operators "compl" and "not"
+    // but allow "compl(" to not become "compl (".
+    if (!Right.is(tok::l_paren)) {
+      if (Left.is(tok::exclaim) && Left.TokenText.equals("not"))
+        return true;
+      if (Left.is(tok::tilde) && Left.TokenText.equals("compl"))
+        return true;
+    }
     return (Style.SpaceAfterLogicalNot && Left.is(tok::exclaim)) ||
            Right.is(TT_BinaryOperator);
+  }
 
   // If the next token is a binary operator or a selector name, we have
   // incorrectly classified the parenthesis as a cast. FIXME: Detect correctly.


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