[clang] [clang-format] Don't align comments over scopes (PR #68743)

[Owen Pan via cfe-commits]

================
@@ -3191,20 +3191,146 @@ TEST_F(FormatTestComments, DontAlignNamespaceComments) {
           "}\n"
           "// Comment";
 
-#if 0
-  // FIXME: The following comment is aligned with the namespace comment.
   verifyFormat("namespace A {\n"
                "  int Foo;\n"
                "  int Bar;\n"
                "} // namespace A\n"
-               " // Comment",
+               "// Comment",
                Input, Style);
-#endif
 
   Style.FixNamespaceComments = false;
   verifyFormat(Input, Style);
 }
 
+TEST_F(FormatTestComments, DontAlignOverScope) {
+  verifyFormat("if (foo) {\n"
+               "  int aLongVariable; // with comment\n"
+               "  int f;             // aligned\n"
+               "} // not aligned\n"
+               "int bar;    // new align\n"
+               "int foobar; // group");
+
+  verifyFormat("if (foo) {\n"
+               "  // something\n"
+               "} else {\n"
+               "  int aLongVariable; // with comment\n"
+               "  int f;             // aligned\n"
+               "} // not aligned\n"
+               "int bar;    // new align\n"
+               "int foobar; // group");
+
+  verifyFormat("if (foo) {\n"
+               "  // something\n"
+               "} else if (foo) {\n"
+               "  int aLongVariable; // with comment\n"
+               "  int f;             // aligned\n"
+               "} // not aligned\n"
+               "int bar;    // new align\n"
+               "int foobar; // group");
+
+  verifyFormat("while (foo) {\n"
+               "  int aLongVariable; // with comment\n"
+               "  int f;             // aligned\n"
+               "} // not aligned\n"
+               "int bar;    // new align\n"
+               "int foobar; // group");
+
+  verifyFormat("for (;;) {\n"
+               "  int aLongVariable; // with comment\n"
+               "  int f;             // aligned\n"
+               "} // not aligned\n"
+               "int bar;    // new align\n"
+               "int foobar; // group");
+
+#if 0
+  // FIXME: Skip do-while
+  verifyFormat("do {\n"
+               "  int aLongVariable; // with comment\n"
+               "  int f;             // aligned\n"
+               "} while (foo); // not aligned\n"
+               "int bar;    // new align\n"
+               "int foobar; // group");
+
+  verifyFormat("do\n"
+               "  int aLongVariable; // with comment\n"
+               "while (foo); // not aigned"
+               "int bar;    // new align\n"
+               "int foobar; // group");
+#endif
+
+  verifyFormat("switch (foo) {\n"
+               "case 7: {\n"
+               "  int aLongVariable; // with comment\n"
+               "  int f;             // aligned\n"
+               "} // case not aligned\n"
+               "} // switch also not aligned\n"
+               "int bar;    // new align\n"
+               "int foobar; // group");
+
+  verifyFormat("switch (foo) {\n"
+               "default: {\n"
+               "  int aLongVariable; // with comment\n"
+               "  int f;             // aligned\n"
+               "} // case not aligned\n"
+               "} // switch also not aligned\n"
+               "int bar;    // new align\n"
+               "int foobar; // group");
+
+  verifyFormat("class C {\n"
+               "  int aLongVariable; // with comment\n"
+               "  int f;             // aligned\n"
+               "}; // not aligned\n"
+               "int bar;    // new align\n"
+               "int foobar; // group");
+
+  verifyFormat("struct S {\n"
+               "  int aLongVariable; // with comment\n"
+               "  int f;             // aligned\n"
+               "}; // not aligned\n"
+               "int bar;    // new align\n"
+               "int foobar; // group");
+
+  verifyFormat("union U {\n"
+               "  int aLongVariable; // with comment\n"
+               "  int f;             // aligned\n"
+               "}; // not aligned\n"
+               "int bar;    // new align\n"
+               "int foobar; // group");
+
+  verifyFormat("enum E {\n"
+               "  aLongVariable, // with comment\n"
+               "  f              // aligned\n"
+               "}; // not aligned\n"
+               "int bar;    // new align\n"
+               "int foobar; // group");
+
+  verifyFormat("void foo() {\n"
+               "  {\n"
+               "    int aLongVariable; // with comment\n"
+               "    int f;             // aligned\n"
+               "  } // not aligned\n"
+               "  int bar;    // new align\n"
+               "  int foobar; // group\n"
+               "}");
+
+  verifyFormat("auto longLambda = [] { // comment\n"
+               "  int aLongVariable;   // with comment\n"
+               "  int f;               // aligned\n"
+               "}; // not aligned\n"
+               "int bar;                             // new align\n"
+               "int foobar;                          // group\n"
+               "auto shortLambda = [] { return 5; }; // aligned");
+
+  // Short Elements
+  verifyFormat("namespace NS {} // namespace NS\n"
+               "class C {}; // Comments\n"
+               "struct S {}; // are\n"
+               "union {}; // not\n"
+               "enum E {}; // aligned\n"
+               "int x;   // evenwhen the braces have no new\n"
+               "int foo; // line in front of them");
----------------
owenca wrote:

Empty `namespace`, `class`, etc. are probably rare to non-existent in real code. If they do exist, I'd argue that their trailing comments should be aligned.

https://github.com/llvm/llvm-project/pull/68743