[clang-format] Fix misattributing preprocessor directives to macros

[jacob-abraham]

Summary

This solves the issue I documented at https://github.com/llvm/llvm-project/issues/58214.

Essentially, a case statement inside a macro greedily adds preprocessor lines such as #include to the macro, even if they are not a part of the macro to begin with. Short quick fix. I tried to do it cleanly, but this was my first attempt at patching clang-format so if there is a cleaner/better way to fix this that would be awesome!

[HazardyKnusperkeks]

Please add a regression test.

[jacob-abraham]

Added regression test

[jacob-abraham]

Fix patch, sorry about that

[HazardyKnusperkeks]

The clang-format tests are (mainly) in clang/unittests/Format/FormatTest.cpp, please put it there.
You should have a Format-Tests (or similar) build target.

[jacob-abraham]

fixed unit tests

[owenpan]

clang/unittests/Format/FormatTest.cpp

2986–2990

We can move it down to take advantage of the shorter ColumnLimit.

3001–3005

We usually don't append a newline at the end of a test case.

[jacob-abraham]

I do not have commit access, can someone make this commit on my behalf? Thank you!

[owenpan]

LGTM.

In D135422#3847053, @jacob-abraham wrote:

I do not have commit access, can someone make this commit on my behalf? Thank you!

We need your name and email address for the authorship.

[jacob-abraham]

We need your name and email address for the authorship.

Name: Jacob Abraham
Email: [e-mail]

[owenpan]

clang/lib/Format/UnwrappedLineFormatter.cpp

654

Did you run git-clang-format?

clang/lib/Format/UnwrappedLineFormatter.cpp

if (Limit == 0 || I + 1 == E ||
       return 0;
     }
     if (I[0]->Last->is(tok::l_brace) || I[1]->First->is(tok::l_brace))
       return 0;
     unsigned NumStmts = 0;
     unsigned Length = 0;
     bool EndsWithComment = false;
     bool InPPDirective = I[0]->InPPDirective;
+    bool InMacroBody = I[0]->InMacroBody;
     const unsigned Level = I[0]->Level;
     for (; NumStmts < 3; ++NumStmts) {
       if (I + 1 + NumStmts == E)
         break;
       const AnnotatedLine *Line = I[1 + NumStmts];
       if (Line->InPPDirective != InPPDirective)
         break;
+      if (Line->InMacroBody != InMacroBody)
+        break;
       if (Line->First->isOneOf(tok::kw_case, tok::kw_default, tok::r_brace))
         break;
       if (Line->First->isOneOf(tok::kw_if, tok::kw_for, tok::kw_switch,
                                tok::kw_while) ||
           EndsWithComment) {
         return 0;
       }
       if (Line->First->is(tok::comment)) {

clang/unittests/Format/FormatTest.cpp

EXPECT_EQ("switch (a) {\n"
                    "}",
                    Style));
   verifyFormat("switch (a) {\n"
                "#if FOO\n"
                "case 0: return 0;\n"
                "#endif\n"
                "}",
                Style);
   verifyFormat("switch (a) {\n"
                "case 1: {\n"
                "}\n"
                "case 2: {\n"
                "  return;\n"
                "}\n"
                "case 3: {\n"
                "  x = 1;\n"
                "  return;\n"
                "}\n"
                "case 4:\n"
                "  if (x)\n"
                "    return;\n"
                "}",
                Style);
   Style.ColumnLimit = 21;
+  verifyFormat("#define X           \\\n"
+               "  case 0: break;\n"
+               "#include \"f\"",
+               Style);
   verifyFormat("switch (a) {\n"
                "case 1: x = 1; break;\n"
                "case 2: return;\n"
                "case 3:\n"
                "case 4:\n"
                "case 5: return;\n"
                "default:\n"
                "  y = 1;\n"