[clang-format] Fix short enums getting wrapped even when denied

[yodaldevoid]

Summary

Single-variant enums were still getting placed on a single line even
when AllowShortEnumsOnASingleLine was false. This fixes that by checking
that setting when looking to merge lines.

[MyDeveloperDay]

Can you test the typedef case you added?

[owenpan]

clang/lib/Format/UnwrappedLineFormatter.cpp

398–403

Nits:

• It's unnecessary to add the checking for a null TheLine->First on line 398 since TheLine->Last is nonnull.
• The suggested assert is optional.
• Since the first token is typedef and the last {, checking for a null Tok on line 400 is unnecessary.

406

[yodaldevoid]

Addressed reviewer comments

• Removed unnecessary null checks
• Added tests for typedefs preceding short enums

[yodaldevoid]

Correct commit email

[HazardyKnusperkeks]

In D116188#3208378, @yodaldevoid wrote:

Correct commit email

Since you only upload a diff, there is no name or email. ;)

[curdeius]

LGTM.

[yodaldevoid]

In D116188#3208456, @HazardyKnusperkeks wrote:

Since you only upload a diff, there is no name or email. ;)

It had looked like arcanist was retaining this information, but I now realize what it was doing.

At any rate, I would appreciate it if someone could merge this for me as I don't have commit access.

Gabriel Smith <[e-mail]>

clang/lib/Format/UnwrappedLineFormatter.cpp

if (Style.BraceWrapping.SplitEmptyRecord &&
               return 0;
           }
         }
       }
     }
 
     // Try to merge a block with left brace wrapped that wasn't yet covered
     if (TheLine->Last->is(tok::l_brace)) {
+      const FormatToken *Tok = TheLine->First;
       bool ShouldMerge = false;
-      if (TheLine->First->isOneOf(tok::kw_class, tok::kw_struct)) {
+      if (Tok->is(tok::kw_typedef)) {
+        Tok = Tok->getNextNonComment();
+        assert(Tok);
+      }
+      if (Tok->isOneOf(tok::kw_class, tok::kw_struct)) {
         ShouldMerge = !Style.BraceWrapping.AfterClass ||
                       (I[1]->First->is(tok::r_brace) &&
                        !Style.BraceWrapping.SplitEmptyRecord);
+      } else if (Tok->is(tok::kw_enum)) {
+        ShouldMerge = Style.AllowShortEnumsOnASingleLine;
       } else {
         ShouldMerge = !Style.BraceWrapping.AfterFunction ||
                       (I[1]->First->is(tok::r_brace) &&
                        !Style.BraceWrapping.SplitEmptyFunction);
       }
       return ShouldMerge ? tryMergeSimpleBlock(I, E, Limit) : 0;
     }
     // Try to merge a function block with left brace wrapped

clang/unittests/Format/FormatTest.cpp

verifyFormat("switch (x) {\n"
                "  break;\n"
                "}");
 }
 
 TEST_F(FormatTest, ShortEnums) {
   FormatStyle Style = getLLVMStyle();
   Style.AllowShortEnumsOnASingleLine = true;
   verifyFormat("enum { A, B, C } ShortEnum1, ShortEnum2;", Style);
+  verifyFormat("typedef enum { A, B, C } ShortEnum1, ShortEnum2;", Style);
   Style.AllowShortEnumsOnASingleLine = false;
   verifyFormat("enum {\n"
                "  A,\n"
                "  B,\n"
                "  C\n"
                "} ShortEnum1, ShortEnum2;",
                Style);
+  verifyFormat("typedef enum {\n"
+               "  A,\n"
+               "  B,\n"
+               "  C\n"
+               "} ShortEnum1, ShortEnum2;",
+               Style);
+  verifyFormat("enum {\n"
+               "  A,\n"
+               "} ShortEnum1, ShortEnum2;",
+               Style);
+  verifyFormat("typedef enum {\n"
+               "  A,\n"
+               "} ShortEnum1, ShortEnum2;",
+               Style);
   Style.BreakBeforeBraces = FormatStyle::BS_Custom;
   Style.BraceWrapping.AfterEnum = true;
   verifyFormat("enum\n"
                "{\n"
                "  A,\n"
                "  B,\n"
                "  C\n"
                "} ShortEnum1, ShortEnum2;",