[clang] 2eff1c3 - [clang-format] Extend AllowShortLoopsOnASingleLine to do ... while loops.

[Mitchell Balan via cfe-commits]

Author: Mitchell Balan
Date: 2020-03-06T11:13:23-05:00
New Revision: 2eff1c3ce48ef529064e2dc006d57c37da0b4d84

URL: https://github.com/llvm/llvm-project/commit/2eff1c3ce48ef529064e2dc006d57c37da0b4d84
DIFF: https://github.com/llvm/llvm-project/commit/2eff1c3ce48ef529064e2dc006d57c37da0b4d84.diff

LOG: [clang-format] Extend AllowShortLoopsOnASingleLine to do ... while loops.
Summary:
If AllowShortLoopsOnASingleLine is enabled,

  do
    a++;
  while (true);

becomes

  do a++;
  while (true);

Reviewers: MyDeveloperDay, mitchell-stellar

Reviewed by: mitchell-stellar

Contributed by: DaanDeMeyer

Subscribers: cfe-commits

Tags: #clang, #clang-format

Differential Revision: https://reviews.llvm.org/D75022

Added: 
    

Modified: 
    clang/lib/Format/UnwrappedLineFormatter.cpp
    clang/unittests/Format/FormatTest.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Format/UnwrappedLineFormatter.cpp b/clang/lib/Format/UnwrappedLineFormatter.cpp
index da9ee41da71b..84ccbec2150d 100644
--- a/clang/lib/Format/UnwrappedLineFormatter.cpp
+++ b/clang/lib/Format/UnwrappedLineFormatter.cpp
@@ -411,7 +411,7 @@ class LineJoiner {
                  ? tryMergeSimpleControlStatement(I, E, Limit)
                  : 0;
     }
-    if (TheLine->First->isOneOf(tok::kw_for, tok::kw_while)) {
+    if (TheLine->First->isOneOf(tok::kw_for, tok::kw_while, tok::kw_do)) {
       return Style.AllowShortLoopsOnASingleLine
                  ? tryMergeSimpleControlStatement(I, E, Limit)
                  : 0;
@@ -514,7 +514,10 @@ class LineJoiner {
       return 0;
     Limit = limitConsideringMacros(I + 1, E, Limit);
     AnnotatedLine &Line = **I;
-    if (Line.Last->isNot(tok::r_paren))
+    if (!Line.First->is(tok::kw_do) && Line.Last->isNot(tok::r_paren))
+      return 0;
+    // Only merge do while if do is the only statement on the line.
+    if (Line.First->is(tok::kw_do) && !Line.Last->is(tok::kw_do))
       return 0;
     if (1 + I[1]->Last->TotalLength > Limit)
       return 0;

diff  --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index cb052ecaf111..a6f35ba27069 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -556,6 +556,30 @@ TEST_F(FormatTest, FormatLoopsWithoutCompoundStatement) {
   verifyFormat("for (;;) /* still don't merge */\n"
                "  continue;",
                AllowsMergedLoops);
+  verifyFormat("do a++;\n"
+               "while (true);",
+               AllowsMergedLoops);
+  verifyFormat("do /* Don't merge */\n"
+               "  a++;\n"
+               "while (true);",
+               AllowsMergedLoops);
+  verifyFormat("do // Don't merge\n"
+               "  a++;\n"
+               "while (true);",
+               AllowsMergedLoops);
+  verifyFormat("do\n"
+               "  // Don't merge\n"
+               "  a++;\n"
+               "while (true);",
+               AllowsMergedLoops);
+  // Without braces labels are interpreted 
diff erently.
+  verifyFormat("{\n"
+               "  do\n"
+               "  label:\n"
+               "    a++;\n"
+               "  while (true);\n"
+               "}",
+               AllowsMergedLoops);
 }
 
 TEST_F(FormatTest, FormatShortBracedStatements) {