[PATCH] D135918: [clang-format] Fix lambda formatting in conditional

[Björn Schäpers via Phabricator via cfe-commits]

HazardyKnusperkeks created this revision.
HazardyKnusperkeks added reviewers: MyDeveloperDay, owenpan, curdeius, rymiel.
HazardyKnusperkeks added a project: clang-format.
Herald added a project: All.
HazardyKnusperkeks requested review of this revision.
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Without the patch UnwrappedLineFormatter::analyzeSolutionSpace just ran out of possible formattings and would put everything just on one line. The problem was that the the line break was forbidden, but putting the conditional colon on the same line is also forbidden.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D135918

Files:
  clang/lib/Format/ContinuationIndenter.cpp
  clang/unittests/Format/FormatTest.cpp


Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -26379,6 +26379,33 @@
                Style);
 }
 
+TEST_F(FormatTest, MultilineLambdaInConditional) {
+  auto Style = getLLVMStyleWithColumns(70);
+  verifyFormat("auto aLengthyIdentifier = oneExpressionSoThatWeBreak ? []() {\n"
+               "  ;\n"
+               "  return 5;\n"
+               "}()\n"
+               "                                                     : 2;",
+               Style);
+
+  Style = getLLVMStyleWithColumns(60);
+  verifyFormat("auto aLengthyIdentifier = oneExpressionSoThatWeBreak\n"
+               "                              ? []() {\n"
+               "                                  ;\n"
+               "                                  return 5;\n"
+               "                                }()\n"
+               "                              : 2;",
+               Style);
+
+  Style = getLLVMStyleWithColumns(40);
+  verifyFormat("auto aLengthyIdentifier =\n"
+               "    oneExpressionSoThatWeBreak ? []() {\n"
+               "      ;\n"
+               "      return 5;\n"
+               "    }()\n"
+               "                               : 2;", Style);
+}
+
 TEST_F(FormatTest, AlignAfterOpenBracketBlockIndent) {
   auto Style = getLLVMStyle();
 
Index: clang/lib/Format/ContinuationIndenter.cpp
===================================================================
--- clang/lib/Format/ContinuationIndenter.cpp
+++ clang/lib/Format/ContinuationIndenter.cpp
@@ -1419,9 +1419,14 @@
       Previous && Previous->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) &&
       !Previous->is(TT_DictLiteral) && State.Stack.size() > 1 &&
       !CurrentState.HasMultipleNestedBlocks) {
-    if (State.Stack[State.Stack.size() - 2].NestedBlockInlined && Newline)
+    if (State.Stack[State.Stack.size() - 2].NestedBlockInlined && Newline &&
+        // Do not forbid line breaks for directly invoced lambdas.
+        (!Current.MatchingParen ||
+         Current.MatchingParen->isNot(TT_LambdaLBrace) || !Current.Next ||
+         Current.Next->isNot(tok::l_paren))) {
       for (ParenState &PState : llvm::drop_end(State.Stack))
         PState.NoLineBreak = true;
+    }
     State.Stack[State.Stack.size() - 2].NestedBlockInlined = false;
   }
   if (Previous && (Previous->isOneOf(TT_BinaryOperator, TT_ConditionalExpr) ||


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