From: Jacek Olesiak <jolesiak@google.com>
Date: Mon, 9 Jul 2018 07:08:45 +0000 (+0000)
Subject: [clang-format/ObjC] Put ObjC method arguments into one line when they fit
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=15e70438359dad2206c30f87afc1c4f6cb063b5e;p=clang

[clang-format/ObjC] Put ObjC method arguments into one line when they fit

Reapply D47195:
Currently BreakBeforeParameter is set to true everytime message receiver spans multiple lines, e.g.:
```
[[object block:^{
  return 42;
}] aa:42 bb:42];
```
will be formatted:
```
[[object block:^{
  return 42;
}] aa:42
   bb:42];
```
even though arguments could fit into one line. This change fixes this behavior.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@336521 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Format/ContinuationIndenter.cpp b/lib/Format/ContinuationIndenter.cpp
index 0862a4e0f9..90d2a99971 100644
--- a/lib/Format/ContinuationIndenter.cpp
+++ b/lib/Format/ContinuationIndenter.cpp
@@ -1398,6 +1398,30 @@ void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
        (Current.is(tok::greater) && Current.is(TT_DictLiteral))))
     State.Stack.pop_back();
 
+  // Reevaluate whether ObjC message arguments fit into one line.
+  // If a receiver spans multiple lines, e.g.:
+  //   [[object block:^{
+  //     return 42;
+  //   }] a:42 b:42];
+  // BreakBeforeParameter is calculated based on an incorrect assumption
+  // (it is checked whether the whole expression fits into one line without
+  // considering a line break inside a message receiver).
+  // We check whether arguements fit after receiver scope closer (into the same
+  // line).
+  if (State.Stack.back().BreakBeforeParameter && Current.MatchingParen &&
+      Current.MatchingParen->Previous) {
+    const FormatToken &CurrentScopeOpener = *Current.MatchingParen->Previous;
+    if (CurrentScopeOpener.is(TT_ObjCMethodExpr) &&
+        CurrentScopeOpener.MatchingParen) {
+      int NecessarySpaceInLine =
+          getLengthToMatchingParen(CurrentScopeOpener, State.Stack) +
+          CurrentScopeOpener.TotalLength - Current.TotalLength - 1;
+      if (State.Column + Current.ColumnWidth + NecessarySpaceInLine <=
+          Style.ColumnLimit)
+        State.Stack.back().BreakBeforeParameter = false;
+    }
+  }
+
   if (Current.is(tok::r_square)) {
     // If this ends the array subscript expr, reset the corresponding value.
     const FormatToken *NextNonComment = Current.getNextNonComment();
diff --git a/unittests/Format/FormatTestObjC.cpp b/unittests/Format/FormatTestObjC.cpp
index 58e75363a5..e56df6d130 100644
--- a/unittests/Format/FormatTestObjC.cpp
+++ b/unittests/Format/FormatTestObjC.cpp
@@ -820,6 +820,48 @@ TEST_F(FormatTestObjC, FormatObjCMethodExpr) {
   verifyFormat("aaaaaa = [aa aa:aa\n"
                "             aa:aa];");
 
+  // Message receiver taking multiple lines.
+  // Non-corner case.
+  verifyFormat("[[object block:^{\n"
+               "  return 42;\n"
+               "}] a:42 b:42];");
+  // Arguments just fit into one line.
+  verifyFormat("[[object block:^{\n"
+               "  return 42;\n"
+               "}] aaaaaaa:42 b:42];");
+  // Arguments just over a column limit.
+  verifyFormat("[[object block:^{\n"
+               "  return 42;\n"
+               "}] aaaaaaa:42\n"
+               "        bb:42];");
+  // Arguments just fit into one line.
+  Style.ColumnLimit = 23;
+  verifyFormat("[[obj a:42\n"
+               "      b:42\n"
+               "      c:42\n"
+               "      d:42] e:42 f:42];");
+
+  // Arguments do not fit into one line with a receiver.
+  Style.ColumnLimit = 20;
+  verifyFormat("[[obj a:42] a:42\n"
+               "            b:42];");
+  verifyFormat("[[obj a:42] a:42\n"
+               "            b:42\n"
+               "            c:42];");
+  verifyFormat("[[obj aaaaaa:42\n"
+               "           b:42]\n"
+               "    cc:42\n"
+               "     d:42];");
+
+  // Avoid breaking receiver expression.
+  Style.ColumnLimit = 30;
+  verifyFormat("fooooooo =\n"
+               "    [[obj fooo] aaa:42\n"
+               "                aaa:42];");
+  verifyFormat("[[[obj foo] bar] aa:42\n"
+               "                 bb:42\n"
+               "                 cc:42];");
+
   Style.ColumnLimit = 70;
   verifyFormat(
       "void f() {\n"