clang-format: Break before/between array subscript expressions.

clang-format used to treat array subscript expressions much like
function call (just replacing () with []). However, this is not really
appropriate especially for expressions with multiple subscripts.

Although it might seem counter-intuitive, the most consistent solution
seems to be to always (if necessary) break before a square bracket,
never after it. Also, multiple subscripts of the same expression should
be aligned if they are on subsequent lines.

Before:
  aaaaaaaaaaaaaaaaaaaaaaaaa[aaaaaaaaaaaaaaaaaaaaaaaaa][
      bbbbbbbbbbbbbbbbbbbbbbbbb] = c;
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa[
      aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa][
      bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb] = ccccccccccc;

After:
  aaaaaaaaaaaaaaaaaaaaaaaaa[aaaaaaaaaaaaaaaaaaaaaaaaa]
                           [bbbbbbbbbbbbbbbbbbbbbbbbb] = c;
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
      [aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa]
      [bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb] = ccccccccccc;

llvm-svn: 186153

1 files changed, 24 insertions, 8 deletions

diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 6e53f92e5a8..50f033ccabb 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -2121,10 +2121,10 @@ TEST_F(FormatTest, PreventConfusingIndents) {
       "        aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa),\n"
       "    aaaaaaaaaaaaaaaaaaaaaaaa);");
   verifyFormat(
-      "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa[\n"
-      "    aaaaaaaaaaaaaaaaaaaaaaaa[\n"
-      "        aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa],\n"
-      "    aaaaaaaaaaaaaaaaaaaaaaaa];");
+      "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n"
+      "    [aaaaaaaaaaaaaaaaaaaaaaaa\n"
+      "         [aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa]\n"
+      "         [aaaaaaaaaaaaaaaaaaaaaaaa]];");
   verifyFormat(
       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa<\n"
       "    aaaaaaaaaaaaaaaaaaaaaaaa<\n"
@@ -3593,11 +3593,11 @@ TEST_F(FormatTest, FormatsCasts) {
 
   verifyFormat("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa *foo = (aaaaaaaaaaaaaaaaa *)\n"
                "    bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;");
+  // FIXME: The indentation here is not ideal.
   verifyFormat(
-      "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa[\n"
-      "    bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb] =\n"
-      "    (*cccccccccccccccc)[\n"
-      "        dddddddddddddddddddddddddddddddddddddddddddddddddddddddd];");
+      "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n"
+      "    [bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb] = (*cccccccccccccccc)\n"
+      "        [dddddddddddddddddddddddddddddddddddddddddddddddddddddddd];");
 }
 
 TEST_F(FormatTest, FormatsFunctionTypes) {
@@ -3677,6 +3677,22 @@ TEST_F(FormatTest, BreaksLongDeclarations) {
                      "                   int aaaaaaaaaaaaaaaaaaaaaaa);");
 }
 
+TEST_F(FormatTest, FormatsArrays) {
+  verifyFormat("aaaaaaaaaaaaaaaaaaaaaaaaa[aaaaaaaaaaaaaaaaaaaaaaaaa]\n"
+               "                         [bbbbbbbbbbbbbbbbbbbbbbbbb] = c;");
+  verifyFormat("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n"
+               "    [bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb] = ccccccccccc;");
+  verifyFormat("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n"
+               "    [a][bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb] = cccccccc;");
+  verifyFormat("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n"
+               "    [aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa]\n"
+               "    [bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb] = ccccccccccc;");
+  verifyFormat(
+      "llvm::outs() << \"aaaaaaaaaaaa: \"\n"
+      "             << (*aaaaaaaiaaaaaaa)[aaaaaaaaaaaaaaaaaaaaaaaaa]\n"
+      "                                  [aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa];");
+}
+
 TEST_F(FormatTest, LineStartsWithSpecialCharacter) {
   verifyFormat("(a)->b();");
   verifyFormat("--a;");