[clang] cc77e33 - [clang-format] Don't apply severe penalty if no possible column formats (#76675)

[via cfe-commits]

Author: James Grant
Date: 2024-01-10T19:32:14-08:00
New Revision: cc77e33271371e6ea29569ba06db9cfd1aac022a

URL: https://github.com/llvm/llvm-project/commit/cc77e33271371e6ea29569ba06db9cfd1aac022a
DIFF: https://github.com/llvm/llvm-project/commit/cc77e33271371e6ea29569ba06db9cfd1aac022a.diff

LOG: [clang-format] Don't apply severe penalty if no possible column formats (#76675)

If there are possible column formats, but they weren't selected because
they don't fit within remaining characters for the current path then
applying severe penalty to induce column layout by selection of a
different path seems fair.

But if due to style configuration or what the input code is, there are
no possible column formats, different paths aren't going to have column
layouts. Seems wrong to apply the severe penalty to induce column
layouts if there are none available.

It just causes selection of sub-optimal paths, e.g. get bad formatting
when brace initializers are used inside lambda bodies.

Fixes #56350

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/clang/lib/Format/FormatToken.cpp b/clang/lib/Format/FormatToken.cpp
index 7a2df8c53952f9..b791c5a26bbe3a 100644
--- a/clang/lib/Format/FormatToken.cpp
+++ b/clang/lib/Format/FormatToken.cpp
@@ -113,8 +113,8 @@ unsigned CommaSeparatedList::formatAfterToken(LineState &State,
   if (!State.NextToken || !State.NextToken->Previous)
     return 0;
 
-  if (Formats.size() == 1)
-    return 0; // Handled by formatFromToken
+  if (Formats.size() <= 1)
+    return 0; // Handled by formatFromToken (1) or avoid severe penalty (0).
 
   // Ensure that we start on the opening brace.
   const FormatToken *LBrace =

diff  --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 25ef5c680af862..c346f382b34314 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -13875,6 +13875,21 @@ TEST_F(FormatTest, FormatsBracedListsInColumnLayout) {
                getLLVMStyleWithColumns(35));
   verifyFormat("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(aaaaaaaaaaaaaaaaaaa, {},\n"
                "                               aaaaaaaaaaaaaaaaaaaaaaa);");
+
+  // No possible column formats, don't want the optimal paths penalized.
+  verifyFormat(
+      "waarudo::unit desk = {\n"
+      "    .s = \"desk\", .p = p, .b = [] { return w::r{3, 10} * w::m; }};");
+  verifyFormat("SomeType something1([](const Input &i) -> Output { return "
+               "Output{1, 2}; },\n"
+               "                    [](const Input &i) -> Output { return "
+               "Output{1, 2}; });");
+  FormatStyle NoBinPacking = getLLVMStyle();
+  NoBinPacking.BinPackParameters = false;
+  verifyFormat("waarudo::unit desk = {\n"
+               "    .s = \"desk\", .p = p, .b = [] { return w::r{3, 10, 1, 1, "
+               "1, 1} * w::m; }};",
+               NoBinPacking);
 }
 
 TEST_F(FormatTest, PullTrivialFunctionDefinitionsIntoSingleLine) {