[clang] [clang-format] Fix BlockIndent compat mapping of AlignAfterOpenBracket (PR #207187)

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llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-format

Author: Sergey Subbotin (ssubbotin)

<details>
<summary>Changes</summary>

be11e2b3d25 (#<!-- -->192283) replaced the `[[fallthrough]]` chain in the `AlignAfterOpenBracket` backward-compatibility switch with explicit per-case assignments. In the `BAS_BlockIndent` case the `BreakBeforeCloseBracket{BracedList,Function,If} = true` assignments are immediately overwritten with `false`, and `BreakAfterOpenBracket{BracedList,Function,If}` (previously inherited from the `BAS_AlwaysBreak` case via fallthrough) are never set. As a result, `AlignAfterOpenBracket: BlockIndent` parses to the same flag set as `Align`, silently dropping the block-indent style for existing configurations.

Restore the pre-#<!-- -->192283 mapping and pin the full BlockIndent flag mapping in ConfigParseTest so the compat shim cannot regress silently again.

Fixes #<!-- -->207186.

Note for the release branch: if #<!-- -->205920 (backport of #<!-- -->192283 to release/22.x) lands, this fix needs to be backported together with it.


---
Full diff: https://github.com/llvm/llvm-project/pull/207187.diff


2 Files Affected:

- (modified) clang/lib/Format/Format.cpp (+5-5) 
- (modified) clang/unittests/Format/ConfigParseTest.cpp (+25) 


``````````diff
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index ecfe5d2ce60d0..037111d8e9e5d 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -1159,14 +1159,14 @@ template <> struct MappingTraits<FormatStyle> {
         break;
       case BAS_BlockIndent:
         Style.AlignAfterOpenBracket = true;
+        Style.BreakAfterOpenBracketBracedList = true;
+        Style.BreakAfterOpenBracketFunction = true;
+        Style.BreakAfterOpenBracketIf = true;
+        Style.BreakAfterOpenBracketLoop = false;
+        Style.BreakAfterOpenBracketSwitch = false;
         Style.BreakBeforeCloseBracketBracedList = true;
         Style.BreakBeforeCloseBracketFunction = true;
         Style.BreakBeforeCloseBracketIf = true;
-        Style.BreakAfterOpenBracketLoop = false;
-        Style.BreakAfterOpenBracketSwitch = false;
-        Style.BreakBeforeCloseBracketBracedList = false;
-        Style.BreakBeforeCloseBracketFunction = false;
-        Style.BreakBeforeCloseBracketIf = false;
         Style.BreakBeforeCloseBracketLoop = false;
         Style.BreakBeforeCloseBracketSwitch = false;
         break;
diff --git a/clang/unittests/Format/ConfigParseTest.cpp b/clang/unittests/Format/ConfigParseTest.cpp
index eeaf5d3f66d96..1bfe3e2a61806 100644
--- a/clang/unittests/Format/ConfigParseTest.cpp
+++ b/clang/unittests/Format/ConfigParseTest.cpp
@@ -652,6 +652,31 @@ TEST(ConfigParseTest, ParsesConfiguration) {
   CHECK_PARSE("AlignAfterOpenBracket: false", AlignAfterOpenBracket, false);
   CHECK_PARSE("AlignAfterOpenBracket: BlockIndent", AlignAfterOpenBracket,
               true);
+  // BlockIndent implies breaking after the open bracket and before the close
+  // bracket of braced lists, function calls/declarations, and if conditions.
+  Style.BreakAfterOpenBracketBracedList = false;
+  Style.BreakAfterOpenBracketFunction = false;
+  Style.BreakAfterOpenBracketIf = false;
+  Style.BreakAfterOpenBracketLoop = true;
+  Style.BreakAfterOpenBracketSwitch = true;
+  Style.BreakBeforeCloseBracketBracedList = false;
+  Style.BreakBeforeCloseBracketFunction = false;
+  Style.BreakBeforeCloseBracketIf = false;
+  Style.BreakBeforeCloseBracketLoop = true;
+  Style.BreakBeforeCloseBracketSwitch = true;
+  EXPECT_EQ(
+      0,
+      parseConfiguration("AlignAfterOpenBracket: BlockIndent", &Style).value());
+  EXPECT_TRUE(Style.BreakAfterOpenBracketBracedList);
+  EXPECT_TRUE(Style.BreakAfterOpenBracketFunction);
+  EXPECT_TRUE(Style.BreakAfterOpenBracketIf);
+  EXPECT_FALSE(Style.BreakAfterOpenBracketLoop);
+  EXPECT_FALSE(Style.BreakAfterOpenBracketSwitch);
+  EXPECT_TRUE(Style.BreakBeforeCloseBracketBracedList);
+  EXPECT_TRUE(Style.BreakBeforeCloseBracketFunction);
+  EXPECT_TRUE(Style.BreakBeforeCloseBracketIf);
+  EXPECT_FALSE(Style.BreakBeforeCloseBracketLoop);
+  EXPECT_FALSE(Style.BreakBeforeCloseBracketSwitch);
   Style.AlignAfterOpenBracket = false;
   CHECK_PARSE("AlignAfterOpenBracket: true", AlignAfterOpenBracket, true);
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/207187