[clang] [clang-format] Reorder TokenAnnotator::canBreakBefore (PR #119044)

[Owen Pan via cfe-commits]

https://github.com/owenca updated https://github.com/llvm/llvm-project/pull/119044

>From c5bf1fc70df08ef94cc32a47d1bdce69c92c2abf Mon Sep 17 00:00:00 2001
From: Gedare Bloom <gedare at rtems.org>
Date: Fri, 6 Dec 2024 16:52:35 -0700
Subject: [PATCH 1/2] [clang-format] Reorder TokenAnnotator::canBreakBefore

Move the checks related to breaking before right braces and right parens
earlier to avoid conflicting checks that prevent breaking based on the
left-hand token.  This allows properly formatting declarations with
pointers and references.
---
 clang/lib/Format/TokenAnnotator.cpp   | 57 ++++++++++++++-------------
 clang/unittests/Format/FormatTest.cpp |  9 +++++
 2 files changed, 38 insertions(+), 28 deletions(-)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index bc5239209f3aab..8d5ec0d0bb71ed 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -6105,6 +6105,35 @@ bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
       return false;
   }
 
+  // We can break before an r_brace if there was a corresponding break after
+  // the l_brace, which is tracked by BreakBeforeClosingBrace, or if we are
+  // in a block indented initialization list.
+  if (Right.is(tok::r_brace)) {
+    return Right.MatchingParen && (Right.MatchingParen->is(BK_Block) ||
+                                   (Right.isBlockIndentedInitRBrace(Style)));
+  }
+
+  // We only break before r_paren if we're in a block indented context.
+  if (Right.is(tok::r_paren)) {
+    if (Style.AlignAfterOpenBracket != FormatStyle::BAS_BlockIndent ||
+        !Right.MatchingParen) {
+      return false;
+    }
+    auto Next = Right.Next;
+    if (Next && Next->is(tok::r_paren))
+      Next = Next->Next;
+    if (Next && Next->is(tok::l_paren))
+      return false;
+    const FormatToken *Previous = Right.MatchingParen->Previous;
+    return !(Previous && (Previous->is(tok::kw_for) || Previous->isIf()));
+  }
+
+  if (Left.isOneOf(tok::r_paren, TT_TrailingAnnotation) &&
+      Right.is(TT_TrailingAnnotation) &&
+      Style.AlignAfterOpenBracket == FormatStyle::BAS_BlockIndent) {
+    return false;
+  }
+
   if (Left.is(tok::at))
     return false;
   if (Left.Tok.getObjCKeywordID() == tok::objc_interface)
@@ -6260,34 +6289,6 @@ bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
     return false;
   }
 
-  // We only break before r_brace if there was a corresponding break before
-  // the l_brace, which is tracked by BreakBeforeClosingBrace.
-  if (Right.is(tok::r_brace)) {
-    return Right.MatchingParen && (Right.MatchingParen->is(BK_Block) ||
-                                   (Right.isBlockIndentedInitRBrace(Style)));
-  }
-
-  // We only break before r_paren if we're in a block indented context.
-  if (Right.is(tok::r_paren)) {
-    if (Style.AlignAfterOpenBracket != FormatStyle::BAS_BlockIndent ||
-        !Right.MatchingParen) {
-      return false;
-    }
-    auto Next = Right.Next;
-    if (Next && Next->is(tok::r_paren))
-      Next = Next->Next;
-    if (Next && Next->is(tok::l_paren))
-      return false;
-    const FormatToken *Previous = Right.MatchingParen->Previous;
-    return !(Previous && (Previous->is(tok::kw_for) || Previous->isIf()));
-  }
-
-  if (Left.isOneOf(tok::r_paren, TT_TrailingAnnotation) &&
-      Right.is(TT_TrailingAnnotation) &&
-      Style.AlignAfterOpenBracket == FormatStyle::BAS_BlockIndent) {
-    return false;
-  }
-
   // Allow breaking after a trailing annotation, e.g. after a method
   // declaration.
   if (Left.is(TT_TrailingAnnotation)) {
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 250e51b5421664..8e9f2695f5f8a8 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -9441,6 +9441,15 @@ TEST_F(FormatTest, AlignsAfterOpenBracket) {
       "    aaaaaaaaaaaaaaaa\n"
       ");",
       Style);
+  verifyFormat("void foo(\n"
+               "    void (*foobarpntr)(\n"
+               "        aaaaaaaaaaaaaaaaaa *,\n"
+               "        bbbbbbbbbbbbbb *,\n"
+               "        cccccccccccccccccccc *,\n"
+               "        dddddddddddddddddd *\n"
+               "    )\n"
+               ");",
+               Style);
   verifyFormat("aaaaaaa<bbbbbbbb> const aaaaaaaaaa{\n"
                "    aaaaaaaaaaaaa(aaaaaaaaaaa, aaaaaaaaaaaaaaaa)\n"
                "};",

>From 19ab2bf53b516e5553d8a631c1972160dc024977 Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Mon, 9 Dec 2024 21:04:33 -0800
Subject: [PATCH 2/2] Update clang/lib/Format/TokenAnnotator.cpp comments

---
 clang/lib/Format/TokenAnnotator.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 8d5ec0d0bb71ed..aaac2ab10a1720 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -6105,9 +6105,9 @@ bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
       return false;
   }
 
-  // We can break before an r_brace if there was a corresponding break after
-  // the l_brace, which is tracked by BreakBeforeClosingBrace, or if we are
-  // in a block indented initialization list.
+  // We can break before an r_brace if there was a break after the matching
+  // l_brace, which is tracked by BreakBeforeClosingBrace, or if we are in a
+  // block-indented initialization list.
   if (Right.is(tok::r_brace)) {
     return Right.MatchingParen && (Right.MatchingParen->is(BK_Block) ||
                                    (Right.isBlockIndentedInitRBrace(Style)));