[clang-format] Merge short inline function in macro definition body

[owenca]

Fix #62356

[llvmbot]

@llvm/pr-subscribers-clang-format

Author: Owen Pan (owenca)

Changes

Fix #62356

---

Full diff: https://github.com/llvm/llvm-project/pull/140366.diff

2 Files Affected:

• (modified) clang/lib/Format/UnwrappedLineFormatter.cpp (+2-2)
• (modified) clang/unittests/Format/FormatTest.cpp (+7)

diff --git a/clang/lib/Format/UnwrappedLineFormatter.cpp b/clang/lib/Format/UnwrappedLineFormatter.cpp
index 1298e3e7bab38..f2ed027b2c047 100644
--- a/clang/lib/Format/UnwrappedLineFormatter.cpp
+++ b/clang/lib/Format/UnwrappedLineFormatter.cpp
@@ -314,8 +314,8 @@ class LineJoiner {
           const AnnotatedLine *Line = nullptr;
           for (auto J = I - 1; J >= AnnotatedLines.begin(); --J) {
             assert(*J);
-            if ((*J)->InPPDirective || (*J)->isComment() ||
-                (*J)->Level > TheLine->Level) {
+            if (((*J)->InPPDirective && !(*J)->InMacroBody) ||
+                (*J)->isComment() || (*J)->Level > TheLine->Level) {
               continue;
             }
             if ((*J)->Level < TheLine->Level ||
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 436beaf68bd2a..4116173b47b51 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -15086,6 +15086,13 @@ TEST_F(FormatTest, PullInlineFunctionDefinitionsIntoSingleLine) {
                "};",
                MergeInlineOnly);
 
+  MergeInlineOnly.AlignEscapedNewlines = FormatStyle::ENAS_Left;
+  verifyFormat("#define Foo                \\\n"
+               "  struct S {               \\\n"
+               "    void foo() { return; } \\\n"
+               "  }",
+               MergeInlineOnly);
+
   // Also verify behavior when BraceWrapping.AfterFunction = true
   MergeInlineOnly.BreakBeforeBraces = FormatStyle::BS_Custom;
   MergeInlineOnly.BraceWrapping.AfterFunction = true;

[llvmbot]

Failed to cherry-pick: 6da2acf

https://github.com/llvm/llvm-project/actions/runs/15177852679

Please manually backport the fix and push it to your github fork. Once this is done, please create a pull request