[lld] Fix -ObjC load behavior with LTO for section names with whitespace (#146654)

This is a fix additional to #92162

In some cases, section names contain a whitespace between the segment
name and the actual section name (e.g. `__TEXT, __swift5_proto`). It is
confirmed by source code of the Swift compiler

This fix allows LTO to work correctly with the `-ObjC` flag in that rare
case when only a section with a whitespace in the name is present in the
linked bitcode module, but there are no sections containing
`__TEXT,__swift`

---------

Co-authored-by: Ураков Александр Сергеевич <a.urakov@tbank.ru>
Co-authored-by: Ellis Hoag <ellis.sparky.hoag@gmail.com>

1 files changed, 11 insertions, 3 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 66ecc69..6e93872 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -293,10 +293,18 @@ static Expected<bool> hasObjCCategoryInModule(BitstreamCursor &Stream) {
       std::string S;
       if (convertToString(Record, 0, S))
         return error("Invalid section name record");
+
       // Check for the i386 and other (x86_64, ARM) conventions
-      if (S.find("__DATA,__objc_catlist") != std::string::npos ||
-          S.find("__OBJC,__category") != std::string::npos ||
-          S.find("__TEXT,__swift") != std::string::npos)
+
+      auto [Segment, Section] = StringRef(S).split(",");
+      Segment = Segment.trim();
+      Section = Section.trim();
+
+      if (Segment == "__DATA" && Section.starts_with("__objc_catlist"))
+        return true;
+      if (Segment == "__OBJC" && Section.starts_with("__category"))
+        return true;
+      if (Segment == "__TEXT" && Section.starts_with("__swift"))
         return true;
       break;
     }