[lld/macho] Fixes the -ObjC flag

When checking the segment name for Swift symbols, we should be checking that they start with `__swift` instead of checking for equality

Fixes the issue https://github.com/llvm/llvm-project/issues/55355

Reviewed By: #lld-macho, keith, thevinster

Differential Revision: https://reviews.llvm.org/D125250

2 files changed, 14 insertions, 6 deletions

diff --git a/lld/MachO/ObjC.cpp b/lld/MachO/ObjC.cpp
index 3c40c5d7181b..fbc129cf6589 100644
--- a/lld/MachO/ObjC.cpp
+++ b/lld/MachO/ObjC.cpp
@@ -40,7 +40,7 @@ template <class LP> static bool objectHasObjCSection(MemoryBufferRef mb) {
       if ((segname == segment_names::data &&
            sectname == section_names::objcCatList) ||
           (segname == segment_names::text &&
-           sectname == section_names::swift)) {
+           sectname.startswith(section_names::swift))) {
         return true;
       }
     }
diff --git a/lld/test/MachO/objc.s b/lld/test/MachO/objc.s
index 9cfd5285e0be..ad7e639d99c2 100644
--- a/lld/test/MachO/objc.s
+++ b/lld/test/MachO/objc.s
@@ -5,11 +5,12 @@
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/has-objc-category.s -o %t/has-objc-category.o
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/has-objc-symbol-and-category.s -o %t/has-objc-symbol-and-category.o
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/has-swift.s -o %t/has-swift.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/has-swift-proto.s -o %t/has-swift-proto.o
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/no-objc.s -o %t/no-objc.o
 ## Make sure we don't mis-parse a 32-bit file as 64-bit
 # RUN: llvm-mc -filetype=obj -triple=armv7-apple-watchos %t/no-objc.s -o %t/wrong-arch.o
-# RUN: llvm-ar rcs %t/libHasSomeObjC.a %t/no-objc.o %t/has-objc-symbol.o %t/has-objc-category.o %t/has-swift.o %t/wrong-arch.o
-# RUN: llvm-ar rcs %t/libHasSomeObjC2.a %t/no-objc.o %t/has-objc-symbol-and-category.o %t/has-swift.o %t/wrong-arch.o
+# RUN: llvm-ar rcs %t/libHasSomeObjC.a %t/no-objc.o %t/has-objc-symbol.o %t/has-objc-category.o %t/has-swift.o %t/has-swift-proto.o %t/wrong-arch.o
+# RUN: llvm-ar rcs %t/libHasSomeObjC2.a %t/no-objc.o %t/has-objc-symbol-and-category.o %t/has-swift.o %t/has-swift-proto.o %t/wrong-arch.o
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/test.s -o %t/test.o
 
@@ -19,19 +20,21 @@
 # RUN: %lld -lSystem %t/test.o -o %t/test -L%t -lHasSomeObjC2 -ObjC
 # RUN: llvm-objdump --section-headers --syms %t/test | FileCheck %s --check-prefix=OBJC
 
-# RUN: %lld -lSystem %t/test.o -o %t/test --start-lib %t/no-objc.o %t/has-objc-symbol.o %t/has-objc-category.o %t/has-swift.o %t/wrong-arch.o --end-lib -ObjC
+# RUN: %lld -lSystem %t/test.o -o %t/test --start-lib %t/no-objc.o %t/has-objc-symbol.o %t/has-objc-category.o %t/has-swift.o %t/has-swift-proto.o %t/wrong-arch.o --end-lib -ObjC
 # RUN: llvm-objdump --section-headers --syms %t/test | FileCheck %s --check-prefix=OBJC
 
 # OBJC:       Sections:
 # OBJC-NEXT:  Idx Name            Size   VMA  Type
 # OBJC-NEXT:    0 __text          {{.*}}      TEXT
 # OBJC-NEXT:    1 __swift         {{.*}}      DATA
-# OBJC-NEXT:    2 __objc_catlist  {{.*}}      DATA
-# OBJC-NEXT:    3 has_objc_symbol {{.*}}      DATA
+# OBJC-NEXT:    2 __swift5_fieldmd{{.*}}      DATA
+# OBJC-NEXT:    3 __objc_catlist  {{.*}}      DATA
+# OBJC-NEXT:    4 has_objc_symbol {{.*}}      DATA
 # OBJC-EMPTY:
 # OBJC-NEXT:  SYMBOL TABLE:
 # OBJC-DAG:   g     F __TEXT,__text _main
 # OBJC-DAG:   g     F __TEXT,__text _OBJC_CLASS_$_MyObject
+# OBJC-DAG:   g     O __TEXT,__swift5_fieldmd $s7somelib4Blah_pMF
 
 # RUN: %lld -lSystem %t/test.o -o %t/test -L%t -lHasSomeObjC
 # RUN: llvm-objdump --section-headers --syms %t/test | FileCheck %s --check-prefix=NO-OBJC
@@ -93,6 +96,11 @@ _has_dup:
 .section __TEXT,__swift
 .quad 0x1234
 
+#--- has-swift-proto.s
+.section __TEXT,__swift5_fieldmd
+.globl $s7somelib4Blah_pMF
+$s7somelib4Blah_pMF:
+
 #--- no-objc.s
 ## This archive member should not be pulled in by -ObjC since it does not
 ## contain any ObjC-related data.