__patchable_function_entries: don't use linkage field 'unique' with -no-integrated-as

.section name, "flags"G, @type, GroupName[, linkage]

As of binutils 2.33, linkage cannot be 'unique'.  For integrated
assembler, we use both 'o' flag and 'unique' linkage to support
--gc-sections and COMDAT with lld.

https://sourceware.org/ml/binutils/2019-11/msg00266.html

1 files changed, 21 insertions, 18 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 1579646352d..6f9aa4dd79f 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -3204,26 +3204,29 @@ void AsmPrinter::emitPatchableFunctionEntries() {
   const unsigned PointerSize = getPointerSize();
   if (TM.getTargetTriple().isOSBinFormatELF()) {
     auto Flags = ELF::SHF_WRITE | ELF::SHF_ALLOC;
-    std::string GroupName;
-    if (F.hasComdat()) {
-      Flags |= ELF::SHF_GROUP;
-      GroupName = F.getComdat()->getName();
-    }
 
-    // As of binutils 2.33, GNU as does not support section flag "o". Use
-    // SHF_LINK_ORDER if we are using the integrated assembler.
-    MCSymbolELF *Link = MAI->useIntegratedAssembler()
-                            ? cast<MCSymbolELF>(CurrentFnSym)
-                            : nullptr;
-    if (Link)
+    // As of binutils 2.33, GNU as does not support section flag "o" or linkage
+    // field "unique". Use SHF_LINK_ORDER if we are using the integrated
+    // assembler.
+    if (MAI->useIntegratedAssembler()) {
       Flags |= ELF::SHF_LINK_ORDER;
-
-    MCSection *Section = getObjFileLowering().SectionForGlobal(&F, TM);
-    auto R = PatchableFunctionEntryID.try_emplace(
-        Section, PatchableFunctionEntryID.size());
-    OutStreamer->SwitchSection(OutContext.getELFSection(
-        "__patchable_function_entries", ELF::SHT_PROGBITS, Flags, 0, GroupName,
-        R.first->second, Link));
+      std::string GroupName;
+      if (F.hasComdat()) {
+        Flags |= ELF::SHF_GROUP;
+        GroupName = F.getComdat()->getName();
+      }
+      MCSection *Section = getObjFileLowering().SectionForGlobal(&F, TM);
+      unsigned UniqueID =
+          PatchableFunctionEntryID
+              .try_emplace(Section, PatchableFunctionEntryID.size())
+              .first->second;
+      OutStreamer->SwitchSection(OutContext.getELFSection(
+          "__patchable_function_entries", ELF::SHT_PROGBITS, Flags, 0,
+          GroupName, UniqueID, cast<MCSymbolELF>(CurrentFnSym)));
+    } else {
+      OutStreamer->SwitchSection(OutContext.getELFSection(
+          "__patchable_function_entries", ELF::SHT_PROGBITS, Flags));
+    }
     EmitAlignment(Align(PointerSize));
     OutStreamer->EmitSymbolValue(CurrentFnBegin, PointerSize);
   }