Introducing the "linker_weak" linkage type. This will be used for Objective-C

metadata types which should be marked as "weak", but which the linker will
remove upon final linkage. For example, the "objc_msgSend_fixup_alloc" symbol is
defined like this:

       .globl l_objc_msgSend_fixup_alloc
       .weak_definition l_objc_msgSend_fixup_alloc
       .section __DATA, __objc_msgrefs, coalesced
       .align 3
l_objc_msgSend_fixup_alloc:
        .quad   _objc_msgSend_fixup
        .quad   L_OBJC_METH_VAR_NAME_1

This is different from the "linker_private" linkage type, because it can't have
the metadata defined with ".weak_definition".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107205 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 8 insertions, 0 deletions

diff --git a/lib/Target/CppBackend/CPPBackend.cpp b/lib/Target/CppBackend/CPPBackend.cpp
index eda08e7..e72763b 100644
--- a/lib/Target/CppBackend/CPPBackend.cpp
+++ b/lib/Target/CppBackend/CPPBackend.cpp
@@ -286,6 +286,8 @@ void CppWriter::printLinkageType(GlobalValue::LinkageTypes LT) {
     Out << "GlobalValue::PrivateLinkage"; break;
   case GlobalValue::LinkerPrivateLinkage:
     Out << "GlobalValue::LinkerPrivateLinkage"; break;
+  case GlobalValue::LinkerWeakLinkage:
+    Out << "GlobalValue::LinkerWeakLinkage"; break;
   case GlobalValue::AvailableExternallyLinkage:
     Out << "GlobalValue::AvailableExternallyLinkage "; break;
   case GlobalValue::LinkOnceAnyLinkage:
diff --git a/lib/Target/Mangler.cpp b/lib/Target/Mangler.cpp
index 4ef017a..fc2f78d 100644
--- a/lib/Target/Mangler.cpp
+++ b/lib/Target/Mangler.cpp
@@ -118,6 +118,9 @@ void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
     } else if (PrefixTy == Mangler::LinkerPrivate) {
       const char *Prefix = MAI.getLinkerPrivateGlobalPrefix();
       OutName.append(Prefix, Prefix+strlen(Prefix));
+    } else if (PrefixTy == Mangler::LinkerWeak) {
+      const char *Prefix = MAI.getLinkerWeakGlobalPrefix();
+      OutName.append(Prefix, Prefix+strlen(Prefix));
     }
 
     const char *Prefix = MAI.getGlobalPrefix();
@@ -182,6 +185,8 @@ void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
     PrefixTy = Mangler::Private;
   else if (GV->hasLinkerPrivateLinkage())
     PrefixTy = Mangler::LinkerPrivate;
+  else if (GV->hasLinkerWeakLinkage())
+    PrefixTy = Mangler::LinkerWeak;
   
   // If this global has a name, handle it simply.
   if (GV->hasName()) {
diff --git a/lib/Target/XCore/AsmPrinter/XCoreAsmPrinter.cpp b/lib/Target/XCore/AsmPrinter/XCoreAsmPrinter.cpp
index c100c59..33a11d0 100644
--- a/lib/Target/XCore/AsmPrinter/XCoreAsmPrinter.cpp
+++ b/lib/Target/XCore/AsmPrinter/XCoreAsmPrinter.cpp
@@ -129,6 +129,7 @@ void XCoreAsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
   case GlobalValue::WeakAnyLinkage:
   case GlobalValue::WeakODRLinkage:
   case GlobalValue::ExternalLinkage:
+  case GlobalValue::LinkerWeakLinkage:
     emitArrayBound(GVSym, GV);
     OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);