Fix logic for not emitting no-dead-strip for some

objects in llvm.used (thanks Anton).  Makes visible
the magic 'l' prefix for symbols on Darwin which are
to be passed through the assembler, then removed at
linktime (previously all references to this had been
hidden in the ObjC FE code, oh well).

llvm-svn: 55973

5 files changed, 18 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 273253ae23c..f041f3be56f 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -452,7 +452,9 @@ const GlobalValue * AsmPrinter::findGlobalValue(const Constant *CV) {
 
 /// EmitLLVMUsedList - For targets that define a TAI::UsedDirective, mark each
 /// global in the specified llvm.used list as being used with this directive.
-/// Non-globals (i.e. internal linkage) should not be emitted.
+/// Internally linked data beginning with the PrivateGlobalPrefix or the
+/// LessPrivateGlobalPrefix does not have the directive emitted (this 
+/// occurs in ObjC metadata).
 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
   const char *Directive = TAI->getUsedDirective();
 
@@ -462,7 +464,17 @@ void AsmPrinter::EmitLLVMUsedList(Constant *List) {
   
   for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
     const GlobalValue *GV = findGlobalValue(InitList->getOperand(i));
-    if (GV && (!GV->hasInternalLinkage() || isa<Function>(GV))) {
+    if (GV) {
+      if (GV->hasInternalLinkage() && !isa<Function>(GV) &&
+          ((strlen(TAI->getPrivateGlobalPrefix()) != 0 &&
+            Mang->getValueName(GV)
+              .substr(0,strlen(TAI->getPrivateGlobalPrefix())) ==
+              TAI->getPrivateGlobalPrefix()) ||
+           (strlen(TAI->getLessPrivateGlobalPrefix()) != 0 &&
+            Mang->getValueName(GV)
+              .substr(0,strlen(TAI->getLessPrivateGlobalPrefix())) ==
+              TAI->getLessPrivateGlobalPrefix())))
+        continue;
       O << Directive;
       EmitConstantValueOnly(InitList->getOperand(i));
       O << '\n';
diff --git a/llvm/lib/Target/ARM/ARMTargetAsmInfo.cpp b/llvm/lib/Target/ARM/ARMTargetAsmInfo.cpp
index 3e057359582..a1a00a2cdae 100644
--- a/llvm/lib/Target/ARM/ARMTargetAsmInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetAsmInfo.cpp
@@ -62,6 +62,7 @@ ARMDarwinTargetAsmInfo::ARMDarwinTargetAsmInfo(const ARMTargetMachine &TM):
 
   GlobalPrefix = "_";
   PrivateGlobalPrefix = "L";
+  LessPrivateGlobalPrefix = "l";
   StringConstantPrefix = "\1LC";
   BSSSection = 0;                       // no BSS section
   ZeroDirective = "\t.space\t";
diff --git a/llvm/lib/Target/PowerPC/PPCTargetAsmInfo.cpp b/llvm/lib/Target/PowerPC/PPCTargetAsmInfo.cpp
index 1b8c1a5fb3c..fc98e57c82a 100644
--- a/llvm/lib/Target/PowerPC/PPCTargetAsmInfo.cpp
+++ b/llvm/lib/Target/PowerPC/PPCTargetAsmInfo.cpp
@@ -38,6 +38,7 @@ PPCDarwinTargetAsmInfo::PPCDarwinTargetAsmInfo(const PPCTargetMachine &TM):
   CommentString = ";";
   GlobalPrefix = "_";
   PrivateGlobalPrefix = "L";
+  LessPrivateGlobalPrefix = "l";
   StringConstantPrefix = "\1LC";
   ConstantPoolSection = "\t.const\t";
   JumpTableDataSection = ".const";
diff --git a/llvm/lib/Target/TargetAsmInfo.cpp b/llvm/lib/Target/TargetAsmInfo.cpp
index 6baebd0ffe7..06b77dd26aa 100644
--- a/llvm/lib/Target/TargetAsmInfo.cpp
+++ b/llvm/lib/Target/TargetAsmInfo.cpp
@@ -50,6 +50,7 @@ TargetAsmInfo::TargetAsmInfo() :
   CommentString("#"),
   GlobalPrefix(""),
   PrivateGlobalPrefix("."),
+  LessPrivateGlobalPrefix(""),
   JumpTableSpecialLabelPrefix(0),
   GlobalVarAddrPrefix(""),
   GlobalVarAddrSuffix(""),
diff --git a/llvm/lib/Target/X86/X86TargetAsmInfo.cpp b/llvm/lib/Target/X86/X86TargetAsmInfo.cpp
index be390c23963..64858f89bd5 100644
--- a/llvm/lib/Target/X86/X86TargetAsmInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetAsmInfo.cpp
@@ -136,6 +136,7 @@ X86DarwinTargetAsmInfo::X86DarwinTargetAsmInfo(const X86TargetMachine &TM):
     Data64bitsDirective = 0;       // we can't emit a 64-bit unit
   ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
   PrivateGlobalPrefix = "L";     // Marker for constant pool idxs
+  LessPrivateGlobalPrefix = "l";  // Marker for some ObjC metadata
   BSSSection = 0;                       // no BSS section.
   ZeroFillDirective = "\t.zerofill\t";  // Uses .zerofill
   if (DTM->getRelocationModel() != Reloc::Static)