Add a new "available_externally" linkage type. This is intended

to support C99 inline, GNU extern inline, etc.  Related bugzilla's
include PR3517, PR3100, & PR2933.  Nothing uses this yet, but it
appears to work.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68940 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 14 insertions, 3 deletions

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index d19e9afaf0..0979ced89a 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -443,7 +443,9 @@ bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
   }
 
   // Ignore debug and non-emitted data.
-  if (GV->getSection() == "llvm.metadata") return true;
+  if (GV->getSection() == "llvm.metadata" ||
+      GV->hasAvailableExternallyLinkage())
+    return true;
   
   if (!GV->hasAppendingLinkage()) return false;
 
diff --git a/lib/CodeGen/AsmPrinter/DwarfWriter.cpp b/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
index d59609b371..4582f4a447 100644
--- a/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
@@ -3519,6 +3519,9 @@ class DwarfException : public Dwarf  {
   ///
   void EmitEHFrame(const FunctionEHFrameInfo &EHFrameInfo) {
     Function::LinkageTypes linkage = EHFrameInfo.function->getLinkage();
+    
+    assert(!EHFrameInfo.function->hasAvailableExternallyLinkage() && 
+           "Should not emit 'available externally' functions at all");
 
     Asm->SwitchToTextSection(TAI->getDwarfEHFrameSection());
 
diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
index bd7105fd28..18a040e554 100644
--- a/lib/CodeGen/MachineFunction.cpp
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -38,8 +38,14 @@ using namespace llvm;
 static AnnotationID MF_AID(
   AnnotationManager::getID("CodeGen::MachineCodeForFunction"));
 
-// Out of line virtual function to home classes.
-void MachineFunctionPass::virtfn() {}
+bool MachineFunctionPass::runOnFunction(Function &F) {
+  // Do not codegen any 'available_externally' functions at all, they have
+  // definitions outside the translation unit.
+  if (F.hasAvailableExternallyLinkage())
+    return false;
+  
+  return runOnMachineFunction(MachineFunction::get(&F));
+}
 
 namespace {
   struct VISIBILITY_HIDDEN Printer : public MachineFunctionPass {