fix a nasty bug where we were not treating available_externally

symbols as declarations in the X86 backend.  This would manifest
on darwin x86-32 as errors like this with -fvisibility=hidden:

symbol '__ZNSbIcED1Ev' can not be undefined in a subtraction expression

This fixes PR7353.

llvm-svn: 105954

llvm/lib/Target/X86/X86Subtarget.cpp

@@ -53,9 +53,12 @@ ClassifyGlobalReference(const GlobalValue *GV, const TargetMachine &TM) const {
   if (GV->hasDLLImportLinkage())
     return X86II::MO_DLLIMPORT;
 
-  // Materializable GVs (in JIT lazy compilation mode) do not require an
-  // extra load from stub.
-  bool isDecl = GV->isDeclaration() && !GV->isMaterializable();
+  // Determine whether this is a reference to a definition or a declaration.
+  // Materializable GVs (in JIT lazy compilation mode) do not require an extra
+  // load from stub.
+  bool isDecl = GV->hasAvailableExternallyLinkage();
+  if (GV->isDeclaration() && !GV->isMaterializable())
+    isDecl = true;
 
   // X86-64 in PIC mode.
   if (isPICStyleRIPRel()) {

llvm/test/CodeGen/X86/hidden-vis-pic.ll

@@ -1,4 +1,27 @@
 ; RUN: llc < %s -mtriple=i386-apple-darwin9 -relocation-model=pic -disable-fp-elim -unwind-tables | FileCheck %s
+
+
+
+; PR7353
+
+define available_externally hidden 
+void @_ZNSbIcED1Ev() nounwind readnone ssp align 2 {
+entry:
+  ret void
+}
+
+define void()* @test1() nounwind {
+entry:
+  ret void()* @_ZNSbIcED1Ev
+}
+
+; This must use movl of the stub, not an lea, since the function isn't being
+; emitted here.
+; CHECK: movl L__ZNSbIcED1Ev$non_lazy_ptr-L1$pb(
+
+
+
+
 ; <rdar://problem/7383328>
 
 @.str = private constant [12 x i8] c"hello world\00", align 1 ; <[12 x i8]*> [#uses=1]
@@ -28,3 +51,5 @@ return:                                           ; preds = %entry
 
 ; CHECK: .private_extern _func.eh
 ; CHECK: .private_extern _main.eh
+
+