From d826bbbb0a803952b13da40ac5f2a53bd15d6f28 Mon Sep 17 00:00:00 2001
From: Mehdi Amini <mehdi.amini@apple.com>
Date: Wed, 20 Apr 2016 17:47:42 +0000
Subject: [PATCH] ModuleLinker: only import what is in GlobalsToImport,
 regarless if it is a function or not.

The alias handling was specific to the old iterative inlining
mechanism, so that is dead now. The variable handling could make a
difference, since we were previously falling through to the normal
selection logic, but we don't observe changes in the validation
because no client seems to rely on it.

Differential Revision: http://reviews.llvm.org/D19307

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266893
---
 llvm/lib/Linker/LinkModules.cpp | 28 ++++++----------------------
 1 file changed, 6 insertions(+), 22 deletions(-)

diff --git a/llvm/lib/Linker/LinkModules.cpp b/llvm/lib/Linker/LinkModules.cpp
index 07785d7..cd3cd52 100644
--- a/llvm/lib/Linker/LinkModules.cpp
+++ b/llvm/lib/Linker/LinkModules.cpp
@@ -268,31 +268,15 @@ bool ModuleLinker::shouldLinkFromSource(bool &LinkFromSrc,
     return false;
   }
 
-  bool SrcIsDeclaration = Src.isDeclarationForLinker();
-  bool DestIsDeclaration = Dest.isDeclarationForLinker();
-
   if (isPerformingImport()) {
-    if (isa<Function>(&Src)) {
-      // For functions, LinkFromSrc iff this is a function requested
-      // for importing. For variables, decide below normally.
-      LinkFromSrc = GlobalsToImport->count(&Src);
-      return false;
-    }
-
-    // Check if this is an alias with an already existing definition
-    // in Dest, which must have come from a prior importing pass from
-    // the same Src module. Unlike imported function and variable
-    // definitions, which are imported as available_externally and are
-    // not definitions for the linker, that is not a valid linkage for
-    // imported aliases which must be definitions. Simply use the existing
-    // Dest copy.
-    if (isa<GlobalAlias>(&Src) && !DestIsDeclaration) {
-      assert(isa<GlobalAlias>(&Dest));
-      LinkFromSrc = false;
-      return false;
-    }
+    // LinkFromSrc iff this is a global requested for importing.
+    LinkFromSrc = GlobalsToImport->count(&Src);
+    return false;
   }
 
+  bool SrcIsDeclaration = Src.isDeclarationForLinker();
+  bool DestIsDeclaration = Dest.isDeclarationForLinker();
+
   if (SrcIsDeclaration) {
     // If Src is external or if both Src & Dest are external..  Just link the
     // external globals, we aren't adding anything.
-- 
2.7.4