[llvm] r252054 - [ThinLTO] Always set linkage type to external when converting alias

[Teresa Johnson via llvm-commits]

Author: tejohnson
Date: Wed Nov  4 10:01:16 2015
New Revision: 252054

URL: http://llvm.org/viewvc/llvm-project?rev=252054&view=rev
Log:
[ThinLTO] Always set linkage type to external when converting alias

When converting an alias to a non-alias when the aliasee is not
imported, ensure that the linkage type is set to external so that it is
a valid linkage type. Added a test case that exposed this issue.

Modified:
    llvm/trunk/lib/Linker/LinkModules.cpp
    llvm/trunk/test/Linker/funcimport.ll

Modified: llvm/trunk/lib/Linker/LinkModules.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Linker/LinkModules.cpp?rev=252054&r1=252053&r2=252054&view=diff
==============================================================================
--- llvm/trunk/lib/Linker/LinkModules.cpp (original)
+++ llvm/trunk/lib/Linker/LinkModules.cpp Wed Nov  4 10:01:16 2015
@@ -841,10 +841,12 @@ GlobalValue *ModuleLinker::copyGlobalAli
       assert(F);
       NewGV = copyFunctionProto(TypeMap, F);
     }
-    // Set the linkage to ExternalWeak, see also comments in
-    // ModuleLinker::getLinkage.
+    // Set the linkage to External or ExternalWeak (see comments in
+    // ModuleLinker::getLinkage for why WeakAny is converted to ExternalWeak).
     if (SGA->hasWeakAnyLinkage())
       NewGV->setLinkage(GlobalValue::ExternalWeakLinkage);
+    else
+      NewGV->setLinkage(GlobalValue::ExternalLinkage);
     // Don't attempt to link body, needs to be a declaration.
     DoNotLinkFromSource.insert(SGA);
     return NewGV;

Modified: llvm/trunk/test/Linker/funcimport.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Linker/funcimport.ll?rev=252054&r1=252053&r2=252054&view=diff
==============================================================================
--- llvm/trunk/test/Linker/funcimport.ll (original)
+++ llvm/trunk/test/Linker/funcimport.ll Wed Nov  4 10:01:16 2015
@@ -14,11 +14,16 @@
 
 ; Ensure that both weak alias to an imported function and strong alias to a
 ; non-imported function are correctly turned into declarations.
+; Also ensures that alias to a linkonce function is turned into a declaration
+; and that the associated linkonce function is not in the output, as it is
+; lazily linked and never referenced/materialized.
 ; RUN: llvm-link %t2.bc -functionindex=%t3.thinlto.bc -import=globalfunc1:%t.bc -S | FileCheck %s --check-prefix=IMPORTGLOB1
 ; IMPORTGLOB1: define available_externally void @globalfunc1
 ; IMPORTGLOB1: declare void @globalfunc2
 ; IMPORTGLOB1: declare extern_weak void @weakalias
 ; IMPORTGLOB1: declare void @analias
+; IMPORTGLOB1: declare void @linkoncealias
+; IMPORTGLOB1-NOT: @linkoncefunc
 
 ; Ensure that weak alias to a non-imported function is correctly
 ; turned into a declaration, but that strong alias to an imported function
@@ -91,6 +96,7 @@
 
 @weakalias = weak alias void (...), bitcast (void ()* @globalfunc1 to void (...)*)
 @analias = alias void (...), bitcast (void ()* @globalfunc2 to void (...)*)
+ at linkoncealias = alias void (...), bitcast (void ()* @linkoncefunc to void (...)*)
 
 define void @globalfunc1() #0 {
 entry:
@@ -101,6 +107,11 @@ define void @globalfunc2() #0 {
 entry:
   ret void
 }
+
+define linkonce_odr void @linkoncefunc() #0 {
+entry:
+  ret void
+}
 
 define i32 @referencestatics(i32 %i) #0 {
 entry: