llvm-extract changes linkages so that functions on both sides of the

split module can see each other. If it is keeping a symbol that already has
a non local linkage, it doesn't need to change it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166908 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/IPO/ExtractGV.cpp

@@ -51,32 +51,44 @@ namespace {
       // Visit the GlobalVariables.
       for (Module::global_iterator I = M.global_begin(), E = M.global_end();
            I != E; ++I) {
-        if (deleteStuff == (bool)Named.count(I) && !I->isDeclaration()) {
+        bool Delete =
-          I->setInitializer(0);
+          deleteStuff == (bool)Named.count(I) && !I->isDeclaration();
-        } else {
+        if (!Delete) {
           if (I->hasAvailableExternallyLinkage())
             continue;
           if (I->getName() == "llvm.global_ctors")
             continue;
         }
 
-        if (I->hasLocalLinkage())
+        bool Local = I->hasLocalLinkage();
+        if (Local)
           I->setVisibility(GlobalValue::HiddenVisibility);
-        I->setLinkage(GlobalValue::ExternalLinkage);
+
+        if (Local || Delete)
+          I->setLinkage(GlobalValue::ExternalLinkage);
+
+        if (Delete)
+          I->setInitializer(0);
       }
 
       // Visit the Functions.
       for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
-        if (deleteStuff == (bool)Named.count(I) && !I->isDeclaration()) {
+        bool Delete =
-          I->deleteBody();
+          deleteStuff == (bool)Named.count(I) && !I->isDeclaration();
-        } else {
+        if (!Delete) {
           if (I->hasAvailableExternallyLinkage())
             continue;
         }
 
-        if (I->hasLocalLinkage())
+        bool Local = I->hasLocalLinkage();
+        if (Local)
           I->setVisibility(GlobalValue::HiddenVisibility);
-        I->setLinkage(GlobalValue::ExternalLinkage);
+
+        if (Local || Delete)
+          I->setLinkage(GlobalValue::ExternalLinkage);
+
+        if (Delete)
+          I->deleteBody();
       }
 
       // Visit the Aliases.
@@ -85,9 +97,10 @@ namespace {
         Module::alias_iterator CurI = I;
         ++I;
 
-        if (CurI->hasLocalLinkage())
+        if (CurI->hasLocalLinkage()) {
           CurI->setVisibility(GlobalValue::HiddenVisibility);
-        CurI->setLinkage(GlobalValue::ExternalLinkage);
+          CurI->setLinkage(GlobalValue::ExternalLinkage);
+        }
 
         if (deleteStuff == (bool)Named.count(CurI)) {
           Type *Ty =  CurI->getType()->getElementType();

test/Other/extract-weak-odr.ll

@@ -0,0 +1,23 @@
+; RUN: llvm-extract -func foo -S < %s | FileCheck %s
+; RUN: llvm-extract -delete -func foo -S < %s | FileCheck --check-prefix=DELETE %s
+
+; Test that we don't convert weak_odr to external definitions.
+
+; CHECK:      @bar = external global i32
+; CHECK:      define weak_odr i32* @foo() {
+; CHECK-NEXT:  ret i32* @bar
+; CHECK-NEXT: }
+
+; DELETE: @bar = weak_odr global i32 42
+; DELETE: declare i32* @foo()
+
+@bar = weak_odr global i32 42
+
+define weak_odr i32*  @foo() {
+  ret i32* @bar
+}
+
+define void @g() {
+  %c = call i32* @foo()
+  ret void
+}

test/Other/extract.ll

@@ -7,18 +7,19 @@
 ; llvm-extract uses lazy bitcode loading, so make sure it correctly reads
 ; from bitcode files in addition to assembly files.
 
-; CHECK: define void @foo() {
+; CHECK: define hidden void @foo() {
 ; CHECK:   ret void
 ; CHECK: }
 
-; The linkonce_odr linkage for foo() should be changed to external linkage.
+; The private linkage for foo() should be changed to external linkage and
-; DELETE: declare void @foo()
+; hidden visibility added.
+; DELETE: declare hidden void @foo()
 ; DELETE: define void @bar() {
 ; DELETE:   call void @foo()
 ; DELETE:   ret void
 ; DELETE: }
 
-define linkonce_odr void @foo() {
+define private void @foo() {
   ret void
 }
 define void @bar() {