Link declaration lazily.

We already linked available_externally and linkonce lazily, this just
adds declarations to the list.

llvm-svn: 254917

llvm/lib/Linker/LinkModules.cpp

@@ -1753,6 +1753,9 @@ bool ModuleLinker::linkIfNeeded(GlobalValue &GV) {
        GV.hasAvailableExternallyLinkage()))
     return false;
 
+  if (GV.isDeclaration())
+    return false;
+
   if (const Comdat *SC = GV.getComdat()) {
     bool LinkFromSrc;
     Comdat::SelectionKind SK;

llvm/test/Linker/2003-04-23-LinkOnceLost.ll

@@ -4,3 +4,7 @@
 
 declare void @foo()
 
+define void @use_foo() {
+  call void @foo()
+  ret void
+}

llvm/test/Linker/2003-05-31-LinkerRename.ll

@@ -6,13 +6,13 @@
 ; CHECK-NEXT:   ret i32 7
 ; CHECK-NEXT: }
 
-; CHECK: declare i32 @foo()
-
 ; CHECK:      define i32 @test() {
 ; CHECK-NEXT:   %X = call i32 @foo()
 ; CHECK-NEXT:   ret i32 %X
 ; CHECK-NEXT: }
 
+; CHECK: declare i32 @foo()
+
 declare i32 @foo()
 
 define i32 @test() {

llvm/test/Linker/ConstantGlobals.ll

@@ -6,3 +6,7 @@
 
 ; CHECK-DAG: @Y = external global [1 x i32]
 @Y = external global [1 x i32]
+
+define [1 x i32]* @use-Y() {
+  ret [1 x i32] *@Y
+}

llvm/test/Linker/Inputs/opaque.ll

@@ -11,3 +11,11 @@ define void @f1()  {
   getelementptr %A, %A* null, i32 0
   ret void
 }
+
+define %A* @use_g2() {
+ ret %A* @g2
+}
+
+define %B* @use_g3() {
+  ret %B* @g3
+}

llvm/test/Linker/Inputs/testlink.ll

@@ -53,4 +53,6 @@ define internal void @testIntern() {
   ret void
 }
 
-declare void @VecSizeCrash1(%VecSize)
+define void @VecSizeCrash1(%VecSize) {
+  ret void
+}

llvm/test/Linker/Inputs/type-unique-dst-types2.ll

@@ -1,3 +1,7 @@
 %A.11 = type { %B }
 %B = type { i8 }
 @g1 = external global %A.11
+
+define %A.11* @use_g1() {
+  ret %A.11* @g1
+}

llvm/test/Linker/Inputs/type-unique-dst-types3.ll

@@ -1,2 +1,6 @@
 %A.11 = type opaque
 @g2 = external global %A.11
+
+define %A.11* @use_g2() {
+  ret %A.11* @g2
+}

llvm/test/Linker/opaque.ll

@@ -19,3 +19,7 @@
 %C = type { %A }
 
 @g1 = external global %B
+
+define %B* @use_g1() {
+  ret %B* @g1
+}

llvm/test/Linker/testlink.ll

@@ -32,6 +32,11 @@
 
 ; CHECK-DAG: @0 = external global i32
 @0 = external global i32
+
+define i32* @use0() {
+  ret i32* @0
+}
+
 ; CHECK-DAG: @Inte = global i32 1
 @Inte = global i32 1
 
@@ -101,4 +106,6 @@ define void @testIntern() {
   ret void
 }
 
-declare void @VecSizeCrash(%VecSize)
+define void @VecSizeCrash(%VecSize) {
+  ret void
+}

llvm/test/Linker/type-unique-dst-types.ll

@@ -17,3 +17,7 @@
 %A = type { %B }
 %B = type { i8 }
 @g3 = external global %A
+
+define %A* @use_g3() {
+  ret %A* @g3
+}

llvm/test/Linker/type-unique-src-type.ll

@@ -10,7 +10,7 @@
 ; CHECK-NEXT: %B = type { %A }
 ; CHECK-NEXT: %A = type { i8 }
 
-; CHECK: @g1 = external global %C.0
+; CHECK: @g1 = global %C.0 zeroinitializer
 ; CHECK:  getelementptr %C.0, %C.0* null, i64 0, i32 0, i32 0
 
 %A   = type { i8 }
@@ -21,4 +21,4 @@ define void @f1() {
   getelementptr %C, %C* null, i64 0, i32 0, i32 0
   ret void
 }
-@g1 = external global %C.0
+@g1 = global %C.0 zeroinitializer

llvm/test/Linker/unnamed-addr1-a.ll

@@ -15,6 +15,11 @@ define weak void @func-b() unnamed_addr { ret void }
 @global-c = common unnamed_addr global i32 0
 ; CHECK-DAG: @global-c = common unnamed_addr global i32 0
 @global-d = external global i32
+
+define i32* @use-global-d() {
+  ret i32* @global-d
+}
+
 ; CHECK-DAG: @global-d = global i32 42
 @global-e = external unnamed_addr global i32
 ; CHECK-DAG: @global-e = unnamed_addr global i32 42
@@ -27,6 +32,11 @@ define weak void @func-b() unnamed_addr { ret void }
 ; CHECK-DAG: @alias-b = unnamed_addr alias i32, i32* @global-f
 
 declare void @func-c()
+define void @use-func-c() {
+  call void @func-c()
+  ret void
+}
+
 ; CHECK-DAG: define weak void @func-c() {
 define weak void @func-d() { ret void }
 ; CHECK-DAG: define weak void @func-d() {

llvm/test/Linker/weakextern.ll

@@ -6,3 +6,7 @@
 @kallsyms_names = extern_weak global [0 x i8]
 @MyVar = extern_weak global i32
 @Inte = extern_weak global i32
+
+define weak [0 x i8]* @use_kallsyms_names() {
+  ret [0 x i8]* @kallsyms_names
+}