diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 44a83167238..308b0e091ac 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -949,6 +949,11 @@ bool AsmPrinter::doFinalization(Module &M) {
       MCSymbol *Name = getSymbol(I);
 
       const GlobalValue *GV = I->getAliasedGlobal();
+      if (GV->isDeclaration()) {
+        report_fatal_error(Name->getName() +
+                           ": Target doesn't support aliases to declarations");
+      }
+
       MCSymbol *Target = getSymbol(GV);
 
       if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
diff --git a/test/CodeGen/ARM/aliases.ll b/test/CodeGen/ARM/aliases.ll
index 4147bd0be07..f55ae10b247 100644
--- a/test/CodeGen/ARM/aliases.ll
+++ b/test/CodeGen/ARM/aliases.ll
@@ -16,13 +16,15 @@
 ; CHECK: .globl	A
 ; CHECK: A = bar
 
-@bar = external global i32
+@bar = global i32 42
 @foo1 = alias i32* @bar
 @foo2 = alias i32* @bar
 
 %FunTy = type i32()
 
-declare i32 @foo_f()
+define i32 @foo_f() {
+  ret i32 0
+}
 @bar_f = alias weak %FunTy* @foo_f
 
 @bar_i = alias internal i32* @bar
diff --git a/test/CodeGen/Generic/2009-03-17-LSR-APInt.ll b/test/CodeGen/Generic/2009-03-17-LSR-APInt.ll
index 6281ada73fc..3f17ce1e0b1 100644
--- a/test/CodeGen/Generic/2009-03-17-LSR-APInt.ll
+++ b/test/CodeGen/Generic/2009-03-17-LSR-APInt.ll
@@ -63,30 +63,58 @@ bb47:		; preds = %bb46, %bb44
 	br label %bb44
 }
 
-declare i32 @pthread_once(i32*, void ()*)
+define i32 @pthread_once(i32*, void ()*) {
+  ret i32 0
+}
 
-declare i8* @pthread_getspecific(i32)
+define i8* @pthread_getspecific(i32) {
+  ret i8* null
+}
 
-declare i32 @pthread_setspecific(i32, i8*)
+define i32 @pthread_setspecific(i32, i8*) {
+  ret i32 0
+}
 
-declare i32 @pthread_create(i64*, %struct.pthread_attr_t*, i8* (i8*)*, i8*)
+define i32 @pthread_create(i64*, %struct.pthread_attr_t*, i8* (i8*)*, i8*) {
+  ret i32 0
+}
 
-declare i32 @pthread_cancel(i64)
+define i32 @pthread_cancel(i64) {
+  ret i32 0
+}
 
-declare i32 @pthread_mutex_lock(%struct.pthread_mutex_t*)
+define i32 @pthread_mutex_lock(%struct.pthread_mutex_t*) {
+  ret i32 0
+}
 
-declare i32 @pthread_mutex_trylock(%struct.pthread_mutex_t*)
+define i32 @pthread_mutex_trylock(%struct.pthread_mutex_t*) {
+  ret i32 0
+}
 
-declare i32 @pthread_mutex_unlock(%struct.pthread_mutex_t*)
+define i32 @pthread_mutex_unlock(%struct.pthread_mutex_t*) {
+  ret i32 0
+}
 
-declare i32 @pthread_mutex_init(%struct.pthread_mutex_t*, %struct.Alignment*)
+define i32 @pthread_mutex_init(%struct.pthread_mutex_t*, %struct.Alignment*) {
+  ret i32 0
+}
 
-declare i32 @pthread_key_create(i32*, void (i8*)*)
+define i32 @pthread_key_create(i32*, void (i8*)*) {
+  ret i32 0
+}
 
-declare i32 @pthread_key_delete(i32)
+define i32 @pthread_key_delete(i32) {
+  ret i32 0
+}
 
-declare i32 @pthread_mutexattr_init(%struct.Alignment*)
+define i32 @pthread_mutexattr_init(%struct.Alignment*) {
+  ret i32 0
+}
 
-declare i32 @pthread_mutexattr_settype(%struct.Alignment*, i32)
+define i32 @pthread_mutexattr_settype(%struct.Alignment*, i32) {
+  ret i32 0
+}
 
-declare i32 @pthread_mutexattr_destroy(%struct.Alignment*)
+define i32 @pthread_mutexattr_destroy(%struct.Alignment*) {
+  ret i32 0
+}
diff --git a/test/CodeGen/PowerPC/mcm-9.ll b/test/CodeGen/PowerPC/mcm-9.ll
index e587f61eaf2..7906b6abea6 100644
--- a/test/CodeGen/PowerPC/mcm-9.ll
+++ b/test/CodeGen/PowerPC/mcm-9.ll
@@ -7,8 +7,7 @@
 target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f128:128:128-v128:128:128-n32:64"
 target triple = "powerpc64-unknown-linux-gnu"
 
-@ei = external global i32
-@a = alias i32* @ei
+@a = external global i32
 
 define signext i32 @test_external() nounwind {
 entry:
diff --git a/test/CodeGen/X86/2007-09-06-ExtWeakAliasee.ll b/test/CodeGen/X86/2007-09-06-ExtWeakAliasee.ll
index c5d2a46f92c..7e37ef5c40d 100644
--- a/test/CodeGen/X86/2007-09-06-ExtWeakAliasee.ll
+++ b/test/CodeGen/X86/2007-09-06-ExtWeakAliasee.ll
@@ -1,4 +1,6 @@
 ; RUN: llc < %s -march=x86 | grep weak | count 2
 @__gthrw_pthread_once = alias weak i32 (i32*, void ()*)* @pthread_once		; <i32 (i32*, void ()*)*> [#uses=0]
 
-declare extern_weak i32 @pthread_once(i32*, void ()*)
+define weak i32 @pthread_once(i32*, void ()*) {
+  ret i32 0
+}
diff --git a/test/CodeGen/X86/2008-03-14-SpillerCrash.ll b/test/CodeGen/X86/2008-03-14-SpillerCrash.ll
index 8946415108f..18b3714f851 100644
--- a/test/CodeGen/X86/2008-03-14-SpillerCrash.ll
+++ b/test/CodeGen/X86/2008-03-14-SpillerCrash.ll
@@ -45,4 +45,6 @@ bb383:		; preds = %bb374.us, %bb311.split
 	ret i64 0
 }
 
-declare i64 @__wcstoll_l(i32*, i32**, i32, %struct.__locale_struct*) nounwind 
+define i64 @__wcstoll_l(i32*, i32**, i32, %struct.__locale_struct*) nounwind {
+  ret i64 0
+}
diff --git a/test/CodeGen/X86/alias-error.ll b/test/CodeGen/X86/alias-error.ll
new file mode 100644
index 00000000000..89b0876a837
--- /dev/null
+++ b/test/CodeGen/X86/alias-error.ll
@@ -0,0 +1,5 @@
+; RUN: not llc < %s -mtriple=i686-pc-linux-gnu %s 2>&1 | FileCheck %s
+
+@a = external global i32
+@b = alias i32* @a
+; CHECK: b: Target doesn't support aliases to declarations
diff --git a/test/CodeGen/X86/aliases.ll b/test/CodeGen/X86/aliases.ll
index 025dcfedb62..d0a262d390d 100644
--- a/test/CodeGen/X86/aliases.ll
+++ b/test/CodeGen/X86/aliases.ll
@@ -1,6 +1,6 @@
 ; RUN: llc < %s -mtriple=i686-pc-linux-gnu -asm-verbose=false | FileCheck %s
 
-@bar = external global i32
+@bar = global i32 42
 
 ; CHECK-DAG: .globl	foo1
 @foo1 = alias i32* @bar
@@ -10,7 +10,9 @@
 
 %FunTy = type i32()
 
-declare i32 @foo_f()
+define i32 @foo_f() {
+  ret i32 0
+}
 ; CHECK-DAG: .weak	bar_f
 @bar_f = alias weak %FunTy* @foo_f
 
diff --git a/test/CodeGen/X86/x86-64-pic-10.ll b/test/CodeGen/X86/x86-64-pic-10.ll
index 3ec172b2b65..da8082b9251 100644
--- a/test/CodeGen/X86/x86-64-pic-10.ll
+++ b/test/CodeGen/X86/x86-64-pic-10.ll
@@ -9,4 +9,6 @@ entry:
         ret void
 }
 
-declare extern_weak i32 @f()
+define weak i32 @f() {
+  ret i32 42
+}
diff --git a/test/CodeGen/XCore/aliases.ll b/test/CodeGen/XCore/aliases.ll
index d4da63c5d9a..b7ad416968f 100644
--- a/test/CodeGen/XCore/aliases.ll
+++ b/test/CodeGen/XCore/aliases.ll
@@ -1,7 +1,9 @@
 ; RUN: llc < %s -march=xcore | FileCheck %s
-declare void @a_val() nounwind
-@b_val = external constant i32, section ".cp.rodata"
-@c_val = external global i32
+define void @a_val() nounwind {
+  ret void
+}
+@b_val = constant i32 42, section ".cp.rodata"
+@c_val = global i32 42
 
 @a = alias void ()* @a_val
 @b = alias i32* @b_val