5 files changed, 128 insertions, 7 deletions
diff --git a/llvm/test/Linker/Inputs/only-needed-debug-metadata.ll b/llvm/test/Linker/Inputs/only-needed-debug-metadata.ll
new file mode 100644
index 00000000000..ec7f02f4d19
--- /dev/null
+++ b/llvm/test/Linker/Inputs/only-needed-debug-metadata.ll
@@ -0,0 +1,27 @@
+@X = external global i32
+
+declare i32 @foo()
+
+define void @bar() !dbg !4 {
+	load i32, i32* @X, !dbg !10
+	call i32 @foo(), !dbg !11
+	ret void, !dbg !12
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8}
+!llvm.ident = !{!9}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.8.0 (trunk 251407) (llvm/trunk 251401)", isOptimized: true, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3)
+!1 = !DIFile(filename: "linkused.b.c", directory: ".")
+!2 = !{}
+!3 = !{!4}
+!4 = distinct !DISubprogram(name: "bar", scope: !1, file: !1, line: 5, type: !5, isLocal: false, isDefinition: true, scopeLine: 5, isOptimized: true, variables: !2)
+!5 = !DISubroutineType(types: !6)
+!6 = !{null}
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{!"clang version 3.8.0 (trunk 251407) (llvm/trunk 251401)"}
+!10 = !DILocation(line: 6, column: 7, scope: !4)
+!11 = !DILocation(line: 6, column: 3, scope: !4)
+!12 = !DILocation(line: 7, column: 1, scope: !4)
diff --git a/llvm/test/Linker/only-needed-debug-metadata.ll b/llvm/test/Linker/only-needed-debug-metadata.ll
new file mode 100644
index 00000000000..f327fe03bf4
--- /dev/null
+++ b/llvm/test/Linker/only-needed-debug-metadata.ll
@@ -0,0 +1,49 @@
+; RUN: llvm-as %s -o %t.bc
+; RUN: llvm-as %p/Inputs/only-needed-debug-metadata.ll -o %t2.bc
+
+; Without -only-needed, we need to link in both DISubprogram.
+; RUN: llvm-link -S %t2.bc %t.bc | FileCheck %s
+; CHECK: distinct !DISubprogram(name: "foo"
+; CHECK: distinct !DISubprogram(name: "unused"
+
+; With -only-needed, we only need to link in foo's DISubprogram.
+; RUN: llvm-link -S -only-needed %t2.bc %t.bc | FileCheck %s -check-prefix=ONLYNEEDED
+; ONLYNEEDED: distinct !DISubprogram(name: "foo"
+; ONLYNEEDED-NOT: distinct !DISubprogram(name: "unused"
+
+@X = global i32 5
+@U = global i32 6
+@U_linkonce = linkonce_odr hidden global i32 6
+define i32 @foo() !dbg !4 {
+    ret i32 7, !dbg !20
+}
+define i32 @unused() !dbg !10 {
+    ret i32 8, !dbg !21
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!16, !17}
+!llvm.ident = !{!18}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.8.0 (trunk 251407) (llvm/trunk 251401)", isOptimized: true, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3, globals: !13)
+!1 = !DIFile(filename: "linkused2.c", directory: "/usr/local/google/home/tejohnson/llvm/tmp")
+!2 = !{}
+!3 = !{!4, !10}
+!4 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 4, type: !5, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: true, variables: !8)
+!5 = !DISubroutineType(types: !6)
+!6 = !{!7, !7}
+!7 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!8 = !{!9}
+!9 = !DILocalVariable(name: "x", arg: 1, scope: !4, file: !1, line: 4, type: !7)
+!10 = distinct !DISubprogram(name: "unused", scope: !1, file: !1, line: 8, type: !11, isLocal: false, isDefinition: true, scopeLine: 8, isOptimized: true, variables: !2)
+!11 = !DISubroutineType(types: !12)
+!12 = !{!7}
+!13 = !{!14, !15}
+!14 = !DIGlobalVariable(name: "X", scope: !0, file: !1, line: 1, type: !7, isLocal: false, isDefinition: true, variable: i32* @X)
+!15 = !DIGlobalVariable(name: "U", scope: !0, file: !1, line: 2, type: !7, isLocal: false, isDefinition: true, variable: i32* @U)
+!16 = !{i32 2, !"Dwarf Version", i32 4}
+!17 = !{i32 2, !"Debug Info Version", i32 3}
+!18 = !{!"clang version 3.8.0 (trunk 251407) (llvm/trunk 251401)"}
+!19 = !DIExpression()
+!20 = !DILocation(line: 4, column: 13, scope: !4)
+!21 = !DILocation(line: 9, column: 3, scope: !10)
diff --git a/llvm/test/Linker/thinlto_funcimport_debug.ll b/llvm/test/Linker/thinlto_funcimport_debug.ll
index 6c33caacf9e..02f43b24c17 100644
--- a/llvm/test/Linker/thinlto_funcimport_debug.ll
+++ b/llvm/test/Linker/thinlto_funcimport_debug.ll
@@ -3,13 +3,22 @@
 ; RUN: llvm-as -function-summary %p/Inputs/thinlto_funcimport_debug.ll -o %t2.bc
 ; RUN: llvm-lto -thinlto -o %t3 %t.bc %t2.bc
 
-; Confirm that we link the metadata for the imported module.
+; If we import func1 and not func2 we should only link DISubprogram for func1
 ; RUN: llvm-link %t2.bc -functionindex=%t3.thinlto.bc -import=func1:%t.bc -S | FileCheck %s
 
 ; CHECK: declare i32 @func2
 ; CHECK: define available_externally i32 @func1
+
+; Extract out the list of subprograms from each compile unit and ensure
+; that neither contains null.
+; CHECK: !{{[0-9]+}} = distinct !DICompileUnit({{.*}} subprograms: ![[SPs1:[0-9]+]]
+; CHECK-NOT: ![[SPs1]] = !{{{.*}}null{{.*}}}
+; CHECK: !{{[0-9]+}} = distinct !DICompileUnit({{.*}} subprograms: ![[SPs2:[0-9]+]]
+; CHECK-NOT: ![[SPs2]] = !{{{.*}}null{{.*}}}
+
 ; CHECK: distinct !DISubprogram(name: "func1"
-; CHECK: distinct !DISubprogram(name: "func2"
+; CHECK-NOT: distinct !DISubprogram(name: "func2"
+
 
 ; ModuleID = 'dbg.o'
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
diff --git a/llvm/test/tools/gold/X86/Inputs/linkonce-weak.ll b/llvm/test/tools/gold/X86/Inputs/linkonce-weak.ll
index f42af8faa84..3b7dad1b1ef 100644
--- a/llvm/test/tools/gold/X86/Inputs/linkonce-weak.ll
+++ b/llvm/test/tools/gold/X86/Inputs/linkonce-weak.ll
@@ -1,3 +1,19 @@
-define weak_odr void @f() {
-  ret void
+define weak_odr void @f() !dbg !4 {
+  ret void, !dbg !10
 }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8}
+!llvm.ident = !{!9}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.8.0 (trunk 251407) (llvm/trunk 251401)", isOptimized: true, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3)
+!1 = !DIFile(filename: "linkonce-weak.c", directory: ".")
+!2 = !{}
+!3 = !{!4}
+!4 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: true, variables: !2)
+!5 = !DISubroutineType(types: !6)
+!6 = !{null}
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{!"clang version 3.8.0 (trunk 251407) (llvm/trunk 251401)"}
+!10 = !DILocation(line: 2, column: 1, scope: !4)
diff --git a/llvm/test/tools/gold/X86/linkonce-weak.ll b/llvm/test/tools/gold/X86/linkonce-weak.ll
index a0cccea56cf..3397c3480a7 100644
--- a/llvm/test/tools/gold/X86/linkonce-weak.ll
+++ b/llvm/test/tools/gold/X86/linkonce-weak.ll
@@ -11,9 +11,29 @@
 ; RUN:    -shared %t2.o %t.o -o %t3.o
 ; RUN: llvm-dis %t3.o -o - | FileCheck %s
 
-define linkonce_odr void @f() {
-  ret void
+define linkonce_odr void @f() !dbg !4 {
+  ret void, !dbg !10
 }
 
 ; Test that we get a weak_odr regardless of the order of the files
-; CHECK: define weak_odr void @f() {
+; CHECK: define weak_odr void @f()
+
+; Test that we only get a single DISubprogram for @f
+; CHECK: !DISubprogram(name: "f"
+; CHECK-NOT: !DISubprogram(name: "f"
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8}
+!llvm.ident = !{!9}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.8.0 (trunk 251407) (llvm/trunk 251401)", isOptimized: true, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3)
+!1 = !DIFile(filename: "linkonce-weak.c", directory: ".")
+!2 = !{}
+!3 = !{!4}
+!4 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: true, variables: !2)
+!5 = !DISubroutineType(types: !6)
+!6 = !{null}
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{!"clang version 3.8.0 (trunk 251407) (llvm/trunk 251401)"}
+!10 = !DILocation(line: 2, column: 1, scope: !4)