4 files changed, 50 insertions, 7 deletions
diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
index 4fe2553687c..c5d39c54430 100644
--- a/llvm/lib/IR/DebugInfo.cpp
+++ b/llvm/lib/IR/DebugInfo.cpp
@@ -79,9 +79,19 @@ void DebugInfoFinder::processModule(const Module &M) {
         processScope(M->getScope());
     }
   }
-  for (auto &F : M.functions())
+  for (auto &F : M.functions()) {
     if (auto *SP = cast_or_null<DISubprogram>(F.getSubprogram()))
       processSubprogram(SP);
+    // There could be subprograms from inlined functions referenced from
+    // instructions only. Walk the function to find them.
+    for (const BasicBlock &BB : F) {
+      for (const Instruction &I : BB) {
+        if (!I.getDebugLoc())
+          continue;
+        processLocation(M, I.getDebugLoc().get());
+      }
+    }
+  }
 }
 
 void DebugInfoFinder::processLocation(const Module &M, const DILocation *Loc) {
diff --git a/llvm/lib/Transforms/IPO/StripSymbols.cpp b/llvm/lib/Transforms/IPO/StripSymbols.cpp
index 4d52f5f3110..fb64367eef9 100644
--- a/llvm/lib/Transforms/IPO/StripSymbols.cpp
+++ b/llvm/lib/Transforms/IPO/StripSymbols.cpp
@@ -324,10 +324,9 @@ bool StripDeadDebugInfo::runOnModule(Module &M) {
   }
 
   std::set<DICompileUnit *> LiveCUs;
-  // Any CU referenced from a function is live.
-  for (Function &F : M.functions()) {
-    DISubprogram *SP = F.getSubprogram();
-    if (SP && SP->getUnit())
+  // Any CU referenced from a subprogram is live.
+  for (DISubprogram *SP : F.subprograms()) {
+    if (SP->getUnit())
       LiveCUs.insert(SP->getUnit());
   }
 
diff --git a/llvm/test/DebugInfo/Generic/debuginfofinder-inlined-cu.ll b/llvm/test/DebugInfo/Generic/debuginfofinder-inlined-cu.ll
new file mode 100644
index 00000000000..313e22d84f3
--- /dev/null
+++ b/llvm/test/DebugInfo/Generic/debuginfofinder-inlined-cu.ll
@@ -0,0 +1,31 @@
+; RUN: opt -analyze -module-debuginfo < %s | FileCheck %s
+
+; Verify that both compile units, even though one compile units's functions
+; were entirely inlined into the other.
+;CHECK: Compile unit: DW_LANG_C99 from /tmp/test1.c
+;CHECK: Compile unit: DW_LANG_C99 from /tmp/test2.c
+;CHECK: Subprogram: f from /tmp/test1.c:1
+;CHECK: Subprogram: g from /tmp/test2.c:1
+
+define void @f() !dbg !4 {
+  ret void, !dbg !15
+}
+
+!llvm.dbg.cu = !{!0, !8}
+!llvm.module.flags = !{!13, !16}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.4 (192092)", isOptimized: false, emissionKind: FullDebug, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
+!1 = !DIFile(filename: "test1.c", directory: "/tmp")
+!2 = !{}
+!4 = distinct !DISubprogram(name: "f", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: false, unit: !0, scopeLine: 1, file: !1, scope: !5, type: !6, variables: !2)
+!5 = !DIFile(filename: "test1.c", directory: "/tmp")
+!6 = !DISubroutineType(types: !7)
+!7 = !{null}
+!8 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.4 (192092)", isOptimized: false, emissionKind: FullDebug, file: !9, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
+!9 = !DIFile(filename: "test2.c", directory: "/tmp")
+!11 = distinct !DISubprogram(name: "g", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: false, unit: !8, scopeLine: 1, file: !9, scope: !12, type: !6, variables: !2)
+!12 = !DIFile(filename: "test2.c", directory: "/tmp")
+!13 = !{i32 2, !"Dwarf Version", i32 4}
+!14 = !DILocation(line: 1, scope: !4)
+!15 = !DILocation(line: 1, scope: !11, inlinedAt: !14)
+!16 = !{i32 1, !"Debug Info Version", i32 3}
diff --git a/llvm/test/Transforms/StripSymbols/strip-dead-debug-info.ll b/llvm/test/Transforms/StripSymbols/strip-dead-debug-info.ll
index eb8ff50137c..d18c07d54a9 100644
--- a/llvm/test/Transforms/StripSymbols/strip-dead-debug-info.ll
+++ b/llvm/test/Transforms/StripSymbols/strip-dead-debug-info.ll
@@ -24,7 +24,7 @@ entry:
 define i32 @foo(i32 %i) #2 !dbg !15 {
 entry:
   tail call void @llvm.dbg.value(metadata i32 %i, i64 0, metadata !18, metadata !19), !dbg !20
-  %.0 = load i32, i32* @xyz, align 4
+  %.0 = load i32, i32* @xyz, align 4, !dbg !30
   ret i32 %.0, !dbg !21
 }
 
@@ -32,7 +32,7 @@ attributes #0 = { nounwind readnone }
 attributes #1 = { nounwind readnone ssp }
 attributes #2 = { nounwind readonly ssp }
 
-!llvm.dbg.cu = !{!4, !23, !24}
+!llvm.dbg.cu = !{!4, !23, !24, !28}
 !llvm.module.flags = !{!9}
 
 !0 = !DIGlobalVariableExpression(var: !1)
@@ -63,3 +63,6 @@ attributes #2 = { nounwind readonly ssp }
 !25 = !{!26}
 !26 = !DIGlobalVariableExpression(var: !27, expr: !DIExpression(DW_OP_constu, 0, DW_OP_stack_value))
 !27 = !DIGlobalVariable(name: "abcd2", scope: !2, file: !2, line: 2, type: !3, isLocal: true, isDefinition: true)
+!28 = distinct !DICompileUnit(language: DW_LANG_C89, file: !2, producer: "InlineTest", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !5, retainedTypes: !5, globals: !5)
+!29 = distinct !DISubprogram(name: "inlinefunc", linkageName: "inlinefunc", scope: null, file: !2, line: 7, type: !16, isLocal: false, isDefinition: true, isOptimized: true, unit: !28)
+!30 = !DILocation(line: 100, scope: !29, inlinedAt: !21)