From 3051c6d5127106e62acf7e44dcad65ef23e2a5d5 Mon Sep 17 00:00:00 2001
From: Adrian Prantl <aprantl@apple.com>
Date: Tue, 20 Sep 2016 18:28:42 +0000
Subject: [PATCH] ASAN: Don't drop debug info attachements for global
 variables. This is a follow-up to r281284. Global Variables now can have !dbg
 attachements, so ASAN should clone these when generating a sanitized copy of
 a global variable.

<rdar://problem/24899262>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281994 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../Instrumentation/AddressSanitizer.cpp      |  7 +++++
 .../AddressSanitizer/debug-info-global-var.ll | 28 +++++++++++++++++++
 2 files changed, 35 insertions(+)
 create mode 100644 test/Instrumentation/AddressSanitizer/debug-info-global-var.ll

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index b601d391f24..c5bcb39992f 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -1534,6 +1534,13 @@ bool AddressSanitizerModule::InstrumentGlobals(IRBuilder<> &IRB, Module &M) {
     NewGlobal->copyAttributesFrom(G);
     NewGlobal->setAlignment(MinRZ);
 
+    // Transfer the debug info.  The payload starts at offset zero so we can
+    // copy the debug info over as is.
+    SmallVector<DIGlobalVariable *, 1> GVs;
+    G->getDebugInfo(GVs);
+    for (auto *GV : GVs)
+      NewGlobal->addDebugInfo(GV);
+
     Value *Indices2[2];
     Indices2[0] = IRB.getInt32(0);
     Indices2[1] = IRB.getInt32(0);
diff --git a/test/Instrumentation/AddressSanitizer/debug-info-global-var.ll b/test/Instrumentation/AddressSanitizer/debug-info-global-var.ll
new file mode 100644
index 00000000000..2848538f328
--- /dev/null
+++ b/test/Instrumentation/AddressSanitizer/debug-info-global-var.ll
@@ -0,0 +1,28 @@
+; RUN: opt < %s -asan -asan-module -S | FileCheck %s
+source_filename = "version.c"
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.12.0"
+
+; CHECK: @version = constant { [5 x i8], [59 x i8] } {{.*}}, !dbg ![[GV:.*]]
+@version = constant [5 x i8] c"4.00\00", align 1, !dbg !0
+
+!llvm.dbg.cu = !{!1}
+!llvm.module.flags = !{!10, !11, !12}
+!llvm.ident = !{!13}
+
+; CHECK: ![[GV]] = distinct !DIGlobalVariable(name: "version"
+; CHECK-NOT: expr:
+!0 = distinct !DIGlobalVariable(name: "version", scope: !1, file: !2, line: 2, type: !5, isLocal: false, isDefinition: true)
+!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2, producer: "clang version 4.0.0 (trunk 281923) (llvm/trunk 281916)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !3, globals: !4)
+!2 = !DIFile(filename: "version.c", directory: "/Volumes/Fusion/Data/radar/24899262")
+!3 = !{}
+!4 = !{!0}
+!5 = !DICompositeType(tag: DW_TAG_array_type, baseType: !6, size: 40, align: 8, elements: !8)
+!6 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !7)
+!7 = !DIBasicType(name: "char", size: 8, align: 8, encoding: DW_ATE_signed_char)
+!8 = !{!9}
+!9 = !DISubrange(count: 5)
+!10 = !{i32 2, !"Dwarf Version", i32 4}
+!11 = !{i32 2, !"Debug Info Version", i32 3}
+!12 = !{i32 1, !"PIC Level", i32 2}
+!13 = !{!"clang version 4.0.0 (trunk 281923) (llvm/trunk 281916)"}
-- 
2.50.1