From 4437df8eedfdaa11b445c34fc3b19a1b14cb3d93 Mon Sep 17 00:00:00 2001
From: David Blaikie <dblaikie@gmail.com>
Date: Thu, 22 Oct 2020 20:08:54 -0700
Subject: [PATCH] DebugInfo: Hash DIE referevences (DW_OP_convert) when
 computing Split DWARF signatures

---
 llvm/include/llvm/CodeGen/DIE.h             |  1 +
 llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp     | 11 ++++++++++-
 llvm/lib/CodeGen/AsmPrinter/DIEHash.h       |  4 +++-
 llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp  |  2 +-
 llvm/test/DebugInfo/X86/convert-debugloc.ll |  5 +++++
 5 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/llvm/include/llvm/CodeGen/DIE.h b/llvm/include/llvm/CodeGen/DIE.h
index fa554be..eaa700f 100644
--- a/llvm/include/llvm/CodeGen/DIE.h
+++ b/llvm/include/llvm/CodeGen/DIE.h
@@ -247,6 +247,7 @@ public:
   unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
 
   void print(raw_ostream &O) const;
+  uint64_t getIndex() const { return Index; }
 };
 
 //===--------------------------------------------------------------------===//
diff --git a/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp b/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp
index f26ef63..da9997e 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp
@@ -12,6 +12,7 @@
 
 #include "DIEHash.h"
 #include "ByteStreamer.h"
+#include "DwarfCompileUnit.h"
 #include "DwarfDebug.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringRef.h"
@@ -214,7 +215,15 @@ void DIEHash::hashDIEEntry(dwarf::Attribute Attribute, dwarf::Tag Tag,
 // all of the data is going to be added as integers.
 void DIEHash::hashBlockData(const DIE::const_value_range &Values) {
   for (const auto &V : Values)
-    Hash.update((uint64_t)V.getDIEInteger().getValue());
+    if (V.getType() == DIEValue::isBaseTypeRef) {
+      const DIE &C =
+          *CU->ExprRefedBaseTypes[V.getDIEBaseTypeRef().getIndex()].Die;
+      StringRef Name = getDIEStringAttr(C, dwarf::DW_AT_name);
+      assert(!Name.empty() &&
+             "Base types referenced from DW_OP_convert should have a name");
+      hashNestedType(C, Name);
+    } else
+      Hash.update((uint64_t)V.getDIEInteger().getValue());
 }
 
 // Hash the contents of a loclistptr class.
diff --git a/llvm/lib/CodeGen/AsmPrinter/DIEHash.h b/llvm/lib/CodeGen/AsmPrinter/DIEHash.h
index 1a69f67..29e1da4c 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DIEHash.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DIEHash.h
@@ -31,7 +31,8 @@ class DIEHash {
   };
 
 public:
-  DIEHash(AsmPrinter *A = nullptr) : AP(A) {}
+  DIEHash(AsmPrinter *A = nullptr, DwarfCompileUnit *CU = nullptr)
+      : AP(A), CU(CU) {}
 
   /// Computes the CU signature.
   uint64_t computeCUSignature(StringRef DWOName, const DIE &Die);
@@ -101,6 +102,7 @@ private:
 private:
   MD5 Hash;
   AsmPrinter *AP;
+  DwarfCompileUnit *CU;
   DenseMap<const DIE *, unsigned> Numbering;
 };
 }
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index f497905..130df99 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1288,7 +1288,7 @@ void DwarfDebug::finalizeModuleInfo() {
                       Asm->TM.Options.MCOptions.SplitDwarfFile);
       // Emit a unique identifier for this CU.
       uint64_t ID =
-          DIEHash(Asm).computeCUSignature(DWOName, TheCU.getUnitDie());
+          DIEHash(Asm, &TheCU).computeCUSignature(DWOName, TheCU.getUnitDie());
       if (getDwarfVersion() >= 5) {
         TheCU.setDWOId(ID);
         SkCU->setDWOId(ID);
diff --git a/llvm/test/DebugInfo/X86/convert-debugloc.ll b/llvm/test/DebugInfo/X86/convert-debugloc.ll
index afe2cb3..2aafacf 100644
--- a/llvm/test/DebugInfo/X86/convert-debugloc.ll
+++ b/llvm/test/DebugInfo/X86/convert-debugloc.ll
@@ -19,6 +19,11 @@
 ; RUN: llc -mtriple=x86_64-pc-linux-gnu -dwarf-version=5 -filetype=obj -O0 < %s -debugger-tune=lldb -dwarf-op-convert=Enable | llvm-dwarfdump - \
 ; RUN:   | FileCheck %s --check-prefix=CONV "--implicit-check-not={{DW_TAG|NULL}}"
 
+; Test DW_OP_convert + Split DWARF
+; RUN: llc -mtriple=x86_64-pc-linux-gnu -dwarf-version=5 -filetype=obj -O0 < %s -debugger-tune=lldb -dwarf-op-convert=Enable -split-dwarf-file=baz.dwo | llvm-dwarfdump - \
+; RUN:   | FileCheck %s --check-prefix=CONV --check-prefix=SPLITCONV --check-prefix=SPLIT "--implicit-check-not={{DW_TAG|NULL}}"
+
+; SPLITCONV: Compile Unit:{{.*}} DWO_id = 0xe91d8d1d7f9782c0
 ; SPLIT: DW_TAG_skeleton_unit
 
 ; CONV: DW_TAG_compile_unit
-- 
2.7.4