From e847f132f76b25f523b16a32f828cac372a7f963 Mon Sep 17 00:00:00 2001
From: David Blaikie <dblaikie@gmail.com>
Date: Fri, 13 Jun 2014 22:35:44 +0000
Subject: [PATCH] DebugInfo: Reference abstract definitions from variables in
 concrete definitions that preceed their first inline definition.

Rather than relying on abstract variables looked up at the time the
concrete variable is created, look them up at the end of the module to
ensure they're referenced even if they're created after the concrete
definition. This completes/matches the work done in r209677 to handle
this for the subprograms themselves.

llvm-svn: 210946
---
 llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp             |  7 ++++++-
 llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h               |  1 +
 llvm/test/DebugInfo/X86/dbg-value-inlined-parameter.ll | 10 ++++------
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 1eb88b9178d4..77bb77d4a5fd 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -791,7 +791,7 @@ void DwarfDebug::finishVariableDefinitions() {
     // DIE::getUnit isn't simple - it walks parent pointers, etc.
     DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
     assert(Unit);
-    DbgVariable *AbsVar = Var->getAbstractVariable();
+    DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
     if (AbsVar && AbsVar->getDIE()) {
       Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
                         *AbsVar->getDIE());
@@ -1081,6 +1081,11 @@ DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
   return nullptr;
 }
 
+DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
+  DIVariable Cleansed;
+  return getExistingAbstractVariable(DV, Cleansed);
+}
+
 DbgVariable *DwarfDebug::createAbstractVariable(DIVariable &Var,
                                                 LexicalScope *Scope) {
   auto AbsDbgVariable = make_unique<DbgVariable>(Var, nullptr, this);
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 88b8a674b3e1..8445b74798f5 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -346,6 +346,7 @@ class DwarfDebug : public AsmPrinterHandler {
   /// \brief Find abstract variable associated with Var.
   DbgVariable *getExistingAbstractVariable(const DIVariable &DV,
                                            DIVariable &Cleansed);
+  DbgVariable *getExistingAbstractVariable(const DIVariable &DV);
   DbgVariable *createAbstractVariable(DIVariable &DV, LexicalScope *Scope);
   DbgVariable *getOrCreateAbstractVariable(DIVariable &Var,
                                            const MDNode *Scope);
diff --git a/llvm/test/DebugInfo/X86/dbg-value-inlined-parameter.ll b/llvm/test/DebugInfo/X86/dbg-value-inlined-parameter.ll
index 2d3cf6e68072..4d18f7dc3063 100644
--- a/llvm/test/DebugInfo/X86/dbg-value-inlined-parameter.ll
+++ b/llvm/test/DebugInfo/X86/dbg-value-inlined-parameter.ll
@@ -7,22 +7,20 @@
 
 ; CHECK: DW_TAG_subprogram
 ; CHECK:   DW_AT_abstract_origin {{.*}}{[[ABS:.*]]}
-; FIXME: An out of line definition preceding an inline usage doesn't properly
-; reference abstract variables.
 ; CHECK:   DW_TAG_formal_parameter
 ; CHECK-NOT: DW_TAG
-; CHECK:     DW_AT_name {{.*}} "sp"
+; CHECK:     DW_AT_abstract_origin {{.*}}{[[ABS_SP:.*]]}
 ; CHECK:   DW_TAG_formal_parameter
 ; CHECK-NOT: DW_TAG
-; CHECK:     DW_AT_name {{.*}} "nums"
+; CHECK:     DW_AT_abstract_origin {{.*}}{[[ABS_NUMS:.*]]}
 
 ; CHECK: [[ABS]]: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
 ; CHECK:   DW_AT_name {{.*}} "foo"
-; CHECK: [[ABS_SP:.*]]:   DW_TAG_formal_parameter
+; CHECK: [[ABS_SP]]:   DW_TAG_formal_parameter
 ; CHECK-NOT: DW_TAG
 ; CHECK:     DW_AT_name {{.*}} "sp"
-; CHECK: [[ABS_NUMS:.*]]:  DW_TAG_formal_parameter
+; CHECK: [[ABS_NUMS]]:  DW_TAG_formal_parameter
 ; CHECK-NOT: DW_TAG
 ; CHECK:     DW_AT_name {{.*}} "nums"