From 084751cd16c3b8017b5a237bd2575b65a6543f79 Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Tue, 20 Apr 2010 00:37:27 +0000
Subject: [PATCH] Remove MachineFunction's DefaultDebugLoc member, and make
 DwarfDebug.cpp responsible for figuring out what that's supposed to be on its
 own.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101844 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/CodeGen/MachineFunction.h        | 17 -----------------
 lib/CodeGen/AsmPrinter/DwarfDebug.cpp         | 17 ++++++++++++++++-
 lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp |  5 -----
 3 files changed, 16 insertions(+), 23 deletions(-)

diff --git a/include/llvm/CodeGen/MachineFunction.h b/include/llvm/CodeGen/MachineFunction.h
index 09d33b16d3c..595872ad2d7 100644
--- a/include/llvm/CodeGen/MachineFunction.h
+++ b/include/llvm/CodeGen/MachineFunction.h
@@ -109,10 +109,6 @@ class MachineFunction {
   typedef ilist<MachineBasicBlock> BasicBlockListType;
   BasicBlockListType BasicBlocks;
 
-  /// Default debug location. Used to print out the debug label at the beginning
-  /// of a function.
-  DebugLoc DefaultDebugLoc;
-
   /// FunctionNumber - This provides a unique ID for each function emitted in
   /// this translation unit.
   ///
@@ -394,19 +390,6 @@ public:
   /// normal 'L' label is returned.
   MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx, 
                          bool isLinkerPrivate = false) const;
-  
-  
-  //===--------------------------------------------------------------------===//
-  // Debug location.
-  //
-
-  /// getDefaultDebugLoc - Get the default debug location for the machine
-  /// function.
-  DebugLoc getDefaultDebugLoc() const { return DefaultDebugLoc; }
-
-  /// setDefaultDebugLoc - Get the default debug location for the machine
-  /// function.
-  void setDefaultDebugLoc(DebugLoc DL) { DefaultDebugLoc = DL; }
 };
 
 //===--------------------------------------------------------------------===//
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 23f08f1df5c..684a409c9ff 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -2283,6 +2283,21 @@ void DwarfDebug::identifyScopeMarkers() {
   }
 }
 
+/// FindFirstDebugLoc - Find the first debug location in the function. This
+/// is intended to be an approximation for the source position of the
+/// beginning of the function.
+static DebugLoc FindFirstDebugLoc(const MachineFunction *MF) {
+  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
+       I != E; ++I)
+    for (MachineBasicBlock::const_iterator MBBI = I->begin(), MBBE = I->end();
+         MBBI != MBBE; ++MBBI) {
+      DebugLoc DL = MBBI->getDebugLoc();
+      if (!DL.isUnknown())
+        return DL;
+    }
+  return DebugLoc();
+}
+
 /// beginFunction - Gather pre-function debug information.  Assumes being
 /// emitted immediately after the function entry point.
 void DwarfDebug::beginFunction(const MachineFunction *MF) {
@@ -2297,7 +2312,7 @@ void DwarfDebug::beginFunction(const MachineFunction *MF) {
 
   // Emit label for the implicitly defined dbg.stoppoint at the start of the
   // function.
-  DebugLoc FDL = MF->getDefaultDebugLoc();
+  DebugLoc FDL = FindFirstDebugLoc(MF);
   if (FDL.isUnknown()) return;
   
   MDNode *Scope = FDL.getScope(MF->getFunction()->getContext());
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 13d8c3818c1..d47c76bbbfa 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -235,11 +235,6 @@ static void SetDebugLoc(const Instruction *I, SelectionDAGBuilder *SDB,
 
   if (FastIS)
     FastIS->setCurDebugLoc(DL);
-
-  // If the function doesn't have a default debug location yet, set
-  // it. This is a total hack.
-  if (MF->getDefaultDebugLoc().isUnknown())
-    MF->setDefaultDebugLoc(DL);
 }
 
 /// ResetDebugLoc - Set MF's and SDB's DebugLocs to Unknown.
-- 
2.34.1