From 39bb29f7fef8bd17d5f684fedb376b55a07b4f14 Mon Sep 17 00:00:00 2001
From: Bill Wendling <isanbard@gmail.com>
Date: Sat, 29 Aug 2009 12:20:54 +0000
Subject: - Add target lowering methods to get the preferred format for the FDE
 and LSDA   encodings. - Make some of the values emitted by the FDEs dependent
 upon the pointer   size. This is in line with how GCC does things. And it has
 the benefit of   working for Darwin in 64-bit mode now.

llvm-svn: 80428
---
 llvm/lib/CodeGen/AsmPrinter/DwarfException.cpp | 47 ++++++++++++++++----------
 1 file changed, 30 insertions(+), 17 deletions(-)

(limited to 'llvm/lib/CodeGen')

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfException.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfException.cpp
index a8d8bfd7590..e32447392f4 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfException.cpp
@@ -22,6 +22,7 @@
 #include "llvm/Target/TargetData.h"
 #include "llvm/Target/TargetFrameInfo.h"
 #include "llvm/Target/TargetLoweringObjectFile.h"
+#include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetOptions.h"
 #include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/Support/Dwarf.h"
@@ -80,6 +81,7 @@ void DwarfException::EmitCIE(const Function *Personality, unsigned Index) {
   EmitLabel("eh_frame_common_begin", Index);
   Asm->EmitInt32((int)0);
   Asm->EOL("CIE Identifier Tag");
+
   Asm->EmitInt8(dwarf::DW_CIE_VERSION);
   Asm->EOL("CIE Version");
 
@@ -91,23 +93,29 @@ void DwarfException::EmitCIE(const Function *Personality, unsigned Index) {
   // Round out reader.
   Asm->EmitULEB128Bytes(1);
   Asm->EOL("CIE Code Alignment Factor");
+
   Asm->EmitSLEB128Bytes(stackGrowth);
   Asm->EOL("CIE Data Alignment Factor");
+
   Asm->EmitInt8(RI->getDwarfRegNum(RI->getRARegister(), true));
   Asm->EOL("CIE Return Address Column");
 
+  unsigned Encoding = 0;
+
   // If there is a personality, we need to indicate the function's location.
   if (Personality) {
     Asm->EmitULEB128Bytes(7);
     Asm->EOL("Augmentation Size");
 
     if (MAI->getNeedsIndirectEncoding()) {
-      Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 |
-                    dwarf::DW_EH_PE_indirect);
-      Asm->EOL("Personality (pcrel sdata4 indirect)");
+      Encoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 |
+        dwarf::DW_EH_PE_indirect;
+      Asm->EmitInt8(Encoding);
+      Asm->EOL("Personality", Encoding);
     } else {
-      Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
-      Asm->EOL("Personality (pcrel sdata4)");
+      Encoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
+      Asm->EmitInt8(Encoding);
+      Asm->EOL("Personality", Encoding);
     }
 
     PrintRelDirective(true);
@@ -118,17 +126,20 @@ void DwarfException::EmitCIE(const Function *Personality, unsigned Index) {
       O << "-" << MAI->getPCSymbol();
     Asm->EOL("Personality");
 
-    Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
-    Asm->EOL("LSDA Encoding (pcrel sdata4)");
+    Encoding = Asm->TM.getTargetLowering()->getPreferredLSDADataFormat();
+    Asm->EmitInt8(Encoding);
+    Asm->EOL("LSDA Encoding", Encoding);
 
-    Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
-    Asm->EOL("FDE Encoding (pcrel sdata4)");
+    Encoding = Asm->TM.getTargetLowering()->getPreferredFDEDataFormat();
+    Asm->EmitInt8(Encoding);
+    Asm->EOL("FDE Encoding", Encoding);
   } else {
     Asm->EmitULEB128Bytes(1);
     Asm->EOL("Augmentation Size");
 
-    Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
-    Asm->EOL("FDE Encoding (pcrel sdata4)");
+    Encoding = Asm->TM.getTargetLowering()->getPreferredFDEDataFormat();
+    Asm->EmitInt8(Encoding);
+    Asm->EOL("FDE Encoding", Encoding);
   }
 
   // Indicate locations of general callee saved registers in frame.
@@ -152,6 +163,7 @@ void DwarfException::EmitFDE(const FunctionEHFrameInfo &EHFrameInfo) {
          "Should not emit 'available externally' functions at all");
 
   const Function *TheFunc = EHFrameInfo.function;
+  bool is4Byte = TD->getPointerSize() == sizeof(int32_t);
 
   Asm->OutStreamer.SwitchSection(Asm->getObjFileLowering().getEHFrameSection());
 
@@ -195,23 +207,22 @@ void DwarfException::EmitFDE(const FunctionEHFrameInfo &EHFrameInfo) {
 
     Asm->EOL("FDE CIE offset");
 
-    EmitReference("eh_func_begin", EHFrameInfo.Number, true, true);
+    EmitReference("eh_func_begin", EHFrameInfo.Number, true, is4Byte);
     Asm->EOL("FDE initial location");
+
     EmitDifference("eh_func_end", EHFrameInfo.Number,
-                   "eh_func_begin", EHFrameInfo.Number, true);
+                   "eh_func_begin", EHFrameInfo.Number, is4Byte);
     Asm->EOL("FDE address range");
 
     // If there is a personality and landing pads then point to the language
     // specific data area in the exception table.
     if (MMI->getPersonalities()[0] != NULL) {
-      bool is4Byte = TD->getPointerSize() == sizeof(int32_t);
-
       Asm->EmitULEB128Bytes(is4Byte ? 4 : 8);
       Asm->EOL("Augmentation size");
 
-      if (EHFrameInfo.hasLandingPads)
+      if (EHFrameInfo.hasLandingPads) {
         EmitReference("exception", EHFrameInfo.Number, true, false);
-      else {
+      } else {
 	if (is4Byte)
 	  Asm->EmitInt32((int)0);
 	else
@@ -918,6 +929,8 @@ void DwarfException::EndFunction() {
                             MF->getFunction()));
   }
 
+  MF = 0;
+
   if (TimePassesIsEnabled)
     ExceptionTimer->stopTimer();
 }
-- 
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