- 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80428 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 30 insertions, 17 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfException.cpp b/lib/CodeGen/AsmPrinter/DwarfException.cpp
index a8d8bfd759..e32447392f 100644
--- a/lib/CodeGen/AsmPrinter/DwarfException.cpp
+++ b/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();
 }