[llvm-commits] [llvm] r122590 - in /llvm/trunk: include/llvm/MC/MCDwarf.h lib/MC/MCDwarf.cpp lib/MC/MCStreamer.cpp test/MC/ELF/cfi-def-cfa-offset.s

[Rafael Espindola]

Author: rafael
Date: Mon Dec 27 22:15:37 2010
New Revision: 122590

URL: http://llvm.org/viewvc/llvm-project?rev=122590&view=rev
Log:
Start adding basic support for emitting the call frame instructions.

Added:
    llvm/trunk/test/MC/ELF/cfi-def-cfa-offset.s
Modified:
    llvm/trunk/include/llvm/MC/MCDwarf.h
    llvm/trunk/lib/MC/MCDwarf.cpp
    llvm/trunk/lib/MC/MCStreamer.cpp

Modified: llvm/trunk/include/llvm/MC/MCDwarf.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCDwarf.h?rev=122590&r1=122589&r2=122590&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCDwarf.h (original)
+++ llvm/trunk/include/llvm/MC/MCDwarf.h Mon Dec 27 22:15:37 2010
@@ -16,6 +16,7 @@
 #define LLVM_MC_MCDWARF_H
 
 #include "llvm/ADT/StringRef.h"
+#include "llvm/CodeGen/MachineLocation.h" // FIXME
 #include "llvm/MC/MCObjectWriter.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/Dwarf.h"
@@ -227,10 +228,13 @@
   };
 
   struct MCDwarfFrameInfo {
+    MCDwarfFrameInfo() : Begin(0), End(0), Personality(0), Lsda(0), Moves(),
+                         PersonalityEncoding(0), LsdaEncoding(0) {}
     MCSymbol *Begin;
     MCSymbol *End;
     const MCSymbol *Personality;
     const MCSymbol *Lsda;
+    std::vector<MachineMove> Moves;
     unsigned PersonalityEncoding;
     unsigned LsdaEncoding;
   };

Modified: llvm/trunk/lib/MC/MCDwarf.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCDwarf.cpp?rev=122590&r1=122589&r2=122590&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCDwarf.cpp (original)
+++ llvm/trunk/lib/MC/MCDwarf.cpp Mon Dec 27 22:15:37 2010
@@ -460,9 +460,11 @@
     if (BaseLabel && Label) {
       MCSymbol *ThisSym = Label;
       if (ThisSym != BaseLabel) {
+        // FIXME: We should relax this instead of using a DW_CFA_advance_loc4
+        // for every address change!
         streamer.EmitIntValue(dwarf::DW_CFA_advance_loc4, 1);
         const MCExpr *Length = MakeStartMinusEndExpr(streamer, *BaseLabel,
-                                                     *ThisSym, 4);
+                                                     *ThisSym, 0);
         streamer.EmitValue(Length, 4);
         BaseLabel = ThisSym;
       }
@@ -672,6 +674,8 @@
   streamer.EmitLabel(augmentationEnd);
   // Call Frame Instructions
 
+  EmitFrameMoves(streamer, frame.Moves, frame.Begin, true);
+
   // Padding
   streamer.EmitValueToAlignment(4);
 

Modified: llvm/trunk/lib/MC/MCStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCStreamer.cpp?rev=122590&r1=122589&r2=122590&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCStreamer.cpp Mon Dec 27 22:15:37 2010
@@ -157,7 +157,7 @@
     report_fatal_error("Starting a frame before finishing the previous one!");
     return true;
   }
-  MCDwarfFrameInfo Frame = {0, 0, 0, 0, 0, 0};
+  MCDwarfFrameInfo Frame;
   Frame.Begin = getContext().CreateTempSymbol();
   EmitLabel(Frame.Begin);
   FrameInfos.push_back(Frame);
@@ -174,6 +174,13 @@
 
 bool MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
   EnsureValidFrame();
+  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
+  MCSymbol *Label = getContext().CreateTempSymbol();
+  EmitLabel(Label);
+  MachineLocation Dest(MachineLocation::VirtualFP);
+  MachineLocation Source(MachineLocation::VirtualFP, -Offset);
+  MachineMove Move(Label, Dest, Source);
+  CurFrame->Moves.push_back(Move);
   return false;
 }
 

Added: llvm/trunk/test/MC/ELF/cfi-def-cfa-offset.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ELF/cfi-def-cfa-offset.s?rev=122590&view=auto
==============================================================================
--- llvm/trunk/test/MC/ELF/cfi-def-cfa-offset.s (added)
+++ llvm/trunk/test/MC/ELF/cfi-def-cfa-offset.s Mon Dec 27 22:15:37 2010
@@ -0,0 +1,49 @@
+// RUN: llvm-mc -filetype=obj -triple x86_64-pc-linux-gnu %s -o - | elf-dump  --dump-section-data | FileCheck %s
+
+f:
+	.cfi_startproc
+	subq	$8, %rsp
+	.cfi_def_cfa_offset 16
+        nop
+	addq	$8, %rsp
+	.cfi_def_cfa_offset 8
+	ret
+	.cfi_endproc
+
+// FIXME: This is a correct but really inefficient coding since
+// we use a CFA_advance_loc4 for every address change!
+
+// CHECK:      # Section 0x00000004
+// CHECK-NEXT: (('sh_name', 0x00000012) # '.eh_frame'
+// CHECK-NEXT:  ('sh_type', 0x00000001)
+// CHECK-NEXT:  ('sh_flags', 0x00000002)
+// CHECK-NEXT:  ('sh_addr', 0x00000000)
+// CHECK-NEXT:  ('sh_offset', 0x00000050)
+// CHECK-NEXT:  ('sh_size', 0x00000038)
+// CHECK-NEXT:  ('sh_link', 0x00000000)
+// CHECK-NEXT:  ('sh_info', 0x00000000)
+// CHECK-NEXT:  ('sh_addralign', 0x00000008)
+// CHECK-NEXT:  ('sh_entsize', 0x00000000)
+// CHECK-NEXT:  ('_section_data', '14000000 00000000 017a5200 01781001 1b0c0708 90010000 1c000000 1c000000 00000000 0a000000 00040400 00000e10 04050000 000e0800')
+// CHECK-NEXT: ),
+
+// CHECK:       # Section 0x00000008
+// CHECK-NEXT: (('sh_name', 0x00000036) # '.rela.eh_frame'
+// CHECK-NEXT:  ('sh_type', 0x00000004)
+// CHECK-NEXT:  ('sh_flags', 0x00000000)
+// CHECK-NEXT:  ('sh_addr', 0x00000000)
+// CHECK-NEXT:  ('sh_offset', 0x00000168)
+// CHECK-NEXT:  ('sh_size', 0x00000018)
+// CHECK-NEXT:  ('sh_link', 0x00000006)
+// CHECK-NEXT:  ('sh_info', 0x00000004)
+// CHECK-NEXT:  ('sh_addralign', 0x00000008)
+// CHECK-NEXT:  ('sh_entsize', 0x00000018)
+// CHECK-NEXT:  ('_relocations', [
+// CHECK-NEXT:   # Relocation 0x00000000
+// CHECK-NEXT:   (('r_offset', 0x00000020)
+// CHECK-NEXT:    ('r_sym', 0x00000002)
+// CHECK-NEXT:    ('r_type', 0x00000002)
+// CHECK-NEXT:    ('r_addend', 0x00000000)
+// CHECK-NEXT:   ),
+// CHECK-NEXT:  ])
+// CHECK-NEXT: ),