[llvm] r177141 - Fix the FDE encoding to be relative on ELF.

[Rafael Espindola]

Author: rafael
Date: Fri Mar 15 00:51:57 2013
New Revision: 177141

URL: http://llvm.org/viewvc/llvm-project?rev=177141&view=rev
Log:
Fix the FDE encoding to be relative on ELF.

This is a very late complement to r130637 which fixed this on x86_64. Fixes
pr15448.

Since it looks like that every elf architecture uses this encoding when using
cfi, make it the default for elf. Just exclude mips64el. It has a lovely
.ll -> .o test (ef_frame.ll) that tests that nothing changes in the binary
content of the .eh_frame produced by llc. Oblige it.

Added:
    llvm/trunk/test/MC/ELF/fde-reloc.s
Modified:
    llvm/trunk/lib/MC/MCObjectFileInfo.cpp

Modified: llvm/trunk/lib/MC/MCObjectFileInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCObjectFileInfo.cpp?rev=177141&r1=177140&r2=177141&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCObjectFileInfo.cpp (original)
+++ llvm/trunk/lib/MC/MCObjectFileInfo.cpp Fri Mar 15 00:51:57 2013
@@ -223,6 +223,11 @@ void MCObjectFileInfo::InitMachOMCObject
 }
 
 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
+  // FIXME: Check this. Mips64el is using the base values, which is most likely
+  // incorrect.
+  if (T.getArch() != Triple::mips64el)
+    FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
+
   if (T.getArch() == Triple::x86) {
     PersonalityEncoding = (RelocM == Reloc::PIC_)
      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
@@ -230,15 +235,13 @@ void MCObjectFileInfo::InitELFMCObjectFi
     LSDAEncoding = (RelocM == Reloc::PIC_)
       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
       : dwarf::DW_EH_PE_absptr;
-    FDEEncoding = FDECFIEncoding = (RelocM == Reloc::PIC_)
+    FDEEncoding = (RelocM == Reloc::PIC_)
       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
       : dwarf::DW_EH_PE_absptr;
     TTypeEncoding = (RelocM == Reloc::PIC_)
      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
      : dwarf::DW_EH_PE_absptr;
   } else if (T.getArch() == Triple::x86_64) {
-    FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
-
     if (RelocM == Reloc::PIC_) {
       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
@@ -261,8 +264,6 @@ void MCObjectFileInfo::InitELFMCObjectFi
         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
     }
   }  else if (T.getArch() ==  Triple::aarch64) {
-    FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
-
     // The small model guarantees static code/data size < 4GB, but not where it
     // will be in memory. Most of these could end up >2GB away so even a signed
     // pc-relative 32-bit address is insufficient, theoretically.
@@ -282,7 +283,6 @@ void MCObjectFileInfo::InitELFMCObjectFi
   } else if (T.getArch() == Triple::ppc64) {
     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
       dwarf::DW_EH_PE_udata8;
-    FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
     FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |

Added: llvm/trunk/test/MC/ELF/fde-reloc.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ELF/fde-reloc.s?rev=177141&view=auto
==============================================================================
--- llvm/trunk/test/MC/ELF/fde-reloc.s (added)
+++ llvm/trunk/test/MC/ELF/fde-reloc.s Fri Mar 15 00:51:57 2013
@@ -0,0 +1,11 @@
+// RUN: llvm-mc -filetype=obj %s -o - -triple x86_64-pc-linux | llvm-objdump -r - | FileCheck --check-prefix=X86-64 %s
+// RUN: llvm-mc -filetype=obj %s -o - -triple i686-pc-linux | llvm-objdump -r - | FileCheck --check-prefix=I686 %s
+
+// PR15448
+
+func:
+	.cfi_startproc
+	.cfi_endproc
+
+// X86-64: R_X86_64_PC32
+// I686: R_386_PC32