Fix the fde encoding used by mips to match gas.

This finally fixes the encoding. The patch also
* Removes eh-frame.ll. It was an unnecessary .ll to .o test that was checking
  the wrong value.
* Merge fde-reloc.s and eh-frame.s into a single test, since the only difference
  was the run lines.
* Don't blindly test the content of the entire .eh_frame section. It makes it
  hard to anyone actually fixing a bug and hitting a difference in a binary
  blob. Instead, use a CHECK for each field and document what is being checked.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178615 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 163 insertions, 112 deletions

diff --git a/lib/MC/MCObjectFileInfo.cpp b/lib/MC/MCObjectFileInfo.cpp
index 0d32ad40e8..d19e79ac64 100644
--- a/lib/MC/MCObjectFileInfo.cpp
+++ b/lib/MC/MCObjectFileInfo.cpp
@@ -223,10 +223,13 @@ void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
 }
 
 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
-  if (T.getArch() != Triple::mips &&
-      T.getArch() != Triple::mipsel &&
-      T.getArch() != Triple::mips64 &&
-      T.getArch() != Triple::mips64el )
+  if (T.getArch() == Triple::mips ||
+      T.getArch() == Triple::mipsel)
+    FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
+  else if (T.getArch() == Triple::mips64 ||
+           T.getArch() == Triple::mips64el)
+    FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
+  else
     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 
   if (T.getArch() == Triple::x86) {
diff --git a/test/MC/Mips/eh-frame.ll b/test/MC/Mips/eh-frame.ll
deleted file mode 100644
index 91c8b43d02..0000000000
--- a/test/MC/Mips/eh-frame.ll
+++ /dev/null
@@ -1,52 +0,0 @@
-; This tests .eh_frame CIE descriptor for the.
-; Data alignment factor
-
-; RUN: llc -filetype=obj -mcpu=mips64r2 -mattr=n64 -march=mips64el %s -o - \
-; RUN: | llvm-objdump -s - | FileCheck %s
-
-; N64
-; CHECK: Contents of section .eh_frame:
-; CHECK-NEXT:  0000 1c000000 00000000 017a504c 52000178  .........zPLR..x
-; CHECK-NEXT:  0010 1f0b0000 00000000 00000000 000c1d00  ................
-; CHECK-NEXT:  0020 2c000000 24000000 00000000 00000000  ,...$...........
-; CHECK-NEXT:  0030 7c000000 00000000 08000000 00000000  |...............
-; CHECK-NEXT:  0040 00440e10 489f019c 02000000 00000000  .D..H...........
-
-; ModuleID = 'simple_throw.cpp'
-
-@_ZTIi = external constant i8*
-@str = private unnamed_addr constant [7 x i8] c"All ok\00"
-
-define i32 @main() {
-entry:
-  %exception.i = tail call i8* @__cxa_allocate_exception(i64 4) nounwind
-  %0 = bitcast i8* %exception.i to i32*
-  store i32 5, i32* %0, align 4
-  invoke void @__cxa_throw(i8* %exception.i, i8* bitcast (i8** @_ZTIi to i8*), i8* null) noreturn
-          to label %.noexc unwind label %return
-
-.noexc:                                           ; preds = %entry
-  unreachable
-
-return:                                           ; preds = %entry
-  %1 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
-          catch i8* null
-  %2 = extractvalue { i8*, i32 } %1, 0
-  %3 = tail call i8* @__cxa_begin_catch(i8* %2) nounwind
-  %puts = tail call i32 @puts(i8* getelementptr inbounds ([7 x i8]* @str, i64 0, i64 0))
-  tail call void @__cxa_end_catch()
-  ret i32 0
-}
-
-declare i32 @__gxx_personality_v0(...)
-
-declare i8* @__cxa_begin_catch(i8*)
-
-declare void @__cxa_end_catch()
-
-declare i8* @__cxa_allocate_exception(i64)
-
-declare void @__cxa_throw(i8*, i8*, i8*)
-
-declare i32 @puts(i8* nocapture) nounwind
-
diff --git a/test/MC/Mips/eh-frame.s b/test/MC/Mips/eh-frame.s
index 56278b8b99..67df21365d 100644
--- a/test/MC/Mips/eh-frame.s
+++ b/test/MC/Mips/eh-frame.s
@@ -1,46 +1,167 @@
-// Assembler generated object test.
-// This tests .eh_frame descriptors minimally.
+// Test the bits of .eh_frame on mips that are already implemented correctly.
 
-// What we really need is a prettyprinter output check not unlike what
-// gnu's readobj generates instead of checking the bits for .eh_frame.
+// FIXME: This test would be a lot cleaner if llvm-objdump had the
+// --dwarf=frames option.
 
-// RUN: llvm-mc -filetype=obj -mcpu=mips32r2 -triple mipsel-unknown-linux -arch=mipsel %s -o - \
-// RUN: | llvm-objdump -s - | FileCheck -check-prefix=CHECK-LEO32 %s
+// RUN: llvm-mc -filetype=obj %s -o %t.o -arch=mips
+// RUN: llvm-objdump -r -s %t.o | FileCheck --check-prefix=MIPS32 %s
 
-// RUN: llvm-mc -filetype=obj -mcpu=mips32r2 -triple mips-unknown-linux -arch=mips %s -o - \
-// RUN: | llvm-objdump -s - | FileCheck -check-prefix=CHECK-BEO32 %s
+// RUN: llvm-mc -filetype=obj %s -o %t.o -arch=mipsel
+// RUN: llvm-objdump -r -s %t.o | FileCheck --check-prefix=MIPS32EL %s
 
-// RUN: llvm-mc -filetype=obj -mcpu=mips64r2 -mattr=n64 -arch=mips64el %s -o - \
-// RUN: | llvm-objdump -s - | FileCheck -check-prefix=CHECK-LE64 %s
+// RUN: llvm-mc -filetype=obj %s -o %t.o -arch=mips64
+// RUN: llvm-objdump -r -s %t.o | FileCheck --check-prefix=MIPS64 %s
 
-// RUN: llvm-mc -filetype=obj -mcpu=mips64r2 -mattr=n64 -arch=mips64 %s -o - \
-// RUN: | llvm-objdump -s - | FileCheck -check-prefix=CHECK-BE64 %s
+// RUN: llvm-mc -filetype=obj %s -o %t.o -arch=mips64el
+// RUN: llvm-objdump -r -s %t.o | FileCheck --check-prefix=MIPS64EL %s
 
-// O32 little endian
-// CHECK-LEO32: Contents of section .eh_frame:
-// CHECK-LEO32-NEXT: 0000 10000000 00000000 017a5200 017c1f01  .........zR..|..
-// CHECK-LEO32-NEXT: 0010 000c1d00 10000000 18000000 00000000  ................
-// CHECK-LEO32-NEXT: 0020 00000000 00000000                    ........
+func:
+	.cfi_startproc
+	.cfi_endproc
 
-// O32 big endian
-// CHECK-BEO32: Contents of section .eh_frame:
-// CHECK-BEO32-NEXT 0000 00000010 00000000 017a5200 017c1f01  .........zR..|..
-// CHECK-BEO32-NEXT 0010 000c1d00 00000010 00000018 00000000  ................
-// CHECK-BEO32-NEXT 0020 00000000 00000000                    ........
+// MIPS32: RELOCATION RECORDS FOR [.eh_frame]:
+// MIPS32-NEXT: R_MIPS_32
+// MIPS32: Contents of section .eh_frame:
+// MIPS32-NEXT: 0000
 
-// N64 little endian
-// CHECK-LE64: Contents of section .eh_frame:
-// CHECK-LE64-NEXT: 0000 10000000 00000000 017a5200 01781f01  .........zR..x..
-// CHECK-LE64-NEXT: 0010 000c1d00 18000000 18000000 00000000  ................
-// CHECK-LE64-NEXT: 0020 00000000 00000000 00000000 00000000  ................
+// Length
+// MIPS32: 00000010
 
-// N64 big endian
-// CHECK-BE64: Contents of section .eh_frame:
-// CHECK-BE64-NEXT: 0000 00000010 00000000 017a5200 01781f01  .........zR..x..
-// CHECK-BE64-NEXT: 0010 000c1d00 00000018 00000018 00000000  ................
-// CHECK-BE64-NEXT: 0020 00000000 00000000 00000000 00000000  ................
+// CIE ID
+// MIPS32: 00000000
 
-func:
-	.cfi_startproc
-	.cfi_endproc
+// Version
+// MIPS32: 01
+
+// Augmentation String
+// MIPS32: 7a5200
+
+// Code Alignment Factor
+// MIPS32: 01
+
+// Data Alignment Factor (-4)
+// MIPS32: 7c
+
+// Return Address Register
+// MIPS32: 1f
+
+// Augmentation Size
+// MIPS32: 01
+
+// MIPS32: .........zR..|..
+// MIPS32-NEXT: 0010
+
+// Augmentation (fde pointer encoding: DW_EH_PE_sdata4)
+// MIPS32: 0b
+// FIXME: The instructions are different from the ones produces by gas.
+
+// MIPS32EL: RELOCATION RECORDS FOR [.eh_frame]:
+// MIPS32EL-NEXT: R_MIPS_32
+// MIPS32EL: Contents of section .eh_frame:
+// MIPS32EL-NEXT: 0000
+
+// Length
+// MIPS32EL: 10000000
+
+// CIE ID
+// MIPS32EL: 00000000
+
+// Version
+// MIPS32EL: 01
+
+// Augmentation String
+// MIPS32EL: 7a5200
+
+// Code Alignment Factor
+// MIPS32EL: 01
+
+// Data Alignment Factor (-4)
+// MIPS32EL: 7c
+
+// Return Address Register
+// MIPS32EL: 1f
+
+// Augmentation Size
+// MIPS32EL: 01
+
+// MIPS32EL: .........zR..|..
+// MIPS32EL-NEXT: 0010
+
+// Augmentation (fde pointer encoding: DW_EH_PE_sdata4)
+// MIPS32EL: 0b
+// FIXME: The instructions are different from the ones produces by gas.
+
+// MIPS64: RELOCATION RECORDS FOR [.eh_frame]:
+// MIPS64-NEXT: R_MIPS_64
+// MIPS64: Contents of section .eh_frame:
+// MIPS64-NEXT: 0000
+
+// Length
+// MIPS64: 00000010
+
+// CIE ID
+// MIPS64: 00000000
+
+// Version
+// MIPS64: 01
+
+// Augmentation String
+// MIPS64: 7a5200
+
+// Code Alignment Factor
+// MIPS64: 01
+
+// Data Alignment Factor (-8). GAS uses -4. Should be ok as long as all
+// offsets we need are a multiple of 8.
+// MIPS64: 78
+
+// Return Address Register
+// MIPS64: 1f
+
+// Augmentation Size
+// MIPS64: 01
+
+// MIPS64: .........zR..x..
+// MIPS64-NEXT: 0010
+
+// Augmentation (fde pointer encoding: DW_EH_PE_sdata8)
+// MIPS64: 0c
+// FIXME: The instructions are different from the ones produces by gas.
+
+
+// MIPS64EL: RELOCATION RECORDS FOR [.eh_frame]:
+// FIXME: llvm-objdump currently misprints the relocations for mips64el
+// MIPS64EL: Contents of section .eh_frame:
+// MIPS64EL-NEXT: 0000
+
+// Length
+// MIPS64EL: 10000000
+
+// CIE ID
+// MIPS64EL: 00000000
+
+// Version
+// MIPS64EL: 01
+
+// Augmentation String
+// MIPS64EL: 7a5200
+
+// Code Alignment Factor
+// MIPS64EL: 01
+
+// Data Alignment Factor (-8). GAS uses -4. Should be ok as long as all
+// offsets we need are a multiple of 8.
+// MIPS64EL: 78
+
+// Return Address Register
+// MIPS64EL: 1f
+
+// Augmentation Size
+// MIPS64EL: 01
+
+// MIPS64EL: .........zR..x..
+// MIPS64EL-NEXT: 0010
 
+// Augmentation (fde pointer encoding: DW_EH_PE_sdata8)
+// MIPS64EL: 0c
+// FIXME: The instructions are different from the ones produces by gas.
diff --git a/test/MC/Mips/fde-reloc.s b/test/MC/Mips/fde-reloc.s
deleted file mode 100644
index 2db5d0b638..0000000000
--- a/test/MC/Mips/fde-reloc.s
+++ /dev/null
@@ -1,21 +0,0 @@
-// This just tests that a relocation of the specified type shows up as the first
-// relocation in the relocation section for .eh_frame when produced by the
-// assembler.
-
-// RUN: llvm-mc -filetype=obj %s -o - -triple mips-unknown-unknown | \
-// RUN: llvm-objdump -r - | FileCheck --check-prefix=MIPS32 %s
-
-// RUN: llvm-mc -filetype=obj %s -o - -triple mips64-unknown-unknown | \
-// RUN: llvm-objdump -r - | FileCheck --check-prefix=MIPS64 %s
-
-// PR15448
-
-func:
-	.cfi_startproc
-	.cfi_endproc
-
-// MIPS32: RELOCATION RECORDS FOR [.eh_frame]:
-// MIPS32-NEXT: R_MIPS_32
-
-// MIPS64: RELOCATION RECORDS FOR [.eh_frame]:
-// MIPS64-NEXT: R_MIPS_64