[mips] Set Personality and LSDA encoding for FreeBSD

[seanbruno]

Yep, this is one of my patches that I'm still carrying to build mips64.

[sdardis]

LGTM.

lib/MC/MCObjectFileInfo.cpp

case Triple::mips64el:
     // generated for relocation.
     PersonalityEncoding = dwarf::DW_EH_PE_indirect;
     // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't
     //        identify N64 from just a triple.
     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
                     dwarf::DW_EH_PE_sdata4;
     // We don't support PC-relative LSDA references in GAS so we use the default
     // DW_EH_PE_absptr for those.
+
+    // FreeBSD must be explicit about the data size and using pcrel since it's
+    // assembler/linker won't do the automatic conversion that the Linux tools
+    // do.
+    if (T.isOSFreeBSD()) {
+      PersonalityEncoding |= dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
+      LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
+    }
     break;
   case Triple::ppc64:
   case Triple::ppc64le:
     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
       dwarf::DW_EH_PE_udata8;
     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
       dwarf::DW_EH_PE_udata8;

test/CodeGen/Mips/ehframe-indirect.ll

-; RUN: llc -mtriple=mipsel-linux-gnu < %s -asm-verbose -relocation-model=pic | FileCheck -check-prefixes=ALL,O32 %s
-; RUN: llc -mtriple=mipsel-linux-android < %s -asm-verbose -relocation-model=pic | FileCheck -check-prefixes=ALL,O32 %s
-; RUN: llc -mtriple=mips64el-linux-gnu -target-abi=n32 < %s -asm-verbose -relocation-model=pic | FileCheck -check-prefixes=ALL,N32 %s
-; RUN: llc -mtriple=mips64el-linux-android -target-abi=n32 < %s -asm-verbose -relocation-model=pic | FileCheck -check-prefixes=ALL,N32 %s
-; RUN: llc -mtriple=mips64el-linux-gnu < %s -asm-verbose -relocation-model=pic | FileCheck -check-prefixes=ALL,N64 %s
-; RUN: llc -mtriple=mips64el-linux-android < %s -asm-verbose -relocation-model=pic | FileCheck -check-prefixes=ALL,N64 %s
+; RUN: llc -mtriple=mipsel-linux-gnu < %s -asm-verbose -relocation-model=pic | \
+; RUN:     FileCheck -check-prefixes=ALL,LINUX,LINUX-O32,O32 %s
+; RUN: llc -mtriple=mipsel-linux-android < %s -asm-verbose -relocation-model=pic | \
+; RUN:     FileCheck -check-prefixes=ALL,LINUX,LINUX-O32,O32 %s
+; RUN: llc -mtriple=mips64el-linux-gnu -target-abi=n32 < %s -asm-verbose -relocation-model=pic | \
+; RUN:     FileCheck -check-prefixes=ALL,LINUX,LINUX-N32,N32 %s
+; RUN: llc -mtriple=mips64el-linux-android -target-abi=n32 < %s -asm-verbose -relocation-model=pic | \
+; RUN:     FileCheck -check-prefixes=ALL,LINUX,LINUX-N32,N32 %s
+; RUN: llc -mtriple=mips64el-linux-gnu < %s -asm-verbose -relocation-model=pic | \
+; RUN:     FileCheck -check-prefixes=ALL,LINUX,LINUX-N64,N64 %s
+; RUN: llc -mtriple=mips64el-linux-android < %s -asm-verbose -relocation-model=pic | \
+; RUN:     FileCheck -check-prefixes=ALL,LINUX,LINUX-N64,N64 %s
+; RUN: llc -mtriple=mips64el-linux-gnu < %s -asm-verbose -relocation-model=pic | \
+; RUN:     FileCheck -check-prefixes=ALL,LINUX,LINUX-N64,N64 %s
+; RUN: llc -mtriple=mips64-unknown-freebsd11.0 < %s -asm-verbose -relocation-model=pic | \
+; RUN:     FileCheck -check-prefixes=ALL,FREEBSD,FREEBSD-N64,N64 %s
 
 @_ZTISt9exception = external constant i8*
 
 define i32 @main() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
 ; ALL: .cfi_startproc
-; ALL: .cfi_personality 128, DW.ref.__gxx_personality_v0
+
+; Linux must rely on the assembler/linker converting the encodings.
+; LINUX: .cfi_personality 128, DW.ref.__gxx_personality_v0
+; LINUX-O32: .cfi_lsda 0, $exception0
+; LINUX-NEW: .cfi_lsda 0, .Lexception0
+
+; FreeBSD can (and must) be more direct about the encodings it wants.
+; FREEBSD: .cfi_personality 155, DW.ref.__gxx_personality_v0
+; FREEBSD-O32: .cfi_lsda 27, $exception0
+; FREEBSD-NEW: .cfi_lsda 27, .Lexception0
 
 entry:
   invoke void @foo() to label %cont unwind label %lpad
 ; ALL: foo
 ; ALL: jalr
 
 lpad:
   %0 = landingpad { i8*, i32 }