atanasyan updated this revision to Diff 367472.
atanasyan retitled this revision from "[WIP][mips] Use pc-relative relocations
in .eh_frame" to "[mips][mc][clang] Use pc-relative relocations in .eh_frame".
atanasyan edited the summary of this revision.
atanasyan edited reviewers, added: emaste, grosbach; removed: sdardis,
dsanders, espindola.
atanasyan added a project: clang.
atanasyan added a comment.
Herald added subscribers: cfe-commits, dang, sdardis.
For compatibility with tools unsupported 64-bit pc-relative relocations the
patch introduces new command line options in Clang: `mmips-pc64-rel` and
`mno-mips-pc64-rel`. These options passed to LLVM by Clang driver as
`-mmips-pc64-rel={true|false}`. I could not find any better way to pass the
option into `MC` layer.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D80392/new/
https://reviews.llvm.org/D80392
Files:
clang/include/clang/Driver/Options.td
clang/lib/Driver/ToolChains/Clang.cpp
clang/test/Driver/mips-features.c
lld/test/ELF/mips-eh_frame-pic.s
llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
llvm/lib/MC/MCObjectFileInfo.cpp
llvm/test/CodeGen/Mips/ehframe-indirect.ll
llvm/test/DebugInfo/Mips/eh_frame.ll
llvm/test/MC/Mips/eh-frame.s
Index: llvm/test/MC/Mips/eh-frame.s
===================================================================
--- llvm/test/MC/Mips/eh-frame.s
+++ llvm/test/MC/Mips/eh-frame.s
@@ -33,14 +33,18 @@
// RUN: llvm-readobj -r %t.o | FileCheck --check-prefixes=RELOCS,PIC64 %s
// RUN: llvm-dwarfdump -eh-frame %t.o | FileCheck --check-prefixes=DWARF64,DWARF64_PIC %s
-/// However using the large code model forces R_MIPS_64 since there is no R_MIPS_PC64 relocation:
// RUN: llvm-mc -filetype=obj %s -o %t.o -triple mips64-unknown-linux-gnu --position-independent --large-code-model
-// RUN: llvm-readobj -r %t.o | FileCheck --check-prefixes=RELOCS,ABS64 %s
-// RUN: llvm-dwarfdump -eh-frame %t.o | FileCheck --check-prefixes=DWARF64,DWARF64_ABS %s
+// RUN: llvm-readobj -r %t.o | FileCheck --check-prefixes=RELOCS,PIC64 %s
+// RUN: llvm-dwarfdump -eh-frame %t.o | FileCheck --check-prefixes=DWARF64,DWARF64_PIC %s
// RUN: llvm-mc -filetype=obj %s -o %t.o -triple mips64el-unknown-linux-gnu --position-independent --large-code-model
-// RUN: llvm-readobj -r %t.o | FileCheck --check-prefixes=RELOCS,ABS64 %s
-// RUN: llvm-dwarfdump -eh-frame %t.o | FileCheck --check-prefixes=DWARF64,DWARF64_ABS %s
+// RUN: llvm-readobj -r %t.o | FileCheck --check-prefixes=RELOCS,PIC64 %s
+// RUN: llvm-dwarfdump -eh-frame %t.o | FileCheck --check-prefixes=DWARF64,DWARF64_PIC %s
+
+// RUN: llvm-mc -filetype=obj %s -o %t.o -triple mips64-unknown-linux-gnu \
+// RUN: --position-independent --large-code-model -mmips-pc64-rel=false
+// RUN: llvm-readobj -r %t.o | FileCheck --check-prefixes=RELOCS,OLD64 %s
+// RUN: llvm-dwarfdump -eh-frame %t.o | FileCheck --check-prefixes=DWARF64,DWARF64_OLD %s
func:
.cfi_startproc
@@ -51,7 +55,8 @@
// ABS32-NEXT: R_MIPS_32
// ABS64-NEXT: R_MIPS_64/R_MIPS_NONE/R_MIPS_NONE
// PIC32-NEXT: R_MIPS_PC32
-// PIC64-NEXT: R_MIPS_PC32/R_MIPS_NONE/R_MIPS_NONE
+// PIC64-NEXT: R_MIPS_PC32/R_MIPS_64/R_MIPS_NONE
+// OLD64-NEXT: R_MIPS_64/R_MIPS_NONE/R_MIPS_NONE
// RELOCS-NEXT: }
// DWARF32: 00000000 00000010 00000000 CIE
@@ -87,14 +92,17 @@
// DWARF64-NEXT: Return address column: 31
// DWARF64_ABS-NEXT: Augmentation data: 0C
// ^^ fde pointer encoding: DW_EH_PE_sdata8
-// DWARF64_PIC: Augmentation data: 1B
-// ^^ fde pointer encoding: DW_EH_PE_pcrel | DW_EH_PE_sdata4
+// DWARF64_PIC: Augmentation data: 1C
+// ^^ fde pointer encoding: DW_EH_PE_pcrel | DW_EH_PE_sdata8
+// DWARF64_OLD: Augmentation data: 0C
+// ^^ fde pointer encoding: DW_EH_PE_sdata8
// DWARF64-EMPTY:
// DWARF64-NEXT: DW_CFA_def_cfa_register: SP_64
// DWARF64_PIC-NEXT: DW_CFA_nop:
//
// DWARF64_ABS: 00000014 00000018 00000018 FDE cie=00000000 pc=00000000...00000000
-// DWARF64_PIC: 00000014 00000010 00000018 FDE cie=00000000 pc=00000000...00000000
+// DWARF64_PIC: 00000014 00000018 00000018 FDE cie=00000000 pc=0000001c...0000001c
+// DWARF64_OLD: 00000014 00000018 00000018 FDE cie=00000000 pc=00000000...00000000
// DWARF64-NEXT: Format: DWARF32
// DWARF64-NEXT: DW_CFA_nop:
// DWARF64-NEXT: DW_CFA_nop:
Index: llvm/test/DebugInfo/Mips/eh_frame.ll
===================================================================
--- llvm/test/DebugInfo/Mips/eh_frame.ll
+++ llvm/test/DebugInfo/Mips/eh_frame.ll
@@ -17,9 +17,9 @@
; STATIC-DAG: R_MIPS_32 00000000 .gcc_except_table
; PIC-LABEL: Relocation section '.rel.eh_frame'
-; PIC-DAG: R_MIPS_32 00000000 DW.ref.__gxx_personality_v0
+; PIC-DAG: R_MIPS_PC32 00000000 DW.ref.__gxx_personality_v0
+; PIC-DAG: R_MIPS_PC32
; PIC-DAG: R_MIPS_PC32
-; PIC-DAG: R_MIPS_32 00000000 .gcc_except_table
; CHECK-READELF: DW.ref.__gxx_personality_v0
; CHECK-READELF-STATIC-NEXT: R_MIPS_32 00000000 .text
Index: llvm/test/CodeGen/Mips/ehframe-indirect.ll
===================================================================
--- llvm/test/CodeGen/Mips/ehframe-indirect.ll
+++ llvm/test/CodeGen/Mips/ehframe-indirect.ll
@@ -1,34 +1,40 @@
; RUN: llc -mtriple=mipsel-linux-gnu < %s -asm-verbose -relocation-model=pic | \
-; RUN: FileCheck -check-prefixes=ALL,LINUX,LINUX-O32,O32 %s
+; RUN: FileCheck -check-prefixes=ALL,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: FileCheck -check-prefixes=ALL,O32 %s
; RUN: llc -mtriple=mips64el-linux-gnu -target-abi=n32 < %s -asm-verbose -relocation-model=pic | \
-; RUN: FileCheck -check-prefixes=ALL,LINUX,LINUX-NEW,N32 %s
+; RUN: FileCheck -check-prefixes=ALL,N32,N32REL %s
; RUN: llc -mtriple=mips64el-linux-gnu < %s -asm-verbose -relocation-model=pic | \
-; RUN: FileCheck -check-prefixes=ALL,LINUX,LINUX-NEW,N64 %s
+; RUN: FileCheck -check-prefixes=ALL,N64,N64REL %s
; RUN: llc -mtriple=mips64el-linux-android < %s -asm-verbose -relocation-model=pic | \
-; RUN: FileCheck -check-prefixes=ALL,LINUX,LINUX-NEW,N64 %s
+; RUN: FileCheck -check-prefixes=ALL,N64,N64REL %s
; RUN: llc -mtriple=mips64el-linux-gnu < %s -asm-verbose -relocation-model=pic | \
-; RUN: FileCheck -check-prefixes=ALL,LINUX,LINUX-NEW,N64 %s
-; RUN: llc -mtriple=mips-unknown-freebsd11.0 < %s -asm-verbose -relocation-model=pic | \
-; RUN: FileCheck -check-prefixes=ALL,FREEBSD,FREEBSD-O32,O32 %s
+; RUN: FileCheck -check-prefixes=ALL,N64,N64REL %s
; RUN: llc -mtriple=mips64-unknown-freebsd11.0 < %s -asm-verbose -relocation-model=pic | \
-; RUN: FileCheck -check-prefixes=ALL,FREEBSD,FREEBSD-NEW,N64 %s
+; RUN: FileCheck -check-prefixes=ALL,N64,N64REL %s
+
+; RUN: llc -mtriple=mips64-linux-gnu -target-abi=n32 -mmips-pc64-rel=false \
+; RUN: -asm-verbose -relocation-model=pic < %s | \
+; RUN: FileCheck -check-prefixes=ALL,N32,N32ABS %s
+; RUN: llc -mtriple=mips64-linux-gnu -mmips-pc64-rel=false \
+; RUN: -asm-verbose -relocation-model=pic < %s | \
+; RUN: FileCheck -check-prefixes=ALL,N64,N64ABS %s
@_ZTISt9exception = external constant i8*
define i32 @main() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
; ALL: .cfi_startproc
-; 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
+; O32: .cfi_personality 155, DW.ref.__gxx_personality_v0
+; O32: .cfi_lsda 27, $exception0
+; N32REL: .cfi_personality 155, DW.ref.__gxx_personality_v0
+; N32REL: .cfi_lsda 27, .Lexception0
+; N32ABS: .cfi_personality 128, DW.ref.__gxx_personality_v0
+; N32ABS: .cfi_lsda 0, .Lexception0
+; N64REL: .cfi_personality 155, DW.ref.__gxx_personality_v0
+; N64REL: .cfi_lsda 27, .Lexception0
+; N64ABS: .cfi_personality 128, DW.ref.__gxx_personality_v0
+; N64ABS: .cfi_lsda 0, .Lexception0
entry:
invoke void @foo() to label %cont unwind label %lpad
Index: llvm/lib/MC/MCObjectFileInfo.cpp
===================================================================
--- llvm/lib/MC/MCObjectFileInfo.cpp
+++ llvm/lib/MC/MCObjectFileInfo.cpp
@@ -21,9 +21,16 @@
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCSectionWasm.h"
#include "llvm/MC/MCSectionXCOFF.h"
+#include "llvm/Support/CommandLine.h"
using namespace llvm;
+namespace llvm {
+cl::opt<bool>
+ MipsPC64Relocation("mmips-pc64-rel", cl::init(true),
+ cl::desc("Use MIPS 64-bit PC-relative relocations"));
+}
+
static bool useCompactUnwind(const Triple &T) {
// Only on darwin.
if (!T.isOSDarwin())
@@ -308,14 +315,11 @@
case Triple::mipsel:
case Triple::mips64:
case Triple::mips64el:
- // We cannot use DW_EH_PE_sdata8 for the large PositionIndependent case
- // since there is no R_MIPS_PC64 relocation (only a 32-bit version).
- if (PositionIndependent && !Large)
- FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
- else
- FDECFIEncoding = Ctx->getAsmInfo()->getCodePointerSize() == 4
- ? dwarf::DW_EH_PE_sdata4
- : dwarf::DW_EH_PE_sdata8;
+ FDECFIEncoding = Ctx->getAsmInfo()->getCodePointerSize() == 4
+ ? dwarf::DW_EH_PE_sdata4
+ : dwarf::DW_EH_PE_sdata8;
+ if (PositionIndependent && (MipsPC64Relocation || T.isMIPS32()))
+ FDECFIEncoding |= dwarf::DW_EH_PE_pcrel;
break;
case Triple::ppc64:
case Triple::ppc64le:
Index: llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
===================================================================
--- llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -70,6 +70,10 @@
using namespace llvm;
using namespace dwarf;
+namespace llvm {
+extern cl::opt<bool> MipsPC64Relocation;
+}
+
static void GetObjCImageInfo(Module &M, unsigned &Version, unsigned &Flags,
StringRef &Section) {
SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
@@ -220,13 +224,9 @@
// 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 (TgtM.getTargetTriple().isOSFreeBSD()) {
+ if (isPositionIndependent() &&
+ (MipsPC64Relocation || TgtM.getTargetTriple().isMIPS32())) {
PersonalityEncoding |= dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
}
Index: lld/test/ELF/mips-eh_frame-pic.s
===================================================================
--- lld/test/ELF/mips-eh_frame-pic.s
+++ lld/test/ELF/mips-eh_frame-pic.s
@@ -12,11 +12,11 @@
## relative addressing.
# NOPIC-ERR: ld.lld: error: can't create dynamic relocation R_MIPS_64 against local symbol in readonly segment
-## For -fPIC, .eh_frame should contain DW_EH_PE_pcrel | DW_EH_PE_sdata4 values:
+## For -fPIC, .eh_frame should contain DW_EH_PE_pcrel | DW_EH_PE_sdata8 values:
# RUN: llvm-mc -filetype=obj -triple=mips64-unknown-linux --position-independent %s -o %t-pic.o
# RUN: llvm-readobj -r %t-pic.o | FileCheck %s --check-prefixes=RELOCS,PIC64-RELOCS
# RUN: ld.lld -shared %t-pic.o -o %t-pic.so
-# RUN: llvm-dwarfdump --eh-frame %t-pic.so | FileCheck %s --check-prefix=PIC-EH-FRAME
+# RUN: llvm-dwarfdump --eh-frame %t-pic.so | FileCheck %s --check-prefix=PIC64-EH-FRAME
## Also check MIPS32:
# RUN: llvm-mc -filetype=obj -triple=mips-unknown-linux %s -o %t-nopic32.o
@@ -31,12 +31,12 @@
# RUN: llvm-mc -filetype=obj -triple=mips-unknown-linux --position-independent %s -o %t-pic32.o
# RUN: llvm-readobj -r %t-pic32.o | FileCheck %s --check-prefixes=RELOCS,PIC32-RELOCS
# RUN: ld.lld -shared %t-pic32.o -o %t-pic32.so
-# RUN: llvm-dwarfdump --eh-frame %t-pic32.so | FileCheck %s --check-prefix=PIC-EH-FRAME
+# RUN: llvm-dwarfdump --eh-frame %t-pic32.so | FileCheck %s --check-prefix=PIC32-EH-FRAME
# RELOCS: .rel{{a?}}.eh_frame {
# ABS32-RELOCS-NEXT: 0x1C R_MIPS_32 .text
# ABS64-RELOCS-NEXT: 0x1C R_MIPS_64/R_MIPS_NONE/R_MIPS_NONE .text
-# PIC64-RELOCS-NEXT: 0x1C R_MIPS_PC32/R_MIPS_NONE/R_MIPS_NONE -
+# PIC64-RELOCS-NEXT: 0x1C R_MIPS_PC32/R_MIPS_64/R_MIPS_NONE -
# PIC32-RELOCS-NEXT: 0x1C R_MIPS_PC32 -
# RELOCS-NEXT: }
@@ -44,10 +44,10 @@
## ^^ fde pointer encoding: DW_EH_PE_sdata8
# ABS32-EH-FRAME: Augmentation data: 0B
## ^^ fde pointer encoding: DW_EH_PE_sdata4
-# PIC-EH-FRAME: Augmentation data: 1B
-## ^^ fde pointer encoding: DW_EH_PE_pcrel | DW_EH_PE_sdata4
-## Note: ld.bfd converts the R_MIPS_64 relocs to DW_EH_PE_pcrel | DW_EH_PE_sdata8
-## for N64 ABI (and DW_EH_PE_pcrel | DW_EH_PE_sdata4 for MIPS32)
+# PIC32-EH-FRAME: Augmentation data: 1B
+## ^^ fde pointer encoding: DW_EH_PE_pcrel | DW_EH_PE_sdata4
+# PIC64-EH-FRAME: Augmentation data: 1C
+## ^^ fde pointer encoding: DW_EH_PE_pcrel | DW_EH_PE_sdata8
.ent func
.global func
Index: clang/test/Driver/mips-features.c
===================================================================
--- clang/test/Driver/mips-features.c
+++ clang/test/Driver/mips-features.c
@@ -456,3 +456,15 @@
// RUN: -mrelax-pic-calls -mno-relax-pic-calls 2>&1 \
// RUN: | FileCheck --check-prefix=CHECK-NO-RELAX-PIC-CALLS %s
// CHECK-NO-RELAX-PIC-CALLS: "-mllvm" "-mips-jalr-reloc=0"
+//
+// -mmips-pc64-rel
+// RUN: %clang -target mips-unknown-linux-gnu -### -c %s \
+// RUN: -mno-mips-pc64-rel -mmips-pc64-rel 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-PC64-REL %s
+// CHECK-PC64-REL-NOT: "-mllvm" "-mmips-pc64-rel=false"
+//
+// -mno-mips-pc64-rel
+// RUN: %clang -target mips-unknown-linux-gnu -### -c %s \
+// RUN: -mmips-pc64-rel -mno-mips-pc64-rel 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-NO-PC64-REL %s
+// CHECK-NO-PC64-REL: "-mllvm" "-mmips-pc64-rel=false"
Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -1980,6 +1980,16 @@
CmdArgs.push_back("-mips-jalr-reloc=0");
}
}
+
+ if (Arg *A = Args.getLastArg(options::OPT_mmips_pc64_rel,
+ options::OPT_mno_mips_pc64_rel)) {
+ CmdArgs.push_back("-mllvm");
+ if (A->getOption().matches(options::OPT_mmips_pc64_rel))
+ CmdArgs.push_back("-mmips-pc64-rel=true");
+ else
+ CmdArgs.push_back("-mmips-pc64-rel=false");
+ A->claim();
+ }
}
void Clang::AddPPCTargetArgs(const ArgList &Args,
Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -3665,6 +3665,13 @@
Group<m_mips_Features_Group>,
HelpText<"Do not produce relaxation hints for linkers to try optimizing PIC "
"call sequences into direct calls (MIPS only)">, Flags<[HelpHidden]>;
+def mmips_pc64_rel : Flag<["-"], "mmips-pc64-rel">,
+ Group<m_mips_Features_Group>,
+ HelpText<"Use MIPS 64-bit PC-relative relocations">, Flags<[HelpHidden]>;
+def mno_mips_pc64_rel : Flag<["-"], "mno-mips-pc64-rel">,
+ Group<m_mips_Features_Group>,
+ HelpText<"Do not use MIPS 64-bit PC-relative relocations">,
+ Flags<[HelpHidden]>;
def mglibc : Flag<["-"], "mglibc">, Group<m_libc_Group>, Flags<[HelpHidden]>;
def muclibc : Flag<["-"], "muclibc">, Group<m_libc_Group>, Flags<[HelpHidden]>;
def module_file_info : Flag<["-"], "module-file-info">, Flags<[NoXarchOption,CC1Option]>, Group<Action_Group>,
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