From 222e781d92541017c3a9c5dd40cb52e334cdb86f Mon Sep 17 00:00:00 2001 From: Ulrich Weigand Date: Mon, 1 Jul 2013 18:19:56 +0000 Subject: [PATCH] [PowerPC] Fix @got references to local symbols A @got reference must always result in a relocation, so that the linker has a chance to set up the GOT entry, even if the symbol happens to be local. Add a PPCELFObjectWriter::ExplicitRelSym routine that enforces a relocation to be emitted for GOT references. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185353 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../MCTargetDesc/PPCELFObjectWriter.cpp | 34 ++++++++++++++ test/MC/PowerPC/ppc64-fixup-explicit.s | 46 +++++++++++++++++++ 2 files changed, 80 insertions(+) create mode 100644 test/MC/PowerPC/ppc64-fixup-explicit.s diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp index c2bf2516699..c26b5458d38 100644 --- a/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp +++ b/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp @@ -30,6 +30,11 @@ namespace { virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, bool IsPCRel, bool IsRelocWithSymbol, int64_t Addend) const; + virtual const MCSymbol *ExplicitRelSym(const MCAssembler &Asm, + const MCValue &Target, + const MCFragment &F, + const MCFixup &Fixup, + bool IsPCRel) const; virtual const MCSymbol *undefinedExplicitRelSym(const MCValue &Target, const MCFixup &Fixup, bool IsPCRel) const; @@ -328,6 +333,35 @@ unsigned PPCELFObjectWriter::GetRelocType(const MCValue &Target, return getRelocTypeInner(Target, Fixup, IsPCRel); } +const MCSymbol *PPCELFObjectWriter::ExplicitRelSym(const MCAssembler &Asm, + const MCValue &Target, + const MCFragment &F, + const MCFixup &Fixup, + bool IsPCRel) const { + assert(Target.getSymA() && "SymA cannot be 0"); + MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ? + MCSymbolRefExpr::VK_None : Target.getSymA()->getKind(); + + bool EmitThisSym; + switch (Modifier) { + // GOT references always need a relocation, even if the + // target symbol is local. + case MCSymbolRefExpr::VK_GOT: + case MCSymbolRefExpr::VK_PPC_GOT_LO: + case MCSymbolRefExpr::VK_PPC_GOT_HI: + case MCSymbolRefExpr::VK_PPC_GOT_HA: + EmitThisSym = true; + break; + default: + EmitThisSym = false; + break; + } + + if (EmitThisSym) + return &Target.getSymA()->getSymbol().AliasedSymbol(); + return NULL; +} + const MCSymbol *PPCELFObjectWriter::undefinedExplicitRelSym(const MCValue &Target, const MCFixup &Fixup, bool IsPCRel) const { diff --git a/test/MC/PowerPC/ppc64-fixup-explicit.s b/test/MC/PowerPC/ppc64-fixup-explicit.s new file mode 100644 index 00000000000..217e057d961 --- /dev/null +++ b/test/MC/PowerPC/ppc64-fixup-explicit.s @@ -0,0 +1,46 @@ + +# RUN: llvm-mc -triple powerpc64-unknown-unknown --show-encoding %s | FileCheck %s + +# RUN: llvm-mc -triple powerpc64-unknown-unknown -filetype=obj %s | \ +# RUN: llvm-readobj -r | FileCheck %s -check-prefix=REL + +# GOT references must result in explicit relocations +# even if the target symbol is local. + +target: + +# CHECK: addi 4, 3, target@GOT # encoding: [0x38,0x83,A,A] +# CHECK-NEXT: # fixup A - offset: 2, value: target@GOT, kind: fixup_ppc_half16 +# CHECK-REL: 0x{{[0-9A-F]*[26AE]}} R_PPC64_GOT16 target 0x0 + addi 4, 3, target@got + +# CHECK: ld 1, target@GOT(2) # encoding: [0xe8,0x22,A,0bAAAAAA00] +# CHECK-NEXT: # fixup A - offset: 2, value: target@GOT, kind: fixup_ppc_half16ds +# CHECK-REL: 0x{{[0-9A-F]*[26AE]}} R_PPC64_GOT16_DS target 0x0 + ld 1, target@got(2) + +# CHECK: addis 3, 2, target@got@ha # encoding: [0x3c,0x62,A,A] +# CHECK-NEXT: # fixup A - offset: 2, value: target@got@ha, kind: fixup_ppc_half16 +# CHECK-REL: 0x{{[0-9A-F]*[26AE]}} R_PPC64_GOT16_HA target 0x0 + addis 3, 2, target@got@ha + +# CHECK: addi 4, 3, target@got@l # encoding: [0x38,0x83,A,A] +# CHECK-NEXT: # fixup A - offset: 2, value: target@got@l, kind: fixup_ppc_half16 +# CHECK-REL: 0x{{[0-9A-F]*[26AE]}} R_PPC64_GOT16_LO target 0x0 + addi 4, 3, target@got@l + +# CHECK: addis 3, 2, target@got@h # encoding: [0x3c,0x62,A,A] +# CHECK-NEXT: # fixup A - offset: 2, value: target@got@h, kind: fixup_ppc_half16 +# CHECK-REL: 0x{{[0-9A-F]*[26AE]}} R_PPC64_GOT16_HI target 0x0 + addis 3, 2, target@got@h + +# CHECK: lwz 1, target@got@l(3) # encoding: [0x80,0x23,A,A] +# CHECK-NEXT: # fixup A - offset: 2, value: target@got@l, kind: fixup_ppc_half16 +# CHECK-REL: 0x{{[0-9A-F]*[26AE]}} R_PPC64_GOT16_LO target 0x0 + lwz 1, target@got@l(3) + +# CHECK: ld 1, target@got@l(3) # encoding: [0xe8,0x23,A,0bAAAAAA00] +# CHECK-NEXT: # fixup A - offset: 2, value: target@got@l, kind: fixup_ppc_half16ds +# CHECK-REL: 0x{{[0-9A-F]*[26AE]}} R_PPC64_GOT16_LO_DS target 0x0 + ld 1, target@got@l(3) + -- 2.34.1