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author | Ulrich Weigand <ulrich.weigand@de.ibm.com> | 2013-07-01 18:19:56 +0000 |
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committer | Ulrich Weigand <ulrich.weigand@de.ibm.com> | 2013-07-01 18:19:56 +0000 |
commit | 222e781d92541017c3a9c5dd40cb52e334cdb86f (patch) | |
tree | 447201dbddf7e9e60aebc77bec1abf475904a848 | |
parent | 62c1baf8b58a40d37f56a5431214e6514e42970f (diff) | |
download | external_llvm-222e781d92541017c3a9c5dd40cb52e334cdb86f.zip external_llvm-222e781d92541017c3a9c5dd40cb52e334cdb86f.tar.gz external_llvm-222e781d92541017c3a9c5dd40cb52e334cdb86f.tar.bz2 |
[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
-rw-r--r-- | lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp | 34 | ||||
-rw-r--r-- | test/MC/PowerPC/ppc64-fixup-explicit.s | 46 |
2 files changed, 80 insertions, 0 deletions
diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp index c2bf251..c26b545 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 0000000..217e057 --- /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) + |