<div dir="ltr">Single letter variables such as S, A or P are chosen after the ELF spec, so that as long as readers are familiar with the spec, it's very easy to digest.<div><br></div><div>Now S is actually S+A. That can be a source of confusion. You want to change the variable name accordingly. I'd name SA.</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Oct 15, 2015 at 8:52 AM, Rafael Espindola via llvm-commits <span dir="ltr"><<a href="mailto:llvm-commits@lists.llvm.org" target="_blank">llvm-commits@lists.llvm.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: rafael<br>
Date: Thu Oct 15 10:52:12 2015<br>
New Revision: 250421<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=250421&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project?rev=250421&view=rev</a><br>
Log:<br>
Centralize the handling of r_addend. NFC.<br>
<br>
When a relocation points to a SHF_MERGE section, the addend has special meaning.<br>
It should be used to find what in the section the relocation points to. It<br>
should not be added to the output position.<br>
<br>
Centralizing it means that the above rule will be implemented once, not once<br>
per target.<br>
<br>
Modified:<br>
lld/trunk/ELF/InputSection.cpp<br>
lld/trunk/ELF/InputSection.h<br>
lld/trunk/ELF/Target.cpp<br>
<br>
Modified: lld/trunk/ELF/InputSection.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputSection.cpp?rev=250421&r1=250420&r2=250421&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputSection.cpp?rev=250421&r1=250420&r2=250421&view=diff</a><br>
==============================================================================<br>
--- lld/trunk/ELF/InputSection.cpp (original)<br>
+++ lld/trunk/ELF/InputSection.cpp Thu Oct 15 10:52:12 2015<br>
@@ -26,6 +26,23 @@ InputSection<ELFT>::InputSection(ObjectF<br>
: File(F), Header(Header) {}<br>
<br>
template <class ELFT><br>
+void InputSection<ELFT>::relocateOne(uint8_t *Buf, uint8_t *BufEnd,<br>
+ const Elf_Rel &Rel, uint32_t Type,<br>
+ uintX_t BaseAddr, uintX_t SymVA) {<br>
+ Target->relocateOne(Buf, BufEnd, reinterpret_cast<const void *>(&Rel), Type,<br>
+ BaseAddr, SymVA);<br>
+}<br>
+<br>
+template <class ELFT><br>
+void InputSection<ELFT>::relocateOne(uint8_t *Buf, uint8_t *BufEnd,<br>
+ const Elf_Rela &Rel, uint32_t Type,<br>
+ uintX_t BaseAddr, uintX_t SymVA) {<br>
+ SymVA += Rel.r_addend;<br>
+ Target->relocateOne(Buf, BufEnd, reinterpret_cast<const void *>(&Rel), Type,<br>
+ BaseAddr, SymVA);<br>
+}<br>
+<br>
+template <class ELFT><br>
template <bool isRela><br>
void InputSection<ELFT>::relocate(<br>
uint8_t *Buf, uint8_t *BufEnd,<br>
@@ -42,8 +59,7 @@ void InputSection<ELFT>::relocate(<br>
const Elf_Shdr *SymTab = File.getSymbolTable();<br>
if (SymIndex < SymTab->sh_info) {<br>
uintX_t SymVA = getLocalRelTarget(File, RI);<br>
- Target->relocateOne(Buf, BufEnd, reinterpret_cast<const void *>(&RI),<br>
- Type, BaseAddr, SymVA);<br>
+ relocateOne(Buf, BufEnd, RI, Type, BaseAddr, SymVA);<br>
continue;<br>
}<br>
<br>
@@ -61,8 +77,7 @@ void InputSection<ELFT>::relocate(<br>
} else if (isa<SharedSymbol<ELFT>>(Body)) {<br>
continue;<br>
}<br>
- Target->relocateOne(Buf, BufEnd, reinterpret_cast<const void *>(&RI), Type,<br>
- BaseAddr, SymVA);<br>
+ relocateOne(Buf, BufEnd, RI, Type, BaseAddr, SymVA);<br>
}<br>
}<br>
<br>
<br>
Modified: lld/trunk/ELF/InputSection.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputSection.h?rev=250421&r1=250420&r2=250421&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputSection.h?rev=250421&r1=250420&r2=250421&view=diff</a><br>
==============================================================================<br>
--- lld/trunk/ELF/InputSection.h (original)<br>
+++ lld/trunk/ELF/InputSection.h Thu Oct 15 10:52:12 2015<br>
@@ -60,6 +60,12 @@ public:<br>
static InputSection<ELFT> Discarded;<br>
<br>
private:<br>
+ static void relocateOne(uint8_t *Buf, uint8_t *BufEnd, const Elf_Rel &Rel,<br>
+ uint32_t Type, uintX_t BaseAddr, uintX_t SymVA);<br>
+<br>
+ static void relocateOne(uint8_t *Buf, uint8_t *BufEnd, const Elf_Rela &Rel,<br>
+ uint32_t Type, uintX_t BaseAddr, uintX_t SymVA);<br>
+<br>
template <bool isRela><br>
void relocate(uint8_t *Buf, uint8_t *BufEnd,<br>
llvm::iterator_range<<br>
<br>
Modified: lld/trunk/ELF/Target.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Target.cpp?rev=250421&r1=250420&r2=250421&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Target.cpp?rev=250421&r1=250420&r2=250421&view=diff</a><br>
==============================================================================<br>
--- lld/trunk/ELF/Target.cpp (original)<br>
+++ lld/trunk/ELF/Target.cpp Thu Oct 15 10:52:12 2015<br>
@@ -294,14 +294,14 @@ void X86_64TargetInfo::relocateOne(uint8<br>
switch (Type) {<br>
case R_X86_64_PC32:<br>
case R_X86_64_GOTPCREL:<br>
- write32le(Loc, SymVA + Rel.r_addend - (BaseAddr + Offset));<br>
+ write32le(Loc, SymVA - (BaseAddr + Offset));<br>
break;<br>
case R_X86_64_64:<br>
- write64le(Loc, SymVA + Rel.r_addend);<br>
+ write64le(Loc, SymVA);<br>
break;<br>
case R_X86_64_32: {<br>
case R_X86_64_32S:<br>
- uint64_t VA = SymVA + Rel.r_addend;<br>
+ uint64_t VA = SymVA;<br>
if (Type == R_X86_64_32 && !isUInt<32>(VA))<br>
error("R_X86_64_32 out of range");<br>
else if (!isInt<32>(VA))<br>
@@ -441,7 +441,6 @@ void PPC64TargetInfo::relocateOne(uint8_<br>
<br>
uint8_t *L = Buf + Rel.r_offset;<br>
uint64_t S = SymVA;<br>
- int64_t A = Rel.r_addend;<br>
uint64_t P = BaseAddr + Rel.r_offset;<br>
uint64_t TB = getPPC64TocBase();<br>
<br>
@@ -453,16 +452,16 @@ void PPC64TargetInfo::relocateOne(uint8_<br>
// For a TOC-relative relocation, adjust the addend and proceed in terms of<br>
// the corresponding ADDR16 relocation type.<br>
switch (Type) {<br>
- case R_PPC64_TOC16: Type = R_PPC64_ADDR16; A -= TB; break;<br>
- case R_PPC64_TOC16_DS: Type = R_PPC64_ADDR16_DS; A -= TB; break;<br>
- case R_PPC64_TOC16_LO: Type = R_PPC64_ADDR16_LO; A -= TB; break;<br>
- case R_PPC64_TOC16_LO_DS: Type = R_PPC64_ADDR16_LO_DS; A -= TB; break;<br>
- case R_PPC64_TOC16_HI: Type = R_PPC64_ADDR16_HI; A -= TB; break;<br>
- case R_PPC64_TOC16_HA: Type = R_PPC64_ADDR16_HA; A -= TB; break;<br>
+ case R_PPC64_TOC16: Type = R_PPC64_ADDR16; S -= TB; break;<br>
+ case R_PPC64_TOC16_DS: Type = R_PPC64_ADDR16_DS; S -= TB; break;<br>
+ case R_PPC64_TOC16_LO: Type = R_PPC64_ADDR16_LO; S -= TB; break;<br>
+ case R_PPC64_TOC16_LO_DS: Type = R_PPC64_ADDR16_LO_DS; S -= TB; break;<br>
+ case R_PPC64_TOC16_HI: Type = R_PPC64_ADDR16_HI; S -= TB; break;<br>
+ case R_PPC64_TOC16_HA: Type = R_PPC64_ADDR16_HA; S -= TB; break;<br>
default: break;<br>
}<br>
<br>
- uint64_t R = S + A;<br>
+ uint64_t R = S;<br>
<br>
switch (Type) {<br>
case R_PPC64_ADDR16:<br>
@@ -616,36 +615,35 @@ void AArch64TargetInfo::relocateOne(uint<br>
<br>
uint8_t *L = Buf + Rel.r_offset;<br>
uint64_t S = SymVA;<br>
- int64_t A = Rel.r_addend;<br>
uint64_t P = BaseAddr + Rel.r_offset;<br>
switch (Type) {<br>
case R_AARCH64_ABS16:<br>
- if (!isInt<16>(S + A))<br>
+ if (!isInt<16>(S))<br>
error("Relocation R_AARCH64_ABS16 out of range");<br>
- write16le(L, S + A);<br>
+ write16le(L, S);<br>
break;<br>
case R_AARCH64_ABS32:<br>
- if (!isInt<32>(S + A))<br>
+ if (!isInt<32>(S))<br>
error("Relocation R_AARCH64_ABS32 out of range");<br>
- write32le(L, S + A);<br>
+ write32le(L, S);<br>
break;<br>
case R_AARCH64_ABS64:<br>
// No overflow check needed.<br>
- write64le(L, S + A);<br>
+ write64le(L, S);<br>
break;<br>
case R_AARCH64_ADD_ABS_LO12_NC:<br>
// No overflow check needed.<br>
- or32le(L, ((S + A) & 0xFFF) << 10);<br>
+ or32le(L, (S & 0xFFF) << 10);<br>
break;<br>
case R_AARCH64_ADR_PREL_LO21: {<br>
- uint64_t X = S + A - P;<br>
+ uint64_t X = S - P;<br>
if (!isInt<21>(X))<br>
error("Relocation R_AARCH64_ADR_PREL_LO21 out of range");<br>
updateAArch64Adr(L, X & 0x1FFFFF);<br>
break;<br>
}<br>
case R_AARCH64_ADR_PREL_PG_HI21: {<br>
- uint64_t X = getAArch64Page(S + A) - getAArch64Page(P);<br>
+ uint64_t X = getAArch64Page(S) - getAArch64Page(P);<br>
if (!isInt<33>(X))<br>
error("Relocation R_AARCH64_ADR_PREL_PG_HI21 out of range");<br>
updateAArch64Adr(L, (X >> 12) & 0x1FFFFF); // X[32:12]<br>
<br>
<br>
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</blockquote></div><br></div>