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[ELF] Ignore R_*_NONE relocs when relocating non-alloc sections 

We shouldn't report an error for R_*_NONE relocs since we're emitting
them when writing relocations to discarded sections.

Differential Revision: https://reviews.llvm.org/D30279

llvm-svn: 295936
This commit is contained in:
Petr Hosek 2017-02-23 06:22:28 +00:00
parent 0d6592a899
commit b27bb59a5d
6 changed files with 31 additions and 7 deletions
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6
lld/ELF/InputSection.cpp
View File

@ -308,6 +308,7 @@ getRelocTargetVA(uint32_t Type, int64_t A, typename ELFT::uint P,
const SymbolBody &Body, RelExpr Expr) {
switch (Expr) {
case R_HINT:
case R_NONE:
case R_TLSDESC_CALL:
llvm_unreachable("cannot relocate hint relocs");
case R_TLSLD:
@ -459,7 +460,10 @@ void InputSection<ELFT>::relocateNonAlloc(uint8_t *Buf, ArrayRef<RelTy> Rels) {
Addend += Target->getImplicitAddend(BufLoc, Type);
SymbolBody &Sym = this->getFile<ELFT>()->getRelocTargetSym(Rel);
if (Target->getRelExpr(Type, Sym) != R_ABS) {
RelExpr Expr = Target->getRelExpr(Type, Sym);
if (Expr == R_NONE)
continue;
if (Expr != R_ABS) {
error(this->getLocation<ELFT>(Offset) + ": has non-ABS reloc");
return;
}

9
lld/ELF/Relocations.cpp
View File

@ -694,6 +694,11 @@ static void scanRelocs(InputSectionBase &C, ArrayRef<RelTy> Rels) {
reportUndefined<ELFT>(Body, C, RI.r_offset);
RelExpr Expr = Target->getRelExpr(Type, Body);
// Ignore "hint" relocations because they are only markers for relaxation.
if (isRelExprOneOf<R_HINT, R_NONE>(Expr))
continue;
bool Preemptible = isPreemptible(Body, Type);
Expr = adjustExpr(*File, Body, IsWrite, Expr, Type, Buf + RI.r_offset, C,
RI.r_offset);
@ -732,9 +737,7 @@ static void scanRelocs(InputSectionBase &C, ArrayRef<RelTy> Rels) {
continue;
}
// Ignore "hint" and TLS Descriptor call relocation because they are
// only markers for relaxation.
if (isRelExprOneOf<R_HINT, R_TLSDESC_CALL>(Expr))
if (Expr == R_TLSDESC_CALL)
continue;
if (needsPlt(Expr) ||

1
lld/ELF/Relocations.h
View File

@ -42,6 +42,7 @@ enum RelExpr {
R_MIPS_TLSGD,
R_MIPS_TLSLD,
R_NEG_TLS,
R_NONE,
R_PAGE_PC,
R_PC,
R_PLT,

6
lld/ELF/Target.cpp
View File

@ -389,7 +389,7 @@ RelExpr X86TargetInfo::getRelExpr(uint32_t Type, const SymbolBody &S) const {
case R_386_TLS_LE_32:
return R_NEG_TLS;
case R_386_NONE:
return R_HINT;
return R_NONE;
default:
error(toString(S.File) + ": unknown relocation type: " + toString(Type));
return R_HINT;
@ -684,7 +684,7 @@ RelExpr X86_64TargetInfo<ELFT>::getRelExpr(uint32_t Type,
case R_X86_64_GOTTPOFF:
return R_GOT_PC;
case R_X86_64_NONE:
return R_HINT;
return R_NONE;
default:
error(toString(S.File) + ": unknown relocation type: " + toString(Type));
return R_HINT;
@ -1715,7 +1715,7 @@ RelExpr ARMTargetInfo::getRelExpr(uint32_t Type, const SymbolBody &S) const {
case R_ARM_THM_MOVT_PREL:
return R_PC;
case R_ARM_NONE:
return R_HINT;
return R_NONE;
case R_ARM_TLS_LE32:
return R_TLS;
}

6
lld/test/ELF/Inputs/relocatable-non-alloc.s Normal file
View File

@ -0,0 +1,6 @@
.section .text.foo,"axG",@progbits,foo,comdat,unique,0
foo:
nop
.section .debug_info
.long .text.foo

10
lld/test/ELF/relocatable-non-alloc.s Normal file
View File

@ -0,0 +1,10 @@
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t1.o
# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %S/Inputs/relocatable-non-alloc.s -o %t2.o
# RUN: ld.lld %t2.o %t2.o -r -o %t3.o
# RUN: ld.lld %t1.o %t3.o -o %t.o | FileCheck -allow-empty %s
# CHECK-NOT: has non-ABS reloc
.globl _start
_start: