[lld] r361164 - [ELF] -z combreloc: sort dynamic relocations by (!is_relative, symbol_index, r_offset)
Fangrui Song via llvm-commits
llvm-commits at lists.llvm.org
Mon May 20 08:25:01 PDT 2019
Author: maskray
Date: Mon May 20 08:25:01 2019
New Revision: 361164
URL: http://llvm.org/viewvc/llvm-project?rev=361164&view=rev
Log:
[ELF] -z combreloc: sort dynamic relocations by (!is_relative,symbol_index,r_offset)
We currently sort dynamic relocations by (!is_relative,symbol_index).
Add r_offset as the third key. This makes `readelf -r` debugging easier
(relocations to the same symbol are ordered by r_offset).
Refactor the test combreloc.s (renamed from combrelocs.s) to check
R_X86_64_RELATIVE, and delete --expand-relocs.
The difference from the reverted D61477 is that we keep !is_relative as
the first key. In local dynamic TLS model, DTPMOD (e.g.
R_ARM_TLS_DTPMOD32 R_X86_64_DTPMOD and R_PPC{,64}_DTPMOD) may use 0 as
the symbol index.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D62141
Added:
lld/trunk/test/ELF/combreloc.s
Removed:
lld/trunk/test/ELF/combrelocs.s
Modified:
lld/trunk/ELF/SyntheticSections.cpp
lld/trunk/test/ELF/i386-got-and-copy.s
Modified: lld/trunk/ELF/SyntheticSections.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SyntheticSections.cpp?rev=361164&r1=361163&r2=361164&view=diff
==============================================================================
--- lld/trunk/ELF/SyntheticSections.cpp (original)
+++ lld/trunk/ELF/SyntheticSections.cpp Mon May 20 08:25:01 2019
@@ -1488,17 +1488,17 @@ RelocationSection<ELFT>::RelocationSecti
this->Entsize = Config->IsRela ? sizeof(Elf_Rela) : sizeof(Elf_Rel);
}
-static bool compRelocations(const DynamicReloc &A, const DynamicReloc &B) {
- bool AIsRel = A.Type == Target->RelativeRel;
- bool BIsRel = B.Type == Target->RelativeRel;
- if (AIsRel != BIsRel)
- return AIsRel;
- return A.getSymIndex() < B.getSymIndex();
-}
-
template <class ELFT> void RelocationSection<ELFT>::writeTo(uint8_t *Buf) {
+ // Sort by (!IsRelative,SymIndex,r_offset). DT_REL[A]COUNT requires us to
+ // place R_*_RELATIVE first. SymIndex is to improve locality, while r_offset
+ // is to make results easier to read.
if (Sort)
- llvm::stable_sort(Relocs, compRelocations);
+ llvm::stable_sort(Relocs, [](const DynamicReloc &A, const DynamicReloc &B) {
+ return std::make_tuple(A.Type != Target->RelativeRel, A.getSymIndex(),
+ A.getOffset()) <
+ std::make_tuple(B.Type != Target->RelativeRel, B.getSymIndex(),
+ B.getOffset());
+ });
for (const DynamicReloc &Rel : Relocs) {
encodeDynamicReloc<ELFT>(reinterpret_cast<Elf_Rela *>(Buf), Rel);
Added: lld/trunk/test/ELF/combreloc.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/combreloc.s?rev=361164&view=auto
==============================================================================
--- lld/trunk/test/ELF/combreloc.s (added)
+++ lld/trunk/test/ELF/combreloc.s Mon May 20 08:25:01 2019
@@ -0,0 +1,48 @@
+# REQUIRES: x86
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t.o
+# RUN: echo 'mov aaa at gotpcrel(%rip), %rax' | llvm-mc -filetype=obj -triple=x86_64 - -o %t1.o
+
+# RUN: ld.lld -shared %t.o %t1.o -o %t.so
+# RUN: llvm-readobj -r --dynamic-table %t.so | FileCheck %s
+# RUN: ld.lld -shared %t.o %t1.o -o %t.so -z combreloc
+# RUN: llvm-readobj -r --dynamic-table %t.so | FileCheck %s
+
+# -z combreloc is the default: sort relocations by (!IsRelative,SymIndex,r_offset),
+# and emit DT_RELACOUNT (except on MIPS) to indicate the number of relative
+# relocations.
+
+# CHECK: Relocations [
+# CHECK-NEXT: Section ({{.*}}) .rela.dyn {
+# CHECK-NEXT: 0x3020 R_X86_64_RELATIVE - 0x3028
+# CHECK-NEXT: 0x20B0 R_X86_64_GLOB_DAT aaa 0x0
+# CHECK-NEXT: 0x3000 R_X86_64_64 aaa 0x0
+# CHECK-NEXT: 0x3018 R_X86_64_64 aaa 0x0
+# CHECK-NEXT: 0x3010 R_X86_64_64 bbb 0x0
+# CHECK-NEXT: 0x3008 R_X86_64_64 ccc 0x0
+# CHECK-NEXT: }
+# CHECK: DynamicSection [
+# CHECK: RELACOUNT 1
+
+# RUN: ld.lld -z nocombreloc -shared %t.o %t1.o -o %t.so
+# RUN: llvm-readobj -r --dynamic-table %t.so | FileCheck --check-prefix=NOCOMB %s
+
+# NOCOMB: Relocations [
+# NOCOMB-NEXT: Section ({{.*}}) .rela.dyn {
+# NOCOMB-NEXT: 0x3000 R_X86_64_64 aaa 0x0
+# NOCOMB-NEXT: 0x3008 R_X86_64_64 ccc 0x0
+# NOCOMB-NEXT: 0x3010 R_X86_64_64 bbb 0x0
+# NOCOMB-NEXT: 0x3018 R_X86_64_64 aaa 0x0
+# NOCOMB-NEXT: 0x3020 R_X86_64_RELATIVE - 0x3028
+# NOCOMB-NEXT: 0x20A0 R_X86_64_GLOB_DAT aaa 0x0
+# NOCOMB-NEXT: }
+# NOCOMB: DynamicSection [
+# NOCOMB-NOT: RELACOUNT
+
+.data
+ .quad aaa
+ .quad ccc
+ .quad bbb
+ .quad aaa
+ .quad relative
+relative:
Removed: lld/trunk/test/ELF/combrelocs.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/combrelocs.s?rev=361163&view=auto
==============================================================================
--- lld/trunk/test/ELF/combrelocs.s (original)
+++ lld/trunk/test/ELF/combrelocs.s (removed)
@@ -1,95 +0,0 @@
-# REQUIRES: x86
-
-# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
-# RUN: ld.lld -shared %t.o -o %t.out
-# RUN: llvm-readobj -r --expand-relocs --dynamic-table %t.out | FileCheck %s
-
-# RUN: ld.lld -shared %t.o -o %t.out -z combreloc
-# RUN: llvm-readobj -r --expand-relocs --dynamic-table %t.out | FileCheck %s
-
-# CHECK: Relocations [
-# CHECK-NEXT: Section ({{.*}}) .rela.dyn {
-# CHECK-NEXT: Relocation {
-# CHECK-NEXT: Offset: 0x2000
-# CHECK-NEXT: Type: R_X86_64_64
-# CHECK-NEXT: Symbol: aaa (1)
-# CHECK-NEXT: Addend: 0x0
-# CHECK-NEXT: }
-# CHECK-NEXT: Relocation {
-# CHECK-NEXT: Offset: 0x2018
-# CHECK-NEXT: Type: R_X86_64_64
-# CHECK-NEXT: Symbol: aaa (1)
-# CHECK-NEXT: Addend: 0x0
-# CHECK-NEXT: }
-# CHECK-NEXT: Relocation {
-# CHECK-NEXT: Offset: 0x2010
-# CHECK-NEXT: Type: R_X86_64_64
-# CHECK-NEXT: Symbol: bbb (2)
-# CHECK-NEXT: Addend: 0x0
-# CHECK-NEXT: }
-# CHECK-NEXT: Relocation {
-# CHECK-NEXT: Offset: 0x2008
-# CHECK-NEXT: Type: R_X86_64_64
-# CHECK-NEXT: Symbol: ccc (3)
-# CHECK-NEXT: Addend: 0x0
-# CHECK-NEXT: }
-# CHECK-NEXT: Relocation {
-# CHECK-NEXT: Offset: 0x2020
-# CHECK-NEXT: Type: R_X86_64_64
-# CHECK-NEXT: Symbol: ddd (4)
-# CHECK-NEXT: Addend: 0x0
-# CHECK-NEXT: }
-# CHECK-NEXT: }
-# CHECK-NEXT: ]
-# CHECK: DynamicSection [
-# CHECK-NEXT: Tag
-# CHECK-NOT: RELACOUNT
-
-# RUN: ld.lld -z nocombreloc -shared %t.o -o %t.out
-# RUN: llvm-readobj -r --expand-relocs --dynamic-table %t.out | \
-# RUN: FileCheck --check-prefix=NOCOMB %s
-
-# NOCOMB: Relocations [
-# NOCOMB-NEXT: Section ({{.*}}) .rela.dyn {
-# NOCOMB-NEXT: Relocation {
-# NOCOMB-NEXT: Offset: 0x2000
-# NOCOMB-NEXT: Type: R_X86_64_64
-# NOCOMB-NEXT: Symbol: aaa (1)
-# NOCOMB-NEXT: Addend: 0x0
-# NOCOMB-NEXT: }
-# NOCOMB-NEXT: Relocation {
-# NOCOMB-NEXT: Offset: 0x2008
-# NOCOMB-NEXT: Type: R_X86_64_64
-# NOCOMB-NEXT: Symbol: ccc (3)
-# NOCOMB-NEXT: Addend: 0x0
-# NOCOMB-NEXT: }
-# NOCOMB-NEXT: Relocation {
-# NOCOMB-NEXT: Offset: 0x2010
-# NOCOMB-NEXT: Type: R_X86_64_64
-# NOCOMB-NEXT: Symbol: bbb (2)
-# NOCOMB-NEXT: Addend: 0x0
-# NOCOMB-NEXT: }
-# NOCOMB-NEXT: Relocation {
-# NOCOMB-NEXT: Offset: 0x2018
-# NOCOMB-NEXT: Type: R_X86_64_64
-# NOCOMB-NEXT: Symbol: aaa (1)
-# NOCOMB-NEXT: Addend: 0x0
-# NOCOMB-NEXT: }
-# NOCOMB-NEXT: Relocation {
-# NOCOMB-NEXT: Offset: 0x2020
-# NOCOMB-NEXT: Type: R_X86_64_64
-# NOCOMB-NEXT: Symbol: ddd (4)
-# NOCOMB-NEXT: Addend: 0x0
-# NOCOMB-NEXT: }
-# NOCOMB-NEXT: }
-# NOCOMB-NEXT: ]
-# NOCOMB: DynamicSection [
-# NOCOMB-NEXT: Tag
-# NOCOMB-NOT: RELACOUNT
-
-.data
- .quad aaa
- .quad ccc
- .quad bbb
- .quad aaa
- .quad ddd
Modified: lld/trunk/test/ELF/i386-got-and-copy.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/i386-got-and-copy.s?rev=361164&r1=361163&r2=361164&view=diff
==============================================================================
--- lld/trunk/test/ELF/i386-got-and-copy.s (original)
+++ lld/trunk/test/ELF/i386-got-and-copy.s Mon May 20 08:25:01 2019
@@ -14,8 +14,8 @@
# CHECK: Relocations [
# CHECK-NEXT: Section (4) .rel.dyn {
-# CHECK-NEXT: 0x{{[0-9A-F]+}} R_386_COPY foo
# CHECK-NEXT: 0x{{[0-9A-F]+}} R_386_GLOB_DAT foo
+# CHECK-NEXT: 0x{{[0-9A-F]+}} R_386_COPY foo
# CHECK-NEXT: }
# CHECK-NEXT: ]
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