[lld] r319526 - [ELF] - Produce relocation section name consistent with output section name when --emit-reloc used with linker script.
George Rimar via llvm-commits
llvm-commits at lists.llvm.org
Fri Dec 1 01:04:52 PST 2017
Author: grimar
Date: Fri Dec 1 01:04:52 2017
New Revision: 319526
URL: http://llvm.org/viewvc/llvm-project?rev=319526&view=rev
Log:
[ELF] - Produce relocation section name consistent with output section name when --emit-reloc used with linker script.
This is for "Bug 35474 - --emit-relocs produces wrongly-named reloc sections".
LLD currently for scripts like:
.text.boot : { *(.text.boot) }
emits relocation section with name .rela.text because does not take
redefined name of output section into account and builds section name
using rules for non-scripted case. Patch fixes this oddness.
Differential revision: https://reviews.llvm.org/D40652
Added:
lld/trunk/test/ELF/linkerscript/emit-reloc-section-names.s
Modified:
lld/trunk/ELF/LinkerScript.cpp
lld/trunk/ELF/SyntheticSections.cpp
lld/trunk/ELF/Writer.cpp
lld/trunk/ELF/Writer.h
lld/trunk/test/ELF/linkerscript/emit-relocs-multiple.s
Modified: lld/trunk/ELF/LinkerScript.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.cpp?rev=319526&r1=319525&r2=319526&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.cpp (original)
+++ lld/trunk/ELF/LinkerScript.cpp Fri Dec 1 01:04:52 2017
@@ -533,7 +533,7 @@ void LinkerScript::addOrphanSections() {
if (!S->Live || S->Parent)
continue;
- StringRef Name = getOutputSectionName(S->Name);
+ StringRef Name = getOutputSectionName(S);
if (Config->OrphanHandling == OrphanHandlingPolicy::Error)
error(toString(S) + " is being placed in '" + Name + "'");
Modified: lld/trunk/ELF/SyntheticSections.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SyntheticSections.cpp?rev=319526&r1=319525&r2=319526&view=diff
==============================================================================
--- lld/trunk/ELF/SyntheticSections.cpp (original)
+++ lld/trunk/ELF/SyntheticSections.cpp Fri Dec 1 01:04:52 2017
@@ -2517,7 +2517,7 @@ void elf::mergeSections() {
if (!MS->Live)
continue;
- StringRef OutsecName = getOutputSectionName(MS->Name);
+ StringRef OutsecName = getOutputSectionName(MS);
uint32_t Alignment = std::max<uint32_t>(MS->Alignment, MS->Entsize);
auto I = llvm::find_if(MergeSections, [=](MergeSyntheticSection *Sec) {
Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=319526&r1=319525&r2=319526&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Fri Dec 1 01:04:52 2017
@@ -87,7 +87,9 @@ private:
};
} // anonymous namespace
-StringRef elf::getOutputSectionName(StringRef Name) {
+StringRef elf::getOutputSectionName(InputSectionBase *S) {
+ StringRef Name = S->Name;
+
// ".zdebug_" is a prefix for ZLIB-compressed sections.
// Because we decompressed input sections, we want to remove 'z'.
if (Name.startswith(".zdebug_"))
@@ -96,13 +98,17 @@ StringRef elf::getOutputSectionName(Stri
if (Config->Relocatable)
return Name;
- // This is for --emit-relocs. If .text.foo is emitted as .text, we want to
- // emit .rela.text.foo as .rel.text for consistency (this is not technically
- // required, but not doing it is odd). This code guarantees that.
- if (Name.startswith(".rel."))
- return Saver.save(".rel" + getOutputSectionName(Name.substr(4)));
- if (Name.startswith(".rela."))
- return Saver.save(".rela" + getOutputSectionName(Name.substr(5)));
+ // This is for --emit-relocs. If .text.foo is emitted as .text.bar, we want
+ // to emit .rela.text.foo as .rela.text.bar for consistency (this is not
+ // technically required, but not doing it is odd). This code guarantees that.
+ if ((S->Type == SHT_REL || S->Type == SHT_RELA) &&
+ !isa<SyntheticSection>(S)) {
+ OutputSection *Out =
+ cast<InputSection>(S)->getRelocatedSection()->getOutputSection();
+ if (S->Type == SHT_RELA)
+ return Saver.save(".rela" + Out->Name);
+ return Saver.save(".rel" + Out->Name);
+ }
for (StringRef V :
{".text.", ".rodata.", ".data.rel.ro.", ".data.", ".bss.rel.ro.",
Modified: lld/trunk/ELF/Writer.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.h?rev=319526&r1=319525&r2=319526&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.h (original)
+++ lld/trunk/ELF/Writer.h Fri Dec 1 01:04:52 2017
@@ -46,7 +46,7 @@ struct PhdrEntry {
bool HasLMA = false;
};
-llvm::StringRef getOutputSectionName(llvm::StringRef Name);
+llvm::StringRef getOutputSectionName(InputSectionBase *S);
template <class ELFT> uint32_t calcMipsEFlags();
Added: lld/trunk/test/ELF/linkerscript/emit-reloc-section-names.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/emit-reloc-section-names.s?rev=319526&view=auto
==============================================================================
--- lld/trunk/test/ELF/linkerscript/emit-reloc-section-names.s (added)
+++ lld/trunk/test/ELF/linkerscript/emit-reloc-section-names.s Fri Dec 1 01:04:52 2017
@@ -0,0 +1,22 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+# RUN: echo "SECTIONS { .text.zed : { *(.text.foo) } \
+# RUN: .text.qux : { *(.text.bar) } }" > %t.script
+# RUN: ld.lld -T %t.script --emit-relocs %t.o -o %t
+# RUN: llvm-objdump -section-headers %t | FileCheck %s
+
+## Check we name relocation sections in according to
+## their target sections names.
+
+# CHECK: .text.zed
+# CHECK: .text.qux
+# CHECK: .rela.text.zed
+# CHECK: .rela.text.qux
+
+.section .text.foo,"ax"
+foo:
+ mov $bar, %rax
+
+.section .text.bar,"ax"
+bar:
+ mov $foo, %rax
Modified: lld/trunk/test/ELF/linkerscript/emit-relocs-multiple.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/emit-relocs-multiple.s?rev=319526&r1=319525&r2=319526&view=diff
==============================================================================
--- lld/trunk/test/ELF/linkerscript/emit-relocs-multiple.s (original)
+++ lld/trunk/test/ELF/linkerscript/emit-relocs-multiple.s Fri Dec 1 01:04:52 2017
@@ -5,7 +5,7 @@
# RUN: llvm-readobj -r %t1 | FileCheck %s
# CHECK: Relocations [
-# CHECK-NEXT: Section {{.*}} .rela.foo {
+# CHECK-NEXT: Section {{.*}} .rela.zed {
# CHECK-NEXT: 0x1 R_X86_64_32 .zed 0x0
# CHECK-NEXT: 0x6 R_X86_64_32 .zed 0x5
# CHECK-NEXT: }
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