[lld] r209987 - [Mips] Implement .{ctors, dtors}.<priority> sections ordering.
Simon Atanasyan
simon at atanasyan.com
Sat May 31 23:28:43 PDT 2014
Author: atanasyan
Date: Sun Jun 1 01:28:42 2014
New Revision: 209987
URL: http://llvm.org/viewvc/llvm-project?rev=209987&view=rev
Log:
[Mips] Implement .{ctors,dtors}.<priority> sections ordering.
Arrange .ctors/.dtors sections in the following order:
.ctors from crtbegin.o or crtbegin?.o
.ctors from regular object files
.ctors.* (sorted) from regular object files
.ctors from crtend.o or crtend?.o
This order is specific for MIPS traget. For example, on X86
the .ctors.* sections are merged into the .init_array section.
Added:
lld/trunk/lib/ReaderWriter/ELF/Mips/MipsCtorsOrderPass.cpp
lld/trunk/lib/ReaderWriter/ELF/Mips/MipsCtorsOrderPass.h
lld/trunk/test/elf/Mips/ctors-order.test
Modified:
lld/trunk/lib/ReaderWriter/ELF/Mips/CMakeLists.txt
lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.cpp
lld/trunk/lib/ReaderWriter/ELF/Mips/MipsTargetHandler.h
Modified: lld/trunk/lib/ReaderWriter/ELF/Mips/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/Mips/CMakeLists.txt?rev=209987&r1=209986&r2=209987&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/ELF/Mips/CMakeLists.txt (original)
+++ lld/trunk/lib/ReaderWriter/ELF/Mips/CMakeLists.txt Sun Jun 1 01:28:42 2014
@@ -1,4 +1,5 @@
add_lld_library(lldMipsELFTarget
+ MipsCtorsOrderPass.cpp
MipsLinkingContext.cpp
MipsRelocationHandler.cpp
MipsRelocationPass.cpp
Added: lld/trunk/lib/ReaderWriter/ELF/Mips/MipsCtorsOrderPass.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/Mips/MipsCtorsOrderPass.cpp?rev=209987&view=auto
==============================================================================
--- lld/trunk/lib/ReaderWriter/ELF/Mips/MipsCtorsOrderPass.cpp (added)
+++ lld/trunk/lib/ReaderWriter/ELF/Mips/MipsCtorsOrderPass.cpp Sun Jun 1 01:28:42 2014
@@ -0,0 +1,74 @@
+//===- lib/ReaderWriter/ELF/Mips/Mips/CtorsOrderPass.cpp ------------------===//
+//
+// The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "MipsCtorsOrderPass.h"
+
+#include <algorithm>
+#include <climits>
+
+using namespace lld;
+using namespace lld::elf;
+
+static bool matchCrtObjName(StringRef objName, StringRef objPath) {
+ if (!objPath.endswith(".o"))
+ return false;
+
+ // check *<objName> case
+ objPath = objPath.drop_back(2);
+ if (objPath.endswith(objName))
+ return true;
+
+ // check *<objName>? case
+ return !objPath.empty() && objPath.drop_back(1).endswith(objName);
+}
+
+static int32_t getSectionPriority(StringRef path, StringRef sectionName) {
+ // Arrange .ctors/.dtors sections in the following order:
+ // .ctors from crtbegin.o or crtbegin?.o
+ // .ctors from regular object files
+ // .ctors.* (sorted) from regular object files
+ // .ctors from crtend.o or crtend?.o
+
+ if (matchCrtObjName("crtbegin", path))
+ return std::numeric_limits<int32_t>::min();
+ if (matchCrtObjName("crtend", path))
+ return std::numeric_limits<int32_t>::max();
+
+ StringRef num = sectionName.drop_front().rsplit('.').second;
+
+ int32_t priority = std::numeric_limits<int32_t>::min() + 1;
+ if (!num.empty())
+ num.getAsInteger(10, priority);
+
+ return priority;
+}
+
+void MipsCtorsOrderPass::perform(std::unique_ptr<MutableFile> &f) {
+ auto definedAtoms = f->definedAtoms();
+
+ auto last = std::stable_partition(definedAtoms.begin(), definedAtoms.end(),
+ [](const DefinedAtom *atom) {
+ if (atom->sectionChoice() != DefinedAtom::sectionCustomRequired)
+ return false;
+
+ StringRef name = atom->customSectionName();
+ return name.startswith(".ctors") || name.startswith(".dtors");
+ });
+
+ std::stable_sort(definedAtoms.begin(), last,
+ [](const DefinedAtom *left, const DefinedAtom *right) {
+ StringRef leftSec = left->customSectionName();
+ StringRef rightSec = right->customSectionName();
+
+ int32_t leftPriority = getSectionPriority(left->file().path(), leftSec);
+ int32_t rightPriority = getSectionPriority(right->file().path(), rightSec);
+
+ return leftPriority < rightPriority;
+ });
+}
Added: lld/trunk/lib/ReaderWriter/ELF/Mips/MipsCtorsOrderPass.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/Mips/MipsCtorsOrderPass.h?rev=209987&view=auto
==============================================================================
--- lld/trunk/lib/ReaderWriter/ELF/Mips/MipsCtorsOrderPass.h (added)
+++ lld/trunk/lib/ReaderWriter/ELF/Mips/MipsCtorsOrderPass.h Sun Jun 1 01:28:42 2014
@@ -0,0 +1,25 @@
+//===- lib/ReaderWriter/ELF/Mips/MipsCtorsOrderPass.h ---------------------===//
+//
+// The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLD_READER_WRITER_ELF_MIPS_MIPS_CTORS_ORDER_PASS_H
+#define LLD_READER_WRITER_ELF_MIPS_MIPS_CTORS_ORDER_PASS_H
+
+#include "lld/Core/Pass.h"
+
+namespace lld {
+namespace elf {
+/// \brief This pass sorts atoms in .{ctors,dtors}.<priority> sections.
+class MipsCtorsOrderPass : public Pass {
+public:
+ void perform(std::unique_ptr<MutableFile> &mergedFile) override;
+};
+}
+}
+
+#endif
Modified: lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.cpp?rev=209987&r1=209986&r2=209987&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.cpp (original)
+++ lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.cpp Sun Jun 1 01:28:42 2014
@@ -8,6 +8,7 @@
//===----------------------------------------------------------------------===//
#include "Atoms.h"
+#include "MipsCtorsOrderPass.h"
#include "MipsLinkingContext.h"
#include "MipsRelocationPass.h"
#include "MipsTargetHandler.h"
@@ -44,6 +45,7 @@ void MipsLinkingContext::addPasses(PassM
if (pass)
pm.add(std::move(pass));
ELFLinkingContext::addPasses(pm);
+ pm.add(std::unique_ptr<Pass>(new elf::MipsCtorsOrderPass()));
}
bool MipsLinkingContext::isDynamicRelocation(const DefinedAtom &,
Modified: lld/trunk/lib/ReaderWriter/ELF/Mips/MipsTargetHandler.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/Mips/MipsTargetHandler.h?rev=209987&r1=209986&r2=209987&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/ELF/Mips/MipsTargetHandler.h (original)
+++ lld/trunk/lib/ReaderWriter/ELF/Mips/MipsTargetHandler.h Sun Jun 1 01:28:42 2014
@@ -43,6 +43,23 @@ public:
order);
}
+ StringRef getSectionName(const DefinedAtom *da) const override {
+ return llvm::StringSwitch<StringRef>(da->customSectionName())
+ .StartsWith(".ctors", ".ctors")
+ .StartsWith(".dtors", ".dtors")
+ .Default(TargetLayout<ELFType>::getSectionName(da));
+ }
+
+ Layout::SegmentType getSegmentType(Section<ELFType> *section) const override {
+ switch (section->order()) {
+ case DefaultLayout<ELFType>::ORDER_CTORS:
+ case DefaultLayout<ELFType>::ORDER_DTORS:
+ return llvm::ELF::PT_LOAD;
+ default:
+ return TargetLayout<ELFType>::getSegmentType(section);
+ }
+ }
+
/// \brief GP offset relative to .got section.
uint64_t getGPOffset() const { return 0x7FF0; }
Added: lld/trunk/test/elf/Mips/ctors-order.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf/Mips/ctors-order.test?rev=209987&view=auto
==============================================================================
--- lld/trunk/test/elf/Mips/ctors-order.test (added)
+++ lld/trunk/test/elf/Mips/ctors-order.test Sun Jun 1 01:28:42 2014
@@ -0,0 +1,163 @@
+# Check ordering of .ctors.* sections.
+
+# RUN: yaml2obj -format=elf -docnum 1 %s > %t-crtbeginS.o
+# RUN: yaml2obj -format=elf -docnum 2 %s > %t-crtendS.o
+# RUN: yaml2obj -format=elf -docnum 3 %s > %t-obj.o
+# RUN: lld -flavor gnu -target mipsel -shared --output-filetype=yaml \
+# RUN: %t-crtbeginS.o %t-obj.o %t-crtendS.o | FileCheck %s
+
+# CHECK: defined-atoms:
+# CHECK-NEXT: - ref-name: L000
+# CHECK-NEXT: type: data
+# CHECK-NEXT: alignment: 2^2
+# CHECK-NEXT: section-choice: custom-required
+# CHECK-NEXT: section-name: .ctors
+# CHECK-NEXT: references:
+# CHECK-NEXT: - kind: layout-after
+# CHECK-NEXT: offset: 0
+# CHECK-NEXT: target: __CTOR_LIST__
+# CHECK-NEXT: - name: __CTOR_LIST__
+# CHECK-NEXT: type: data
+# CHECK-NEXT: content: [ FF, FF, FF, FF ]
+# CHECK-NEXT: alignment: 2^2
+# CHECK-NEXT: section-choice: custom-required
+# CHECK-NEXT: section-name: .ctors
+# CHECK-NEXT: references:
+# CHECK-NEXT: - kind: in-group
+# CHECK-NEXT: offset: 0
+# CHECK-NEXT: target: L000
+# CHECK-NEXT: - type: data
+# CHECK-NEXT: content: [ 11, 11, 11, 11 ]
+# CHECK-NEXT: alignment: 2^2
+# CHECK-NEXT: section-choice: custom-required
+# CHECK-NEXT: section-name: .ctors.1
+# CHECK-NEXT: - type: data
+# CHECK-NEXT: content: [ 22, 22, 22, 22 ]
+# CHECK-NEXT: alignment: 2^2
+# CHECK-NEXT: section-choice: custom-required
+# CHECK-NEXT: section-name: .ctors.2
+# CHECK-NEXT: - ref-name: L005
+# CHECK-NEXT: type: data
+# CHECK-NEXT: alignment: 2^2
+# CHECK-NEXT: section-choice: custom-required
+# CHECK-NEXT: section-name: .ctors
+# CHECK-NEXT: references:
+# CHECK-NEXT: - kind: layout-after
+# CHECK-NEXT: offset: 0
+# CHECK-NEXT: target: __CTOR_END__
+# CHECK-NEXT: - name: __CTOR_END__
+# CHECK-NEXT: type: data
+# CHECK-NEXT: content: [ 00, 00, 00, 00 ]
+# CHECK-NEXT: alignment: 2^2
+# CHECK-NEXT: section-choice: custom-required
+# CHECK-NEXT: section-name: .ctors
+
+# crtbeginS.o
+---
+FileHeader:
+ Class: ELFCLASS32
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_MIPS
+ Flags: [ EF_MIPS_NOREORDER, EF_MIPS_CPIC,
+ EF_MIPS_ABI_O32, EF_MIPS_ARCH_32R2 ]
+Sections:
+ - Name: .ctors
+ Type: SHT_PROGBITS
+ Flags: [ SHF_WRITE, SHF_ALLOC ]
+ AddressAlign: 0x04
+ Content: 'FFFFFFFF'
+
+Symbols:
+ Local:
+ - Name: .ctors
+ Type: STT_SECTION
+ Section: .ctors
+ - Name: __CTOR_LIST__
+ Type: STT_OBJECT
+ Section: .ctors
+
+# crtendS.o
+---
+FileHeader:
+ Class: ELFCLASS32
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_MIPS
+ Flags: [ EF_MIPS_NOREORDER, EF_MIPS_CPIC,
+ EF_MIPS_ABI_O32, EF_MIPS_ARCH_32R2 ]
+Sections:
+ - Name: .text
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+ AddressAlign: 0x04
+ Size: 0x0F
+ - Name: .rel.text
+ Type: SHT_REL
+ Link: .symtab
+ Info: .text
+ AddressAlign: 0x04
+ Relocations:
+ - Offset: 0x00
+ Symbol: .ctors
+ Type: R_MIPS_HI16
+ - Offset: 0x04
+ Symbol: .ctors
+ Type: R_MIPS_LO16
+ - Offset: 0x08
+ Symbol: .ctors
+ Type: R_MIPS_HI16
+ - Offset: 0x0C
+ Symbol: .ctors
+ Type: R_MIPS_LO16
+ - Name: .ctors
+ Type: SHT_PROGBITS
+ Flags: [ SHF_WRITE, SHF_ALLOC ]
+ AddressAlign: 0x04
+ Size: 0x04
+
+Symbols:
+ Local:
+ - Name: .text
+ Type: STT_SECTION
+ Section: .text
+ - Name: .ctors
+ Type: STT_SECTION
+ Section: .ctors
+ - Name: __CTOR_END__
+ Type: STT_OBJECT
+ Section: .ctors
+ - Name: __do_global_ctors_aux
+ Type: STT_FUNC
+ Section: .text
+
+# obj.o
+---
+FileHeader:
+ Class: ELFCLASS32
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_MIPS
+ Flags: [ EF_MIPS_NOREORDER, EF_MIPS_CPIC,
+ EF_MIPS_ABI_O32, EF_MIPS_ARCH_32 ]
+Sections:
+ - Name: .ctors.2
+ Type: SHT_PROGBITS
+ Flags: [ SHF_WRITE, SHF_ALLOC ]
+ AddressAlign: 0x04
+ Content: '22222222'
+ - Name: .ctors.1
+ Type: SHT_PROGBITS
+ Flags: [ SHF_WRITE, SHF_ALLOC ]
+ AddressAlign: 0x04
+ Content: '11111111'
+
+Symbols:
+ Local:
+ - Name: .ctors.2
+ Type: STT_SECTION
+ Section: .ctors.2
+ - Name: .ctors.1
+ Type: STT_SECTION
+ Section: .ctors.1
+...
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