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espindolaespindola
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Move the support for using .init_array from ARM to the generic
TargetLoweringObjectFileELF. Use this to support it on X86. Unlike ARM, on X86 it is not easy to find out if .init_array should be used or not, so the decision is made via TargetOptions and defaults to off. Add a command line option to llc that enables it. llvm-svn: 158692
1 parent 9ea8f7e commit ca3e0ee

10 files changed

+99
-54
lines changed

‎llvm/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h

+3
Original file line numberDiff line numberDiff line change
@@ -33,6 +33,8 @@ namespace llvm {
3333

3434

3535
class TargetLoweringObjectFileELF : public TargetLoweringObjectFile {
36+
bool UseInitArray;
37+
3638
public:
3739
virtual ~TargetLoweringObjectFileELF() {}
3840

@@ -66,6 +68,7 @@ class TargetLoweringObjectFileELF : public TargetLoweringObjectFile {
6668
getCFIPersonalitySymbol(const GlobalValue *GV, Mangler *Mang,
6769
MachineModuleInfo *MMI) const;
6870

71+
void InitializeELF(bool UseInitArray_);
6972
virtual const MCSection *
7073
getStaticCtorSection(unsigned Priority = 65535) const;
7174
virtual const MCSection *

‎llvm/include/llvm/Target/TargetOptions.h

+5-1
Original file line numberDiff line numberDiff line change
@@ -43,7 +43,7 @@ namespace llvm {
4343
StackAlignmentOverride(0), RealignStack(true),
4444
DisableJumpTables(false), EnableFastISel(false),
4545
PositionIndependentExecutable(false), EnableSegmentedStacks(false),
46-
TrapFuncName(""), FloatABIType(FloatABI::Default)
46+
UseInitArray(false), TrapFuncName(""), FloatABIType(FloatABI::Default)
4747
{}
4848

4949
/// PrintMachineCode - This flag is enabled when the -print-machineinstrs
@@ -172,6 +172,10 @@ namespace llvm {
172172

173173
unsigned EnableSegmentedStacks : 1;
174174

175+
/// UseInitArray - Use .init_array instead of .ctors for static
176+
/// constructors.
177+
unsigned UseInitArray : 1;
178+
175179
/// getTrapFunctionName - If this returns a non-empty string, this means
176180
/// isel should lower Intrinsic::trap to a call to the specified function
177181
/// name instead of an ISD::TRAP node.

‎llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp

+40-8
Original file line numberDiff line numberDiff line change
@@ -349,10 +349,17 @@ TargetLoweringObjectFileELF::getStaticCtorSection(unsigned Priority) const {
349349
if (Priority == 65535)
350350
return StaticCtorSection;
351351

352-
std::string Name = std::string(".ctors.") + utostr(65535 - Priority);
353-
return getContext().getELFSection(Name, ELF::SHT_PROGBITS,
354-
ELF::SHF_ALLOC |ELF::SHF_WRITE,
355-
SectionKind::getDataRel());
352+
if (UseInitArray) {
353+
std::string Name = std::string(".init_array.") + utostr(Priority);
354+
return getContext().getELFSection(Name, ELF::SHT_INIT_ARRAY,
355+
ELF::SHF_ALLOC | ELF::SHF_WRITE,
356+
SectionKind::getDataRel());
357+
} else {
358+
std::string Name = std::string(".ctors.") + utostr(65535 - Priority);
359+
return getContext().getELFSection(Name, ELF::SHT_PROGBITS,
360+
ELF::SHF_ALLOC |ELF::SHF_WRITE,
361+
SectionKind::getDataRel());
362+
}
356363
}
357364

358365
const MCSection *
@@ -362,10 +369,35 @@ TargetLoweringObjectFileELF::getStaticDtorSection(unsigned Priority) const {
362369
if (Priority == 65535)
363370
return StaticDtorSection;
364371

365-
std::string Name = std::string(".dtors.") + utostr(65535 - Priority);
366-
return getContext().getELFSection(Name, ELF::SHT_PROGBITS,
367-
ELF::SHF_ALLOC |ELF::SHF_WRITE,
368-
SectionKind::getDataRel());
372+
if (UseInitArray) {
373+
std::string Name = std::string(".fini_array.") + utostr(Priority);
374+
return getContext().getELFSection(Name, ELF::SHT_FINI_ARRAY,
375+
ELF::SHF_ALLOC | ELF::SHF_WRITE,
376+
SectionKind::getDataRel());
377+
} else {
378+
std::string Name = std::string(".dtors.") + utostr(65535 - Priority);
379+
return getContext().getELFSection(Name, ELF::SHT_PROGBITS,
380+
ELF::SHF_ALLOC |ELF::SHF_WRITE,
381+
SectionKind::getDataRel());
382+
}
383+
}
384+
385+
void
386+
TargetLoweringObjectFileELF::InitializeELF(bool UseInitArray_) {
387+
UseInitArray = UseInitArray_;
388+
if (!UseInitArray)
389+
return;
390+
391+
StaticCtorSection =
392+
getContext().getELFSection(".init_array", ELF::SHT_INIT_ARRAY,
393+
ELF::SHF_WRITE |
394+
ELF::SHF_ALLOC,
395+
SectionKind::getDataRel());
396+
StaticDtorSection =
397+
getContext().getELFSection(".fini_array", ELF::SHT_FINI_ARRAY,
398+
ELF::SHF_WRITE |
399+
ELF::SHF_ALLOC,
400+
SectionKind::getDataRel());
369401
}
370402

371403
//===----------------------------------------------------------------------===//

‎llvm/lib/Target/ARM/ARMTargetObjectFile.cpp

+2-41
Original file line numberDiff line numberDiff line change
@@ -24,20 +24,11 @@ using namespace dwarf;
2424

2525
void ARMElfTargetObjectFile::Initialize(MCContext &Ctx,
2626
const TargetMachine &TM) {
27+
bool isAAPCS_ABI = TM.getSubtarget<ARMSubtarget>().isAAPCS_ABI();
2728
TargetLoweringObjectFileELF::Initialize(Ctx, TM);
28-
isAAPCS_ABI = TM.getSubtarget<ARMSubtarget>().isAAPCS_ABI();
29+
InitializeELF(isAAPCS_ABI);
2930

3031
if (isAAPCS_ABI) {
31-
StaticCtorSection =
32-
getContext().getELFSection(".init_array", ELF::SHT_INIT_ARRAY,
33-
ELF::SHF_WRITE |
34-
ELF::SHF_ALLOC,
35-
SectionKind::getDataRel());
36-
StaticDtorSection =
37-
getContext().getELFSection(".fini_array", ELF::SHT_FINI_ARRAY,
38-
ELF::SHF_WRITE |
39-
ELF::SHF_ALLOC,
40-
SectionKind::getDataRel());
4132
LSDASection = NULL;
4233
}
4334

@@ -47,33 +38,3 @@ void ARMElfTargetObjectFile::Initialize(MCContext &Ctx,
4738
0,
4839
SectionKind::getMetadata());
4940
}
50-
51-
const MCSection *
52-
ARMElfTargetObjectFile::getStaticCtorSection(unsigned Priority) const {
53-
if (!isAAPCS_ABI)
54-
return TargetLoweringObjectFileELF::getStaticCtorSection(Priority);
55-
56-
if (Priority == 65535)
57-
return StaticCtorSection;
58-
59-
// Emit ctors in priority order.
60-
std::string Name = std::string(".init_array.") + utostr(Priority);
61-
return getContext().getELFSection(Name, ELF::SHT_INIT_ARRAY,
62-
ELF::SHF_ALLOC | ELF::SHF_WRITE,
63-
SectionKind::getDataRel());
64-
}
65-
66-
const MCSection *
67-
ARMElfTargetObjectFile::getStaticDtorSection(unsigned Priority) const {
68-
if (!isAAPCS_ABI)
69-
return TargetLoweringObjectFileELF::getStaticDtorSection(Priority);
70-
71-
if (Priority == 65535)
72-
return StaticDtorSection;
73-
74-
// Emit dtors in priority order.
75-
std::string Name = std::string(".fini_array.") + utostr(Priority);
76-
return getContext().getELFSection(Name, ELF::SHT_FINI_ARRAY,
77-
ELF::SHF_ALLOC | ELF::SHF_WRITE,
78-
SectionKind::getDataRel());
79-
}

‎llvm/lib/Target/ARM/ARMTargetObjectFile.h

-4
Original file line numberDiff line numberDiff line change
@@ -20,7 +20,6 @@ class TargetMachine;
2020
class ARMElfTargetObjectFile : public TargetLoweringObjectFileELF {
2121
protected:
2222
const MCSection *AttributesSection;
23-
bool isAAPCS_ABI;
2423
public:
2524
ARMElfTargetObjectFile() :
2625
TargetLoweringObjectFileELF(),
@@ -32,9 +31,6 @@ class ARMElfTargetObjectFile : public TargetLoweringObjectFileELF {
3231
virtual const MCSection *getAttributesSection() const {
3332
return AttributesSection;
3433
}
35-
36-
const MCSection * getStaticCtorSection(unsigned Priority) const;
37-
const MCSection * getStaticDtorSection(unsigned Priority) const;
3834
};
3935

4036
} // end namespace llvm

‎llvm/lib/Target/X86/X86ISelLowering.cpp

+2
Original file line numberDiff line numberDiff line change
@@ -140,6 +140,8 @@ static TargetLoweringObjectFile *createTLOF(X86TargetMachine &TM) {
140140
return new TargetLoweringObjectFileMachO();
141141
}
142142

143+
if (Subtarget->isTargetLinux())
144+
return new X86LinuxTargetObjectFile();
143145
if (Subtarget->isTargetELF())
144146
return new TargetLoweringObjectFileELF();
145147
if (Subtarget->isTargetCOFF() && !Subtarget->isTargetEnvMacho())

‎llvm/lib/Target/X86/X86TargetObjectFile.cpp

+9
Original file line numberDiff line numberDiff line change
@@ -9,12 +9,15 @@
99

1010
#include "X86TargetObjectFile.h"
1111
#include "X86TargetMachine.h"
12+
#include "llvm/ADT/StringExtras.h"
1213
#include "llvm/CodeGen/MachineModuleInfoImpls.h"
1314
#include "llvm/MC/MCContext.h"
1415
#include "llvm/MC/MCExpr.h"
16+
#include "llvm/MC/MCSectionELF.h"
1517
#include "llvm/MC/MCSectionMachO.h"
1618
#include "llvm/Target/Mangler.h"
1719
#include "llvm/Support/Dwarf.h"
20+
#include "llvm/Support/ELF.h"
1821
using namespace llvm;
1922
using namespace dwarf;
2023

@@ -42,3 +45,9 @@ getCFIPersonalitySymbol(const GlobalValue *GV, Mangler *Mang,
4245
MachineModuleInfo *MMI) const {
4346
return Mang->getSymbol(GV);
4447
}
48+
49+
void
50+
X86LinuxTargetObjectFile::Initialize(MCContext &Ctx, const TargetMachine &TM) {
51+
TargetLoweringObjectFileELF::Initialize(Ctx, TM);
52+
InitializeELF(TM.Options.UseInitArray);
53+
}

‎llvm/lib/Target/X86/X86TargetObjectFile.h

+6
Original file line numberDiff line numberDiff line change
@@ -32,6 +32,12 @@ namespace llvm {
3232
MachineModuleInfo *MMI) const;
3333
};
3434

35+
/// X86LinuxTargetObjectFile - This implementation is used for linux x86
36+
/// and x86-64.
37+
class X86LinuxTargetObjectFile : public TargetLoweringObjectFileELF {
38+
virtual void Initialize(MCContext &Ctx, const TargetMachine &TM);
39+
};
40+
3541
} // end namespace llvm
3642

3743
#endif

‎llvm/test/CodeGen/X86/constructor.ll

+27
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,27 @@
1+
; RUN: llc < %s | FileCheck --check-prefix=CTOR %s
2+
; RUN: llc -use-init-array < %s | FileCheck --check-prefix=INIT-ARRAY %s
3+
@llvm.global_ctors = appending global [2 x { i32, void ()* }] [{ i32, void ()* } { i32 65535, void ()* @f }, { i32, void ()* } { i32 15, void ()* @g }]
4+
5+
define void @f() {
6+
entry:
7+
ret void
8+
}
9+
10+
define void @g() {
11+
entry:
12+
ret void
13+
}
14+
15+
; CTOR: .section .ctors.65520,"aw",@progbits
16+
; CTOR-NEXT: .align 8
17+
; CTOR-NEXT: .quad g
18+
; CTOR-NEXT: .section .ctors,"aw",@progbits
19+
; CTOR-NEXT: .align 8
20+
; CTOR-NEXT: .quad f
21+
22+
; INIT-ARRAY: .section .init_array.15,"aw",@init_array
23+
; INIT-ARRAY-NEXT: .align 8
24+
; INIT-ARRAY-NEXT: .quad g
25+
; INIT-ARRAY-NEXT: .section .init_array,"aw",@init_array
26+
; INIT-ARRAY-NEXT: .align 8
27+
; INIT-ARRAY-NEXT: .quad f

‎llvm/tools/llc/llc.cpp

+5
Original file line numberDiff line numberDiff line change
@@ -244,6 +244,10 @@ SegmentedStacks("segmented-stacks",
244244
cl::desc("Use segmented stacks if possible."),
245245
cl::init(false));
246246

247+
static cl::opt<bool>
248+
UseInitArray("use-init-array",
249+
cl::desc("Use .init_array instead of .ctors."),
250+
cl::init(false));
247251

248252
// GetFileNameRoot - Helper function to get the basename of a filename.
249253
static inline std::string
@@ -418,6 +422,7 @@ int main(int argc, char **argv) {
418422
Options.TrapFuncName = TrapFuncName;
419423
Options.PositionIndependentExecutable = EnablePIE;
420424
Options.EnableSegmentedStacks = SegmentedStacks;
425+
Options.UseInitArray = UseInitArray;
421426

422427
std::auto_ptr<TargetMachine>
423428
target(TheTarget->createTargetMachine(TheTriple.getTriple(),

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