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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158692 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h b/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
index 5a4213625baec189e16d39536b35d1bef96d9f16..9849e92f7decb3710f35c57dd03ebb341d07e742 100644 (file)
--- a/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
+++ b/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
@@ -33,6 +33,8 @@ namespace llvm {
 
 
 class TargetLoweringObjectFileELF : public TargetLoweringObjectFile {
+  bool UseInitArray;
+
 public:
   virtual ~TargetLoweringObjectFileELF() {}
 
@@ -66,6 +68,7 @@ public:
   getCFIPersonalitySymbol(const GlobalValue *GV, Mangler *Mang,
                           MachineModuleInfo *MMI) const;
 
+  void InitializeELF(bool UseInitArray_);
   virtual const MCSection *
   getStaticCtorSection(unsigned Priority = 65535) const;
   virtual const MCSection *

diff --git a/include/llvm/Target/TargetOptions.h b/include/llvm/Target/TargetOptions.h
index 12a275731536710caebf37dd27236749945bae21..bc60673589f60a40b40a2bcdcfa80f378bf4c66b 100644 (file)
--- a/include/llvm/Target/TargetOptions.h
+++ b/include/llvm/Target/TargetOptions.h
@@ -43,7 +43,7 @@ namespace llvm {
           StackAlignmentOverride(0), RealignStack(true),
           DisableJumpTables(false), EnableFastISel(false),
           PositionIndependentExecutable(false), EnableSegmentedStacks(false),
-          TrapFuncName(""), FloatABIType(FloatABI::Default)
+          UseInitArray(false), TrapFuncName(""), FloatABIType(FloatABI::Default)
     {}
 
     /// PrintMachineCode - This flag is enabled when the -print-machineinstrs
@@ -172,6 +172,10 @@ namespace llvm {
 
     unsigned EnableSegmentedStacks : 1;
 
+    /// UseInitArray - Use .init_array instead of .ctors for static
+    /// constructors.
+    unsigned UseInitArray : 1;
+
     /// getTrapFunctionName - If this returns a non-empty string, this means
     /// isel should lower Intrinsic::trap to a call to the specified function
     /// name instead of an ISD::TRAP node.

diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 7a89e3ca6304c8613dc06950cd9688a85335b07a..6842eec4864d416971fb57f7f9da4c64abb6bc3a 100644 (file)
--- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -349,10 +349,17 @@ TargetLoweringObjectFileELF::getStaticCtorSection(unsigned Priority) const {
   if (Priority == 65535)
     return StaticCtorSection;
 
-  std::string Name = std::string(".ctors.") + utostr(65535 - Priority);
-  return getContext().getELFSection(Name, ELF::SHT_PROGBITS,
-                                    ELF::SHF_ALLOC |ELF::SHF_WRITE,
-                                    SectionKind::getDataRel());
+  if (UseInitArray) {
+    std::string Name = std::string(".init_array.") + utostr(Priority);
+    return getContext().getELFSection(Name, ELF::SHT_INIT_ARRAY,
+                                      ELF::SHF_ALLOC | ELF::SHF_WRITE,
+                                      SectionKind::getDataRel());
+  } else {
+    std::string Name = std::string(".ctors.") + utostr(65535 - Priority);
+    return getContext().getELFSection(Name, ELF::SHT_PROGBITS,
+                                      ELF::SHF_ALLOC |ELF::SHF_WRITE,
+                                      SectionKind::getDataRel());
+  }
 }
 
 const MCSection *
@@ -362,10 +369,35 @@ TargetLoweringObjectFileELF::getStaticDtorSection(unsigned Priority) const {
   if (Priority == 65535)
     return StaticDtorSection;
 
-  std::string Name = std::string(".dtors.") + utostr(65535 - Priority);
-  return getContext().getELFSection(Name, ELF::SHT_PROGBITS,
-                                    ELF::SHF_ALLOC |ELF::SHF_WRITE,
-                                    SectionKind::getDataRel());
+  if (UseInitArray) {
+    std::string Name = std::string(".fini_array.") + utostr(Priority);
+    return getContext().getELFSection(Name, ELF::SHT_FINI_ARRAY,
+                                      ELF::SHF_ALLOC | ELF::SHF_WRITE,
+                                      SectionKind::getDataRel());
+  } else {
+    std::string Name = std::string(".dtors.") + utostr(65535 - Priority);
+    return getContext().getELFSection(Name, ELF::SHT_PROGBITS,
+                                      ELF::SHF_ALLOC |ELF::SHF_WRITE,
+                                      SectionKind::getDataRel());
+  }
+}
+
+void
+TargetLoweringObjectFileELF::InitializeELF(bool UseInitArray_) {
+  UseInitArray = UseInitArray_;
+  if (!UseInitArray)
+    return;
+
+  StaticCtorSection =
+    getContext().getELFSection(".init_array", ELF::SHT_INIT_ARRAY,
+                               ELF::SHF_WRITE |
+                               ELF::SHF_ALLOC,
+                               SectionKind::getDataRel());
+  StaticDtorSection =
+    getContext().getELFSection(".fini_array", ELF::SHT_FINI_ARRAY,
+                               ELF::SHF_WRITE |
+                               ELF::SHF_ALLOC,
+                               SectionKind::getDataRel());
 }
 
 //===----------------------------------------------------------------------===//

diff --git a/lib/Target/ARM/ARMTargetObjectFile.cpp b/lib/Target/ARM/ARMTargetObjectFile.cpp
index a5ea1c202e2cc4de1a8c5287b5d42f2e83a2d376..3d85ca7d6995d1af5d68a3c77e9331a29d29c9ce 100644 (file)
--- a/lib/Target/ARM/ARMTargetObjectFile.cpp
+++ b/lib/Target/ARM/ARMTargetObjectFile.cpp
@@ -24,20 +24,11 @@ using namespace dwarf;
 
 void ARMElfTargetObjectFile::Initialize(MCContext &Ctx,
                                         const TargetMachine &TM) {
+  bool isAAPCS_ABI = TM.getSubtarget<ARMSubtarget>().isAAPCS_ABI();
   TargetLoweringObjectFileELF::Initialize(Ctx, TM);
-  isAAPCS_ABI = TM.getSubtarget<ARMSubtarget>().isAAPCS_ABI();
+  InitializeELF(isAAPCS_ABI);
 
   if (isAAPCS_ABI) {
-    StaticCtorSection =
-      getContext().getELFSection(".init_array", ELF::SHT_INIT_ARRAY,
-                                 ELF::SHF_WRITE |
-                                 ELF::SHF_ALLOC,
-                                 SectionKind::getDataRel());
-    StaticDtorSection =
-      getContext().getELFSection(".fini_array", ELF::SHT_FINI_ARRAY,
-                                 ELF::SHF_WRITE |
-                                 ELF::SHF_ALLOC,
-                                 SectionKind::getDataRel());
     LSDASection = NULL;
   }
 
@@ -47,33 +38,3 @@ void ARMElfTargetObjectFile::Initialize(MCContext &Ctx,
                                0,
                                SectionKind::getMetadata());
 }
-
-const MCSection *
-ARMElfTargetObjectFile::getStaticCtorSection(unsigned Priority) const {
-  if (!isAAPCS_ABI)
-    return TargetLoweringObjectFileELF::getStaticCtorSection(Priority);
-
-  if (Priority == 65535)
-    return StaticCtorSection;
-
-  // Emit ctors in priority order.
-  std::string Name = std::string(".init_array.") + utostr(Priority);
-  return getContext().getELFSection(Name, ELF::SHT_INIT_ARRAY,
-                                    ELF::SHF_ALLOC | ELF::SHF_WRITE,
-                                    SectionKind::getDataRel());
-}
-
-const MCSection *
-ARMElfTargetObjectFile::getStaticDtorSection(unsigned Priority) const {
-  if (!isAAPCS_ABI)
-    return TargetLoweringObjectFileELF::getStaticDtorSection(Priority);
-
-  if (Priority == 65535)
-    return StaticDtorSection;
-
-  // Emit dtors in priority order.
-  std::string Name = std::string(".fini_array.") + utostr(Priority);
-  return getContext().getELFSection(Name, ELF::SHT_FINI_ARRAY,
-                                    ELF::SHF_ALLOC | ELF::SHF_WRITE,
-                                    SectionKind::getDataRel());
-}

diff --git a/lib/Target/ARM/ARMTargetObjectFile.h b/lib/Target/ARM/ARMTargetObjectFile.h
index ff210604148d14b30ba2940195dde7e9d7c69998..c6a7261439d7b084166fc908e7e970214ebea90f 100644 (file)
--- a/lib/Target/ARM/ARMTargetObjectFile.h
+++ b/lib/Target/ARM/ARMTargetObjectFile.h
@@ -20,7 +20,6 @@ class TargetMachine;
 class ARMElfTargetObjectFile : public TargetLoweringObjectFileELF {
 protected:
   const MCSection *AttributesSection;
-  bool isAAPCS_ABI;
 public:
   ARMElfTargetObjectFile() :
     TargetLoweringObjectFileELF(),
@@ -32,9 +31,6 @@ public:
   virtual const MCSection *getAttributesSection() const {
     return AttributesSection;
   }
-
-  const MCSection * getStaticCtorSection(unsigned Priority) const;
-  const MCSection * getStaticDtorSection(unsigned Priority) const;
 };
 
 } // end namespace llvm

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 74902c69cad8554ae5369449f1760fd2ac3d4a39..dec8d07d99f2317bdf5c1fd19a8f229e1a9ae4f8 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -140,6 +140,8 @@ static TargetLoweringObjectFile *createTLOF(X86TargetMachine &TM) {
     return new TargetLoweringObjectFileMachO();
   }
 
+  if (Subtarget->isTargetLinux())
+    return new X86LinuxTargetObjectFile();
   if (Subtarget->isTargetELF())
     return new TargetLoweringObjectFileELF();
   if (Subtarget->isTargetCOFF() && !Subtarget->isTargetEnvMacho())

diff --git a/lib/Target/X86/X86TargetObjectFile.cpp b/lib/Target/X86/X86TargetObjectFile.cpp
index 718f35ea84ac6f802097d00821ea4ce88c17b7cd..b8d673facc8e217a5c211dbbae3f9f5f21f5db4c 100644 (file)
--- a/lib/Target/X86/X86TargetObjectFile.cpp
+++ b/lib/Target/X86/X86TargetObjectFile.cpp
@@ -9,12 +9,15 @@
 
 #include "X86TargetObjectFile.h"
 #include "X86TargetMachine.h"
+#include "llvm/ADT/StringExtras.h"
 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCSectionELF.h"
 #include "llvm/MC/MCSectionMachO.h"
 #include "llvm/Target/Mangler.h"
 #include "llvm/Support/Dwarf.h"
+#include "llvm/Support/ELF.h"
 using namespace llvm;
 using namespace dwarf;
 
@@ -42,3 +45,9 @@ getCFIPersonalitySymbol(const GlobalValue *GV, Mangler *Mang,
                         MachineModuleInfo *MMI) const {
   return Mang->getSymbol(GV);
 }
+
+void
+X86LinuxTargetObjectFile::Initialize(MCContext &Ctx, const TargetMachine &TM) {
+  TargetLoweringObjectFileELF::Initialize(Ctx, TM);
+  InitializeELF(TM.Options.UseInitArray);
+}

diff --git a/lib/Target/X86/X86TargetObjectFile.h b/lib/Target/X86/X86TargetObjectFile.h
index a02a36809ef2d52181ed37467a861f1ee15d620e..7698b59d69a59dbd17507fcad5f871fd6231a331 100644 (file)
--- a/lib/Target/X86/X86TargetObjectFile.h
+++ b/lib/Target/X86/X86TargetObjectFile.h
@@ -32,6 +32,12 @@ namespace llvm {
                             MachineModuleInfo *MMI) const;
   };
 
+  /// X86LinuxTargetObjectFile - This implementation is used for linux x86
+  /// and x86-64.
+  class X86LinuxTargetObjectFile : public TargetLoweringObjectFileELF {
+    virtual void Initialize(MCContext &Ctx, const TargetMachine &TM);
+  };
+
 } // end namespace llvm
 
 #endif

diff --git a/test/CodeGen/X86/constructor.ll b/test/CodeGen/X86/constructor.ll
new file mode 100644 (file)
index 0000000..f6dec16
--- /dev/null
+++ b/test/CodeGen/X86/constructor.ll
@@ -0,0 +1,27 @@
+; RUN: llc < %s | FileCheck --check-prefix=CTOR %s
+; RUN: llc -use-init-array < %s | FileCheck --check-prefix=INIT-ARRAY %s
+@llvm.global_ctors = appending global [2 x { i32, void ()* }] [{ i32, void ()* } { i32 65535, void ()* @f }, { i32, void ()* } { i32 15, void ()* @g }]
+
+define void @f() {
+entry:
+  ret void
+}
+
+define void @g() {
+entry:
+  ret void
+}
+
+; CTOR:                .section        .ctors.65520,"aw",@progbits
+; CTOR-NEXT:   .align  8
+; CTOR-NEXT:   .quad   g
+; CTOR-NEXT:   .section        .ctors,"aw",@progbits
+; CTOR-NEXT:   .align  8
+; CTOR-NEXT:   .quad   f
+
+; INIT-ARRAY:          .section        .init_array.15,"aw",@init_array
+; INIT-ARRAY-NEXT:     .align  8
+; INIT-ARRAY-NEXT:     .quad   g
+; INIT-ARRAY-NEXT:     .section        .init_array,"aw",@init_array
+; INIT-ARRAY-NEXT:     .align  8
+; INIT-ARRAY-NEXT:     .quad   f

diff --git a/tools/llc/llc.cpp b/tools/llc/llc.cpp
index a99d0b787a1022a20fa41c0e5e2aca02f511ba2d..d0880913baf7c5f19b5c2f842b99130e62906d71 100644 (file)
--- a/tools/llc/llc.cpp
+++ b/tools/llc/llc.cpp
@@ -244,6 +244,10 @@ SegmentedStacks("segmented-stacks",
   cl::desc("Use segmented stacks if possible."),
   cl::init(false));
 
+static cl::opt<bool>
+UseInitArray("use-init-array",
+  cl::desc("Use .init_array instead of .ctors."),
+  cl::init(false));
 
 // GetFileNameRoot - Helper function to get the basename of a filename.
 static inline std::string
@@ -418,6 +422,7 @@ int main(int argc, char **argv) {
   Options.TrapFuncName = TrapFuncName;
   Options.PositionIndependentExecutable = EnablePIE;
   Options.EnableSegmentedStacks = SegmentedStacks;
+  Options.UseInitArray = UseInitArray;
 
   std::auto_ptr<TargetMachine>
     target(TheTarget->createTargetMachine(TheTriple.getTriple(),