Properly emit ctors / dtors with priorities into desired sections

and let linker handle the rest.

This finally fixes PR5329



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148990 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 81 insertions, 31 deletions

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 0e6c613..d67b164 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1207,12 +1207,8 @@ bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
 
   assert(GV->hasInitializer() && "Not a special LLVM global!");
 
-  const TargetData *TD = TM.getTargetData();
-  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
   if (GV->getName() == "llvm.global_ctors") {
-    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
-    EmitAlignment(Align);
-    EmitXXStructorList(GV->getInitializer());
+    EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
 
     if (TM.getRelocationModel() == Reloc::Static &&
         MAI->hasStaticCtorDtorReferenceInStaticMode()) {
@@ -1224,9 +1220,7 @@ bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
   }
 
   if (GV->getName() == "llvm.global_dtors") {
-    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
-    EmitAlignment(Align);
-    EmitXXStructorList(GV->getInitializer());
+    EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
 
     if (TM.getRelocationModel() == Reloc::Static &&
         MAI->hasStaticCtorDtorReferenceInStaticMode()) {
@@ -1256,7 +1250,7 @@ void AsmPrinter::EmitLLVMUsedList(const Constant *List) {
   }
 }
 
-typedef std::pair<int, Constant*> Structor;
+typedef std::pair<unsigned, Constant*> Structor;
 
 static bool priority_order(const Structor& lhs, const Structor& rhs) {
   return lhs.first < rhs.first;
@@ -1264,7 +1258,7 @@ static bool priority_order(const Structor& lhs, const Structor& rhs) {
 
 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
 /// priority.
-void AsmPrinter::EmitXXStructorList(const Constant *List) {
+void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
   // Should be an array of '{ int, void ()* }' structs.  The first value is the
   // init priority.
   if (!isa<ConstantArray>(List)) return;
@@ -1290,19 +1284,20 @@ void AsmPrinter::EmitXXStructorList(const Constant *List) {
                                        CS->getOperand(1)));
   }
 
-  // Emit the function pointers in reverse priority order.
-  switch (getObjFileLowering().getStructorOutputOrder()) {
-  case Structors::None:
-    break;
-  case Structors::PriorityOrder:
-    std::sort(Structors.begin(), Structors.end(), priority_order);
-    break;
-  case Structors::ReversePriorityOrder:
-    std::sort(Structors.rbegin(), Structors.rend(), priority_order);
-    break;
-  }
-  for (unsigned i = 0, e = Structors.size(); i != e; ++i)
+  // Emit the function pointers in the target-specific order
+  const TargetData *TD = TM.getTargetData();
+  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
+  std::stable_sort(Structors.begin(), Structors.end(), priority_order);
+  for (unsigned i = 0, e = Structors.size(); i != e; ++i) {
+    const MCSection *OutputSection =
+      (isCtor ?
+       getObjFileLowering().getStaticCtorSection(Structors[i].first) :
+       getObjFileLowering().getStaticDtorSection(Structors[i].first));
+    OutStreamer.SwitchSection(OutputSection);
+    if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
+      EmitAlignment(Align);
     EmitGlobalConstant(Structors[i].second);
+  }
 }
 
 //===--------------------------------------------------------------------===//
diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index a6999f6..fd67d62 100644
--- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -340,6 +340,32 @@ getExprForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang,
     getExprForDwarfGlobalReference(GV, Mang, MMI, Encoding, Streamer);
 }
 
+const MCSection *
+TargetLoweringObjectFileELF::getStaticCtorSection(unsigned Priority) const {
+  // The default scheme is .ctor / .dtor, so we have to invert the priority
+  // numbering.
+  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());
+}
+
+const MCSection *
+TargetLoweringObjectFileELF::getStaticDtorSection(unsigned Priority) const {
+  // The default scheme is .ctor / .dtor, so we have to invert the priority
+  // numbering.
+  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());
+}
+
 //===----------------------------------------------------------------------===//
 //                                 MachO
 //===----------------------------------------------------------------------===//
diff --git a/lib/MC/MCObjectFileInfo.cpp b/lib/MC/MCObjectFileInfo.cpp
index 32ba924..4c03aaa 100644
--- a/lib/MC/MCObjectFileInfo.cpp
+++ b/lib/MC/MCObjectFileInfo.cpp
@@ -31,8 +31,6 @@ void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
     CommDirectiveSupportsAlignment = false;
 
-  StructorOutputOrder = Structors::PriorityOrder;
-
   TextSection // .text
     = Ctx->getMachOSection("__TEXT", "__text",
                            MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
@@ -260,12 +258,10 @@ void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
     }
   }
 
-  StructorOutputOrder = Structors::ReversePriorityOrder;
-
   // ELF
   BSSSection =
     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
-                       ELF::SHF_WRITE |ELF::SHF_ALLOC,
+                       ELF::SHF_WRITE | ELF::SHF_ALLOC,
                        SectionKind::getBSS());
 
   TextSection =
@@ -389,8 +385,6 @@ void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
 
 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
   // COFF
-  StructorOutputOrder = Structors::ReversePriorityOrder;
-
   TextSection =
     Ctx->getCOFFSection(".text",
                         COFF::IMAGE_SCN_CNT_CODE |
diff --git a/lib/Target/ARM/ARMTargetObjectFile.cpp b/lib/Target/ARM/ARMTargetObjectFile.cpp
index 721a225..a5ea1c2 100644
--- a/lib/Target/ARM/ARMTargetObjectFile.cpp
+++ b/lib/Target/ARM/ARMTargetObjectFile.cpp
@@ -14,6 +14,7 @@
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/ELF.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/ADT/StringExtras.h"
 using namespace llvm;
 using namespace dwarf;
 
@@ -24,8 +25,9 @@ using namespace dwarf;
 void ARMElfTargetObjectFile::Initialize(MCContext &Ctx,
                                         const TargetMachine &TM) {
   TargetLoweringObjectFileELF::Initialize(Ctx, TM);
+  isAAPCS_ABI = TM.getSubtarget<ARMSubtarget>().isAAPCS_ABI();
 
-  if (TM.getSubtarget<ARMSubtarget>().isAAPCS_ABI()) {
+  if (isAAPCS_ABI) {
     StaticCtorSection =
       getContext().getELFSection(".init_array", ELF::SHT_INIT_ARRAY,
                                  ELF::SHF_WRITE |
@@ -36,7 +38,6 @@ void ARMElfTargetObjectFile::Initialize(MCContext &Ctx,
                                  ELF::SHF_WRITE |
                                  ELF::SHF_ALLOC,
                                  SectionKind::getDataRel());
-    StructorOutputOrder = Structors::PriorityOrder;
     LSDASection = NULL;
   }
 
@@ -46,3 +47,33 @@ 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 c6a7261..ff21060 100644
--- a/lib/Target/ARM/ARMTargetObjectFile.h
+++ b/lib/Target/ARM/ARMTargetObjectFile.h
@@ -20,6 +20,7 @@ class TargetMachine;
 class ARMElfTargetObjectFile : public TargetLoweringObjectFileELF {
 protected:
   const MCSection *AttributesSection;
+  bool isAAPCS_ABI;
 public:
   ARMElfTargetObjectFile() :
     TargetLoweringObjectFileELF(),
@@ -31,6 +32,9 @@ public:
   virtual const MCSection *getAttributesSection() const {
     return AttributesSection;
   }
+
+  const MCSection * getStaticCtorSection(unsigned Priority) const;
+  const MCSection * getStaticDtorSection(unsigned Priority) const;
 };
 
 } // end namespace llvm