Darwin wants ctors/dtors to be ordered the other way round to linux.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139015 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCAsmInfo.h

@@ -36,6 +36,10 @@ namespace llvm {
     enum LCOMMType { None, NoAlignment, ByteAlignment };
   }
 
+  namespace Structors {
+    enum OutputOrder { None, PriorityOrder, ReversePriorityOrder };
+  }
+
   /// MCAsmInfo - This class is intended to be used as a base class for asm
   /// properties and features specific to the target.
   class MCAsmInfo {
@@ -68,6 +72,11 @@ namespace llvm {
     /// the macho-specific .tbss directive for emitting thread local BSS Symbols
     bool HasMachoTBSSDirective;                 // Default is false.
 
+    /// StructorOutputOrder - Whether the static ctor/dtor list should be output
+    /// in no particular order, in order of increasing priority or the reverse:
+    /// in order of decreasing priority (the default).
+    Structors::OutputOrder StructorOutputOrder; // Default is reverse order.
+
     /// HasStaticCtorDtorReferenceInStaticMode - True if the compiler should
     /// emit a ".reference .constructors_used" or ".reference .destructors_used"
     /// directive after the a static ctor/dtor list.  This directive is only
@@ -395,6 +404,9 @@ namespace llvm {
     //
     bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
     bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; }
+    Structors::OutputOrder getStructorOutputOrder() const {
+      return StructorOutputOrder;
+    }
     bool hasStaticCtorDtorReferenceInStaticMode() const {
       return HasStaticCtorDtorReferenceInStaticMode;
     }

lib/CodeGen/AsmPrinter/AsmPrinter.cpp

@@ -1265,7 +1265,16 @@ void AsmPrinter::EmitXXStructorList(const Constant *List) {
   }
 
   // Emit the function pointers in reverse priority order.
+  switch (MAI->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)
     EmitGlobalConstant(Structors[i].second);
 }

lib/MC/MCAsmInfo.cpp

@@ -29,6 +29,7 @@ MCAsmInfo::MCAsmInfo() {
   HasSubsectionsViaSymbols = false;
   HasMachoZeroFillDirective = false;
   HasMachoTBSSDirective = false;
+  StructorOutputOrder = Structors::ReversePriorityOrder;
   HasStaticCtorDtorReferenceInStaticMode = false;
   LinkerRequiresNonEmptyDwarfLines = false;
   MaxInstLength = 4;

lib/MC/MCAsmInfoDarwin.cpp

@@ -39,6 +39,7 @@ MCAsmInfoDarwin::MCAsmInfoDarwin() {
   ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
   HasMachoZeroFillDirective = true;  // Uses .zerofill
   HasMachoTBSSDirective = true; // Uses .tbss
+  StructorOutputOrder = Structors::PriorityOrder;
   HasStaticCtorDtorReferenceInStaticMode = true;
 
   // FIXME: Darwin 10 and newer don't need this.

test/CodeGen/X86/2011-08-29-InitOrder.ll

@@ -1,17 +1,24 @@
-; RUN: llc < %s -mtriple=i386-linux-gnu | FileCheck %s
+; RUN: llc < %s -mtriple=i386-linux-gnu | FileCheck %s --check-prefix=CHECK-DEFAULT
+; RUN: llc < %s -mtriple=i386-apple-darwin | FileCheck %s --check-prefix=CHECK-DARWIN
 ; PR5329
 
 @llvm.global_ctors = appending global [3 x { i32, void ()* }] [{ i32, void ()* } { i32 2000, void ()* @construct_2 }, { i32, void ()* } { i32 3000, void ()* @construct_3 }, { i32, void ()* } { i32 1000, void ()* @construct_1 }]
-; CHECK: ctors
-; CHECK: construct_3
-; CHECK: construct_2
-; CHECK: construct_1
+; CHECK-DEFAULT: construct_3
+; CHECK-DEFAULT: construct_2
+; CHECK-DEFAULT: construct_1
+
+; CHECK-DARWIN: construct_1
+; CHECK-DARWIN: construct_2
+; CHECK-DARWIN: construct_3
 
 @llvm.global_dtors = appending global [3 x { i32, void ()* }] [{ i32, void ()* } { i32 2000, void ()* @destruct_2 }, { i32, void ()* } { i32 1000, void ()* @destruct_1 }, { i32, void ()* } { i32 3000, void ()* @destruct_3 }]
-; CHECK: dtors
-; CHECK: destruct_3
-; CHECK: destruct_2
-; CHECK: destruct_1
+; CHECK-DEFAULT: destruct_3
+; CHECK-DEFAULT: destruct_2
+; CHECK-DEFAULT: destruct_1
+
+; CHECK-DARWIN: destruct_1
+; CHECK-DARWIN: destruct_2
+; CHECK-DARWIN: destruct_3
 
 declare void @construct_1()
 declare void @construct_2()