[CFI] Remove LinkerSubsectionsViaSymbols.

Since D17854 LinkerSubsectionsViaSymbols is unnecessary.

It is interfering with ThinLTO implementation of CFI-ICall, where
the aliases used on the !LinkerSubsectionsViaSymbols branch are
needed to export jump tables to ThinLTO backends.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304582 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/IPO/LowerTypeTests.cpp b/lib/Transforms/IPO/LowerTypeTests.cpp
index 7bec50d9d25f8464d1f82890db10dd88d0e030c0..eb6f05b653c7cf0584877acfb44ac063e2fe913b 100644 (file)
--- a/lib/Transforms/IPO/LowerTypeTests.cpp
+++ b/lib/Transforms/IPO/LowerTypeTests.cpp
@@ -235,7 +235,6 @@ class LowerTypeTestsModule {
   ModuleSummaryIndex *ExportSummary;
   const ModuleSummaryIndex *ImportSummary;
 
-  bool LinkerSubsectionsViaSymbols;
   Triple::ArchType Arch;
   Triple::OSType OS;
   Triple::ObjectFormatType ObjectFormat;
@@ -475,13 +474,9 @@ void LowerTypeTestsModule::allocateByteArrays() {
     // Create an alias instead of RAUW'ing the gep directly. On x86 this ensures
     // that the pc-relative displacement is folded into the lea instead of the
     // test instruction getting another displacement.
-    if (LinkerSubsectionsViaSymbols) {
-      BAI->ByteArray->replaceAllUsesWith(GEP);
-    } else {
-      GlobalAlias *Alias = GlobalAlias::create(
-          Int8Ty, 0, GlobalValue::PrivateLinkage, "bits", GEP, &M);
-      BAI->ByteArray->replaceAllUsesWith(Alias);
-    }
+    GlobalAlias *Alias = GlobalAlias::create(
+        Int8Ty, 0, GlobalValue::PrivateLinkage, "bits", GEP, &M);
+    BAI->ByteArray->replaceAllUsesWith(Alias);
     BAI->ByteArray->eraseFromParent();
   }
 
@@ -502,7 +497,7 @@ Value *LowerTypeTestsModule::createBitSetTest(IRBuilder<> &B,
     return createMaskedBitTest(B, TIL.InlineBits, BitOffset);
   } else {
     Constant *ByteArray = TIL.TheByteArray;
-    if (!LinkerSubsectionsViaSymbols && AvoidReuse && !ImportSummary) {
+    if (AvoidReuse && !ImportSummary) {
       // Each use of the byte array uses a different alias. This makes the
       // backend less likely to reuse previously computed byte array addresses,
       // improving the security of the CFI mechanism based on this pass.
@@ -680,17 +675,13 @@ void LowerTypeTestsModule::buildBitSetsFromGlobalVariables(
                                       ConstantInt::get(Int32Ty, I * 2)};
     Constant *CombinedGlobalElemPtr = ConstantExpr::getGetElementPtr(
         NewInit->getType(), CombinedGlobal, CombinedGlobalIdxs);
-    if (LinkerSubsectionsViaSymbols) {
-      GV->replaceAllUsesWith(CombinedGlobalElemPtr);
-    } else {
-      assert(GV->getType()->getAddressSpace() == 0);
-      GlobalAlias *GAlias = GlobalAlias::create(NewTy->getElementType(I * 2), 0,
-                                                GV->getLinkage(), "",
-                                                CombinedGlobalElemPtr, &M);
-      GAlias->setVisibility(GV->getVisibility());
-      GAlias->takeName(GV);
-      GV->replaceAllUsesWith(GAlias);
-    }
+    assert(GV->getType()->getAddressSpace() == 0);
+    GlobalAlias *GAlias =
+        GlobalAlias::create(NewTy->getElementType(I * 2), 0, GV->getLinkage(),
+                            "", CombinedGlobalElemPtr, &M);
+    GAlias->setVisibility(GV->getVisibility());
+    GAlias->takeName(GV);
+    GV->replaceAllUsesWith(GAlias);
     GV->eraseFromParent();
   }
 }
@@ -1166,8 +1157,7 @@ void LowerTypeTestsModule::buildBitSetsFromFunctionsNative(
             ArrayRef<Constant *>{ConstantInt::get(IntPtrTy, 0),
                                  ConstantInt::get(IntPtrTy, I)}),
         F->getType());
-    if (LinkerSubsectionsViaSymbols || F->isDeclarationForLinker()) {
-
+    if (F->isDeclarationForLinker()) {
       if (F->isWeakForLinker())
         replaceWeakDeclarationWithJumpTablePtr(F, CombinedGlobalElemPtr);
       else
@@ -1302,7 +1292,6 @@ LowerTypeTestsModule::LowerTypeTestsModule(
     : M(M), ExportSummary(ExportSummary), ImportSummary(ImportSummary) {
   assert(!(ExportSummary && ImportSummary));
   Triple TargetTriple(M.getTargetTriple());
-  LinkerSubsectionsViaSymbols = TargetTriple.isMacOSX();
   Arch = TargetTriple.getArch();
   OS = TargetTriple.getOS();
   ObjectFormat = TargetTriple.getObjectFormat();

diff --git a/test/Transforms/LowerTypeTests/simple.ll b/test/Transforms/LowerTypeTests/simple.ll
index cedfcb4a63a077949f1645e203f1a12f2e150e18..aae17c05d60644cca39cf6d5824c03014ace135c 100644 (file)
--- a/test/Transforms/LowerTypeTests/simple.ll
+++ b/test/Transforms/LowerTypeTests/simple.ll
@@ -1,5 +1,5 @@
 ; RUN: opt -S -lowertypetests < %s | FileCheck %s
-; RUN: opt -S -lowertypetests -mtriple=x86_64-apple-macosx10.8.0 < %s | FileCheck -check-prefix=CHECK-DARWIN %s
+; RUN: opt -S -lowertypetests -mtriple=x86_64-apple-macosx10.8.0 < %s | FileCheck %s
 ; RUN: opt -S -O3 < %s | FileCheck -check-prefix=CHECK-NODISCARD %s
 
 target datalayout = "e-p:32:32"
@@ -39,20 +39,6 @@ target datalayout = "e-p:32:32"
 ; CHECK: @c = protected alias i32, getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }, { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G]], i32 0, i32 4)
 ; CHECK: @d = alias [2 x i32], getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }, { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G]], i32 0, i32 6)
 
-; CHECK-DARWIN: @aptr = constant i32* getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }, { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G:@[^ ]*]], i32 0, i32 0)
-@aptr = constant i32* @a
-
-; CHECK-DARWIN: @bptr = constant [63 x i32]* getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }, { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G]], i32 0, i32 2)
-@bptr = constant [63 x i32]* @b
-
-; CHECK-DARWIN: @cptr = constant i32* getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }, { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G]], i32 0, i32 4)
-@cptr = constant i32* @c
-
-; CHECK-DARWIN: @dptr = constant [2 x i32]* getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }, { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G]], i32 0, i32 6)
-@dptr = constant [2 x i32]* @d
-
-; CHECK-DARWIN: [[G]] = private constant
-
 ; CHECK: @bits{{[0-9]*}} = private alias i8, getelementptr inbounds ([68 x i8], [68 x i8]* [[BA]], i32 0, i32 0)
 ; CHECK: @bits.{{[0-9]*}} = private alias i8, getelementptr inbounds ([68 x i8], [68 x i8]* [[BA]], i32 0, i32 0)