LowerTypeTests: Use jump table entry type as value type of jump table alias.

The motivation for this is that it causes the jump table entry's symbol
to have an st_size equal to the jump table entry size, instead of being
equal to the size of the entire jump table, which is incorrect and can
lead to unexpected behavior in binary analysis tools that rely on the
size field such as Bloaty.

Reviewers: fmayer

Reviewed By: fmayer

Pull Request: #144462

Author: pcc

llvm/lib/Transforms/IPO/LowerTypeTests.cpp

@@ -1701,8 +1701,9 @@ void LowerTypeTestsModule::buildBitSetsFromFunctionsNative(
                        GlobalValue::PrivateLinkage,
                        M.getDataLayout().getProgramAddressSpace(),
                        ".cfi.jumptable", &M);
+  ArrayType *JumpTableEntryType = ArrayType::get(Int8Ty, EntrySize);
   ArrayType *JumpTableType =
-      ArrayType::get(ArrayType::get(Int8Ty, EntrySize), Functions.size());
+      ArrayType::get(JumpTableEntryType, Functions.size());
   auto JumpTable = ConstantExpr::getPointerCast(
       JumpTableFn, PointerType::getUnqual(M.getContext()));
 
@@ -1723,7 +1724,7 @@ void LowerTypeTestsModule::buildBitSetsFromFunctionsNative(
     if (!IsJumpTableCanonical) {
       GlobalValue::LinkageTypes LT = IsExported ? GlobalValue::ExternalLinkage
                                                 : GlobalValue::InternalLinkage;
-      GlobalAlias *JtAlias = GlobalAlias::create(F->getValueType(), 0, LT,
+      GlobalAlias *JtAlias = GlobalAlias::create(JumpTableEntryType, 0, LT,
                                                  F->getName() + ".cfi_jt",
                                                  CombinedGlobalElemPtr, &M);
       if (IsExported)
@@ -1748,8 +1749,9 @@ void LowerTypeTestsModule::buildBitSetsFromFunctionsNative(
     } else {
       assert(F->getType()->getAddressSpace() == 0);
 
-      GlobalAlias *FAlias = GlobalAlias::create(
-          F->getValueType(), 0, F->getLinkage(), "", CombinedGlobalElemPtr, &M);
+      GlobalAlias *FAlias =
+          GlobalAlias::create(JumpTableEntryType, 0, F->getLinkage(), "",
+                              CombinedGlobalElemPtr, &M);
       FAlias->setVisibility(F->getVisibility());
       FAlias->takeName(F);
       if (FAlias->hasName()) {

llvm/test/Transforms/LowerTypeTests/blockaddress-2.ll

@@ -1,7 +1,7 @@
 ; RUN: opt -S %s -passes=lowertypetests | FileCheck %s
 
 ; CHECK: @badfileops = internal global %struct.f { ptr @bad_f, ptr @bad_f }
-; CHECK: @bad_f = internal alias void (), ptr @.cfi.jumptable
+; CHECK: @bad_f = internal alias [8 x i8], ptr @.cfi.jumptable
 ; CHECK: define internal void @bad_f.cfi() !type !0 {
 ; CHECK-NEXT:  ret void
 

llvm/test/Transforms/LowerTypeTests/cfi-icall-alias.ll

@@ -12,7 +12,7 @@ RUN: opt test1.bc -passes=lowertypetests -lowertypetests-read-summary=in.yaml \
 RUN:   -lowertypetests-summary-action=export -lowertypetests-write-summary=exported.yaml \
 RUN:   -S -o - | FileCheck %s --check-prefix=REGULAR
 REGULAR: @__typeid__ZTSFvvE_global_addr = hidden alias i8, ptr @.cfi.jumptable
-REGULAR: @f = alias void (), ptr @.cfi.jumptable
+REGULAR: @f = alias [8 x i8], ptr @.cfi.jumptable
 REGULAR: define private void @.cfi.jumptable()
 
 ;; CHECK that @llvm.type.test() is lowered to an actual check.

llvm/test/Transforms/LowerTypeTests/export-alias.ll

@@ -1,7 +1,7 @@
 ; RUN: opt -S %s -passes=lowertypetests -lowertypetests-summary-action=export -lowertypetests-read-summary=%S/Inputs/exported-funcs.yaml | FileCheck %s
 ;
-; CHECK: @alias1 = weak alias void (), ptr @external_addrtaken
-; CHECK: @alias2 = hidden alias void (), ptr @external_addrtaken
+; CHECK: @alias1 = weak alias [8 x i8], ptr @external_addrtaken
+; CHECK: @alias2 = hidden alias [8 x i8], ptr @external_addrtaken
 ; CHECK-NOT: @alias3 = alias
 ; CHECK-NOT: @not_present
 

llvm/test/Transforms/LowerTypeTests/export-icall.ll

@@ -40,15 +40,15 @@ define void @f3(i32 %x) !type !8 {
 ; CHECK-DAG: @__typeid_typeid1_align = hidden alias i8, inttoptr (i64 3 to ptr)
 ; CHECK-DAG: @__typeid_typeid1_size_m1 = hidden alias i8, inttoptr (i64 4 to ptr)
 
-; CHECK-DAG: @h                    = alias void (i8), ptr [[JT1]]
-; CHECK-DAG: @f                    = alias void (i32), {{.*}}getelementptr {{.*}}ptr [[JT1]]
-; CHECK-DAG: @f2                   = alias void (i32), {{.*}}getelementptr {{.*}}ptr [[JT1]]
-; CHECK-DAG: @external.cfi_jt      = hidden alias void (), {{.*}}getelementptr {{.*}}ptr [[JT1]]
-; CHECK-DAG: @external_weak.cfi_jt = hidden alias void (), {{.*}}getelementptr {{.*}}ptr [[JT1]]
+; CHECK-DAG: @h                    = alias [8 x i8], ptr [[JT1]]
+; CHECK-DAG: @f                    = alias [8 x i8], {{.*}}getelementptr {{.*}}ptr [[JT1]]
+; CHECK-DAG: @f2                   = alias [8 x i8], {{.*}}getelementptr {{.*}}ptr [[JT1]]
+; CHECK-DAG: @external.cfi_jt      = hidden alias [8 x i8], {{.*}}getelementptr {{.*}}ptr [[JT1]]
+; CHECK-DAG: @external_weak.cfi_jt = hidden alias [8 x i8], {{.*}}getelementptr {{.*}}ptr [[JT1]]
 
 ; CHECK-DAG: @__typeid_typeid2_global_addr = hidden alias i8, ptr [[JT2:.*]]
 
-; CHECK-DAG: @g                    = alias void (), ptr [[JT2]]
+; CHECK-DAG: @g                    = alias [8 x i8], ptr [[JT2]]
 
 ; CHECK-DAG: define hidden void @h.cfi(i8 {{.*}}) !type !{{.*}}
 ; CHECK-DAG: declare !type !{{.*}} void @external()

llvm/test/Transforms/LowerTypeTests/function-disjoint.ll

@@ -5,8 +5,8 @@
 
 target datalayout = "e-p:64:64"
 
-; X64: @g = alias void (), ptr @[[JT1:.*]]
-; X64: @f = alias void (), ptr @[[JT0:.*]]
+; X64: @g = alias [8 x i8], ptr @[[JT1:.*]]
+; X64: @f = alias [8 x i8], ptr @[[JT0:.*]]
 
 ; WASM32: private constant [0 x i8] zeroinitializer
 @0 = private unnamed_addr constant [2 x ptr] [ptr @f, ptr @g], align 16

llvm/test/Transforms/LowerTypeTests/function.ll

@@ -28,14 +28,13 @@ target datalayout = "e-p:64:64"
 ; NATIVE: private constant [0 x i8] zeroinitializer
 ; WASM32: private constant [0 x i8] zeroinitializer
 
-; NATIVE: @f = alias void (), ptr @[[JT:.*]]
-
-; X86: @g = internal alias void (), getelementptr inbounds ([2 x [8 x i8]], ptr @[[JT]], i64 0, i64 1)
-; ARM: @g = internal alias void (), getelementptr inbounds ([2 x [4 x i8]], ptr @[[JT]], i64 0, i64 1)
-; THUMB: @g = internal alias void (), getelementptr inbounds ([2 x [4 x i8]], ptr @[[JT]], i64 0, i64 1)
-; THUMBV6M: @g = internal alias void (), getelementptr inbounds ([2 x [16 x i8]], ptr @[[JT]], i64 0, i64 1)
-; RISCV: @g = internal alias void (), getelementptr inbounds ([2 x [8 x i8]], ptr @[[JT]], i64 0, i64 1)
-; LOONGARCH64: @g = internal alias void (), getelementptr inbounds ([2 x [8 x i8]], ptr @[[JT]], i64 0, i64 1)
+; JT4: @f = alias [4 x i8], ptr @[[JT:.*]]
+; JT8: @f = alias [8 x i8], ptr @[[JT:.*]]
+; JT16: @f = alias [16 x i8], ptr @[[JT:.*]]
+
+; JT4: @g = internal alias [4 x i8], getelementptr inbounds ([2 x [4 x i8]], ptr @[[JT]], i64 0, i64 1)
+; JT8: @g = internal alias [8 x i8], getelementptr inbounds ([2 x [8 x i8]], ptr @[[JT]], i64 0, i64 1)
+; JT16: @g = internal alias [16 x i8], getelementptr inbounds ([2 x [16 x i8]], ptr @[[JT]], i64 0, i64 1)
 
 ; NATIVE: define hidden void @f.cfi()
 ; WASM32: define void @f() !type !{{[0-9]+}} !wasm.index ![[I0:[0-9]+]]

llvm/test/Transforms/LowerTypeTests/icall-branch-funnel.ll

@@ -6,8 +6,8 @@ target triple = "x86_64-unknown-linux"
 ; CHECK: @0 = private constant { i32, [0 x i8], i32 } { i32 1, [0 x i8] zeroinitializer, i32 2 }
 ; CHECK: @g1 = alias i32, ptr @0
 ; CHECK: @g2 = alias i32, getelementptr inbounds ({ i32, [0 x i8], i32 }, ptr @0, i32 0, i32 2)
-; CHECK: @f1 = alias void (), ptr @.cfi.jumptable
-; CHECK: @f2 = alias void (), getelementptr inbounds ([2 x [8 x i8]], ptr @.cfi.jumptable, i64 0, i64 1)
+; CHECK: @f1 = alias [8 x i8], ptr @.cfi.jumptable
+; CHECK: @f2 = alias [8 x i8], getelementptr inbounds ([2 x [8 x i8]], ptr @.cfi.jumptable, i64 0, i64 1)
 
 @g1 = constant i32 1
 @g2 = constant i32 2

llvm/test/Transforms/LowerTypeTests/pr37625.ll

@@ -11,4 +11,4 @@ declare !type !2 extern_weak void @external_addrtaken(i8)
 !1 = !{!"external_addrtaken", i8 0, !2}
 !2 = !{i64 0, !"typeid1"}
 
-; CHECK-DAG: @external_addrtaken = alias void (i8), ptr @.cfi.jumptable
+; CHECK-DAG: @external_addrtaken = alias [8 x i8], ptr @.cfi.jumptable

llvm/test/Transforms/LowerTypeTests/section.ll

@@ -5,7 +5,7 @@
 
 target triple = "x86_64-unknown-linux-gnu"
 
-; CHECK: @f = alias void (), ptr @[[JT:.*]]
+; CHECK: @f = alias [8 x i8], ptr @[[JT:.*]]
 ; CHECK: define hidden void @f.cfi() section "xxx"
 
 define void @f() section "xxx" !type !0 {