llvm · pcc · Jul 17, 2025 · Jul 18, 2025 · Aug 27, 2025 · Aug 27, 2025
diff --git a/compiler-rt/test/cfi/mfcall.cpp b/compiler-rt/test/cfi/mfcall.cpp
@@ -63,12 +63,12 @@ int main(int argc, char **argv) {
   switch (argv[1][0]) {
     case 'a':
       // A: runtime error: control flow integrity check for type 'int (S::*)()' failed during non-virtual pointer to member function call
-      // A: note: S::f1() defined here
+      // A: note: S::f1() {{.*}}defined here
       (s.*bitcast<S_int>(&S::f1))();
       break;
     case 'b':
       // B: runtime error: control flow integrity check for type 'int (T::*)()' failed during non-virtual pointer to member function call
-      // B: note: S::f2() defined here
+      // B: note: S::f2() {{.*}}defined here
       (t.*bitcast<T_int>(&S::f2))();
       break;
     case 'c':

diff --git a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
@@ -30,6 +30,7 @@
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/Analysis/TypeMetadataUtils.h"
 #include "llvm/Analysis/ValueTracking.h"
+#include "llvm/BinaryFormat/ELF.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/Constant.h"
@@ -498,6 +499,10 @@ class LowerTypeTestsModule {
   GlobalVariable *GlobalAnnotation;
   DenseSet<Value *> FunctionAnnotations;
 
+  // Cross-DSO CFI emits jumptable entries for exported functions as well as
+  // address taken functions in case they are address taken in other modules.
+  bool CrossDsoCfi = M.getModuleFlag("Cross-DSO CFI") != nullptr;
+
   bool shouldExportConstantsAsAbsoluteSymbols();
   uint8_t *exportTypeId(StringRef TypeId, const TypeIdLowering &TIL);
   TypeIdLowering importTypeId(StringRef TypeId);
@@ -1531,6 +1536,20 @@ Triple::ArchType LowerTypeTestsModule::selectJumpTableArmEncoding(
 void LowerTypeTestsModule::createJumpTable(
     Function *F, ArrayRef<GlobalTypeMember *> Functions,
     Triple::ArchType JumpTableArch) {
+  unsigned JumpTableEntrySize = getJumpTableEntrySize(JumpTableArch);
+  // Give the jumptable section this type in order to enable jumptable
+  // relaxation. Only do this if cross-DSO CFI is disabled because jumptable
+  // relaxation violates cross-DSO CFI's restrictions on the ordering of the
+  // jumptable relative to other sections.
+  if (!CrossDsoCfi)
+    F->setMetadata(LLVMContext::MD_elf_section_properties,
+                   MDNode::get(F->getContext(),
+                               ArrayRef<Metadata *>{
+                                   ConstantAsMetadata::get(ConstantInt::get(
+                                       Int64Ty, ELF::SHT_LLVM_CFI_JUMP_TABLE)),
+                                   ConstantAsMetadata::get(ConstantInt::get(
+                                       Int64Ty, JumpTableEntrySize))}));
+
   BasicBlock *BB = BasicBlock::Create(M.getContext(), "entry", F);
   IRBuilder<> IRB(BB);
 
@@ -1551,7 +1570,7 @@ void LowerTypeTestsModule::createJumpTable(
   IRB.CreateUnreachable();
 
   // Align the whole table by entry size.
-  F->setAlignment(Align(getJumpTableEntrySize(JumpTableArch)));
+  F->setPreferredAlignment(Align(JumpTableEntrySize));
   // Skip prologue.
   // Disabled on win32 due to https://llvm.org/bugs/show_bug.cgi?id=28641#c3.
   // Luckily, this function does not get any prologue even without the
@@ -2115,10 +2134,6 @@ bool LowerTypeTestsModule::lower() {
   unsigned CurUniqueId = 0;
   SmallVector<MDNode *, 2> Types;
 
-  // Cross-DSO CFI emits jumptable entries for exported functions as well as
-  // address taken functions in case they are address taken in other modules.
-  const bool CrossDsoCfi = M.getModuleFlag("Cross-DSO CFI") != nullptr;
-
   struct ExportedFunctionInfo {
     CfiFunctionLinkage Linkage;
     MDNode *FuncMD; // {name, linkage, type[, type...]}

diff --git a/llvm/test/Transforms/LowerTypeTests/aarch64-jumptable.ll b/llvm/test/Transforms/LowerTypeTests/aarch64-jumptable.ll
@@ -49,7 +49,7 @@ define i1 @foo(ptr %p) {
 ;
 ; AARCH64: Function Attrs: naked noinline
 ; AARCH64-LABEL: define private void @.cfi.jumptable
-; AARCH64-SAME: () #[[ATTR1:[0-9]+]] align 8 {
+; AARCH64-SAME: () #[[ATTR1:[0-9]+]] prefalign 8
 ; AARCH64-NEXT:  entry:
 ; AARCH64-NEXT:    call void asm sideeffect "bti c\0Ab $0\0A", "s"(ptr @f.cfi)
 ; AARCH64-NEXT:    call void asm sideeffect "bti c\0Ab $0\0A", "s"(ptr @g.cfi)

diff --git a/llvm/test/Transforms/LowerTypeTests/cfi-nounwind-direct-call.ll b/llvm/test/Transforms/LowerTypeTests/cfi-nounwind-direct-call.ll
@@ -153,7 +153,7 @@ attributes #6 = { noreturn nounwind }
 ;
 ; CHECK: Function Attrs: naked nocf_check noinline nounwind
 ; CHECK-LABEL: define internal void @_Z9nothrow_ei.cfi_jt
-; CHECK-SAME: () #[[ATTR5:[0-9]+]] align 8 {
+; CHECK-SAME: () #[[ATTR5:[0-9]+]] prefalign 8 {
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    tail call void asm sideeffect "jmp ${0:c}@plt\0Aint3\0Aint3\0Aint3\0A", "s"(ptr nonnull @_Z9nothrow_ei) #[[ATTR7:[0-9]+]]
 ; CHECK-NEXT:    unreachable

diff --git a/llvm/test/Transforms/LowerTypeTests/cfi-unwind-direct-call.ll b/llvm/test/Transforms/LowerTypeTests/cfi-unwind-direct-call.ll
@@ -221,7 +221,7 @@ attributes #8 = { noreturn nounwind }
 ;
 ; CHECK: Function Attrs: naked nocf_check noinline
 ; CHECK-LABEL: define internal void @_Z7throw_ei.cfi_jt(
-; CHECK-SAME: ) #[[ATTR5:[0-9]+]] align 8 {
+; CHECK-SAME: ) #[[ATTR5:[0-9]+]] prefalign 8 {
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    tail call void asm sideeffect "jmp ${0:c}@plt\0Aint3\0Aint3\0Aint3\0A", "s"(ptr nonnull @_Z7throw_ei) #[[ATTR6]]
 ; CHECK-NEXT:    unreachable

diff --git a/llvm/test/Transforms/LowerTypeTests/function-arm-thumb.ll b/llvm/test/Transforms/LowerTypeTests/function-arm-thumb.ll
@@ -33,14 +33,14 @@ define void @addrtaken() {
 !0 = !{i32 0, !"typeid1"}
 !1 = !{i32 0, !"typeid2"}
 
-; CHECK: define private void {{.*}} #[[AT:.*]] align 4 {
+; CHECK: define private void {{.*}} #[[AT:.*]] prefalign 4
 ; CHECK-NEXT: entry:
 ; CHECK-NEXT:  call void asm sideeffect "b.w $0\0A", "s"(ptr @f1.cfi)
 ; CHECK-NEXT:  call void asm sideeffect "b.w $0\0A", "s"(ptr @g1.cfi)
 ; CHECK-NEXT:  unreachable
 ; CHECK-NEXT: }
 
-; CHECK: define private void {{.*}} #[[AA:.*]] align 4 {
+; CHECK: define private void {{.*}} #[[AA:.*]] prefalign 4
 ; CHECK-NEXT: entry:
 ; CHECK-NEXT:  call void asm sideeffect "b $0\0A", "s"(ptr @f2.cfi)
 ; CHECK-NEXT:  call void asm sideeffect "b $0\0A", "s"(ptr @g2.cfi)

diff --git a/llvm/test/Transforms/LowerTypeTests/function-disjoint.ll b/llvm/test/Transforms/LowerTypeTests/function-disjoint.ll
@@ -39,10 +39,10 @@ define i1 @foo(ptr %p) {
   ret i1 %z
 }
 
-; X64: define private void @[[JT1]]() #{{.*}} align 8 {
+; X64: define private void @[[JT1]]() #{{.*}} prefalign 8
 ; X64:   call void asm sideeffect "jmp ${0:c}@plt\0Aint3\0Aint3\0Aint3\0A", "s"(ptr @g.cfi)
 
-; X64: define private void @[[JT0]]() #{{.*}} align 8 {
+; X64: define private void @[[JT0]]() #{{.*}} prefalign 8
 ; X64:   call void asm sideeffect "jmp ${0:c}@plt\0Aint3\0Aint3\0Aint3\0A", "s"(ptr @f.cfi)
 
 ; WASM32: ![[I1]] = !{i64 2}

diff --git a/llvm/test/Transforms/LowerTypeTests/function-ext.ll b/llvm/test/Transforms/LowerTypeTests/function-ext.ll
@@ -37,5 +37,5 @@ declare i1 @llvm.type.test(ptr %ptr, metadata %bitset) nounwind readnone
 !0 = !{i64 0, !"type1"}
 !1 = !{i64 0, !"type2"}
 
-; X64: define private void @[[JT]]() #{{.*}} align {{.*}} {
+; X64: define private void @[[JT]]() #{{.*}} prefalign {{.*}} {
 ; X64:   call void asm sideeffect "jmp ${0:c}@plt\0Aint3\0Aint3\0Aint3\0A", "s"(ptr @foo1)
diff --git a/llvm/test/Transforms/LowerTypeTests/function-weak.ll b/llvm/test/Transforms/LowerTypeTests/function-weak.ll
@@ -133,10 +133,10 @@ define i1 @foo(ptr %p) {
   ret i1 %x
 }
 
-; X86: define private void @[[JT]]() #{{.*}} align 8 {
-; ARM: define private void @[[JT]]() #{{.*}} align 4 {
-; RISCV: define private void @[[JT]]() #{{.*}} align 8 {
-; LOONGARCH64: define private void @[[JT]]() #{{.*}} align 8 {
+; X86: define private void @[[JT]]() #{{.*}} prefalign 8
+; ARM: define private void @[[JT]]() #{{.*}} prefalign 4
+; RISCV: define private void @[[JT]]() #{{.*}} prefalign 8
+; LOONGARCH64: define private void @[[JT]]() #{{.*}} prefalign 8
 
 ; CHECK-LABEL: define internal void @__cfi_global_var_init() section ".text.startup" {
 ; CHECK-NEXT: entry:

diff --git a/llvm/test/Transforms/LowerTypeTests/function.ll b/llvm/test/Transforms/LowerTypeTests/function.ll
@@ -62,9 +62,9 @@ define i1 @foo(ptr %p) {
   ret i1 %x
 }
 
-; JT4:  define private void @[[JT]]() #[[ATTR:.*]] align 4 {
-; JT8:  define private void @[[JT]]() #[[ATTR:.*]] align 8 {
-; JT16: define private void @[[JT]]() #[[ATTR:.*]] align 16 {
+; JT4:  define private void @[[JT]]() #[[ATTR:.*]] prefalign 4 !elf_section_properties ![[PROP:[0-9]*]] {
+; JT8:  define private void @[[JT]]() #[[ATTR:.*]] prefalign 8 !elf_section_properties ![[PROP:[0-9]*]] {
+; JT16: define private void @[[JT]]() #[[ATTR:.*]] prefalign 16 !elf_section_properties ![[PROP:[0-9]*]] {
 
 ; X86:      jmp ${0:c}@plt
 ; X86-SAME: int3
@@ -122,5 +122,9 @@ define i1 @foo(ptr %p) {
 ; RISCV: attributes #[[ATTR]] = { naked noinline "target-features"="-c,-relax" }
 ; LOONGARCH64: attributes #[[ATTR]] = { naked noinline }
 
+; JT4: ![[PROP]] =  !{i64 1879002126, i64 4}
+; JT8: ![[PROP]] =  !{i64 1879002126, i64 8}
+; JT16: ![[PROP]] =  !{i64 1879002126, i64 16}
+
 ; WASM32: ![[I0]] = !{i64 1}
 ; WASM32: ![[I1]] = !{i64 2}
diff --git a/llvm/test/Transforms/LowerTypeTests/section.ll b/llvm/test/Transforms/LowerTypeTests/section.ll
@@ -19,7 +19,7 @@ entry:
   ret i1 %0
 }
 
-; CHECK: define private void @[[JT]]() #{{.*}} align {{.*}} {
+; CHECK: define private void @[[JT]]() #{{.*}} prefalign {{.*}} {
 
 declare i1 @llvm.type.test(ptr, metadata) nounwind readnone
 

diff --git a/llvm/test/Transforms/LowerTypeTests/x86-jumptable.ll b/llvm/test/Transforms/LowerTypeTests/x86-jumptable.ll
@@ -23,7 +23,7 @@ define i1 @foo(ptr %p) {
 !0 = !{i32 0, !"typeid1"}
 !1 = !{i32 8, !"cf-protection-branch", i32 1}
 
-; X86:         define private void @.cfi.jumptable() #[[#ATTR:]] align 16 {
+; X86:         define private void @.cfi.jumptable() #[[#ATTR:]] prefalign 16
 ; X86-NEXT:    entry:
 ; X86_32-NEXT:   call void asm sideeffect "endbr32\0Ajmp ${0:c}@plt\0A.balign 16, 0xcc\0A", "s"(ptr @f.cfi)
 ; X86_32-NEXT:   call void asm sideeffect "endbr32\0Ajmp ${0:c}@plt\0A.balign 16, 0xcc\0A", "s"(ptr @g.cfi)

diff --git a/llvm/test/Transforms/MergeFunc/cfi-thunk-merging.ll b/llvm/test/Transforms/MergeFunc/cfi-thunk-merging.ll
@@ -201,7 +201,7 @@ attributes #3 = { noreturn nounwind }
 ;
 ;
 ; LOWERTYPETESTS-LABEL: define private void @.cfi.jumptable
-; LOWERTYPETESTS-SAME: () #[[ATTR3:[0-9]+]] align 8 {
+; LOWERTYPETESTS-SAME: () #[[ATTR3:[0-9]+]] prefalign 8 !elf_section_properties {{.*}} {
 ; LOWERTYPETESTS-NEXT:  entry:
 ; LOWERTYPETESTS-NEXT:    call void asm sideeffect "jmp ${0:c}@plt\0Aint3\0Aint3\0Aint3\0A", "s"(ptr @f)
 ; LOWERTYPETESTS-NEXT:    call void asm sideeffect "jmp ${0:c}@plt\0Aint3\0Aint3\0Aint3\0A", "s"(ptr @f_thunk)