Merge pull request #84811 from rjmccall/verify-dead-end-edges

Strengthen the SIL verifier's rules for edges into dead-end regions

test/SIL/store_borrow_verify_errors.sil

@@ -55,11 +55,16 @@ bb3:
   return %1 : $()
 }
 
-// CHECK: Begin Error in function test_missing_end_borrow
-// CHECK: SIL verification failed: inconsistent active-operations sets entering basic block: state.ActiveOps == foundState.ActiveOps || isUnreachable()
-// CHECK: Verifying instruction:
-// CHECK: ->   br bb3                                       // id: %5
-// CHECK: End Error in function test_missing_end_borrow
+// CHECK:      Begin Error in function test_missing_end_borrow
+// CHECK-NEXT: SIL verification failed: inconsistent active-operations sets entering basic block
+// CHECK-NEXT: Entering basic block bb3
+// CHECK-NEXT: Current active operations: []
+// CHECK-NEXT: Recorded active operations: [
+// CHECK-NEXT:   %2 = store_borrow %0 to %1 : $*Klass
+// CHECK-NEXT: ]
+// CHECK-NEXT: Verifying instruction:
+// CHECK-NEXT: ->   br bb3                                       // id: %5
+// CHECK-NEXT: End Error in function test_missing_end_borrow
 sil [ossa] @test_missing_end_borrow_dead : $@convention(thin) (@guaranteed Klass) -> () {
 bb0(%0 : @guaranteed $Klass):
   %stk = alloc_stack $Klass

test/SIL/verifier-fail-stack.sil

@@ -0,0 +1,333 @@
+// RUN: %target-sil-opt -verify-continue-on-failure -o /dev/null %s 2>&1 | %FileCheck %s
+
+// REQUIRES: asserts
+
+sil_stage canonical
+
+import Builtin
+
+//   Check that join points normally require the stack to match.
+// CHECK-LABEL: Begin Error in function require_match_1
+// CHECK-LABEL: Begin Error in function require_match_1
+// CHECK:       SIL verification failed: inconsistent stack states entering basic block
+// CHECK-NEXT:  Entering basic block bb3
+// CHECK-NEXT:  Current stack state: []
+// CHECK-NEXT:  Recorded stack state: [
+// CHECK-NEXT:    %0 = alloc_stack $Builtin.Int32
+// CHECK-NEXT:  ]
+// CHECK-LABEL: End Error in function require_match_1
+sil @require_match_1 : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  dealloc_stack %0
+  br bb3
+
+bb2:
+  br bb3
+
+bb3:
+  %result = tuple ()
+  return %result : $()
+}
+
+//   Same as above, just with the branches switched around.
+// CHECK-LABEL: Begin Error in function require_match_2
+// CHECK-LABEL: Begin Error in function require_match_2
+// CHECK:       SIL verification failed: inconsistent stack states entering basic block
+// CHECK-NEXT:  Entering basic block bb3
+// CHECK-NEXT:  Current stack state: [
+// CHECK-NEXT:    %0 = alloc_stack $Builtin.Int32
+// CHECK-NEXT:  ]
+// CHECK-NEXT:  Recorded stack state: []
+// CHECK-LABEL: End Error in function require_match_2
+sil @require_match_2 : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  br bb3
+
+bb2:
+  dealloc_stack %0
+  br bb3
+
+bb3:
+  %result = tuple ()
+  return %result : $()
+}
+
+//   Check that such a join point is okay if it's a branch into a dead-end region.
+// CHECK-NOT:   Begin Error in function merge_unreachable_okay_1
+sil @merge_unreachable_okay_1 : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  dealloc_stack %0
+  br bb3
+
+bb2:
+  br bb3
+
+bb3:
+  unreachable
+}
+
+//   Same as above, just with the branches switched around.
+// CHECK-NOT:   Begin Error in function merge_unreachable_okay_1
+sil @merge_unreachable_okay_2 : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  br bb3
+
+bb2:
+  dealloc_stack %0
+  br bb3
+
+bb3:
+  unreachable
+}
+
+//   Check that it's not okay to subsequently dealloc the allocation.
+// CHECK-LABEL: Begin Error in function merge_unreachable_then_dealloc_1
+// CHECK:       SIL verification failed: deallocating allocation that is not the top of the stack
+// CHECK-NEXT:  Current stack state: []
+// CHECK-NEXT:  Stack allocation:
+// CHECK-NEXT:    %0 = alloc_stack $Builtin.Int32
+// CHECK-LABEL: End Error in function merge_unreachable_then_dealloc_1
+sil @merge_unreachable_then_dealloc_1 : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  dealloc_stack %0
+  br bb3
+
+bb2:
+  br bb3
+
+bb3:
+  dealloc_stack %0
+  unreachable
+}
+
+//   Same as above, just with the branches switched around.
+// CHECK-LABEL: Begin Error in function merge_unreachable_then_dealloc_2
+// CHECK:       SIL verification failed: deallocating allocation that is not the top of the stack
+// CHECK-NEXT:  Current stack state: []
+// CHECK-NEXT:  Stack allocation:
+// CHECK-NEXT:    %0 = alloc_stack $Builtin.Int32
+// CHECK-LABEL: End Error in function merge_unreachable_then_dealloc_2
+sil @merge_unreachable_then_dealloc_2 : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  br bb3
+
+bb2:
+  dealloc_stack %0
+  br bb3
+
+bb3:
+  dealloc_stack %0
+  unreachable
+}
+
+//   Parallel branches with inconsistent stack state into a dead-end loop
+// CHECK-NOT:   Begin Error in function parallel_branches_into_dead_1
+sil @parallel_branches_into_dead_1 : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  dealloc_stack %0
+  br bb3
+
+bb2:
+  br bb4
+
+bb3:
+  br bb4
+
+bb4:
+  br bb3
+}
+
+//   Same as above, just with the dealloc switched around to trigger
+//   a different visitation pattern.
+// CHECK-NOT:   Begin Error in function parallel_branches_into_dead_2
+sil @parallel_branches_into_dead_2 : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  br bb3
+
+bb2:
+  dealloc_stack %0
+  br bb4
+
+bb3:
+  br bb4
+
+bb4:
+  br bb3
+}
+
+//   Add an unreachable block that also branches to the dead-end region to
+//   make sure we don't fail to visit anything.
+// CHECK-NOT:   Begin Error in function parallel_branches_into_dead_with_unreachable_block
+sil @parallel_branches_into_dead_with_unreachable_block : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  br bb3
+
+bb2:
+  dealloc_stack %0
+  br bb4
+
+bb3:
+  br bb4
+
+bb4:
+  br bb3
+
+bb5: // unreachable
+  br bb3
+}
+
+//   Parallel branches with inconsistent stack state into a dead-end loop
+//   that contains a dealloc
+// CHECK-LABEL:   Begin Error in function parallel_branches_into_dead_dealloc_1
+// CHECK-NEXT:    SIL verification failed: deallocating allocation that is not the top of the stack
+sil @parallel_branches_into_dead_dealloc_1 : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  dealloc_stack %0
+  br bb3
+
+bb2:
+  br bb4
+
+bb3:
+  dealloc_stack %0
+  br bb4
+
+bb4:
+  br bb3
+}
+
+//   Same as above, just with the dealloc switched around to trigger
+//   a different visitation pattern.
+// CHECK-LABEL:   Begin Error in function parallel_branches_into_dead_dealloc_2
+// CHECK-NEXT:    SIL verification failed: deallocating allocation that is not the top of the stack
+sil @parallel_branches_into_dead_dealloc_2 : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  dealloc_stack %0
+  br bb3
+
+bb2:
+  br bb4
+
+bb3:
+  br bb4
+
+bb4:
+  dealloc_stack %0
+  br bb3
+}
+
+//   Yet another visitation pattern.
+// CHECK-LABEL:   Begin Error in function parallel_branches_into_dead_dealloc_3
+// CHECK-NEXT:    SIL verification failed: deallocating allocation that is not the top of the stack
+sil @parallel_branches_into_dead_dealloc_3 : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  br bb3
+
+bb2:
+  dealloc_stack %0
+  br bb4
+
+bb3:
+  dealloc_stack %0
+  br bb4
+
+bb4:
+  br bb3
+}
+
+//   Yet another visitation pattern.
+// CHECK-LABEL:   Begin Error in function parallel_branches_into_dead_dealloc_4
+// CHECK-NEXT:    SIL verification failed: deallocating allocation that is not the top of the stack
+sil @parallel_branches_into_dead_dealloc_4 : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  br bb3
+
+bb2:
+  dealloc_stack %0
+  br bb4
+
+bb3:
+  br bb4
+
+bb4:
+  dealloc_stack %0
+  br bb3
+}
+
+//   And again, add an unreachable block.
+// CHECK-LABEL:   Begin Error in function parallel_branches_into_dead_dealloc_with_unreachable_block
+// CHECK-NEXT:    SIL verification failed: deallocating allocation that is not the top of the stack
+sil @parallel_branches_into_dead_dealloc_with_unreachable_block : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_stack $Builtin.Int32
+  cond_br undef, bb1, bb2
+
+bb1:
+  br bb3
+
+bb2:
+  dealloc_stack %0
+  br bb4
+
+bb3:
+  dealloc_stack %0
+  br bb4
+
+bb4:
+  br bb3
+
+bb5: // unreachable
+  br bb3
+}

test/SIL/verifier_loweredsil_failures.sil

@@ -19,7 +19,10 @@ sil @alloc_pack_metadata_before_tuple : $@convention(thin) () -> () {
 }
 
 // CHECK-LABEL: Begin Error in function dealloc_pack_metadata_with_bad_operand
-// CHECK:       SIL verification failed: stack dealloc does not match most recent stack alloc:
+// CHECK:       SIL verification failed: deallocating allocation that is not the top of the stack
+// CHECK-LABEL: End Error in function dealloc_pack_metadata_with_bad_operand
+// CHECK-LABEL: Begin Error in function dealloc_pack_metadata_with_bad_operand
+// CHECK:       SIL verification failed: return with stack allocs that haven't been deallocated
 // CHECK-LABEL: End Error in function dealloc_pack_metadata_with_bad_operand
 // CHECK-LABEL: Begin Error in function dealloc_pack_metadata_with_bad_operand
 // CHECK:       SIL verification failed: Must have alloc_pack_metadata operand