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[5.1] SILOptimizer: fix a stupid bug in StackNesting which can cause a miscompile in functions with unreachable blocks. #22963

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Merged
merged 1 commit into from
Mar 1, 2019
Merged

[5.1] SILOptimizer: fix a stupid bug in StackNesting which can cause a miscompile in functions with unreachable blocks. #22963

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2 changes: 1 addition & 1 deletion lib/SILOptimizer/Utils/StackNesting.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -97,7 +97,7 @@ bool StackNesting::solve() {
bool initVal = false;
for (BlockInfo &BI : BlockInfos) {
BI.AliveStackLocsAtEntry.resize(StackLocs.size(), initVal);
initVal = false;
initVal = true;
}

// First step: do a forward dataflow analysis to get the live stack locations
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54 changes: 39 additions & 15 deletions test/SILOptimizer/allocbox_to_stack.sil
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Expand Up @@ -819,8 +819,6 @@ bb0(%0 : $Int):
// CHECK-NEXT: [[STACK1:%[0-9]+]] = alloc_stack $Bool
// CHECK-NEXT: [[BOX:%[0-9]+]] = alloc_stack $Int
// CHECK: bb1:
// CHECK-NEXT: dealloc_stack [[BOX]]
// CHECK-NEXT: dealloc_stack [[STACK1]]
// CHECK-NEXT: [[STACK2:%[0-9]+]] = alloc_stack $Bool
// CHECK-NEXT: dealloc_stack [[STACK2]]
// CHECK-NEXT: unreachable
Expand Down Expand Up @@ -859,7 +857,6 @@ bb2:
// CHECK-NEXT: [[STACK2:%[0-9]+]] = alloc_stack $Bool
// CHECK-NEXT: dealloc_stack [[STACK2]]
// CHECK-NEXT: dealloc_stack [[BOX]]
// CHECK-NEXT: dealloc_stack [[STACK1]]
// CHECK-NEXT: unreachable
// CHECK: bb2:
// CHECK: store
Expand Down Expand Up @@ -894,8 +891,6 @@ bb2:
// CHECK-NEXT: [[BOX:%[0-9]+]] = alloc_stack $Int
// CHECK-NEXT: [[STACK:%[0-9]+]] = alloc_stack $Bool
// CHECK: bb1:
// CHECK-NEXT: dealloc_stack [[STACK]]
// CHECK-NEXT: dealloc_stack [[BOX]]
// CHECK-NEXT: unreachable
// CHECK: bb2:
// CHECK: store
Expand Down Expand Up @@ -954,7 +949,6 @@ bb2:
// CHECK: bb0(%0 : $Int):
// CHECK-NEXT: [[BOX:%[0-9]+]] = alloc_stack $Int
// CHECK: bb1:
// CHECK-NEXT: dealloc_stack [[BOX]]
// CHECK-NEXT: {{.*}} = alloc_stack $Bool
// CHECK-NEXT: {{.*}} = alloc_stack $Bool
// CHECK-NEXT: unreachable
Expand Down Expand Up @@ -1014,30 +1008,60 @@ bb3:
return %3 : $Int
}

// CHECK-LABEL: sil @nesting_and_unreachable7
// CHECK: bb0(%0 : $Bool):
// CHECK-NEXT: [[AB:%[0-9]+]] = alloc_stack $Bool
// CHECK-NEXT: [[AI:%[0-9]+]] = alloc_stack $Int
// CHECK-NEXT: cond_br
// CHECK: bb1:
// CHECK-NEXT: dealloc_stack [[AI]]
// CHECK-NEXT: br bb3
// CHECK: bb2:
// CHECK-NEXT: dealloc_stack [[AI]]
// CHECK-NEXT: br bb3
// CHECK: bb3:
// CHECK-NEXT: store
// CHECK-NEXT: load
// CHECK-NEXT: unreachable
sil @nesting_and_unreachable7 : $@convention(thin) (Bool) -> Bool {
bb0(%0 : $Bool):
%as1 = alloc_stack $Bool
%1 = alloc_box ${ var Int }
%1a = project_box %1 : ${ var Int }, 0
cond_br undef, bb1, bb2

bb1:
strong_release %1 : ${ var Int }
br bb3

bb2:
strong_release %1 : ${ var Int }
br bb3

bb3:
store %0 to %as1 : $*Bool
%3 = load %as1 : $*Bool
unreachable
}
// CHECK-LABEL: sil @nesting_and_unreachable_critical_edge
// CHECK: bb0(%0 : $Int):
// CHECK-NEXT: [[BOX:%[0-9]+]] = alloc_stack $Int
// CHECK-NEXT: [[STACK1:%[0-9]+]] = alloc_stack $Bool
// CHECK-NEXT: cond_br
// CHECK: bb1:
// CHECK-NEXT: dealloc_stack [[STACK1]]
// CHECK-NEXT: br bb5
// CHECK: bb2:
// CHECK-NEXT: [[STACK2:%[0-9]+]] = alloc_stack $Bool
// CHECK-NEXT: cond_br
// CHECK: bb3:
// CHECK: bb2:
// CHECK-NEXT: dealloc_stack [[STACK2]]
// CHECK-NEXT: dealloc_stack [[STACK1]]
// CHECK-NEXT: br bb5
// CHECK: bb4:
// CHECK-NEXT: br bb4
// CHECK: bb3:
// CHECK: store
// CHECK: dealloc_stack [[STACK2]]
// CHECK-NEXT: dealloc_stack [[STACK1]]
// CHECK-NEXT: dealloc_stack [[BOX]]
// CHECK-NEXT: tuple
// CHECK-NEXT: return
// CHECK: bb5:
// CHECK-NEXT: dealloc_stack [[BOX]]
// CHECK: bb4:
// CHECK-NEXT: unreachable
sil @nesting_and_unreachable_critical_edge : $(Int) -> () {
bb0(%0 : $Int):
Expand Down
19 changes: 4 additions & 15 deletions test/SILOptimizer/allocbox_to_stack_ownership.sil
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Expand Up @@ -814,8 +814,6 @@ bb0(%0 : $Int):
// CHECK-NEXT: [[STACK1:%[0-9]+]] = alloc_stack $Bool
// CHECK-NEXT: [[BOX:%[0-9]+]] = alloc_stack $Int
// CHECK: bb1:
// CHECK-NEXT: dealloc_stack [[BOX]]
// CHECK-NEXT: dealloc_stack [[STACK1]]
// CHECK-NEXT: [[STACK2:%[0-9]+]] = alloc_stack $Bool
// CHECK-NEXT: dealloc_stack [[STACK2]]
// CHECK-NEXT: unreachable
Expand Down Expand Up @@ -854,7 +852,6 @@ bb2:
// CHECK-NEXT: [[STACK2:%[0-9]+]] = alloc_stack $Bool
// CHECK-NEXT: dealloc_stack [[STACK2]]
// CHECK-NEXT: dealloc_stack [[BOX]]
// CHECK-NEXT: dealloc_stack [[STACK1]]
// CHECK-NEXT: unreachable
// CHECK: bb2:
// CHECK: store
Expand Down Expand Up @@ -889,8 +886,6 @@ bb2:
// CHECK-NEXT: [[BOX:%[0-9]+]] = alloc_stack $Int
// CHECK-NEXT: [[STACK:%[0-9]+]] = alloc_stack $Bool
// CHECK: bb1:
// CHECK-NEXT: dealloc_stack [[STACK]]
// CHECK-NEXT: dealloc_stack [[BOX]]
// CHECK-NEXT: unreachable
// CHECK: bb2:
// CHECK: store
Expand Down Expand Up @@ -949,7 +944,6 @@ bb2:
// CHECK: bb0(%0 : $Int):
// CHECK-NEXT: [[BOX:%[0-9]+]] = alloc_stack $Int
// CHECK: bb1:
// CHECK-NEXT: dealloc_stack [[BOX]]
// CHECK-NEXT: {{.*}} = alloc_stack $Bool
// CHECK-NEXT: {{.*}} = alloc_stack $Bool
// CHECK-NEXT: unreachable
Expand Down Expand Up @@ -983,24 +977,19 @@ bb2:
// CHECK-NEXT: [[STACK1:%[0-9]+]] = alloc_stack $Bool
// CHECK-NEXT: cond_br
// CHECK: bb1:
// CHECK-NEXT: dealloc_stack [[STACK1]]
// CHECK-NEXT: br bb5
// CHECK: bb2:
// CHECK-NEXT: [[STACK2:%[0-9]+]] = alloc_stack $Bool
// CHECK-NEXT: cond_br
// CHECK: bb3:
// CHECK: bb2:
// CHECK-NEXT: dealloc_stack [[STACK2]]
// CHECK-NEXT: dealloc_stack [[STACK1]]
// CHECK-NEXT: br bb5
// CHECK: bb4:
// CHECK-NEXT: br bb4
// CHECK: bb3:
// CHECK: store
// CHECK: dealloc_stack [[STACK2]]
// CHECK-NEXT: dealloc_stack [[STACK1]]
// CHECK-NEXT: dealloc_stack [[BOX]]
// CHECK-NEXT: tuple
// CHECK-NEXT: return
// CHECK: bb5:
// CHECK-NEXT: dealloc_stack [[BOX]]
// CHECK: bb4:
// CHECK-NEXT: unreachable
sil [ossa] @nesting_and_unreachable_critical_edge : $@convention(thin) (Int) -> () {
bb0(%0 : $Int):
Expand Down
2 changes: 0 additions & 2 deletions test/SILOptimizer/inline_begin_apply.sil
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Expand Up @@ -494,8 +494,6 @@ bb0:
// CHECK: dealloc_stack [[A32]] : $*Builtin.Int32
// CHECK: unreachable
// CHECK: bb2:
// CHECK: dealloc_stack [[A32]] : $*Builtin.Int32
// CHECK: dealloc_stack [[A16]] : $*Builtin.Int16
// CHECK: unreachable
// CHECK: bb3:
// CHECK: dealloc_stack [[A32]] : $*Builtin.Int32
Expand Down
5 changes: 2 additions & 3 deletions test/SILOptimizer/stack-nesting-wrong-scope.swift
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Expand Up @@ -4,9 +4,8 @@
// RUN: -Xllvm -sil-print-debuginfo -o %t -module-name red 2>&1 | %FileCheck %s

// CHECK: bb5(%33 : @owned $Error):
// CHECK: dealloc_stack %6 : $*ThrowAddrOnlyStruct<T>, loc {{.*}}:27:68, scope 2
// CHECK: dealloc_stack %3 : $*ThrowAddrOnlyStruct<T>, loc {{.*}}:27:68, scope 2
// CHECK: br bb4(%33 : $Error), loc {{.*}}:27:15, scope 2
// CHECK: dealloc_stack %6 : $*ThrowAddrOnlyStruct<T>, loc {{.*}}:26:68, scope 2
// CHECK: br bb4(%33 : $Error), loc {{.*}}:26:15, scope 2

protocol Patatino {
init()
Expand Down