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[InstCombine] Fix crash when alloc functions are missing alloc-family #138310

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Merged
merged 1 commit into from
May 3, 2025
Merged

[InstCombine] Fix crash when alloc functions are missing alloc-family #138310

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6 changes: 2 additions & 4 deletions llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3300,16 +3300,14 @@ static bool isAllocSiteRemovable(Instruction *AI,
continue;
}

if (getFreedOperand(cast<CallBase>(I), &TLI) == PI &&
if (Family && getFreedOperand(cast<CallBase>(I), &TLI) == PI &&
getAllocationFamily(I, &TLI) == Family) {
assert(Family);
Users.emplace_back(I);
continue;
}

if (getReallocatedOperand(cast<CallBase>(I)) == PI &&
if (Family && getReallocatedOperand(cast<CallBase>(I)) == PI &&
getAllocationFamily(I, &TLI) == Family) {
assert(Family);
Users.emplace_back(I);
Worklist.push_back(I);
continue;
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20 changes: 19 additions & 1 deletion llvm/test/Transforms/InstCombine/malloc-free-mismatched.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,7 @@

define dso_local i32 @_Z6answeri(i32 %0) {
; CHECK-LABEL: @_Z6answeri(
; CHECK-NEXT: [[TMP2:%.*]] = call noalias nonnull dereferenceable(80) ptr @_Znam(i64 80) #[[ATTR2:[0-9]+]]
; CHECK-NEXT: [[TMP2:%.*]] = call noalias nonnull dereferenceable(80) ptr @_Znam(i64 80) #[[ATTR4:[0-9]+]]
; CHECK-NEXT: call void @free(ptr [[TMP2]])
; CHECK-NEXT: ret i32 42
;
Expand All @@ -25,11 +25,29 @@ define void @test_alloca() {
ret void
}

; Test that missing `alloc-family` attributes don't crash LLVM
; https://github.com/llvm/llvm-project/issues/63749

define void @no_family() {
; CHECK-LABEL: @no_family(
; CHECK-NEXT: [[ALLOC:%.*]] = call ptr @customalloc(i64 64)
; CHECK-NEXT: call void @customfree(ptr [[ALLOC]])
; CHECK-NEXT: ret void
;
%alloc = call ptr @customalloc(i64 64)
call void @customfree(ptr %alloc)
ret void
}


; Function Attrs: nobuiltin allocsize(0)
declare dso_local nonnull ptr @_Znam(i64) #1

; Function Attrs: nounwind
declare dso_local void @free(ptr) allockind("free") "alloc-family"="malloc"

declare ptr @customalloc(i64) allockind("alloc")
declare void @customfree(ptr allocptr) allockind("free")

attributes #0 = { builtin allocsize(0) }
attributes #1 = { nobuiltin allocsize(0) allockind("alloc,uninitialized") "alloc-family"="_Znam" }