[llvm] [GlobalOpt] Bail out for ConstantPtrAuth in isSimpleEnoughtToCommit. (PR #143400)
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Wed Jun 11 12:38:27 PDT 2025
https://github.com/fhahn updated https://github.com/llvm/llvm-project/pull/143400
>From a6cef539be94e7c76735c50adf0f3d179fb01c3b Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Mon, 9 Jun 2025 16:29:19 +0100
Subject: [PATCH 1/3] [GlobalOpt] Bail out for ConstantPtrAuth in
isSimpleEnoughtToCommit.
Bail out for ConstantPtrAuth constants in isSimpleEnoughValueToCommitHelper
to prevent crash in cast<ConstantExpr> below.
---
llvm/lib/Transforms/Utils/Evaluator.cpp | 3 +++
.../global-constructor-ptrauth-constant.ll | 27 +++++++++++++++++++
2 files changed, 30 insertions(+)
create mode 100644 llvm/test/Transforms/GlobalOpt/global-constructor-ptrauth-constant.ll
diff --git a/llvm/lib/Transforms/Utils/Evaluator.cpp b/llvm/lib/Transforms/Utils/Evaluator.cpp
index 2af447aadce22..ecdcdf55d5089 100644
--- a/llvm/lib/Transforms/Utils/Evaluator.cpp
+++ b/llvm/lib/Transforms/Utils/Evaluator.cpp
@@ -74,6 +74,9 @@ isSimpleEnoughValueToCommitHelper(Constant *C,
return true;
}
+ if (isa<ConstantPtrAuth>(C))
+ return false;
+
// We don't know exactly what relocations are allowed in constant expressions,
// so we allow &global+constantoffset, which is safe and uniformly supported
// across targets.
diff --git a/llvm/test/Transforms/GlobalOpt/global-constructor-ptrauth-constant.ll b/llvm/test/Transforms/GlobalOpt/global-constructor-ptrauth-constant.ll
new file mode 100644
index 0000000000000..ef64b3eb1147c
--- /dev/null
+++ b/llvm/test/Transforms/GlobalOpt/global-constructor-ptrauth-constant.ll
@@ -0,0 +1,27 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals all --version 5
+; RUN: opt -p globalopt -S %s | FileCheck %s
+
+ at llvm.global_ctors = appending global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @ctor, ptr null }]
+
+ at foo = internal global ptr null
+
+declare void @user(ptr)
+
+;.
+; CHECK: @llvm.global_ctors = appending global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @ctor, ptr null }]
+; CHECK: @foo = internal global ptr null
+;.
+define void @ctor() {
+; CHECK-LABEL: define void @ctor() {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: [[DST:%.*]] = alloca ptr, align 8
+; CHECK-NEXT: store ptr ptrauth (ptr @foo, i32 0), ptr [[DST]], align 8
+; CHECK-NEXT: call void @user(ptr [[DST]])
+; CHECK-NEXT: ret void
+;
+entry:
+ %dst = alloca ptr, align 8
+ store ptr ptrauth (ptr @foo, i32 0), ptr %dst, align 8
+ call void @user(ptr %dst)
+ ret void
+}
>From 8a97ffe148eddcbcabfe698b101628d44484c91c Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Tue, 10 Jun 2025 09:11:02 +0100
Subject: [PATCH 2/3] !fixup use dyn_cast
---
llvm/lib/Transforms/Utils/Evaluator.cpp | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/llvm/lib/Transforms/Utils/Evaluator.cpp b/llvm/lib/Transforms/Utils/Evaluator.cpp
index ecdcdf55d5089..d1db2ee29f3a2 100644
--- a/llvm/lib/Transforms/Utils/Evaluator.cpp
+++ b/llvm/lib/Transforms/Utils/Evaluator.cpp
@@ -74,13 +74,12 @@ isSimpleEnoughValueToCommitHelper(Constant *C,
return true;
}
- if (isa<ConstantPtrAuth>(C))
- return false;
-
// We don't know exactly what relocations are allowed in constant expressions,
// so we allow &global+constantoffset, which is safe and uniformly supported
// across targets.
- ConstantExpr *CE = cast<ConstantExpr>(C);
+ ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
+ if (!CE)
+ return false;
switch (CE->getOpcode()) {
case Instruction::BitCast:
// Bitcast is fine if the casted value is fine.
>From 956c7c042497160e4676d03c161e4e286728208d Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Wed, 11 Jun 2025 20:35:40 +0100
Subject: [PATCH 3/3] !fixup add tests with nocfi, dso_local_equivalent
constsnts.
---
.../global-constructor-complex-constants.ll | 61 +++++++++++++++++++
.../global-constructor-ptrauth-constant.ll | 27 --------
2 files changed, 61 insertions(+), 27 deletions(-)
create mode 100644 llvm/test/Transforms/GlobalOpt/global-constructor-complex-constants.ll
delete mode 100644 llvm/test/Transforms/GlobalOpt/global-constructor-ptrauth-constant.ll
diff --git a/llvm/test/Transforms/GlobalOpt/global-constructor-complex-constants.ll b/llvm/test/Transforms/GlobalOpt/global-constructor-complex-constants.ll
new file mode 100644
index 0000000000000..6d38540874f69
--- /dev/null
+++ b/llvm/test/Transforms/GlobalOpt/global-constructor-complex-constants.ll
@@ -0,0 +1,61 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals all --version 5
+; RUN: opt -p globalopt -S %s | FileCheck %s
+
+ at llvm.global_ctors = appending global [3 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @ctor, ptr null }, { i32, ptr, ptr } { i32 65535, ptr @ctor_nocfi, ptr null }, { i32, ptr, ptr } { i32 65535, ptr @ctor_dso_local_equivalent, ptr null }]
+
+ at foo = internal global ptr null
+
+declare void @user(ptr)
+
+;.
+; CHECK: @llvm.global_ctors = appending global [2 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @ctor, ptr null }, { i32, ptr, ptr } { i32 65535, ptr @ctor_nocfi, ptr null }]
+; CHECK: @foo = internal global ptr null
+;.
+define void @ctor() {
+; CHECK-LABEL: define void @ctor() {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: [[DST:%.*]] = alloca ptr, align 8
+; CHECK-NEXT: store ptr ptrauth (ptr @foo, i32 0), ptr [[DST]], align 8
+; CHECK-NEXT: call void @user(ptr [[DST]])
+; CHECK-NEXT: ret void
+;
+entry:
+ %dst = alloca ptr, align 8
+ store ptr ptrauth (ptr @foo, i32 0), ptr %dst, align 8
+ call void @user(ptr %dst)
+ ret void
+}
+
+define void @ctor_nocfi() {
+; CHECK-LABEL: define void @ctor() {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: [[DST:%.*]] = alloca ptr, align 8
+; CHECK-NEXT: store ptr ptrauth (ptr @foo, i32 0), ptr [[DST]], align 8
+; CHECK-NEXT: call void @user(ptr [[DST]])
+; CHECK-NEXT: ret void
+;
+entry:
+ %dst = alloca ptr, align 8
+ store ptr no_cfi @foo, ptr %dst, align 8
+ call void @user(ptr %dst)
+ ret void
+}
+
+define void @fn() {
+ ret void
+}
+
+define void @ctor_dso_local_equivalent() {
+; CHECK-LABEL: define void @ctor() {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: [[DST:%.*]] = alloca ptr, align 8
+; CHECK-NEXT: store ptr ptrauth (ptr @foo, i32 0), ptr [[DST]], align 8
+; CHECK-NEXT: call void @user(ptr [[DST]])
+; CHECK-NEXT: ret void
+;
+entry:
+ %dst = alloca ptr, align 8
+ store ptr dso_local_equivalent @fn, ptr %dst, align 8
+ call void @user(ptr %dst)
+ ret void
+}
diff --git a/llvm/test/Transforms/GlobalOpt/global-constructor-ptrauth-constant.ll b/llvm/test/Transforms/GlobalOpt/global-constructor-ptrauth-constant.ll
deleted file mode 100644
index ef64b3eb1147c..0000000000000
--- a/llvm/test/Transforms/GlobalOpt/global-constructor-ptrauth-constant.ll
+++ /dev/null
@@ -1,27 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals all --version 5
-; RUN: opt -p globalopt -S %s | FileCheck %s
-
- at llvm.global_ctors = appending global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @ctor, ptr null }]
-
- at foo = internal global ptr null
-
-declare void @user(ptr)
-
-;.
-; CHECK: @llvm.global_ctors = appending global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @ctor, ptr null }]
-; CHECK: @foo = internal global ptr null
-;.
-define void @ctor() {
-; CHECK-LABEL: define void @ctor() {
-; CHECK-NEXT: [[ENTRY:.*:]]
-; CHECK-NEXT: [[DST:%.*]] = alloca ptr, align 8
-; CHECK-NEXT: store ptr ptrauth (ptr @foo, i32 0), ptr [[DST]], align 8
-; CHECK-NEXT: call void @user(ptr [[DST]])
-; CHECK-NEXT: ret void
-;
-entry:
- %dst = alloca ptr, align 8
- store ptr ptrauth (ptr @foo, i32 0), ptr %dst, align 8
- call void @user(ptr %dst)
- ret void
-}
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