[llvm] [IR] Add the sanitize_concurrency function attribute (PR #225779)
Joseph Huber via llvm-commits
llvm-commits at lists.llvm.org
Wed Sep 23 07:01:36 PDT 2026
https://github.com/jhuber6 created https://github.com/llvm/llvm-project/pull/225779
This introduces a new concurrency sanitizer attribute to be used with
the runtime of the same name. This has no major change and simply
updates the IR to handle it properly. This attribute is invalid when
combined with the thread sanitizer one as they are mutually exclusive.
---
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>From 2aadefb4879fb4f0942d9b4c34dd9aa8ce011c3b Mon Sep 17 00:00:00 2001
From: Joseph Huber <huberjn at outlook.com>
Date: Mon, 20 Jul 2026 16:16:19 -0500
Subject: [PATCH] [IR] Add the sanitize_concurrency function attribute
This introduces a new concurrency sanitizer attribute to be used with
the runtime of the same name. This has no major change and simply
updates the IR to handle it properly. This attribute is invalid when
combined with the thread sanitizer one as they are mutually exclusive.
---
llvm/docs/LangRef.md | 4 ++++
llvm/include/llvm/Bitcode/LLVMBitCodes.h | 1 +
llvm/include/llvm/IR/Attributes.td | 5 +++++
llvm/lib/Analysis/Loads.cpp | 1 +
llvm/lib/Bitcode/Reader/BitcodeReader.cpp | 2 ++
llvm/lib/Bitcode/Writer/BitcodeWriter.cpp | 2 ++
llvm/lib/CodeGen/ShrinkWrap.cpp | 1 +
llvm/lib/IR/Verifier.cpp | 6 ++++++
llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp | 1 +
llvm/lib/Transforms/IPO/HotColdSplitting.cpp | 1 +
llvm/lib/Transforms/Scalar/ExpandMemCmp.cpp | 1 +
llvm/lib/Transforms/Utils/CodeExtractor.cpp | 1 +
llvm/test/Bitcode/attributes.ll | 6 ++++++
llvm/test/Bitcode/compatibility.ll | 8 ++++++--
llvm/test/Verifier/sanitize-concurrency-attrs.ll | 9 +++++++++
15 files changed, 47 insertions(+), 2 deletions(-)
create mode 100644 llvm/test/Verifier/sanitize-concurrency-attrs.ll
diff --git a/llvm/docs/LangRef.md b/llvm/docs/LangRef.md
index a4816d337e02b3..dac4650466be15 100644
--- a/llvm/docs/LangRef.md
+++ b/llvm/docs/LangRef.md
@@ -2714,6 +2714,10 @@ fn -> other_fn -> other_fn ; fn is norecurse
: This attribute indicates that ThreadSanitizer checks
(dynamic thread safety analysis) are enabled for this function.
+`sanitize_concurrency`
+: This attribute indicates that ConcurrencySanitizer checks
+ (probabilistic data race detection) are enabled for this function.
+
`sanitize_hwaddress`
: This attribute indicates that HWAddressSanitizer checks
(dynamic address safety analysis based on tagged pointers) are enabled for
diff --git a/llvm/include/llvm/Bitcode/LLVMBitCodes.h b/llvm/include/llvm/Bitcode/LLVMBitCodes.h
index 4099b57f5482e2..0e024945440e9c 100644
--- a/llvm/include/llvm/Bitcode/LLVMBitCodes.h
+++ b/llvm/include/llvm/Bitcode/LLVMBitCodes.h
@@ -831,6 +831,7 @@ enum AttributeKindCodes {
ATTR_KIND_FLATTEN = 108,
ATTR_KIND_NOIPA = 109,
ATTR_KIND_NOFREEOBJ = 110,
+ ATTR_KIND_SANITIZE_CONCURRENCY = 111,
};
enum ComdatSelectionKindCodes {
diff --git a/llvm/include/llvm/IR/Attributes.td b/llvm/include/llvm/IR/Attributes.td
index c43b499061ddc7..449b24db9458e4 100644
--- a/llvm/include/llvm/IR/Attributes.td
+++ b/llvm/include/llvm/IR/Attributes.td
@@ -342,6 +342,10 @@ def SanitizeAddress : EnumAttr<"sanitize_address", IntersectPreserve, [FnAttr]>;
/// ThreadSanitizer is on.
def SanitizeThread : EnumAttr<"sanitize_thread", IntersectPreserve, [FnAttr]>;
+/// ConcurrencySanitizer is on.
+def SanitizeConcurrency
+ : EnumAttr<"sanitize_concurrency", IntersectPreserve, [FnAttr]>;
+
/// TypeSanitizer is on.
def SanitizeType : EnumAttr<"sanitize_type", IntersectPreserve, [FnAttr]>;
@@ -465,6 +469,7 @@ class CompatRuleStrAttr<string F, string Attr> : CompatRule<F> {
def : CompatRule<"isEqual<SanitizeAddressAttr>">;
def : CompatRule<"isEqual<SanitizeThreadAttr>">;
+def : CompatRule<"isEqual<SanitizeConcurrencyAttr>">;
def : CompatRule<"isEqual<SanitizeTypeAttr>">;
def : CompatRule<"isEqual<SanitizeMemoryAttr>">;
def : CompatRule<"isEqual<SanitizeHWAddressAttr>">;
diff --git a/llvm/lib/Analysis/Loads.cpp b/llvm/lib/Analysis/Loads.cpp
index 2e8c884e13729c..4016fe70493767 100644
--- a/llvm/lib/Analysis/Loads.cpp
+++ b/llvm/lib/Analysis/Loads.cpp
@@ -444,6 +444,7 @@ static bool suppressSpeculativeLoadForSanitizers(const Instruction &CtxI) {
const Function &F = *CtxI.getFunction();
// Speculative load may create a race that did not exist in the source.
return F.hasFnAttribute(Attribute::SanitizeThread) ||
+ F.hasFnAttribute(Attribute::SanitizeConcurrency) ||
// Speculative load may load data from dirty regions.
F.hasFnAttribute(Attribute::SanitizeAddress) ||
F.hasFnAttribute(Attribute::SanitizeHWAddress);
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index d75e85b0b0f9e1..a0cd1bf84e3c44 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -2266,6 +2266,8 @@ static Attribute::AttrKind getAttrFromCode(uint64_t Code) {
return Attribute::SanitizeHWAddress;
case bitc::ATTR_KIND_SANITIZE_THREAD:
return Attribute::SanitizeThread;
+ case bitc::ATTR_KIND_SANITIZE_CONCURRENCY:
+ return Attribute::SanitizeConcurrency;
case bitc::ATTR_KIND_SANITIZE_TYPE:
return Attribute::SanitizeType;
case bitc::ATTR_KIND_SANITIZE_MEMORY:
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index c99a1edd31fb45..9dc93dc885e8da 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -950,6 +950,8 @@ static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
return bitc::ATTR_KIND_SANITIZE_HWADDRESS;
case Attribute::SanitizeThread:
return bitc::ATTR_KIND_SANITIZE_THREAD;
+ case Attribute::SanitizeConcurrency:
+ return bitc::ATTR_KIND_SANITIZE_CONCURRENCY;
case Attribute::SanitizeType:
return bitc::ATTR_KIND_SANITIZE_TYPE;
case Attribute::SanitizeMemory:
diff --git a/llvm/lib/CodeGen/ShrinkWrap.cpp b/llvm/lib/CodeGen/ShrinkWrap.cpp
index 32cae27489c39a..8328ce7175b78a 100644
--- a/llvm/lib/CodeGen/ShrinkWrap.cpp
+++ b/llvm/lib/CodeGen/ShrinkWrap.cpp
@@ -1051,6 +1051,7 @@ bool ShrinkWrapImpl::isShrinkWrapEnabled(const MachineFunction &MF) {
// sanitizers to be able to get a correct stack frame.
!(MF.getFunction().hasFnAttribute(Attribute::SanitizeAddress) ||
MF.getFunction().hasFnAttribute(Attribute::SanitizeThread) ||
+ MF.getFunction().hasFnAttribute(Attribute::SanitizeConcurrency) ||
MF.getFunction().hasFnAttribute(Attribute::SanitizeMemory) ||
MF.getFunction().hasFnAttribute(Attribute::SanitizeType) ||
MF.getFunction().hasFnAttribute(Attribute::SanitizeHWAddress));
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 1440b95896474f..b4a0a395b1ba8d 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -2555,6 +2555,12 @@ void Verifier::verifyFunctionAttrs(FunctionType *FT, AttributeList Attrs,
"'sanitize_realtime and sanitize_realtime_blocking' are incompatible!",
V);
+ Check(!(Attrs.hasFnAttr(Attribute::SanitizeThread) &&
+ Attrs.hasFnAttr(Attribute::SanitizeConcurrency)),
+ "Attributes 'sanitize_thread and sanitize_concurrency' are "
+ "incompatible!",
+ V);
+
if (Attrs.hasFnAttr(Attribute::OptimizeForDebugging)) {
Check(!Attrs.hasFnAttr(Attribute::OptimizeForSize),
"Attributes 'optsize and optdebug' are incompatible!", V);
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp b/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp
index 2ed1be7c2ade05..a535081b5a74ad 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp
@@ -141,6 +141,7 @@ static bool isDSAddress(const Constant *C) {
static bool hasSanitizerAttributes(const Function &F) {
return F.hasFnAttribute(Attribute::SanitizeAddress) ||
F.hasFnAttribute(Attribute::SanitizeThread) ||
+ F.hasFnAttribute(Attribute::SanitizeConcurrency) ||
F.hasFnAttribute(Attribute::SanitizeMemory) ||
F.hasFnAttribute(Attribute::SanitizeHWAddress) ||
F.hasFnAttribute(Attribute::SanitizeMemTag);
diff --git a/llvm/lib/Transforms/IPO/HotColdSplitting.cpp b/llvm/lib/Transforms/IPO/HotColdSplitting.cpp
index 97183c76a079ba..d76b0bf78ae0da 100644
--- a/llvm/lib/Transforms/IPO/HotColdSplitting.cpp
+++ b/llvm/lib/Transforms/IPO/HotColdSplitting.cpp
@@ -269,6 +269,7 @@ bool HotColdSplitting::shouldOutlineFrom(const Function &F) const {
if (F.hasFnAttribute(Attribute::SanitizeAddress) ||
F.hasFnAttribute(Attribute::SanitizeHWAddress) ||
F.hasFnAttribute(Attribute::SanitizeThread) ||
+ F.hasFnAttribute(Attribute::SanitizeConcurrency) ||
F.hasFnAttribute(Attribute::SanitizeMemory))
return false;
diff --git a/llvm/lib/Transforms/Scalar/ExpandMemCmp.cpp b/llvm/lib/Transforms/Scalar/ExpandMemCmp.cpp
index e05a5d2e9e5855..637ba0600fb740 100644
--- a/llvm/lib/Transforms/Scalar/ExpandMemCmp.cpp
+++ b/llvm/lib/Transforms/Scalar/ExpandMemCmp.cpp
@@ -1102,6 +1102,7 @@ PreservedAnalyses ExpandMemCmpPass::run(Function &F,
if (F.hasFnAttribute(Attribute::SanitizeAddress) ||
F.hasFnAttribute(Attribute::SanitizeMemory) ||
F.hasFnAttribute(Attribute::SanitizeThread) ||
+ F.hasFnAttribute(Attribute::SanitizeConcurrency) ||
F.hasFnAttribute(Attribute::SanitizeHWAddress))
return PreservedAnalyses::all();
diff --git a/llvm/lib/Transforms/Utils/CodeExtractor.cpp b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
index 6a53688fb70272..123ec196fb381b 100644
--- a/llvm/lib/Transforms/Utils/CodeExtractor.cpp
+++ b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
@@ -1008,6 +1008,7 @@ Function *CodeExtractor::constructFunctionDeclaration(
case Attribute::SanitizeMemory:
case Attribute::SanitizeNumericalStability:
case Attribute::SanitizeThread:
+ case Attribute::SanitizeConcurrency:
case Attribute::SanitizeType:
case Attribute::SanitizeHWAddress:
case Attribute::SanitizeMemTag:
diff --git a/llvm/test/Bitcode/attributes.ll b/llvm/test/Bitcode/attributes.ll
index ae5e806a592107..9cf0bda60f2050 100644
--- a/llvm/test/Bitcode/attributes.ll
+++ b/llvm/test/Bitcode/attributes.ll
@@ -607,6 +607,11 @@ define nofreeobj ptr @nofreeobj(ptr nofreeobj %p) {
ret ptr %p
}
+; CHECK: define void @f_sanitize_concurrency() [[SANITIZE_CONCURRENCY:#[0-9]+]]
+define void @f_sanitize_concurrency() sanitize_concurrency {
+ ret void
+}
+
; CHECK: attributes #0 = { noreturn }
; CHECK: attributes #1 = { nounwind }
; CHECK: attributes #2 = { memory(none) }
@@ -671,4 +676,5 @@ define nofreeobj ptr @nofreeobj(ptr nofreeobj %p) {
; CHECK: attributes [[OPTDEBUG]] = { optdebug }
; CHECK: attributes [[NODIVERGENCESOURCE]] = { nodivergencesource }
; CHECK: attributes [[NOIPA]] = { noipa }
+; CHECK: attributes [[SANITIZE_CONCURRENCY]] = { sanitize_concurrency }
; CHECK: attributes #[[NOBUILTIN]] = { nobuiltin }
diff --git a/llvm/test/Bitcode/compatibility.ll b/llvm/test/Bitcode/compatibility.ll
index d8784b4d8a2f21..3a5a9be9afca5e 100644
--- a/llvm/test/Bitcode/compatibility.ll
+++ b/llvm/test/Bitcode/compatibility.ll
@@ -1827,7 +1827,7 @@ exit:
; CHECK: select <2 x i1> <i1 true, i1 false>, <2 x i8> <i8 2, i8 3>, <2 x i8> <i8 3, i8 2>
call void @f.nobuiltin() builtin
- ; CHECK: call void @f.nobuiltin() #87
+ ; CHECK: call void @f.nobuiltin() #88
call fastcc noalias ptr @f.noalias() noinline
; CHECK: call fastcc noalias ptr @f.noalias() #12
@@ -2536,6 +2536,9 @@ define void @denormal_fpenv__preservesign_preservesign_float_dynamic_dynamic() d
ret void
}
+declare void @f.sanitize_concurrency() sanitize_concurrency
+; CHECK: declare void @f.sanitize_concurrency() #87
+
; CHECK: attributes #0 = { alignstack=4 }
; CHECK: attributes #1 = { alignstack=8 }
; CHECK: attributes #2 = { alwaysinline }
@@ -2623,7 +2626,8 @@ define void @denormal_fpenv__preservesign_preservesign_float_dynamic_dynamic() d
; CHECK: attributes #84 = { denormal_fpenv(float: dynamic|positivezero) }
; CHECK: attributes #85 = { denormal_fpenv(float: dynamic) }
; CHECK: attributes #86 = { denormal_fpenv(preservesign, float: dynamic) }
-; CHECK: attributes #87 = { builtin }
+; CHECK: attributes #87 = { sanitize_concurrency }
+; CHECK: attributes #88 = { builtin }
;; Metadata
diff --git a/llvm/test/Verifier/sanitize-concurrency-attrs.ll b/llvm/test/Verifier/sanitize-concurrency-attrs.ll
new file mode 100644
index 00000000000000..70fda2f06f5232
--- /dev/null
+++ b/llvm/test/Verifier/sanitize-concurrency-attrs.ll
@@ -0,0 +1,9 @@
+; RUN: not llvm-as -disable-output %s 2>&1 | FileCheck %s
+
+; CHECK: Attributes 'sanitize_thread and sanitize_concurrency' are incompatible!
+; CHECK-NEXT: ptr @sanitize_unsafe
+define void @sanitize_unsafe() #0 {
+ ret void
+}
+
+attributes #0 = { sanitize_thread sanitize_concurrency }
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