[Mlir-commits] [mlir] [mlir] Replace LLVM_ATTRIBUTE_UNUSED with [[maybe_unused]] (NFC) (PR #163703)
Kazu Hirata
llvmlistbot at llvm.org
Wed Oct 15 22:38:56 PDT 2025
https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/163703
This patch replaces LLVM_ATTRIBUTE_UNUSED with [[maybe_unused]],
introduced as part of C++17.
>From 2956dc930c5c28142eeb76304531c0ea1a28f2fc Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Tue, 14 Oct 2025 09:15:14 -0700
Subject: [PATCH] [mlir] Replace LLVM_ATTRIBUTE_UNUSED with [[maybe_unused]]
(NFC)
This patch replaces LLVM_ATTRIBUTE_UNUSED with [[maybe_unused]],
introduced as part of C++17.
---
mlir/include/mlir/Dialect/Affine/LoopUtils.h | 2 +-
mlir/lib/Analysis/FlatLinearValueConstraints.cpp | 9 +++++----
mlir/lib/Analysis/Presburger/Simplex.cpp | 2 +-
mlir/lib/Dialect/Affine/IR/AffineOps.cpp | 10 +++++-----
mlir/lib/Dialect/Affine/Utils/LoopUtils.cpp | 5 ++---
mlir/lib/Dialect/LLVMIR/IR/LLVMTypes.cpp | 6 +++---
mlir/lib/Dialect/SparseTensor/IR/Detail/Var.cpp | 4 ++--
.../SparseTensor/Transforms/Utils/LoopEmitter.cpp | 4 ++--
mlir/lib/Dialect/Transform/IR/TransformTypes.cpp | 6 +++---
mlir/lib/IR/MLIRContext.cpp | 2 +-
mlir/lib/Tools/PDLL/CodeGen/CPPGen.cpp | 2 +-
.../Transform/TestTransformDialectExtension.cpp | 6 +++---
mlir/test/mlir-pdll/CodeGen/CPP/general.pdll | 2 +-
mlir/tools/mlir-tblgen/LLVMIRConversionGen.cpp | 13 ++++++-------
mlir/tools/mlir-tblgen/RewriterGen.cpp | 2 +-
mlir/unittests/Dialect/SparseTensor/MergerTest.cpp | 3 +--
16 files changed, 38 insertions(+), 40 deletions(-)
diff --git a/mlir/include/mlir/Dialect/Affine/LoopUtils.h b/mlir/include/mlir/Dialect/Affine/LoopUtils.h
index 9b59af73977d3..830c394f0bde6 100644
--- a/mlir/include/mlir/Dialect/Affine/LoopUtils.h
+++ b/mlir/include/mlir/Dialect/Affine/LoopUtils.h
@@ -61,7 +61,7 @@ LogicalResult loopUnrollUpToFactor(AffineForOp forOp, uint64_t unrollFactor);
/// Returns true if `loops` is a perfectly nested loop nest, where loops appear
/// in it from outermost to innermost.
-bool LLVM_ATTRIBUTE_UNUSED isPerfectlyNested(ArrayRef<AffineForOp> loops);
+[[maybe_unused]] bool isPerfectlyNested(ArrayRef<AffineForOp> loops);
/// Get perfectly nested sequence of loops starting at root of loop nest
/// (the first op being another AffineFor, and the second op - a terminator).
diff --git a/mlir/lib/Analysis/FlatLinearValueConstraints.cpp b/mlir/lib/Analysis/FlatLinearValueConstraints.cpp
index 30ce1fb320017..6588b53cbd9f8 100644
--- a/mlir/lib/Analysis/FlatLinearValueConstraints.cpp
+++ b/mlir/lib/Analysis/FlatLinearValueConstraints.cpp
@@ -1244,8 +1244,9 @@ bool FlatLinearValueConstraints::areVarsAlignedWithOther(
/// Checks if the SSA values associated with `cst`'s variables in range
/// [start, end) are unique.
-static bool LLVM_ATTRIBUTE_UNUSED areVarsUnique(
- const FlatLinearValueConstraints &cst, unsigned start, unsigned end) {
+[[maybe_unused]] static bool
+areVarsUnique(const FlatLinearValueConstraints &cst, unsigned start,
+ unsigned end) {
assert(start <= cst.getNumDimAndSymbolVars() &&
"Start position out of bounds");
@@ -1267,14 +1268,14 @@ static bool LLVM_ATTRIBUTE_UNUSED areVarsUnique(
}
/// Checks if the SSA values associated with `cst`'s variables are unique.
-static bool LLVM_ATTRIBUTE_UNUSED
+[[maybe_unused]] static bool
areVarsUnique(const FlatLinearValueConstraints &cst) {
return areVarsUnique(cst, 0, cst.getNumDimAndSymbolVars());
}
/// Checks if the SSA values associated with `cst`'s variables of kind `kind`
/// are unique.
-static bool LLVM_ATTRIBUTE_UNUSED
+[[maybe_unused]] static bool
areVarsUnique(const FlatLinearValueConstraints &cst, VarKind kind) {
if (kind == VarKind::SetDim)
diff --git a/mlir/lib/Analysis/Presburger/Simplex.cpp b/mlir/lib/Analysis/Presburger/Simplex.cpp
index a1cbe2990c67d..547a4c2c99db7 100644
--- a/mlir/lib/Analysis/Presburger/Simplex.cpp
+++ b/mlir/lib/Analysis/Presburger/Simplex.cpp
@@ -34,7 +34,7 @@ using Direction = Simplex::Direction;
const int nullIndex = std::numeric_limits<int>::max();
// Return a + scale*b;
-LLVM_ATTRIBUTE_UNUSED
+[[maybe_unused]]
static SmallVector<DynamicAPInt, 8>
scaleAndAddForAssert(ArrayRef<DynamicAPInt> a, const DynamicAPInt &scale,
ArrayRef<DynamicAPInt> b) {
diff --git a/mlir/lib/Dialect/Affine/IR/AffineOps.cpp b/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
index 7e5ce26b5f733..1f419ddd5c9b9 100644
--- a/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
+++ b/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
@@ -125,9 +125,9 @@ static bool remainsLegalAfterInline(OpTy op, Region *src, Region *dest,
// Use "unused attribute" marker to silence clang-tidy warning stemming from
// the inability to see through "llvm::TypeSwitch".
template <>
-bool LLVM_ATTRIBUTE_UNUSED remainsLegalAfterInline(AffineApplyOp op,
- Region *src, Region *dest,
- const IRMapping &mapping) {
+[[maybe_unused]] bool remainsLegalAfterInline(AffineApplyOp op, Region *src,
+ Region *dest,
+ const IRMapping &mapping) {
// If it's a valid dimension, we need to check that it remains so.
if (isValidDim(op.getResult(), src))
return remainsLegalAfterInline(
@@ -1032,8 +1032,8 @@ static void simplifyMinOrMaxExprWithOperands(AffineMap &map,
/// Simplify the map while exploiting information on the values in `operands`.
// Use "unused attribute" marker to silence warning stemming from the inability
// to see through the template expansion.
-static void LLVM_ATTRIBUTE_UNUSED
-simplifyMapWithOperands(AffineMap &map, ArrayRef<Value> operands) {
+[[maybe_unused]] static void simplifyMapWithOperands(AffineMap &map,
+ ArrayRef<Value> operands) {
assert(map.getNumInputs() == operands.size() && "invalid operands for map");
SmallVector<AffineExpr> newResults;
newResults.reserve(map.getNumResults());
diff --git a/mlir/lib/Dialect/Affine/Utils/LoopUtils.cpp b/mlir/lib/Dialect/Affine/Utils/LoopUtils.cpp
index cd216efb66992..4743941deff3f 100644
--- a/mlir/lib/Dialect/Affine/Utils/LoopUtils.cpp
+++ b/mlir/lib/Dialect/Affine/Utils/LoopUtils.cpp
@@ -1357,7 +1357,7 @@ bool mlir::affine::isValidLoopInterchangePermutation(
/// Returns true if `loops` is a perfectly nested loop nest, where loops appear
/// in it from outermost to innermost.
-bool LLVM_ATTRIBUTE_UNUSED
+[[maybe_unused]] bool
mlir::affine::isPerfectlyNested(ArrayRef<AffineForOp> loops) {
assert(!loops.empty() && "no loops provided");
@@ -1920,8 +1920,7 @@ generatePointWiseCopy(Location loc, Value memref, Value fastMemRef,
return copyNestRoot;
}
-static InFlightDiagnostic LLVM_ATTRIBUTE_UNUSED
-emitRemarkForBlock(Block &block) {
+[[maybe_unused]] static InFlightDiagnostic emitRemarkForBlock(Block &block) {
return block.getParentOp()->emitRemark();
}
diff --git a/mlir/lib/Dialect/LLVMIR/IR/LLVMTypes.cpp b/mlir/lib/Dialect/LLVMIR/IR/LLVMTypes.cpp
index 01a16ce2d8a7f..ac35eea66e9d6 100644
--- a/mlir/lib/Dialect/LLVMIR/IR/LLVMTypes.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/LLVMTypes.cpp
@@ -134,10 +134,10 @@ static void printExtTypeParams(AsmPrinter &p, ArrayRef<Type> typeParams,
/// These are unused for now.
/// TODO: Move over to these once more types have been migrated to TypeDef.
-LLVM_ATTRIBUTE_UNUSED static OptionalParseResult
+[[maybe_unused]] static OptionalParseResult
generatedTypeParser(AsmParser &parser, StringRef *mnemonic, Type &value);
-LLVM_ATTRIBUTE_UNUSED static LogicalResult
-generatedTypePrinter(Type def, AsmPrinter &printer);
+[[maybe_unused]] static LogicalResult generatedTypePrinter(Type def,
+ AsmPrinter &printer);
#include "mlir/Dialect/LLVMIR/LLVMTypeInterfaces.cpp.inc"
diff --git a/mlir/lib/Dialect/SparseTensor/IR/Detail/Var.cpp b/mlir/lib/Dialect/SparseTensor/IR/Detail/Var.cpp
index a1711a69ce8d6..069191c21b091 100644
--- a/mlir/lib/Dialect/SparseTensor/IR/Detail/Var.cpp
+++ b/mlir/lib/Dialect/SparseTensor/IR/Detail/Var.cpp
@@ -143,8 +143,8 @@ void VarInfo::setNum(Var::Num n) {
/// Helper function for `assertUsageConsistency` to better handle SMLoc
/// mismatches.
-LLVM_ATTRIBUTE_UNUSED static llvm::SMLoc
-minSMLoc(AsmParser &parser, llvm::SMLoc sm1, llvm::SMLoc sm2) {
+[[maybe_unused]] static llvm::SMLoc minSMLoc(AsmParser &parser, llvm::SMLoc sm1,
+ llvm::SMLoc sm2) {
const auto loc1 = dyn_cast<FileLineColLoc>(parser.getEncodedSourceLoc(sm1));
assert(loc1 && "Could not get `FileLineColLoc` for first `SMLoc`");
const auto loc2 = dyn_cast<FileLineColLoc>(parser.getEncodedSourceLoc(sm2));
diff --git a/mlir/lib/Dialect/SparseTensor/Transforms/Utils/LoopEmitter.cpp b/mlir/lib/Dialect/SparseTensor/Transforms/Utils/LoopEmitter.cpp
index f53950242e10c..684c088eb9b0f 100644
--- a/mlir/lib/Dialect/SparseTensor/Transforms/Utils/LoopEmitter.cpp
+++ b/mlir/lib/Dialect/SparseTensor/Transforms/Utils/LoopEmitter.cpp
@@ -43,8 +43,8 @@ using namespace mlir::sparse_tensor;
//===----------------------------------------------------------------------===//
#ifndef NDEBUG
-LLVM_ATTRIBUTE_UNUSED static void dumpIndexMemRef(OpBuilder &builder,
- Location loc, Value memref) {
+[[maybe_unused]] static void dumpIndexMemRef(OpBuilder &builder, Location loc,
+ Value memref) {
memref = memref::CastOp::create(
builder, loc, UnrankedMemRefType::get(builder.getIndexType(), 0), memref);
createFuncCall(builder, loc, "printMemrefInd", TypeRange{},
diff --git a/mlir/lib/Dialect/Transform/IR/TransformTypes.cpp b/mlir/lib/Dialect/Transform/IR/TransformTypes.cpp
index 9a24c2baebabb..a2cff6acecd5a 100644
--- a/mlir/lib/Dialect/Transform/IR/TransformTypes.cpp
+++ b/mlir/lib/Dialect/Transform/IR/TransformTypes.cpp
@@ -21,10 +21,10 @@ using namespace mlir;
// These are automatically generated by ODS but are not used as the Transform
// dialect uses a different dispatch mechanism to support dialect extensions.
-LLVM_ATTRIBUTE_UNUSED static OptionalParseResult
+[[maybe_unused]] static OptionalParseResult
generatedTypeParser(AsmParser &parser, StringRef *mnemonic, Type &value);
-LLVM_ATTRIBUTE_UNUSED static LogicalResult
-generatedTypePrinter(Type def, AsmPrinter &printer);
+[[maybe_unused]] static LogicalResult generatedTypePrinter(Type def,
+ AsmPrinter &printer);
#define GET_TYPEDEF_CLASSES
#include "mlir/Dialect/Transform/IR/TransformTypes.cpp.inc"
diff --git a/mlir/lib/IR/MLIRContext.cpp b/mlir/lib/IR/MLIRContext.cpp
index 89b81cfb1e2f9..5f63fe6d81662 100644
--- a/mlir/lib/IR/MLIRContext.cpp
+++ b/mlir/lib/IR/MLIRContext.cpp
@@ -1204,7 +1204,7 @@ AffineMap AffineMap::getImpl(unsigned dimCount, unsigned symbolCount,
/// present in result expressions is less than `dimCount` and the highest index
/// of symbolic identifier present in result expressions is less than
/// `symbolCount`.
-LLVM_ATTRIBUTE_UNUSED static bool
+[[maybe_unused]] static bool
willBeValidAffineMap(unsigned dimCount, unsigned symbolCount,
ArrayRef<AffineExpr> results) {
int64_t maxDimPosition = -1;
diff --git a/mlir/lib/Tools/PDLL/CodeGen/CPPGen.cpp b/mlir/lib/Tools/PDLL/CodeGen/CPPGen.cpp
index 9670285e767b8..3fda5a7a93344 100644
--- a/mlir/lib/Tools/PDLL/CodeGen/CPPGen.cpp
+++ b/mlir/lib/Tools/PDLL/CodeGen/CPPGen.cpp
@@ -93,7 +93,7 @@ void CodeGen::generate(const ast::Module &astModule, ModuleOp module) {
// Emit function to add the generated matchers to the pattern list.
os << "template <typename... ConfigsT>\n"
- "static void LLVM_ATTRIBUTE_UNUSED populateGeneratedPDLLPatterns("
+ "[[maybe_unused]] static void populateGeneratedPDLLPatterns("
"::mlir::RewritePatternSet &patterns, ConfigsT &&...configs) {\n";
for (const auto &name : patternNames)
os << " patterns.add<" << name
diff --git a/mlir/test/lib/Dialect/Transform/TestTransformDialectExtension.cpp b/mlir/test/lib/Dialect/Transform/TestTransformDialectExtension.cpp
index 97fc699636566..496f18bc49fad 100644
--- a/mlir/test/lib/Dialect/Transform/TestTransformDialectExtension.cpp
+++ b/mlir/test/lib/Dialect/Transform/TestTransformDialectExtension.cpp
@@ -938,10 +938,10 @@ class TestTransformDialectExtension
// These are automatically generated by ODS but are not used as the Transform
// dialect uses a different dispatch mechanism to support dialect extensions.
-LLVM_ATTRIBUTE_UNUSED static OptionalParseResult
+[[maybe_unused]] static OptionalParseResult
generatedTypeParser(AsmParser &parser, StringRef *mnemonic, Type &value);
-LLVM_ATTRIBUTE_UNUSED static LogicalResult
-generatedTypePrinter(Type def, AsmPrinter &printer);
+[[maybe_unused]] static LogicalResult generatedTypePrinter(Type def,
+ AsmPrinter &printer);
#define GET_TYPEDEF_CLASSES
#include "TestTransformDialectExtensionTypes.cpp.inc"
diff --git a/mlir/test/mlir-pdll/CodeGen/CPP/general.pdll b/mlir/test/mlir-pdll/CodeGen/CPP/general.pdll
index 4e869e5dbcebe..4be30d86dda35 100644
--- a/mlir/test/mlir-pdll/CodeGen/CPP/general.pdll
+++ b/mlir/test/mlir-pdll/CodeGen/CPP/general.pdll
@@ -28,7 +28,7 @@
// CHECK: operation "test.op3"
// CHECK: )mlir", context), std::forward<ConfigsT>(configs)...)
-// CHECK: static void LLVM_ATTRIBUTE_UNUSED populateGeneratedPDLLPatterns(::mlir::RewritePatternSet &patterns, ConfigsT &&...configs) {
+// CHECK{LITERAL}: [[maybe_unused]] static void populateGeneratedPDLLPatterns(::mlir::RewritePatternSet &patterns, ConfigsT &&...configs) {
// CHECK-NEXT: patterns.add<GeneratedPDLLPattern0>(patterns.getContext(), configs...);
// CHECK-NEXT: patterns.add<NamedPattern>(patterns.getContext(), configs...);
// CHECK-NEXT: patterns.add<GeneratedPDLLPattern1>(patterns.getContext(), configs...);
diff --git a/mlir/tools/mlir-tblgen/LLVMIRConversionGen.cpp b/mlir/tools/mlir-tblgen/LLVMIRConversionGen.cpp
index 96af14d36817b..11a2db4a1cc67 100644
--- a/mlir/tools/mlir-tblgen/LLVMIRConversionGen.cpp
+++ b/mlir/tools/mlir-tblgen/LLVMIRConversionGen.cpp
@@ -416,7 +416,7 @@ static void emitOneEnumToConversion(const Record *record, raw_ostream &os) {
// Emit the function converting the enum attribute to its LLVM counterpart.
os << formatv(
- "static LLVM_ATTRIBUTE_UNUSED {0} convert{1}ToLLVM({2}::{1} value) {{\n",
+ "[[maybe_unused]] static {0} convert{1}ToLLVM({2}::{1} value) {{\n",
llvmClass, cppClassName, cppNamespace);
os << " switch (value) {\n";
@@ -444,7 +444,7 @@ static void emitOneCEnumToConversion(const Record *record, raw_ostream &os) {
StringRef cppNamespace = enumAttr.getCppNamespace();
// Emit the function converting the enum attribute to its LLVM counterpart.
- os << formatv("static LLVM_ATTRIBUTE_UNUSED int64_t "
+ os << formatv("[[maybe_unused]] static int64_t "
"convert{0}ToLLVM({1}::{0} value) {{\n",
cppClassName, cppNamespace);
os << " switch (value) {\n";
@@ -474,7 +474,7 @@ static void emitOneEnumFromConversion(const Record *record, raw_ostream &os) {
StringRef cppNamespace = enumInfo.getCppNamespace();
// Emit the function converting the enum attribute from its LLVM counterpart.
- os << formatv("inline LLVM_ATTRIBUTE_UNUSED {0}::{1} convert{1}FromLLVM({2} "
+ os << formatv("[[maybe_unused]] inline {0}::{1} convert{1}FromLLVM({2} "
"value) {{\n",
cppNamespace, cppClassName, llvmClass);
os << " switch (value) {\n";
@@ -509,10 +509,9 @@ static void emitOneCEnumFromConversion(const Record *record, raw_ostream &os) {
StringRef cppNamespace = enumInfo.getCppNamespace();
// Emit the function converting the enum attribute from its LLVM counterpart.
- os << formatv(
- "inline LLVM_ATTRIBUTE_UNUSED {0}::{1} convert{1}FromLLVM(int64_t "
- "value) {{\n",
- cppNamespace, cppClassName);
+ os << formatv("[[maybe_unused]] inline {0}::{1} convert{1}FromLLVM(int64_t "
+ "value) {{\n",
+ cppNamespace, cppClassName);
os << " switch (value) {\n";
for (const auto &enumerant : enumInfo.getAllCases()) {
diff --git a/mlir/tools/mlir-tblgen/RewriterGen.cpp b/mlir/tools/mlir-tblgen/RewriterGen.cpp
index 40bc1a9c3868c..c3034bb843c4a 100644
--- a/mlir/tools/mlir-tblgen/RewriterGen.cpp
+++ b/mlir/tools/mlir-tblgen/RewriterGen.cpp
@@ -2120,7 +2120,7 @@ static void emitRewriters(const RecordKeeper &records, raw_ostream &os) {
}
// Emit function to add the generated matchers to the pattern list.
- os << "void LLVM_ATTRIBUTE_UNUSED populateWithGenerated("
+ os << "[[maybe_unused]] void populateWithGenerated("
"::mlir::RewritePatternSet &patterns) {\n";
for (const auto &name : rewriterNames) {
os << " patterns.add<" << name << ">(patterns.getContext());\n";
diff --git a/mlir/unittests/Dialect/SparseTensor/MergerTest.cpp b/mlir/unittests/Dialect/SparseTensor/MergerTest.cpp
index fe26fc1f1d366..2a583059d2e0a 100644
--- a/mlir/unittests/Dialect/SparseTensor/MergerTest.cpp
+++ b/mlir/unittests/Dialect/SparseTensor/MergerTest.cpp
@@ -113,8 +113,7 @@ static Match tensorMatch(TensorId tid) { return Match(tid); }
static Match synZeroMatch() { return Match(); }
#define IMPL_BINOP_PATTERN(OP, KIND) \
- LLVM_ATTRIBUTE_UNUSED static Match OP##Match(const Match &e0, \
- const Match &e1) { \
+ [[maybe_unused]] static Match OP##Match(const Match &e0, const Match &e1) { \
return Match(KIND, e0, e1); \
}
FOREVERY_BINOP(IMPL_BINOP_PATTERN)
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