[clang] [CIR] Fix warnings related to unused variables in release builds (PR #151412)
Andy Kaylor via cfe-commits
cfe-commits at lists.llvm.org
Thu Jul 31 09:51:54 PDT 2025
https://github.com/andykaylor updated https://github.com/llvm/llvm-project/pull/151412
>From ceabe27febbb5bcde8c2f1f887e06a1e21270296 Mon Sep 17 00:00:00 2001
From: Andy Kaylor <akaylor at nvidia.com>
Date: Wed, 30 Jul 2025 15:30:18 -0700
Subject: [PATCH 1/4] [CIR] Fix warnings related to unused variables in release
builds
This fixes a number of warnings in release builds due to variables that were
only being used in asserts. Some of these variables will later be used
in non-debug code, but for now they are unused in release builds.
---
clang/lib/CIR/CodeGen/CIRGenCall.h | 2 +-
clang/lib/CIR/CodeGen/CIRGenExpr.cpp | 5 +++--
clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp | 3 +++
clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp | 2 +-
clang/lib/CIR/CodeGen/CIRGenFunction.cpp | 2 +-
clang/lib/CIR/CodeGen/CIRGenModule.cpp | 4 +---
clang/lib/CIR/CodeGen/CIRGenStmt.cpp | 4 ++--
7 files changed, 12 insertions(+), 10 deletions(-)
diff --git a/clang/lib/CIR/CodeGen/CIRGenCall.h b/clang/lib/CIR/CodeGen/CIRGenCall.h
index a78956b4df887..28576a15068fa 100644
--- a/clang/lib/CIR/CodeGen/CIRGenCall.h
+++ b/clang/lib/CIR/CodeGen/CIRGenCall.h
@@ -137,7 +137,7 @@ struct CallArg {
/// A data-flow flag to make sure getRValue and/or copyInto are not
/// called twice for duplicated IR emission.
- mutable bool isUsed;
+ [[maybe_unused]] mutable bool isUsed;
public:
clang::QualType ty;
diff --git a/clang/lib/CIR/CodeGen/CIRGenExpr.cpp b/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
index c18498f80e99f..1ff3a206bca27 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
@@ -1472,9 +1472,10 @@ Address CIRGenFunction::emitArrayToPointerDecay(const Expr *e) {
if (e->getType()->isVariableArrayType())
return addr;
- auto pointeeTy = mlir::cast<cir::ArrayType>(lvalueAddrTy.getPointee());
+ [[maybe_unused]] auto pointeeTy =
+ mlir::cast<cir::ArrayType>(lvalueAddrTy.getPointee());
- mlir::Type arrayTy = convertType(e->getType());
+ [[maybe_unused]] mlir::Type arrayTy = convertType(e->getType());
assert(mlir::isa<cir::ArrayType>(arrayTy) && "expected array");
assert(pointeeTy == arrayTy);
diff --git a/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp b/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp
index 18d2860030a6d..858d8adca97bc 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp
@@ -154,12 +154,15 @@ class ComplexExprEmitter : public StmtVisitor<ComplexExprEmitter, mlir::Value> {
};
} // namespace
+#ifndef NDEBUG
+// Only used in asserts
static const ComplexType *getComplexType(QualType type) {
type = type.getCanonicalType();
if (const ComplexType *comp = dyn_cast<ComplexType>(type))
return comp;
return cast<ComplexType>(cast<AtomicType>(type)->getValueType());
}
+#endif // NDEBUG
LValue ComplexExprEmitter::emitBinAssignLValue(const BinaryOperator *e,
mlir::Value &value) {
diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
index 2523b0ff33787..f62be49ee7af3 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
@@ -439,7 +439,7 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
value = builder.getTrue(cgf.getLoc(e->getExprLoc()));
} else if (type->isIntegerType()) {
QualType promotedType;
- bool canPerformLossyDemotionCheck = false;
+ [[maybe_unused]] bool canPerformLossyDemotionCheck = false;
if (cgf.getContext().isPromotableIntegerType(type)) {
promotedType = cgf.getContext().getPromotedIntegerType(type);
assert(promotedType != type && "Shouldn't promote to the same type.");
diff --git a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
index c65d0254bf8e6..a9643ba08164c 100644
--- a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
@@ -216,7 +216,7 @@ void CIRGenFunction::emitAndUpdateRetAlloca(QualType type, mlir::Location loc,
void CIRGenFunction::declare(mlir::Value addrVal, const Decl *var, QualType ty,
mlir::Location loc, CharUnits alignment,
bool isParam) {
- const auto *namedVar = dyn_cast_or_null<NamedDecl>(var);
+ [[maybe_unused]] const auto *namedVar = dyn_cast_or_null<NamedDecl>(var);
assert(namedVar && "Needs a named decl");
assert(!cir::MissingFeatures::cgfSymbolTable());
diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.cpp b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
index 623b84f031c13..192e10b698d4d 100644
--- a/clang/lib/CIR/CodeGen/CIRGenModule.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
@@ -656,8 +656,6 @@ mlir::Value CIRGenModule::getAddrOfGlobalVar(const VarDecl *d, mlir::Type ty,
void CIRGenModule::emitGlobalVarDefinition(const clang::VarDecl *vd,
bool isTentative) {
- const QualType astTy = vd->getType();
-
if (getLangOpts().OpenCL || getLangOpts().OpenMPIsTargetDevice) {
errorNYI(vd->getSourceRange(), "emit OpenCL/OpenMP global variable");
return;
@@ -701,7 +699,7 @@ void CIRGenModule::emitGlobalVarDefinition(const clang::VarDecl *vd,
// never attempt to emit a tentative definition if a real one
// exists. A use may still exists, however, so we still may need
// to do a RAUW.
- assert(!astTy->isIncompleteType() && "Unexpected incomplete type");
+ assert(!vd->getType()->isIncompleteType() && "Unexpected incomplete type");
init = builder.getZeroInitAttr(convertType(vd->getType()));
} else {
emitter.emplace(*this);
diff --git a/clang/lib/CIR/CodeGen/CIRGenStmt.cpp b/clang/lib/CIR/CodeGen/CIRGenStmt.cpp
index 21bee3312eb0f..77f1b13325cec 100644
--- a/clang/lib/CIR/CodeGen/CIRGenStmt.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenStmt.cpp
@@ -80,12 +80,12 @@ mlir::LogicalResult CIRGenFunction::emitStmt(const Stmt *s,
#include "clang/AST/StmtNodes.inc"
{
// Remember the block we came in on.
- mlir::Block *incoming = builder.getInsertionBlock();
+ [[maybe_unused]] mlir::Block *incoming = builder.getInsertionBlock();
assert(incoming && "expression emission must have an insertion point");
emitIgnoredExpr(cast<Expr>(s));
- mlir::Block *outgoing = builder.getInsertionBlock();
+ [[maybe_unused]] mlir::Block *outgoing = builder.getInsertionBlock();
assert(outgoing && "expression emission cleared block!");
return mlir::success();
}
>From 5fa22893548dd384b19beb3066bd53acff14f3fe Mon Sep 17 00:00:00 2001
From: Andy Kaylor <akaylor at nvidia.com>
Date: Wed, 30 Jul 2025 15:58:39 -0700
Subject: [PATCH 2/4] Fold namedVar into the assert.
---
clang/lib/CIR/CodeGen/CIRGenFunction.cpp | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
index a9643ba08164c..3f76609c0928a 100644
--- a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
@@ -216,8 +216,7 @@ void CIRGenFunction::emitAndUpdateRetAlloca(QualType type, mlir::Location loc,
void CIRGenFunction::declare(mlir::Value addrVal, const Decl *var, QualType ty,
mlir::Location loc, CharUnits alignment,
bool isParam) {
- [[maybe_unused]] const auto *namedVar = dyn_cast_or_null<NamedDecl>(var);
- assert(namedVar && "Needs a named decl");
+ assert(mlir::isa<NamedDecl>(var) && "Needs a named decl");
assert(!cir::MissingFeatures::cgfSymbolTable());
auto allocaOp = cast<cir::AllocaOp>(addrVal.getDefiningOp());
>From bd8f03b9e38039ea6c231ccb9af9a15a3f059ad2 Mon Sep 17 00:00:00 2001
From: Andy Kaylor <akaylor at nvidia.com>
Date: Wed, 30 Jul 2025 16:04:09 -0700
Subject: [PATCH 3/4] Remove unused incoming and outgoing vars. Comment on why
they aren't needed.
---
clang/lib/CIR/CodeGen/CIRGenStmt.cpp | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/clang/lib/CIR/CodeGen/CIRGenStmt.cpp b/clang/lib/CIR/CodeGen/CIRGenStmt.cpp
index 77f1b13325cec..220836753b1f2 100644
--- a/clang/lib/CIR/CodeGen/CIRGenStmt.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenStmt.cpp
@@ -79,14 +79,15 @@ mlir::LogicalResult CIRGenFunction::emitStmt(const Stmt *s,
#define EXPR(Type, Base) case Stmt::Type##Class:
#include "clang/AST/StmtNodes.inc"
{
- // Remember the block we came in on.
- [[maybe_unused]] mlir::Block *incoming = builder.getInsertionBlock();
- assert(incoming && "expression emission must have an insertion point");
+ assert(builder.getInsertionBlock() &&
+ "expression emission must have an insertion point");
emitIgnoredExpr(cast<Expr>(s));
- [[maybe_unused]] mlir::Block *outgoing = builder.getInsertionBlock();
- assert(outgoing && "expression emission cleared block!");
+ // Classic codegen has a check here to see if the emitter created a new
+ // block that isn't used (comparing the incoming and outgoing insertion
+ // points) and deletes the outgoing block if it's not used. In CIR, we
+ // will handle that during the cir.canonicalize pass.
return mlir::success();
}
case Stmt::IfStmtClass:
>From c794a251ce155b7f87e84238e9c219bc1d248515 Mon Sep 17 00:00:00 2001
From: Andy Kaylor <akaylor at nvidia.com>
Date: Thu, 31 Jul 2025 09:51:27 -0700
Subject: [PATCH 4/4] Fix bad namespacer
---
clang/lib/CIR/CodeGen/CIRGenFunction.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
index 3f76609c0928a..e533632323fa0 100644
--- a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
@@ -216,7 +216,7 @@ void CIRGenFunction::emitAndUpdateRetAlloca(QualType type, mlir::Location loc,
void CIRGenFunction::declare(mlir::Value addrVal, const Decl *var, QualType ty,
mlir::Location loc, CharUnits alignment,
bool isParam) {
- assert(mlir::isa<NamedDecl>(var) && "Needs a named decl");
+ assert(isa<NamedDecl>(var) && "Needs a named decl");
assert(!cir::MissingFeatures::cgfSymbolTable());
auto allocaOp = cast<cir::AllocaOp>(addrVal.getDefiningOp());
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