Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2853,6 +2853,10 @@
def err_attribute_aligned_too_great : Error<
"requested alignment must be %0 bytes or smaller">;
+def warn_assume_aligned_too_great
+ : Warning<"requested alignment must be %0 bytes or smaller; assumption "
+ "ignored">,
+ InGroup<DiagGroup<"builtin-assume-aligned-alignment">>;
def warn_redeclaration_without_attribute_prev_attribute_ignored : Warning<
"%q0 redeclared without %1 attribute: previous %1 ignored">,
InGroup<MicrosoftInconsistentDllImport>;
Index: clang/lib/CodeGen/CGBuiltin.cpp
===================================================================
--- clang/lib/CodeGen/CGBuiltin.cpp
+++ clang/lib/CodeGen/CGBuiltin.cpp
@@ -2048,11 +2048,10 @@
Value *AlignmentValue = EmitScalarExpr(E->getArg(1));
ConstantInt *AlignmentCI = cast<ConstantInt>(AlignmentValue);
- unsigned Alignment = (unsigned)AlignmentCI->getZExtValue();
EmitAlignmentAssumption(PtrValue, Ptr,
/*The expr loc is sufficient.*/ SourceLocation(),
- Alignment, OffsetValue);
+ AlignmentCI, OffsetValue);
return RValue::get(PtrValue);
}
case Builtin::BI__assume:
Index: clang/lib/CodeGen/CGCall.cpp
===================================================================
--- clang/lib/CodeGen/CGCall.cpp
+++ clang/lib/CodeGen/CGCall.cpp
@@ -4569,7 +4569,7 @@
llvm::Value *Alignment = EmitScalarExpr(AA->getAlignment());
llvm::ConstantInt *AlignmentCI = cast<llvm::ConstantInt>(Alignment);
EmitAlignmentAssumption(Ret.getScalarVal(), RetTy, Loc, AA->getLocation(),
- AlignmentCI->getZExtValue(), OffsetValue);
+ AlignmentCI, OffsetValue);
} else if (const auto *AA = TargetDecl->getAttr<AllocAlignAttr>()) {
llvm::Value *AlignmentVal = CallArgs[AA->getParamIndex().getLLVMIndex()]
.getRValue(*this)
Index: clang/lib/CodeGen/CGExprScalar.cpp
===================================================================
--- clang/lib/CodeGen/CGExprScalar.cpp
+++ clang/lib/CodeGen/CGExprScalar.cpp
@@ -294,8 +294,7 @@
Value *AlignmentValue = CGF.EmitScalarExpr(AVAttr->getAlignment());
llvm::ConstantInt *AlignmentCI = cast<llvm::ConstantInt>(AlignmentValue);
- CGF.EmitAlignmentAssumption(V, E, AVAttr->getLocation(),
- AlignmentCI->getZExtValue());
+ CGF.EmitAlignmentAssumption(V, E, AVAttr->getLocation(), AlignmentCI);
}
/// EmitLoadOfLValue - Given an expression with complex type that represents a
Index: clang/lib/CodeGen/CGStmtOpenMP.cpp
===================================================================
--- clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -1519,14 +1519,14 @@
if (!CGF.HaveInsertPoint())
return;
for (const auto *Clause : D.getClausesOfKind<OMPAlignedClause>()) {
- unsigned ClauseAlignment = 0;
+ size_t ClauseAlignment = 0;
if (const Expr *AlignmentExpr = Clause->getAlignment()) {
auto *AlignmentCI =
cast<llvm::ConstantInt>(CGF.EmitScalarExpr(AlignmentExpr));
- ClauseAlignment = static_cast<unsigned>(AlignmentCI->getZExtValue());
+ ClauseAlignment = AlignmentCI->getZExtValue();
}
for (const Expr *E : Clause->varlists()) {
- unsigned Alignment = ClauseAlignment;
+ size_t Alignment = ClauseAlignment;
if (Alignment == 0) {
// OpenMP [2.8.1, Description]
// If no optional parameter is specified, implementation-defined default
@@ -1542,7 +1542,8 @@
if (Alignment != 0) {
llvm::Value *PtrValue = CGF.EmitScalarExpr(E);
CGF.EmitAlignmentAssumption(
- PtrValue, E, /*No second loc needed*/ SourceLocation(), Alignment);
+ PtrValue, E, /*No second loc needed*/ SourceLocation(),
+ llvm::ConstantInt::get(CGF.SizeTy, Alignment));
}
}
}
Index: clang/lib/CodeGen/CodeGenFunction.h
===================================================================
--- clang/lib/CodeGen/CodeGenFunction.h
+++ clang/lib/CodeGen/CodeGenFunction.h
@@ -2829,13 +2829,8 @@
llvm::Value *Alignment,
llvm::Value *OffsetValue = nullptr);
- void EmitAlignmentAssumption(llvm::Value *PtrValue, QualType Ty,
- SourceLocation Loc, SourceLocation AssumptionLoc,
- unsigned Alignment,
- llvm::Value *OffsetValue = nullptr);
-
void EmitAlignmentAssumption(llvm::Value *PtrValue, const Expr *E,
- SourceLocation AssumptionLoc, unsigned Alignment,
+ SourceLocation AssumptionLoc, llvm::Value *Alignment,
llvm::Value *OffsetValue = nullptr);
//===--------------------------------------------------------------------===//
Index: clang/lib/CodeGen/CodeGenFunction.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenFunction.cpp
+++ clang/lib/CodeGen/CodeGenFunction.cpp
@@ -2057,24 +2057,9 @@
}
void CodeGenFunction::EmitAlignmentAssumption(llvm::Value *PtrValue,
- QualType Ty, SourceLocation Loc,
- SourceLocation AssumptionLoc,
- unsigned Alignment,
- llvm::Value *OffsetValue) {
- llvm::Value *TheCheck;
- llvm::Instruction *Assumption = Builder.CreateAlignmentAssumption(
- CGM.getDataLayout(), PtrValue, Alignment, OffsetValue, &TheCheck);
- if (SanOpts.has(SanitizerKind::Alignment)) {
- llvm::Value *AlignmentVal = llvm::ConstantInt::get(IntPtrTy, Alignment);
- EmitAlignmentAssumptionCheck(PtrValue, Ty, Loc, AssumptionLoc, AlignmentVal,
- OffsetValue, TheCheck, Assumption);
- }
-}
-
-void CodeGenFunction::EmitAlignmentAssumption(llvm::Value *PtrValue,
const Expr *E,
SourceLocation AssumptionLoc,
- unsigned Alignment,
+ llvm::Value *Alignment,
llvm::Value *OffsetValue) {
if (auto *CE = dyn_cast<CastExpr>(E))
E = CE->getSubExprAsWritten();
Index: clang/lib/Sema/SemaChecking.cpp
===================================================================
--- clang/lib/Sema/SemaChecking.cpp
+++ clang/lib/Sema/SemaChecking.cpp
@@ -6063,6 +6063,14 @@
if (!Result.isPowerOf2())
return Diag(TheCall->getBeginLoc(), diag::err_alignment_not_power_of_two)
<< Arg->getSourceRange();
+
+ // Alignment calculations can wrap around if it's greater than 2**28.
+ unsigned MaximumAlignment =
+ Context.getTargetInfo().getTriple().isOSBinFormatCOFF() ? 8192
+ : 268435456;
+ if (Result > MaximumAlignment)
+ Diag(TheCall->getBeginLoc(), diag::warn_assume_aligned_too_great)
+ << Arg->getSourceRange() << MaximumAlignment;
}
if (NumArgs > 2) {
Index: clang/test/Sema/builtin-assume-aligned.c
===================================================================
--- clang/test/Sema/builtin-assume-aligned.c
+++ clang/test/Sema/builtin-assume-aligned.c
@@ -58,3 +58,7 @@
void *test_no_fn_proto() __attribute__((assume_aligned())); // expected-error {{'assume_aligned' attribute takes at least 1 argument}}
void *test_no_fn_proto() __attribute__((assume_aligned(32, 45, 37))); // expected-error {{'assume_aligned' attribute takes no more than 2 arguments}}
+int pr43638(int *a) {
+ a = __builtin_assume_aligned(a, 4294967296); // expected-warning {{requested alignment must be %0 bytes or smaller; assumption ignored}}
+return a[0];
+}