r374450 - Fix __builtin_assume_aligned with too large values.
Erich Keane via cfe-commits
cfe-commits at lists.llvm.org
Thu Oct 10 14:08:29 PDT 2019
Author: erichkeane
Date: Thu Oct 10 14:08:28 2019
New Revision: 374450
URL: http://llvm.org/viewvc/llvm-project?rev=374450&view=rev
Log:
Fix __builtin_assume_aligned with too large values.
Code to handle __builtin_assume_aligned was allowing larger values, but
would convert this to unsigned along the way. This patch removes the
EmitAssumeAligned overloads that take unsigned to do away with this
problem.
Additionally, it adds a warning that values greater than 1 <<29 are
ignored by LLVM.
Differential Revision: https://reviews.llvm.org/D68824
Modified:
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/lib/CodeGen/CGBuiltin.cpp
cfe/trunk/lib/CodeGen/CGCall.cpp
cfe/trunk/lib/CodeGen/CGExprScalar.cpp
cfe/trunk/lib/CodeGen/CGStmtOpenMP.cpp
cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
cfe/trunk/lib/CodeGen/CodeGenFunction.h
cfe/trunk/lib/Sema/SemaChecking.cpp
cfe/trunk/test/Sema/builtin-assume-aligned.c
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=374450&r1=374449&r2=374450&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Thu Oct 10 14:08:28 2019
@@ -2853,6 +2853,10 @@ def err_alignment_dependent_typedef_name
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>;
Modified: cfe/trunk/lib/CodeGen/CGBuiltin.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGBuiltin.cpp?rev=374450&r1=374449&r2=374450&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGBuiltin.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGBuiltin.cpp Thu Oct 10 14:08:28 2019
@@ -2048,11 +2048,10 @@ RValue CodeGenFunction::EmitBuiltinExpr(
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:
Modified: cfe/trunk/lib/CodeGen/CGCall.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCall.cpp?rev=374450&r1=374449&r2=374450&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCall.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCall.cpp Thu Oct 10 14:08:28 2019
@@ -4569,7 +4569,7 @@ RValue CodeGenFunction::EmitCall(const C
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)
Modified: cfe/trunk/lib/CodeGen/CGExprScalar.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprScalar.cpp?rev=374450&r1=374449&r2=374450&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprScalar.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprScalar.cpp Thu Oct 10 14:08:28 2019
@@ -294,8 +294,7 @@ public:
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
Modified: cfe/trunk/lib/CodeGen/CGStmtOpenMP.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGStmtOpenMP.cpp?rev=374450&r1=374449&r2=374450&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGStmtOpenMP.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGStmtOpenMP.cpp Thu Oct 10 14:08:28 2019
@@ -1519,14 +1519,14 @@ static void emitAlignedClause(CodeGenFun
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 @@ static void emitAlignedClause(CodeGenFun
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));
}
}
}
Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.cpp?rev=374450&r1=374449&r2=374450&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.cpp Thu Oct 10 14:08:28 2019
@@ -2057,24 +2057,9 @@ void CodeGenFunction::EmitAlignmentAssum
}
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();
Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.h?rev=374450&r1=374449&r2=374450&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.h (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.h Thu Oct 10 14:08:28 2019
@@ -2829,13 +2829,8 @@ public:
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);
//===--------------------------------------------------------------------===//
Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=374450&r1=374449&r2=374450&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
+++ cfe/trunk/lib/Sema/SemaChecking.cpp Thu Oct 10 14:08:28 2019
@@ -6063,6 +6063,16 @@ bool Sema::SemaBuiltinAssumeAligned(Call
if (!Result.isPowerOf2())
return Diag(TheCall->getBeginLoc(), diag::err_alignment_not_power_of_two)
<< Arg->getSourceRange();
+
+ // FIXME: this should probably use llvm::Value::MaximumAlignment, however
+ // doing so results in a linking issue in GCC in a couple of assemblies.
+ // 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) {
Modified: cfe/trunk/test/Sema/builtin-assume-aligned.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/builtin-assume-aligned.c?rev=374450&r1=374449&r2=374450&view=diff
==============================================================================
--- cfe/trunk/test/Sema/builtin-assume-aligned.c (original)
+++ cfe/trunk/test/Sema/builtin-assume-aligned.c Thu Oct 10 14:08:28 2019
@@ -58,3 +58,7 @@ void *test_no_fn_proto() __attribute__((
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 268435456 bytes or smaller; assumption ignored}}
+return a[0];
+}
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