void created this revision.
void added a reviewer: rsmith.
Herald added subscribers: cfe-commits, kristina.
Herald added a reviewer: shafik.
A __builtin_constant_p may end up with a constant after inlining. Use
the is.constant intrinsic if it's a variable that's in a context where
it may resolve to a constant, e.g., an argument to a function after
inlining.
Repository:
rC Clang
https://reviews.llvm.org/D54355
Files:
include/clang/AST/Expr.h
lib/AST/ASTImporter.cpp
lib/AST/Expr.cpp
lib/AST/ExprConstant.cpp
lib/CodeGen/CGBuiltin.cpp
lib/Sema/SemaDeclCXX.cpp
lib/Sema/SemaExpr.cpp
lib/Sema/SemaOverload.cpp
lib/Sema/SemaTemplateDeduction.cpp
lib/Sema/SemaType.cpp
lib/StaticAnalyzer/Core/ExprEngine.cpp
test/Analysis/builtin-functions.cpp
test/SemaCXX/compound-literal.cpp
Index: test/SemaCXX/compound-literal.cpp
===================================================================
--- test/SemaCXX/compound-literal.cpp
+++ test/SemaCXX/compound-literal.cpp
@@ -36,8 +36,8 @@
POD p = (POD){1, 2};
// CHECK-NOT: CXXBindTemporaryExpr {{.*}} 'brace_initializers::POD'
- // CHECK: ConstantExpr {{.*}} 'brace_initializers::POD'
- // CHECK-NEXT: CompoundLiteralExpr {{.*}} 'brace_initializers::POD'
+ // CHECK: CompoundLiteralExpr {{.*}} 'brace_initializers::POD'
+ // CHECK-NEXT: ConstantExpr {{.*}} 'brace_initializers::POD'
// CHECK-NEXT: InitListExpr {{.*}} 'brace_initializers::POD'
// CHECK-NEXT: IntegerLiteral {{.*}} 1{{$}}
// CHECK-NEXT: IntegerLiteral {{.*}} 2{{$}}
Index: test/Analysis/builtin-functions.cpp
===================================================================
--- test/Analysis/builtin-functions.cpp
+++ test/Analysis/builtin-functions.cpp
@@ -70,14 +70,14 @@
const int j = 2;
constexpr int k = 3;
clang_analyzer_eval(__builtin_constant_p(42) == 1); // expected-warning {{TRUE}}
- clang_analyzer_eval(__builtin_constant_p(i) == 0); // expected-warning {{TRUE}}
+ clang_analyzer_eval(__builtin_constant_p(i) == 0); // expected-warning {{UNKNOWN}}
clang_analyzer_eval(__builtin_constant_p(j) == 1); // expected-warning {{TRUE}}
clang_analyzer_eval(__builtin_constant_p(k) == 1); // expected-warning {{TRUE}}
- clang_analyzer_eval(__builtin_constant_p(i + 42) == 0); // expected-warning {{TRUE}}
+ clang_analyzer_eval(__builtin_constant_p(i + 42) == 0); // expected-warning {{UNKNOWN}}
clang_analyzer_eval(__builtin_constant_p(j + 42) == 1); // expected-warning {{TRUE}}
clang_analyzer_eval(__builtin_constant_p(k + 42) == 1); // expected-warning {{TRUE}}
clang_analyzer_eval(__builtin_constant_p(" ") == 1); // expected-warning {{TRUE}}
- clang_analyzer_eval(__builtin_constant_p(test_constant_p) == 0); // expected-warning {{TRUE}}
+ clang_analyzer_eval(__builtin_constant_p(test_constant_p) == 0); // expected-warning {{UNKNOWN}}
clang_analyzer_eval(__builtin_constant_p(k - 3) == 0); // expected-warning {{FALSE}}
clang_analyzer_eval(__builtin_constant_p(k - 3) == 1); // expected-warning {{TRUE}}
}
Index: lib/StaticAnalyzer/Core/ExprEngine.cpp
===================================================================
--- lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -1283,9 +1283,6 @@
break;
case Expr::ConstantExprClass:
- // Handled due to it being a wrapper class.
- break;
-
case Stmt::ExprWithCleanupsClass:
// Handled due to fully linearised CFG.
break;
Index: lib/Sema/SemaType.cpp
===================================================================
--- lib/Sema/SemaType.cpp
+++ lib/Sema/SemaType.cpp
@@ -2233,10 +2233,6 @@
T = Context.getConstantArrayType(T, ConstVal, ASM, Quals);
}
- if (ArraySize && !CurContext->isFunctionOrMethod())
- // A file-scoped array must have a constant array size.
- ArraySize = new (Context) ConstantExpr(ArraySize);
-
// OpenCL v1.2 s6.9.d: variable length arrays are not supported.
if (getLangOpts().OpenCL && T->isVariableArrayType()) {
Diag(Loc, diag::err_opencl_vla);
Index: lib/Sema/SemaTemplateDeduction.cpp
===================================================================
--- lib/Sema/SemaTemplateDeduction.cpp
+++ lib/Sema/SemaTemplateDeduction.cpp
@@ -178,6 +178,8 @@
while (true) {
if (ImplicitCastExpr *IC = dyn_cast<ImplicitCastExpr>(E))
E = IC->getSubExpr();
+ else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(E))
+ E = CE->getSubExpr();
else if (SubstNonTypeTemplateParmExpr *Subst =
dyn_cast<SubstNonTypeTemplateParmExpr>(E))
E = Subst->getReplacement();
@@ -5225,6 +5227,8 @@
while (true) {
if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
E = ICE->getSubExpr();
+ else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(E))
+ E = CE->getSubExpr();
else if (const SubstNonTypeTemplateParmExpr *Subst =
dyn_cast<SubstNonTypeTemplateParmExpr>(E))
E = Subst->getReplacement();
Index: lib/Sema/SemaOverload.cpp
===================================================================
--- lib/Sema/SemaOverload.cpp
+++ lib/Sema/SemaOverload.cpp
@@ -5444,7 +5444,7 @@
if (Notes.empty()) {
// It's a constant expression.
- return new (S.Context) ConstantExpr(Result.get());
+ return ConstantExpr::Create(S.Context, Result.get());
}
}
Index: lib/Sema/SemaExpr.cpp
===================================================================
--- lib/Sema/SemaExpr.cpp
+++ lib/Sema/SemaExpr.cpp
@@ -4899,6 +4899,14 @@
unsigned NumParams = Proto->getNumParams();
bool Invalid = false;
size_t ArgIx = 0;
+
+ unsigned ICEArguments = 0;
+ if (FDecl)
+ if (auto BuiltinID = FDecl->getBuiltinID()) {
+ ASTContext::GetBuiltinTypeError Error;
+ Context.GetBuiltinType(BuiltinID, Error, &ICEArguments);
+ }
+
// Continue to check argument types (even if we have too few/many args).
for (unsigned i = FirstParam; i < NumParams; i++) {
QualType ProtoArgType = Proto->getParamType(i);
@@ -4962,6 +4970,9 @@
// Check for violations of C99 static array rules (C99 6.7.5.3p7).
CheckStaticArrayArgument(CallLoc, Param, Arg);
+ if ((ICEArguments & (1 << (ArgIx - 1))) != 0)
+ Arg = ConstantExpr::Create(Context, Arg);
+
AllArgs.push_back(Arg);
}
@@ -5769,15 +5780,16 @@
? VK_RValue
: VK_LValue;
+ if (isFileScope)
+ LiteralExpr = ConstantExpr::Create(Context, LiteralExpr);
Expr *E = new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType,
VK, LiteralExpr, isFileScope);
if (isFileScope) {
if (!LiteralExpr->isTypeDependent() &&
!LiteralExpr->isValueDependent() &&
!literalType->isDependentType()) // C99 6.5.2.5p3
if (CheckForConstantInitializer(LiteralExpr, literalType))
return ExprError();
- E = new (Context) ConstantExpr(E);
} else if (literalType.getAddressSpace() != LangAS::opencl_private &&
literalType.getAddressSpace() != LangAS::Default) {
// Embedded-C extensions to C99 6.5.2.5:
@@ -14141,12 +14153,15 @@
return ExprError();
}
+ if (!CurContext->isFunctionOrMethod())
+ E = ConstantExpr::Create(Context, E);
+
// Circumvent ICE checking in C++11 to avoid evaluating the expression twice
// in the non-ICE case.
if (!getLangOpts().CPlusPlus11 && E->isIntegerConstantExpr(Context)) {
if (Result)
*Result = E->EvaluateKnownConstIntCheckOverflow(Context);
- return new (Context) ConstantExpr(E);
+ return E;
}
Expr::EvalResult EvalResult;
@@ -14164,7 +14179,7 @@
if (Folded && getLangOpts().CPlusPlus11 && Notes.empty()) {
if (Result)
*Result = EvalResult.Val.getInt();
- return new (Context) ConstantExpr(E);
+ return E;
}
// If our only note is the usual "invalid subexpression" note, just point
@@ -14192,7 +14207,7 @@
if (Result)
*Result = EvalResult.Val.getInt();
- return new (Context) ConstantExpr(E);
+ return E;
}
namespace {
Index: lib/Sema/SemaDeclCXX.cpp
===================================================================
--- lib/Sema/SemaDeclCXX.cpp
+++ lib/Sema/SemaDeclCXX.cpp
@@ -13861,6 +13861,8 @@
ExprResult Converted = PerformContextuallyConvertToBool(AssertExpr);
if (Converted.isInvalid())
Failed = true;
+ else
+ Converted = ConstantExpr::Create(Context, Converted.get());
llvm::APSInt Cond;
if (!Failed && VerifyIntegerConstantExpression(Converted.get(), &Cond,
Index: lib/CodeGen/CGBuiltin.cpp
===================================================================
--- lib/CodeGen/CGBuiltin.cpp
+++ lib/CodeGen/CGBuiltin.cpp
@@ -1918,6 +1918,19 @@
case Builtin::BI__builtin_rotateright64:
return emitRotate(E, true);
+ case Builtin::BI__builtin_constant_p: {
+ if (CGM.getCodeGenOpts().OptimizationLevel == 0)
+ // At -O0, we don't perform inlining, so we don't need to delay the
+ // processing.
+ return RValue::get(ConstantInt::get(Int32Ty, 0));
+ if (auto *DRE = dyn_cast<DeclRefExpr>(E->getArg(0)->IgnoreImplicit()))
+ if (DRE->getType()->isAggregateType())
+ return RValue::get(ConstantInt::get(Int32Ty, 0));
+ Value *Arg = EmitScalarExpr(E->getArg(0));
+ Value *F = CGM.getIntrinsic(Intrinsic::is_constant, Arg->getType());
+ Value *Call = Builder.CreateCall(F, Arg);
+ return RValue::get(Builder.CreateZExtOrBitCast(Call, Int32Ty));
+ }
case Builtin::BI__builtin_object_size: {
unsigned Type =
E->getArg(1)->EvaluateKnownConstInt(getContext()).getZExtValue();
Index: lib/AST/ExprConstant.cpp
===================================================================
--- lib/AST/ExprConstant.cpp
+++ lib/AST/ExprConstant.cpp
@@ -45,6 +45,7 @@
#include "clang/AST/TypeLoc.h"
#include "clang/Basic/Builtins.h"
#include "clang/Basic/TargetInfo.h"
+#include "llvm/Support/SaveAndRestore.h"
#include "llvm/Support/raw_ostream.h"
#include <cstring>
#include <functional>
@@ -721,6 +722,10 @@
/// Whether or not we're currently speculatively evaluating.
bool IsSpeculativelyEvaluating;
+ /// Whether or not we're in a context where the front end requires a
+ /// constant value.
+ bool InConstantContext;
+
enum EvaluationMode {
/// Evaluate as a constant expression. Stop if we find that the expression
/// is not a constant expression.
@@ -782,7 +787,7 @@
EvaluatingDecl((const ValueDecl *)nullptr),
EvaluatingDeclValue(nullptr), HasActiveDiagnostic(false),
HasFoldFailureDiagnostic(false), IsSpeculativelyEvaluating(false),
- EvalMode(Mode) {}
+ InConstantContext(false), EvalMode(Mode) {}
void setEvaluatingDecl(APValue::LValueBase Base, APValue &Value) {
EvaluatingDecl = Base;
@@ -7347,6 +7352,8 @@
// Visitor Methods
//===--------------------------------------------------------------------===//
+ bool VisitConstantExpr(const ConstantExpr *E);
+
bool VisitIntegerLiteral(const IntegerLiteral *E) {
return Success(E->getValue(), E);
}
@@ -8087,6 +8094,11 @@
return true;
}
+bool IntExprEvaluator::VisitConstantExpr(const ConstantExpr *E) {
+ llvm::SaveAndRestore<bool> InConstantContext(Info.InConstantContext, true);
+ return ExprEvaluatorBaseTy::VisitConstantExpr(E);
+}
+
bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
if (unsigned BuiltinOp = E->getBuiltinCallee())
return VisitBuiltinCallExpr(E, BuiltinOp);
@@ -8174,8 +8186,20 @@
return Success(Val.countLeadingZeros(), E);
}
- case Builtin::BI__builtin_constant_p:
- return Success(EvaluateBuiltinConstantP(Info.Ctx, E->getArg(0)), E);
+ case Builtin::BI__builtin_constant_p: {
+ auto Arg = E->getArg(0);
+ if (EvaluateBuiltinConstantP(Info.Ctx, Arg))
+ return Success(true, E);
+ auto ArgTy = Arg->IgnoreImplicit()->getType();
+ if (!Info.InConstantContext && !Arg->HasSideEffects(Info.Ctx) &&
+ !ArgTy->isAggregateType() && !ArgTy->isPointerType()) {
+ // We can delay calculation of __builtin_constant_p until after
+ // inlining. Note: This diagnostic won't be shown to the user.
+ Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
+ return false;
+ }
+ return Success(false, E);
+ }
case Builtin::BI__builtin_ctz:
case Builtin::BI__builtin_ctzl:
Index: lib/AST/Expr.cpp
===================================================================
--- lib/AST/Expr.cpp
+++ lib/AST/Expr.cpp
@@ -2585,8 +2585,8 @@
E = NTTP->getReplacement();
continue;
}
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(E)) {
- E = CE->getSubExpr();
+ if (FullExpr *FE = dyn_cast<FullExpr>(E)) {
+ E = FE->getSubExpr();
continue;
}
return E;
@@ -2610,8 +2610,8 @@
E = NTTP->getReplacement();
continue;
}
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(E)) {
- E = CE->getSubExpr();
+ if (FullExpr *FE = dyn_cast<FullExpr>(E)) {
+ E = FE->getSubExpr();
continue;
}
return E;
@@ -2639,8 +2639,8 @@
= dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
E = NTTP->getReplacement();
continue;
- } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(E)) {
- E = CE->getSubExpr();
+ } else if (FullExpr *FE = dyn_cast<FullExpr>(E)) {
+ E = FE->getSubExpr();
continue;
}
break;
@@ -2683,8 +2683,8 @@
E = NTTP->getReplacement();
continue;
}
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(E)) {
- E = CE->getSubExpr();
+ if (FullExpr *FE = dyn_cast<FullExpr>(E)) {
+ E = FE->getSubExpr();
continue;
}
return E;
@@ -2911,6 +2911,10 @@
break;
}
+ case ConstantExprClass: {
+ const Expr *Exp = cast<ConstantExpr>(this)->getSubExpr();
+ return Exp->isConstantInitializer(Ctx, false, Culprit);
+ }
case CompoundLiteralExprClass: {
// This handles gcc's extension that allows global initializers like
// "struct x {int x;} x = (struct x) {};".
Index: lib/AST/ASTImporter.cpp
===================================================================
--- lib/AST/ASTImporter.cpp
+++ lib/AST/ASTImporter.cpp
@@ -6375,7 +6375,7 @@
Expr *ToSubExpr;
std::tie(ToSubExpr) = *Imp;
- return new (Importer.getToContext()) ConstantExpr(ToSubExpr);
+ return ConstantExpr::Create(Importer.getToContext(), ToSubExpr);
}
ExpectedStmt ASTNodeImporter::VisitParenExpr(ParenExpr *E) {
Index: include/clang/AST/Expr.h
===================================================================
--- include/clang/AST/Expr.h
+++ include/clang/AST/Expr.h
@@ -901,10 +901,16 @@
/// ConstantExpr - An expression that occurs in a constant context.
class ConstantExpr : public FullExpr {
-public:
ConstantExpr(Expr *subexpr)
: FullExpr(ConstantExprClass, subexpr) {}
+public:
+ static ConstantExpr *Create(const ASTContext &Context, Expr *E) {
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(E))
+ return CE;
+ return new (Context) ConstantExpr(E);
+ }
+
/// Build an empty constant expression wrapper.
explicit ConstantExpr(EmptyShell Empty)
: FullExpr(ConstantExprClass, Empty) {}
@@ -3070,8 +3076,8 @@
while (true)
if (ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
e = ice->getSubExpr();
- else if (ConstantExpr *ce = dyn_cast<ConstantExpr>(e))
- e = ce->getSubExpr();
+ else if (FullExpr *fe = dyn_cast<FullExpr>(e))
+ e = fe->getSubExpr();
else
break;
return e;
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
