Author: rsmith
Date: Thu Sep 13 15:47:33 2018
New Revision: 342192
URL: http://llvm.org/viewvc/llvm-project?rev=342192&view=rev
Log:
Fix crash on call to __builtin_memcpy with a null pointer to an
incomplete type.
Also improve the diagnostics for similar situations.
Modified:
cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td
cfe/trunk/lib/AST/APValue.cpp
cfe/trunk/lib/AST/ExprConstant.cpp
cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp
cfe/trunk/test/SemaCXX/constexpr-string.cpp
Modified: cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td?rev=342192&r1=342191&r2=342192&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td Thu Sep 13 15:47:33 2018
@@ -163,6 +163,10 @@ def note_constexpr_unsupported_unsized_a
def note_constexpr_unsized_array_indexed : Note<
"indexing of array without known bound is not allowed "
"in a constant expression">;
+def note_constexpr_memcpy_null : Note<
+ "%select{source|destination}2 of "
+ "'%select{%select{memcpy|wmemcpy}1|%select{memmove|wmemmove}1}0' "
+ "is %3">;
def note_constexpr_memcpy_type_pun : Note<
"cannot constant evaluate '%select{memcpy|memmove}0' from object of "
"type %1 to object of type %2">;
Modified: cfe/trunk/lib/AST/APValue.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/APValue.cpp?rev=342192&r1=342191&r2=342192&view=diff
==============================================================================
--- cfe/trunk/lib/AST/APValue.cpp (original)
+++ cfe/trunk/lib/AST/APValue.cpp Thu Sep 13 15:47:33 2018
@@ -416,18 +416,26 @@ void APValue::printPretty(raw_ostream &O
<< GetApproxValue(getComplexFloatImag()) << "i";
return;
case APValue::LValue: {
- LValueBase Base = getLValueBase();
- if (!Base) {
- Out << "0";
- return;
- }
-
bool IsReference = Ty->isReferenceType();
QualType InnerTy
= IsReference ? Ty.getNonReferenceType() : Ty->getPointeeType();
if (InnerTy.isNull())
InnerTy = Ty;
+ LValueBase Base = getLValueBase();
+ if (!Base) {
+ if (isNullPointer()) {
+ Out << (Ctx.getLangOpts().CPlusPlus11 ? "nullptr" : "0");
+ } else if (IsReference) {
+ Out << "*(" << InnerTy.stream(Ctx.getPrintingPolicy()) << "*)"
+ << getLValueOffset().getQuantity();
+ } else {
+ Out << "(" << Ty.stream(Ctx.getPrintingPolicy()) << ")"
+ << getLValueOffset().getQuantity();
+ }
+ return;
+ }
+
if (!hasLValuePath()) {
// No lvalue path: just print the offset.
CharUnits O = getLValueOffset();
Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=342192&r1=342191&r2=342192&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Thu Sep 13 15:47:33 2018
@@ -6191,12 +6191,12 @@ bool PointerExprEvaluator::VisitBuiltinC
BuiltinOp == Builtin::BI__builtin_wmemmove;
// The result of mem* is the first argument.
- if (!Visit(E->getArg(0)) || Result.Designator.Invalid)
+ if (!Visit(E->getArg(0)))
return false;
LValue Dest = Result;
LValue Src;
- if (!EvaluatePointer(E->getArg(1), Src, Info) || Src.Designator.Invalid)
+ if (!EvaluatePointer(E->getArg(1), Src, Info))
return false;
APSInt N;
@@ -6209,6 +6209,20 @@ bool PointerExprEvaluator::VisitBuiltinC
if (!N)
return true;
+ // Otherwise, if either of the operands is null, we can't proceed. Don't
+ // try to determine the type of the copied objects, because there aren't
+ // any.
+ if (!Src.Base || !Dest.Base) {
+ APValue Val;
+ (!Src.Base ? Src : Dest).moveInto(Val);
+ Info.FFDiag(E, diag::note_constexpr_memcpy_null)
+ << Move << WChar << !!Src.Base
+ << Val.getAsString(Info.Ctx, E->getArg(0)->getType());
+ return false;
+ }
+ if (Src.Designator.Invalid || Dest.Designator.Invalid)
+ return false;
+
// We require that Src and Dest are both pointers to arrays of
// trivially-copyable type. (For the wide version, the designator will be
// invalid if the designated object is not a wchar_t.)
Modified: cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp?rev=342192&r1=342191&r2=342192&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp (original)
+++ cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp Thu Sep 13 15:47:33
2018
@@ -253,7 +253,7 @@ namespace FunctionPointers {
static_assert(1 + Apply(Select(4), 5) + Apply(Select(3), 7) == 42, "");
- constexpr int Invalid = Apply(Select(0), 0); // expected-error {{must be
initialized by a constant expression}} expected-note {{in call to 'Apply(0,
0)'}}
+ constexpr int Invalid = Apply(Select(0), 0); // expected-error {{must be
initialized by a constant expression}} expected-note {{in call to
'Apply(nullptr, 0)'}}
}
Modified: cfe/trunk/test/SemaCXX/constexpr-string.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constexpr-string.cpp?rev=342192&r1=342191&r2=342192&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/constexpr-string.cpp (original)
+++ cfe/trunk/test/SemaCXX/constexpr-string.cpp Thu Sep 13 15:47:33 2018
@@ -317,6 +317,23 @@ namespace MemcpyEtc {
static_assert(test_wmemmove(0, 3, 2) == 4234); // expected-error
{{constant}} expected-note {{in call}}
static_assert(test_wmemmove(2, 0, 3) == 4234); // expected-error
{{constant}} expected-note {{in call}}
+#define fold(x) (__builtin_constant_p(0) ? (x) : (x))
+
+ wchar_t global;
+ constexpr wchar_t *null = 0;
+ static_assert(__builtin_memcpy(&global, null, sizeof(wchar_t))); //
expected-error {{}} expected-note {{source of 'memcpy' is nullptr}}
+ static_assert(__builtin_memmove(&global, null, sizeof(wchar_t))); //
expected-error {{}} expected-note {{source of 'memmove' is nullptr}}
+ static_assert(__builtin_wmemcpy(&global, null, sizeof(wchar_t))); //
expected-error {{}} expected-note {{source of 'wmemcpy' is nullptr}}
+ static_assert(__builtin_wmemmove(&global, null, sizeof(wchar_t))); //
expected-error {{}} expected-note {{source of 'wmemmove' is nullptr}}
+ static_assert(__builtin_memcpy(null, &global, sizeof(wchar_t))); //
expected-error {{}} expected-note {{destination of 'memcpy' is nullptr}}
+ static_assert(__builtin_memmove(null, &global, sizeof(wchar_t))); //
expected-error {{}} expected-note {{destination of 'memmove' is nullptr}}
+ static_assert(__builtin_wmemcpy(null, &global, sizeof(wchar_t))); //
expected-error {{}} expected-note {{destination of 'wmemcpy' is nullptr}}
+ static_assert(__builtin_wmemmove(null, &global, sizeof(wchar_t))); //
expected-error {{}} expected-note {{destination of 'wmemmove' is nullptr}}
+ static_assert(__builtin_memcpy(&global, fold((wchar_t*)123),
sizeof(wchar_t))); // expected-error {{}} expected-note {{source of 'memcpy' is
(void *)123}}
+ static_assert(__builtin_memcpy(fold(reinterpret_cast<wchar_t*>(123)),
&global, sizeof(wchar_t))); // expected-error {{}} expected-note {{destination
of 'memcpy' is (void *)123}}
+ constexpr struct Incomplete *null_incomplete = 0;
+ static_assert(__builtin_memcpy(null_incomplete, null_incomplete,
sizeof(wchar_t))); // expected-error {{}} expected-note {{source of 'memcpy' is
nullptr}}
+
// Copying is permitted for any trivially-copyable type.
struct Trivial { char k; short s; constexpr bool ok() { return k == 3 && s
== 4; } };
constexpr bool test_trivial() {
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