[clang] eef5798 - [clang][Interp] Create full type info for dummy pointers
Timm Bäder via cfe-commits
cfe-commits at lists.llvm.org
Mon Apr 22 01:04:33 PDT 2024
Author: Timm Bäder
Date: 2024-04-22T10:04:09+02:00
New Revision: eef5798844a6ed489c28b37113f3bcaafd1d6e68
URL: https://github.com/llvm/llvm-project/commit/eef5798844a6ed489c28b37113f3bcaafd1d6e68
DIFF: https://github.com/llvm/llvm-project/commit/eef5798844a6ed489c28b37113f3bcaafd1d6e68.diff
LOG: [clang][Interp] Create full type info for dummy pointers
Added:
Modified:
clang/lib/AST/Interp/Descriptor.cpp
clang/lib/AST/Interp/Descriptor.h
clang/lib/AST/Interp/Interp.h
clang/lib/AST/Interp/Pointer.cpp
clang/lib/AST/Interp/Program.cpp
clang/test/AST/Interp/builtin-align-cxx.cpp
clang/test/AST/Interp/c.c
Removed:
################################################################################
diff --git a/clang/lib/AST/Interp/Descriptor.cpp b/clang/lib/AST/Interp/Descriptor.cpp
index a4ccc0236d292c..6704444fccdd6a 100644
--- a/clang/lib/AST/Interp/Descriptor.cpp
+++ b/clang/lib/AST/Interp/Descriptor.cpp
@@ -309,14 +309,6 @@ Descriptor::Descriptor(const DeclTy &D)
assert(Source && "Missing source");
}
-/// Dummy array.
-Descriptor::Descriptor(const DeclTy &D, UnknownSize)
- : Source(D), ElemSize(1), Size(UnknownSizeMark), MDSize(0),
- AllocSize(MDSize), ElemRecord(nullptr), IsConst(true), IsMutable(false),
- IsTemporary(false), IsArray(true), IsDummy(true) {
- assert(Source && "Missing source");
-}
-
QualType Descriptor::getType() const {
if (auto *E = asExpr())
return E->getType();
diff --git a/clang/lib/AST/Interp/Descriptor.h b/clang/lib/AST/Interp/Descriptor.h
index c386fc8ac7b09d..f8a574c9b3a023 100644
--- a/clang/lib/AST/Interp/Descriptor.h
+++ b/clang/lib/AST/Interp/Descriptor.h
@@ -125,7 +125,7 @@ struct Descriptor final {
/// Flag indicating if the block is an array.
const bool IsArray = false;
/// Flag indicating if this is a dummy descriptor.
- const bool IsDummy = false;
+ bool IsDummy = false;
/// Storage management methods.
const BlockCtorFn CtorFn = nullptr;
@@ -159,8 +159,8 @@ struct Descriptor final {
/// Allocates a dummy descriptor.
Descriptor(const DeclTy &D);
- /// Allocates a dummy array descriptor.
- Descriptor(const DeclTy &D, UnknownSize);
+ /// Make this descriptor a dummy descriptor.
+ void makeDummy() { IsDummy = true; }
QualType getType() const;
QualType getElemQualType() const;
diff --git a/clang/lib/AST/Interp/Interp.h b/clang/lib/AST/Interp/Interp.h
index cebedf59e0593f..813bd02030cbfa 100644
--- a/clang/lib/AST/Interp/Interp.h
+++ b/clang/lib/AST/Interp/Interp.h
@@ -823,9 +823,9 @@ inline bool CmpHelperEQ<Pointer>(InterpState &S, CodePtr OpPC, CompareFn Fn) {
// element in the same array are NOT equal. They have the same Base value,
// but a
diff erent Offset. This is a pretty rare case, so we fix this here
// by comparing pointers to the first elements.
- if (!LHS.isZero() && !LHS.isDummy() && LHS.isArrayRoot())
+ if (!LHS.isZero() && LHS.isArrayRoot())
VL = LHS.atIndex(0).getByteOffset();
- if (!RHS.isZero() && !RHS.isDummy() && RHS.isArrayRoot())
+ if (!RHS.isZero() && RHS.isArrayRoot())
VR = RHS.atIndex(0).getByteOffset();
S.Stk.push<BoolT>(BoolT::from(Fn(Compare(VL, VR))));
@@ -1241,14 +1241,16 @@ inline bool GetPtrField(InterpState &S, CodePtr OpPC, uint32_t Off) {
!CheckNull(S, OpPC, Ptr, CSK_Field))
return false;
- if (CheckDummy(S, OpPC, Ptr)) {
- if (!CheckExtern(S, OpPC, Ptr))
- return false;
- if (!CheckRange(S, OpPC, Ptr, CSK_Field))
- return false;
- if (!CheckSubobject(S, OpPC, Ptr, CSK_Field))
- return false;
- }
+ if (!CheckExtern(S, OpPC, Ptr))
+ return false;
+ if (!CheckRange(S, OpPC, Ptr, CSK_Field))
+ return false;
+ if (!CheckSubobject(S, OpPC, Ptr, CSK_Field))
+ return false;
+
+ if (Ptr.isBlockPointer() && Off > Ptr.block()->getSize())
+ return false;
+
S.Stk.push<Pointer>(Ptr.atField(Off));
return true;
}
@@ -1992,11 +1994,6 @@ inline bool ArrayElemPtr(InterpState &S, CodePtr OpPC) {
if (!Ptr.isZero()) {
if (!CheckArray(S, OpPC, Ptr))
return false;
-
- if (Ptr.isDummy()) {
- S.Stk.push<Pointer>(Ptr);
- return true;
- }
}
if (!OffsetHelper<T, ArithOp::Add>(S, OpPC, Offset, Ptr))
@@ -2013,11 +2010,6 @@ inline bool ArrayElemPtrPop(InterpState &S, CodePtr OpPC) {
if (!Ptr.isZero()) {
if (!CheckArray(S, OpPC, Ptr))
return false;
-
- if (Ptr.isDummy()) {
- S.Stk.push<Pointer>(Ptr);
- return true;
- }
}
if (!OffsetHelper<T, ArithOp::Add>(S, OpPC, Offset, Ptr))
@@ -2053,12 +2045,12 @@ inline bool ArrayElemPop(InterpState &S, CodePtr OpPC, uint32_t Index) {
inline bool ArrayDecay(InterpState &S, CodePtr OpPC) {
const Pointer &Ptr = S.Stk.pop<Pointer>();
- if (Ptr.isZero() || Ptr.isDummy()) {
+ if (Ptr.isZero()) {
S.Stk.push<Pointer>(Ptr);
return true;
}
- if (!Ptr.isUnknownSizeArray()) {
+ if (!Ptr.isUnknownSizeArray() || Ptr.isDummy()) {
S.Stk.push<Pointer>(Ptr.atIndex(0));
return true;
}
diff --git a/clang/lib/AST/Interp/Pointer.cpp b/clang/lib/AST/Interp/Pointer.cpp
index 5ef31671ae7be5..c7708de8d8c79c 100644
--- a/clang/lib/AST/Interp/Pointer.cpp
+++ b/clang/lib/AST/Interp/Pointer.cpp
@@ -139,9 +139,10 @@ APValue Pointer::toAPValue() const {
else
llvm_unreachable("Invalid allocation type");
- if (isDummy() || isUnknownSizeArray() || Desc->asExpr())
+ if (isDummy() || isUnknownSizeArray() || Desc->asExpr()) {
return APValue(Base, CharUnits::Zero(), Path,
/*IsOnePastEnd=*/false, /*IsNullPtr=*/false);
+ }
// TODO: compute the offset into the object.
CharUnits Offset = CharUnits::Zero();
diff --git a/clang/lib/AST/Interp/Program.cpp b/clang/lib/AST/Interp/Program.cpp
index 2c8c6781b34833..f4c004dd082169 100644
--- a/clang/lib/AST/Interp/Program.cpp
+++ b/clang/lib/AST/Interp/Program.cpp
@@ -148,17 +148,20 @@ std::optional<unsigned> Program::getOrCreateDummy(const ValueDecl *VD) {
if (auto It = DummyVariables.find(VD); It != DummyVariables.end())
return It->second;
- // Create dummy descriptor.
- // We create desriptors of 'array of unknown size' if the type is an array
- // type _and_ the size isn't known (it's not a ConstantArrayType). If the size
- // is known however, we create a regular dummy pointer.
Descriptor *Desc;
- if (const auto *AT = VD->getType()->getAsArrayTypeUnsafe();
- AT && !isa<ConstantArrayType>(AT))
- Desc = allocateDescriptor(VD, Descriptor::UnknownSize{});
+ if (std::optional<PrimType> T = Ctx.classify(VD->getType()))
+ Desc = createDescriptor(VD, *T, std::nullopt, true, false);
else
+ Desc = createDescriptor(VD, VD->getType().getTypePtr(), std::nullopt, true,
+ false);
+ if (!Desc)
Desc = allocateDescriptor(VD);
+ assert(Desc);
+ Desc->makeDummy();
+
+ assert(Desc->isDummy());
+
// Allocate a block for storage.
unsigned I = Globals.size();
@@ -314,8 +317,7 @@ Record *Program::getOrCreateRecord(const RecordDecl *RD) {
for (const FieldDecl *FD : RD->fields()) {
// Note that we DO create fields and descriptors
// for unnamed bitfields here, even though we later ignore
- // them everywhere. That's because so the FieldDecl's
- // getFieldIndex() matches.
+ // them everywhere. That's so the FieldDecl's getFieldIndex() matches.
// Reserve space for the field's descriptor and the offset.
BaseSize += align(sizeof(InlineDescriptor));
@@ -348,6 +350,7 @@ Descriptor *Program::createDescriptor(const DeclTy &D, const Type *Ty,
Descriptor::MetadataSize MDSize,
bool IsConst, bool IsTemporary,
bool IsMutable, const Expr *Init) {
+
// Classes and structures.
if (const auto *RT = Ty->getAs<RecordType>()) {
if (const auto *Record = getOrCreateRecord(RT->getDecl()))
diff --git a/clang/test/AST/Interp/builtin-align-cxx.cpp b/clang/test/AST/Interp/builtin-align-cxx.cpp
index 62d73dba929b2c..c4103953df026a 100644
--- a/clang/test/AST/Interp/builtin-align-cxx.cpp
+++ b/clang/test/AST/Interp/builtin-align-cxx.cpp
@@ -2,19 +2,6 @@
// RUN: %clang_cc1 -triple=x86_64-unknown-unknown -std=c++11 %s -fsyntax-only -verify=expected,both -fexperimental-new-constant-interpreter
// RUN: %clang_cc1 -triple=x86_64-unknown-unknown -std=c++11 %s -fsyntax-only -verify=ref,both
-
-/// This is just a copy of the one from test/SemaCXX/ with some of the
-/// diagnostic output adapted.
-/// Also, align32array has an initializer now, which means it's not just
-/// a dummy pointer for us and we do actually have type information for it.
-/// In the future, we need to retain type information for dummy pointers as
-/// well, so here is a test that will break once we do that:
-namespace {
- _Alignas(32) char heh[4];
- static_assert(!__builtin_is_aligned(&heh[1], 4), ""); // expected-error {{failed}}
-}
-
-
// Check that we don't crash when using dependent types in __builtin_align:
template <typename a, a b>
void *c(void *d) { // both-note{{candidate template ignored}}
@@ -177,7 +164,7 @@ static_assert(wrap_align_up(static_cast<bool>(1), const_value(1 << 21)), ""); //
// both-note at -1{{in instantiation of function template specialization 'wrap_align_up<bool>' requested here}}
// Check constant evaluation for pointers:
-_Alignas(32) char align32array[128] = {};
+_Alignas(32) char align32array[128];
static_assert(&align32array[0] == &align32array[0], "");
// __builtin_align_up/down can be constant evaluated as a no-op for values
// that are known to have greater alignment:
diff --git a/clang/test/AST/Interp/c.c b/clang/test/AST/Interp/c.c
index 5ae9b1dc7bff86..db6739e8b19cb9 100644
--- a/clang/test/AST/Interp/c.c
+++ b/clang/test/AST/Interp/c.c
@@ -257,3 +257,7 @@ int Y __attribute__((annotate(
42,
(struct TestStruct) { .a = 1, .b = 2 }
)));
+
+/// This tests that we have full type info, even for values we cannot read.
+int dummyarray[5];
+_Static_assert(&dummyarray[0] < &dummyarray[1], ""); // pedantic-warning {{GNU extension}}
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