[clang] 6172960 - [clang][Interp] Basic support for bit fields
Timm Bäder via cfe-commits
cfe-commits at lists.llvm.org
Tue Oct 10 04:50:24 PDT 2023
Author: Timm Bäder
Date: 2023-10-10T13:38:26+02:00
New Revision: 6172960ceae2cbee743214af59018ea108f231d9
URL: https://github.com/llvm/llvm-project/commit/6172960ceae2cbee743214af59018ea108f231d9
DIFF: https://github.com/llvm/llvm-project/commit/6172960ceae2cbee743214af59018ea108f231d9.diff
LOG: [clang][Interp] Basic support for bit fields
Differential Revision: https://reviews.llvm.org/D155548
Added:
clang/test/AST/Interp/bitfields.cpp
Modified:
clang/lib/AST/Interp/ByteCodeExprGen.cpp
clang/lib/AST/Interp/ByteCodeStmtGen.cpp
clang/lib/AST/Interp/Interp.h
clang/lib/AST/Interp/Record.h
Removed:
################################################################################
diff --git a/clang/lib/AST/Interp/ByteCodeExprGen.cpp b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
index 9bd040a208b3f95..e7a431ddee6f002 100644
--- a/clang/lib/AST/Interp/ByteCodeExprGen.cpp
+++ b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -342,8 +342,10 @@ bool ByteCodeExprGen<Emitter>::VisitBinaryOperator(const BinaryOperator *BO) {
return Discard(this->emitDiv(*T, BO));
case BO_Assign:
if (DiscardResult)
- return this->emitStorePop(*T, BO);
- return this->emitStore(*T, BO);
+ return LHS->refersToBitField() ? this->emitStoreBitFieldPop(*T, BO)
+ : this->emitStorePop(*T, BO);
+ return LHS->refersToBitField() ? this->emitStoreBitField(*T, BO)
+ : this->emitStore(*T, BO);
case BO_And:
return Discard(this->emitBitAnd(*T, BO));
case BO_Or:
@@ -547,8 +549,15 @@ bool ByteCodeExprGen<Emitter>::visitInitList(ArrayRef<const Expr *> Inits,
const Record::Field *FieldToInit = R->getField(InitIndex);
if (!this->visit(Init))
return false;
- if (!this->emitInitField(*T, FieldToInit->Offset, E))
- return false;
+
+ if (FieldToInit->isBitField()) {
+ if (!this->emitInitBitField(*T, FieldToInit, E))
+ return false;
+ } else {
+ if (!this->emitInitField(*T, FieldToInit->Offset, E))
+ return false;
+ }
+
if (!this->emitPopPtr(E))
return false;
++InitIndex;
diff --git a/clang/lib/AST/Interp/ByteCodeStmtGen.cpp b/clang/lib/AST/Interp/ByteCodeStmtGen.cpp
index a81c82c38955e9c..6193a8d55a14685 100644
--- a/clang/lib/AST/Interp/ByteCodeStmtGen.cpp
+++ b/clang/lib/AST/Interp/ByteCodeStmtGen.cpp
@@ -166,8 +166,13 @@ bool ByteCodeStmtGen<Emitter>::visitFunc(const FunctionDecl *F) {
if (!this->visit(InitExpr))
return false;
- if (!this->emitInitThisField(*T, F->Offset, InitExpr))
- return false;
+ if (F->isBitField()) {
+ if (!this->emitInitThisBitField(*T, F, InitExpr))
+ return false;
+ } else {
+ if (!this->emitInitThisField(*T, F->Offset, InitExpr))
+ return false;
+ }
} else {
// Non-primitive case. Get a pointer to the field-to-initialize
// on the stack and call visitInitialzer() for it.
diff --git a/clang/lib/AST/Interp/Interp.h b/clang/lib/AST/Interp/Interp.h
index 47dc1d08c9c4d8b..25ce93ac03d3733 100644
--- a/clang/lib/AST/Interp/Interp.h
+++ b/clang/lib/AST/Interp/Interp.h
@@ -1071,6 +1071,7 @@ bool InitThisField(InterpState &S, CodePtr OpPC, uint32_t I) {
template <PrimType Name, class T = typename PrimConv<Name>::T>
bool InitThisBitField(InterpState &S, CodePtr OpPC, const Record::Field *F) {
+ assert(F->isBitField());
if (S.checkingPotentialConstantExpression())
return false;
const Pointer &This = S.Current->getThis();
@@ -1112,8 +1113,9 @@ bool InitField(InterpState &S, CodePtr OpPC, uint32_t I) {
template <PrimType Name, class T = typename PrimConv<Name>::T>
bool InitBitField(InterpState &S, CodePtr OpPC, const Record::Field *F) {
+ assert(F->isBitField());
const T &Value = S.Stk.pop<T>();
- const Pointer &Field = S.Stk.pop<Pointer>().atField(F->Offset);
+ const Pointer &Field = S.Stk.peek<Pointer>().atField(F->Offset);
Field.deref<T>() = Value.truncate(F->Decl->getBitWidthValue(S.getCtx()));
Field.activate();
Field.initialize();
@@ -1334,11 +1336,10 @@ bool StoreBitField(InterpState &S, CodePtr OpPC) {
return false;
if (!Ptr.isRoot())
Ptr.initialize();
- if (auto *FD = Ptr.getField()) {
+ if (const auto *FD = Ptr.getField())
Ptr.deref<T>() = Value.truncate(FD->getBitWidthValue(S.getCtx()));
- } else {
+ else
Ptr.deref<T>() = Value;
- }
return true;
}
@@ -1350,11 +1351,10 @@ bool StoreBitFieldPop(InterpState &S, CodePtr OpPC) {
return false;
if (!Ptr.isRoot())
Ptr.initialize();
- if (auto *FD = Ptr.getField()) {
+ if (const auto *FD = Ptr.getField())
Ptr.deref<T>() = Value.truncate(FD->getBitWidthValue(S.getCtx()));
- } else {
+ else
Ptr.deref<T>() = Value;
- }
return true;
}
diff --git a/clang/lib/AST/Interp/Record.h b/clang/lib/AST/Interp/Record.h
index b81070aa77e8413..b0952af2d1ac6cc 100644
--- a/clang/lib/AST/Interp/Record.h
+++ b/clang/lib/AST/Interp/Record.h
@@ -29,6 +29,7 @@ class Record final {
const FieldDecl *Decl;
unsigned Offset;
Descriptor *Desc;
+ bool isBitField() const { return Decl->isBitField(); }
};
/// Describes a base class.
diff --git a/clang/test/AST/Interp/bitfields.cpp b/clang/test/AST/Interp/bitfields.cpp
new file mode 100644
index 000000000000000..e078704fce51ff0
--- /dev/null
+++ b/clang/test/AST/Interp/bitfields.cpp
@@ -0,0 +1,47 @@
+// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -Wno-bitfield-constant-conversion -verify %s
+// RUN: %clang_cc1 -verify=ref -Wno-bitfield-constant-conversion %s
+
+// expected-no-diagnostics
+// ref-no-diagnostics
+
+namespace Basic {
+ struct A {
+ unsigned int a : 2;
+ constexpr A() : a(0) {}
+ constexpr A(int a) : a(a) {}
+ };
+
+ constexpr A a{1};
+ static_assert(a.a == 1, "");
+
+ constexpr A a2{10};
+ static_assert(a2.a == 2, "");
+
+
+ constexpr int storeA() {
+ A a;
+ a.a = 10;
+
+ return a.a;
+ }
+ static_assert(storeA() == 2, "");
+
+ constexpr int storeA2() {
+ A a;
+ return a.a = 10;
+ }
+ static_assert(storeA2() == 2, "");
+
+ // TODO: +=, -=, etc. operators.
+}
+
+namespace Overflow {
+ struct A {int c:3;};
+
+ constexpr int f() {
+ A a1{3};
+ return a1.c++;
+ }
+
+ static_assert(f() == 3, "");
+}
More information about the cfe-commits
mailing list