[clang][bytecode] Create implicit variables for wider base types #156658
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@llvm/pr-subscribers-clang Author: Timm Baeder (tbaederr) ChangesIf we create an implicit local variable for a derived-to-base cast, we still should allocate enough space for the entire derived type. Fixes #156219 Full diff: https://github.com/llvm/llvm-project/pull/156658.diff 2 Files Affected:
diff --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
index 89ff5d27a4143..908c2c15cb041 100644
--- a/clang/lib/AST/ByteCode/Compiler.cpp
+++ b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -4191,6 +4191,19 @@ template <class Emitter> bool Compiler<Emitter>::delegate(const Expr *E) {
return this->Visit(E);
}
+static const Expr *stripDerivedToBaseCasts(const Expr *E) {
+ if (const auto *PE = dyn_cast<ParenExpr>(E))
+ return stripDerivedToBaseCasts(PE->getSubExpr());
+
+ if (const auto *CE = dyn_cast<CastExpr>(E);
+ CE && (CE->getCastKind() == CK_DerivedToBase ||
+ CE->getCastKind() == CK_UncheckedDerivedToBase ||
+ CE->getCastKind() == CK_NoOp))
+ return stripDerivedToBaseCasts(CE->getSubExpr());
+
+ return E;
+}
+
template <class Emitter> bool Compiler<Emitter>::visit(const Expr *E) {
if (E->getType().isNull())
return false;
@@ -4200,7 +4213,7 @@ template <class Emitter> bool Compiler<Emitter>::visit(const Expr *E) {
// Create local variable to hold the return value.
if (!E->isGLValue() && !canClassify(E->getType())) {
- UnsignedOrNone LocalIndex = allocateLocal(E);
+ UnsignedOrNone LocalIndex = allocateLocal(stripDerivedToBaseCasts(E));
if (!LocalIndex)
return false;
@@ -5078,18 +5091,6 @@ bool Compiler<Emitter>::VisitBuiltinCallExpr(const CallExpr *E,
return true;
}
-static const Expr *stripDerivedToBaseCasts(const Expr *E) {
- if (const auto *PE = dyn_cast<ParenExpr>(E))
- return stripDerivedToBaseCasts(PE->getSubExpr());
-
- if (const auto *CE = dyn_cast<CastExpr>(E);
- CE &&
- (CE->getCastKind() == CK_DerivedToBase || CE->getCastKind() == CK_NoOp))
- return stripDerivedToBaseCasts(CE->getSubExpr());
-
- return E;
-}
-
template <class Emitter>
bool Compiler<Emitter>::VisitCallExpr(const CallExpr *E) {
const FunctionDecl *FuncDecl = E->getDirectCallee();
diff --git a/clang/test/AST/ByteCode/cxx03.cpp b/clang/test/AST/ByteCode/cxx03.cpp
index 70ae4134842b5..10e5232b9f873 100644
--- a/clang/test/AST/ByteCode/cxx03.cpp
+++ b/clang/test/AST/ByteCode/cxx03.cpp
@@ -29,3 +29,14 @@ void LambdaAccessingADummy() {
int d;
int a9[1] = {[d = 0] = 1}; // both-error {{is not an integral constant expression}}
}
+
+const int p = 10;
+struct B {
+ int a;
+ void *p;
+};
+struct B2 : B {
+ void *q;
+};
+_Static_assert(&(B2().a) == &p, ""); // both-error {{taking the address of a temporary object of type 'int'}} \
+ // both-error {{not an integral constant expression}}
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If we create an implicit local variable for a derived-to-base cast, we still should allocate enough space for the entire derived type. Fixes llvm#156219
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If we create an implicit local variable for a derived-to-base cast, we still should allocate enough space for the entire derived type.
Fixes #156219