[Clang][counted-by] Bail out of visitor for LValueToRValue cast #125571
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An LValueToRValue cast shouldn't be ignored, so bail out of the visitor if we encounter one.
llvmbot
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clang
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@llvm/pr-subscribers-clang Author: Bill Wendling (bwendling) ChangesAn LValueToRValue cast shouldn't be ignored, so bail out of the visitor if we encounter one. Full diff: https://github.com/llvm/llvm-project/pull/125571.diff 1 Files Affected:
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 11fa295dad9524..339bcd14c5bc8c 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1055,20 +1055,20 @@ namespace {
/// StructFieldAccess is a simple visitor class to grab the first MemberExpr
/// from an Expr. It records any ArraySubscriptExpr we meet along the way.
class StructFieldAccess
- : public ConstStmtVisitor<StructFieldAccess, const MemberExpr *> {
+ : public ConstStmtVisitor<StructFieldAccess, const Expr *> {
bool AddrOfSeen = false;
public:
const ArraySubscriptExpr *ASE = nullptr;
- const MemberExpr *VisitMemberExpr(const MemberExpr *E) {
+ const Expr *VisitMemberExpr(const MemberExpr *E) {
if (AddrOfSeen && E->getType()->isArrayType())
// Avoid forms like '&ptr->array'.
return nullptr;
return E;
}
- const MemberExpr *VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
+ const Expr *VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
if (ASE)
// We don't support multiple subscripts.
return nullptr;
@@ -1077,17 +1077,19 @@ class StructFieldAccess
ASE = E;
return Visit(E->getBase());
}
- const MemberExpr *VisitCastExpr(const CastExpr *E) {
+ const Expr *VisitCastExpr(const CastExpr *E) {
+ if (E->getCastKind() == CK_LValueToRValue)
+ return E;
return Visit(E->getSubExpr());
}
- const MemberExpr *VisitParenExpr(const ParenExpr *E) {
+ const Expr *VisitParenExpr(const ParenExpr *E) {
return Visit(E->getSubExpr());
}
- const MemberExpr *VisitUnaryAddrOf(const clang::UnaryOperator *E) {
+ const Expr *VisitUnaryAddrOf(const clang::UnaryOperator *E) {
AddrOfSeen = true;
return Visit(E->getSubExpr());
}
- const MemberExpr *VisitUnaryDeref(const clang::UnaryOperator *E) {
+ const Expr *VisitUnaryDeref(const clang::UnaryOperator *E) {
AddrOfSeen = false;
return Visit(E->getSubExpr());
}
@@ -1188,7 +1190,7 @@ CodeGenFunction::emitCountedByMemberSize(const Expr *E, llvm::Value *EmittedE,
// GCC does for consistency's sake.
StructFieldAccess Visitor;
- const MemberExpr *ME = Visitor.Visit(E);
+ const MemberExpr *ME = dyn_cast_if_present<MemberExpr>(Visitor.Visit(E));
if (!ME)
return nullptr;
|
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@llvm/pr-subscribers-clang-codegen Author: Bill Wendling (bwendling) ChangesAn LValueToRValue cast shouldn't be ignored, so bail out of the visitor if we encounter one. Full diff: https://github.com/llvm/llvm-project/pull/125571.diff 1 Files Affected:
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 11fa295dad9524..339bcd14c5bc8c 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1055,20 +1055,20 @@ namespace {
/// StructFieldAccess is a simple visitor class to grab the first MemberExpr
/// from an Expr. It records any ArraySubscriptExpr we meet along the way.
class StructFieldAccess
- : public ConstStmtVisitor<StructFieldAccess, const MemberExpr *> {
+ : public ConstStmtVisitor<StructFieldAccess, const Expr *> {
bool AddrOfSeen = false;
public:
const ArraySubscriptExpr *ASE = nullptr;
- const MemberExpr *VisitMemberExpr(const MemberExpr *E) {
+ const Expr *VisitMemberExpr(const MemberExpr *E) {
if (AddrOfSeen && E->getType()->isArrayType())
// Avoid forms like '&ptr->array'.
return nullptr;
return E;
}
- const MemberExpr *VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
+ const Expr *VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
if (ASE)
// We don't support multiple subscripts.
return nullptr;
@@ -1077,17 +1077,19 @@ class StructFieldAccess
ASE = E;
return Visit(E->getBase());
}
- const MemberExpr *VisitCastExpr(const CastExpr *E) {
+ const Expr *VisitCastExpr(const CastExpr *E) {
+ if (E->getCastKind() == CK_LValueToRValue)
+ return E;
return Visit(E->getSubExpr());
}
- const MemberExpr *VisitParenExpr(const ParenExpr *E) {
+ const Expr *VisitParenExpr(const ParenExpr *E) {
return Visit(E->getSubExpr());
}
- const MemberExpr *VisitUnaryAddrOf(const clang::UnaryOperator *E) {
+ const Expr *VisitUnaryAddrOf(const clang::UnaryOperator *E) {
AddrOfSeen = true;
return Visit(E->getSubExpr());
}
- const MemberExpr *VisitUnaryDeref(const clang::UnaryOperator *E) {
+ const Expr *VisitUnaryDeref(const clang::UnaryOperator *E) {
AddrOfSeen = false;
return Visit(E->getSubExpr());
}
@@ -1188,7 +1190,7 @@ CodeGenFunction::emitCountedByMemberSize(const Expr *E, llvm::Value *EmittedE,
// GCC does for consistency's sake.
StructFieldAccess Visitor;
- const MemberExpr *ME = Visitor.Visit(E);
+ const MemberExpr *ME = dyn_cast_if_present<MemberExpr>(Visitor.Visit(E));
if (!ME)
return nullptr;
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This change didn't affect the tests, which is either good or bad, depending on your point of view. I assume that it's okay because we're looking for a |
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My expectation was that this would affect the tests from #125298, because the MemberExpr there is a child of an LValueToRValue conversion. I could be missing something, though? |
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Those tests are meant to bail out if the MemberExpr is a pointer. That patch may be superseded by this patch? |
Icohedron
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Feb 11, 2025
…#125571) An LValueToRValue cast shouldn't be ignored, so bail out of the visitor if we encounter one.
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An LValueToRValue cast shouldn't be ignored, so bail out of the visitor if we encounter one.