[AST] CastExpr: BasePathSize is not large enough.
Summary:
rC337815 / D49508 had to cannibalize one bit of `CastExprBitfields::BasePathSize` in order to squeeze `PartOfExplicitCast` boolean.
That reduced the maximal value of `PartOfExplicitCast` from 9 bits (~512) down to 8 bits (~256).
Apparently, that mattered. Too bad there weren't any tests.
It caused [[ https://bugs.llvm.org/show_bug.cgi?id=38356 | PR38356 ]].
So we need to increase `PartOfExplicitCast` back at least to 9 bits, or a bit more.
For obvious reasons, we can't do that in `CastExprBitfields` - that would blow up the size of every `Expr`.
So we need to either just add a variable into the `CastExpr` (as done here),
or use `llvm::TrailingObjects`. The latter does not seem to be straight-forward.
Perhaps, that needs to be done not for the `CastExpr` itself, but for all of it's `final` children.
Reviewers: rjmccall, rsmith, erichkeane
Reviewed By: rjmccall
Subscribers: bricci, hans, cfe-commits, waddlesplash
Differential Revision: https://reviews.llvm.org/D50050
llvm-svn: 338489
diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index dd1996d..7556c76 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -1734,6 +1734,21 @@
return nullptr;
}
+CastExpr::BasePathSizeTy *CastExpr::BasePathSize() {
+ assert(!path_empty());
+ switch (getStmtClass()) {
+#define ABSTRACT_STMT(x)
+#define CASTEXPR(Type, Base) \
+ case Stmt::Type##Class: \
+ return static_cast<Type *>(this) \
+ ->getTrailingObjects<CastExpr::BasePathSizeTy>();
+#define STMT(Type, Base)
+#include "clang/AST/StmtNodes.inc"
+ default:
+ llvm_unreachable("non-cast expressions not possible here");
+ }
+}
+
CXXBaseSpecifier **CastExpr::path_buffer() {
switch (getStmtClass()) {
#define ABSTRACT_STMT(x)
@@ -1772,7 +1787,9 @@
const CXXCastPath *BasePath,
ExprValueKind VK) {
unsigned PathSize = (BasePath ? BasePath->size() : 0);
- void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
+ void *Buffer =
+ C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
+ PathSize ? 1 : 0, PathSize));
ImplicitCastExpr *E =
new (Buffer) ImplicitCastExpr(T, Kind, Operand, PathSize, VK);
if (PathSize)
@@ -1783,7 +1800,9 @@
ImplicitCastExpr *ImplicitCastExpr::CreateEmpty(const ASTContext &C,
unsigned PathSize) {
- void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
+ void *Buffer =
+ C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
+ PathSize ? 1 : 0, PathSize));
return new (Buffer) ImplicitCastExpr(EmptyShell(), PathSize);
}
@@ -1794,7 +1813,9 @@
TypeSourceInfo *WrittenTy,
SourceLocation L, SourceLocation R) {
unsigned PathSize = (BasePath ? BasePath->size() : 0);
- void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
+ void *Buffer =
+ C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
+ PathSize ? 1 : 0, PathSize));
CStyleCastExpr *E =
new (Buffer) CStyleCastExpr(T, VK, K, Op, PathSize, WrittenTy, L, R);
if (PathSize)
@@ -1805,7 +1826,9 @@
CStyleCastExpr *CStyleCastExpr::CreateEmpty(const ASTContext &C,
unsigned PathSize) {
- void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
+ void *Buffer =
+ C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
+ PathSize ? 1 : 0, PathSize));
return new (Buffer) CStyleCastExpr(EmptyShell(), PathSize);
}