[Sema] Mark implicitly-inserted ICE's as being part of explicit cast (PR38166)
Summary:
As discussed in [[ https://bugs.llvm.org/show_bug.cgi?id=38166 | PR38166 ]], we need to be able to distinqush whether the cast
we are visiting is actually a cast, or part of an `ExplicitCast`.
There are at least four ways to get there:
1. Introduce a new `CastKind`, and use it instead of `IntegralCast` if we are in `ExplicitCast`.
Would work, but does not scale - what if we will need more of these cast kinds?
2. Introduce a flag in `CastExprBits`, whether this cast is part of `ExplicitCast` or not.
Would work, but it isn't immediately clear where it needs to be set.
2. Fix `ScalarExprEmitter::VisitCastExpr()` to visit these `NoOp` casts.
As pointed out by @rsmith, CodeGenFunction::EmitMaterializeTemporaryExpr calls
skipRValueSubobjectAdjustments, which steps over the CK_NoOp cast`,
which explains why we currently don't visit those.
This is probably impossible, as @efriedma points out, that is intentional as per `[class.temporary]` in the standard
3. And the simplest one, just record which NoOp casts we skip.
It just kinda works as-is afterwards.
But, the approach with a flag is the least intrusive one, and is probably the best one overall.
Reviewers: rsmith, rjmccall, majnemer, efriedma
Reviewed By: rsmith
Subscribers: cfe-commits, aaron.ballman, vsk, llvm-commits, rsmith
Differential Revision: https://reviews.llvm.org/D49508
llvm-svn: 337815
diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index 2b7de79..ee03b6d 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -723,6 +723,7 @@
assert(NumBaseSpecs == E->path_size());
E->setSubExpr(Record.readSubExpr());
E->setCastKind((CastKind)Record.readInt());
+ E->setIsPartOfExplicitCast(Record.readInt());
CastExpr::path_iterator BaseI = E->path_begin();
while (NumBaseSpecs--) {
auto *BaseSpec = new (Record.getContext()) CXXBaseSpecifier;
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index 1fac13e..61d9fed 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -2192,6 +2192,7 @@
// CastExpr
Abv->Add(BitCodeAbbrevOp(0)); // PathSize
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 6)); // CastKind
+ Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // PartOfExplicitCast
// ImplicitCastExpr
ExprImplicitCastAbbrev = Stream.EmitAbbrev(std::move(Abv));
diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index b79e80e..79156dc 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -665,6 +665,7 @@
Record.push_back(E->path_size());
Record.AddStmt(E->getSubExpr());
Record.push_back(E->getCastKind()); // FIXME: stable encoding
+ Record.push_back(E->getIsPartOfExplicitCast());
for (CastExpr::path_iterator
PI = E->path_begin(), PE = E->path_end(); PI != PE; ++PI)