]> granicus.if.org Git - clang/commit
[Sema] Mark implicitly-inserted ICE's as being part of explicit cast (PR38166)
authorRoman Lebedev <lebedev.ri@gmail.com>
Tue, 24 Jul 2018 08:16:50 +0000 (08:16 +0000)
committerRoman Lebedev <lebedev.ri@gmail.com>
Tue, 24 Jul 2018 08:16:50 +0000 (08:16 +0000)
commit03e3fc09a8ccc11a30ab6be813d4b5eb91dad1b3
tree05a43893e75a3266953ad9dfbec90973a51f186f
parent8bc411272bb860c0e22764eccaef4b0f9b55e905
[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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@337815 91177308-0d34-0410-b5e6-96231b3b80d8
include/clang/AST/Expr.h
include/clang/AST/Stmt.h
lib/AST/ASTDumper.cpp
lib/Sema/SemaCast.cpp
lib/Serialization/ASTReaderStmt.cpp
lib/Serialization/ASTWriterDecl.cpp
lib/Serialization/ASTWriterStmt.cpp
test/PCH/cxx_exprs.cpp
test/Sema/multistep-explicit-cast.c [new file with mode: 0644]
test/SemaCXX/multistep-explicit-cast.cpp [new file with mode: 0644]
test/SemaOpenCL/multistep-explicit-cast.cl [new file with mode: 0644]