Panic with double insertion of type when combining CRTP with static assert, nested templates, and inner classes

[pcwalton]

Input C/C++ Header

Tricky one here. This one also comes from Folly and is as minimal as I could get it. Removing pretty much any line makes the problem go away. In particular I'm suspicious of the static_assert…

template<class T>
class ClassA {
public:
    class ClassAInner {
    public:
        T *x;
    };
};

template<class D, class I>
class ClassB {
public:
    void foo() {
        ((D *)nullptr)->quux();
    }
};

template<typename T>
class ClassC {
    struct ClassCInnerA;

    struct ClassCInnerB {
        ClassCInnerA *cache;
    };
    static_assert(__is_pod(ClassCInnerB), "");

    struct ClassCInnerA {
        ClassCInnerB *member;
    };

public:
    class ClassCInnerCRTP : public ClassB<ClassCInnerCRTP, typename ClassA<ClassCInnerA>::ClassAInner> {
    public:
        void quux() {
            ((typename ClassA<ClassCInnerA>::ClassAInner *)nullptr)->x->member;
        }
    };
};

class ClassD : public ClassB<ClassD, ClassC<int>::ClassCInnerCRTP> {
public:
    void bar() {
        ((ClassC<int>::ClassCInnerCRTP *)nullptr)->foo();
    }
};

Bindgen Invocation

$ bindgen test.h -- -std=c++11

Actual Results

thread 'main' panicked at 'assertion failed: `(left == right)`
  left: `Some(TypeId(ItemId(51)))`,
 right: `None`', src/ir/context.rs:745:13
stack backtrace:
   0: rust_begin_unwind
             at /rustc/7af1f55ae359e731c2c303f5d98e42a1a8163af0/library/std/src/panicking.rs:493:5
   1: core::panicking::panic_fmt
             at /rustc/7af1f55ae359e731c2c303f5d98e42a1a8163af0/library/core/src/panicking.rs:92:14
   2: core::panicking::assert_failed_inner
             at /rustc/7af1f55ae359e731c2c303f5d98e42a1a8163af0/library/core/src/panicking.rs:160:17
   3: core::panicking::assert_failed
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/panicking.rs:117:5
   4: bindgen::ir::context::BindgenContext::add_item
             at ./src/ir/context.rs:745:13
   5: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_with_id
             at ./src/ir/item.rs:1653:17
   6: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_or_ref_with_id
             at ./src/ir/item.rs:1496:20
   7: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_or_ref
             at ./src/ir/item.rs:1469:9
   8: bindgen::ir::ty::Type::from_clang_ty
             at ./src/ir/ty.rs:1074:25
   9: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_with_id
             at ./src/ir/item.rs:1646:22
  10: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_or_ref_with_id
             at ./src/ir/item.rs:1496:20
  11: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_or_ref
             at ./src/ir/item.rs:1469:9
  12: bindgen::ir::comp::CompInfo::from_ty::{{closure}}
             at ./src/ir/comp.rs:1336:38
  13: bindgen::clang::visit_children
             at ./src/clang.rs:906:5
  14: __ZN5clang8cxcursor13CursorVisitor5VisitE8CXCursorb
  15: __ZN5clang8cxcursor13CursorVisitor23handleDeclForVisitationEPKNS_4DeclE
  16: __ZN5clang8cxcursor13CursorVisitor16VisitDeclContextEPNS_11DeclContextE
  17: __ZN5clang8cxcursor13CursorVisitor18VisitCXXRecordDeclEPNS_13CXXRecordDeclE
  18: __ZN5clang8cxcursor13CursorVisitor13VisitChildrenE8CXCursor
  19: _clang_visitChildren
  20: clang_sys::clang_visitChildren
             at /Users/pcwalton/.cargo/registry/src/github.com-1ecc6299db9ec823/clang-sys-1.0.3/src/link.rs:165:17
  21: bindgen::clang::Cursor::visit
             at ./src/clang.rs:406:13
  22: bindgen::ir::comp::CompInfo::from_ty
             at ./src/ir/comp.rs:1292:9
  23: bindgen::ir::ty::Type::from_clang_ty
             at ./src/ir/ty.rs:1138:35
  24: bindgen::ir::ty::Type::from_clang_ty
             at ./src/ir/ty.rs:1178:28
  25: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_with_id
             at ./src/ir/item.rs:1646:22
  26: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_or_ref_with_id
             at ./src/ir/item.rs:1496:20
  27: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_or_ref
             at ./src/ir/item.rs:1469:9
  28: bindgen::ir::template::TemplateInstantiation::from_ty::{{closure}}::{{closure}}
             at ./src/ir/template.rs:236:25
  29: core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &mut F>::call_once
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/ops/function.rs:280:13
  30: core::option::Option<T>::map
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/option.rs:487:29
  31: <core::iter::adapters::map::Map<I,F> as core::iter::traits::iterator::Iterator>::next
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/iter/adapters/map.rs:101:9
  32: alloc::vec::Vec<T,A>::extend_desugared
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc/src/vec/mod.rs:2501:35
  33: <alloc::vec::Vec<T,A> as alloc::vec::spec_extend::SpecExtend<T,I>>::spec_extend
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc/src/vec/spec_extend.rs:18:9
  34: <alloc::vec::Vec<T> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<T,I>>::from_iter
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc/src/vec/spec_from_iter_nested.rs:37:9
  35: <alloc::vec::Vec<T> as alloc::vec::spec_from_iter::SpecFromIter<T,I>>::from_iter
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc/src/vec/spec_from_iter.rs:36:9
  36: <alloc::vec::Vec<T> as core::iter::traits::collect::FromIterator<T>>::from_iter
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc/src/vec/mod.rs:2406:9
  37: core::iter::traits::iterator::Iterator::collect
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/iter/traits/iterator.rs:1798:9
  38: bindgen::ir::template::TemplateInstantiation::from_ty::{{closure}}
             at ./src/ir/template.rs:233:17
  39: core::option::Option<T>::map_or
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/option.rs:514:24
  40: bindgen::ir::template::TemplateInstantiation::from_ty
             at ./src/ir/template.rs:227:29
  41: bindgen::ir::ty::Type::from_clang_ty
             at ./src/ir/ty.rs:794:19
  42: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_with_id
             at ./src/ir/item.rs:1646:22
  43: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_or_ref_with_id
             at ./src/ir/item.rs:1496:20
  44: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_or_ref
             at ./src/ir/item.rs:1469:9
  45: bindgen::ir::comp::CompInfo::from_ty::{{closure}}
             at ./src/ir/comp.rs:1453:25
  46: bindgen::clang::visit_children
             at ./src/clang.rs:906:5
  47: __ZN5clang8cxcursor13CursorVisitor5VisitE8CXCursorb
  48: __ZN5clang8cxcursor13CursorVisitor18VisitCXXRecordDeclEPNS_13CXXRecordDeclE
  49: __ZN5clang8cxcursor13CursorVisitor13VisitChildrenE8CXCursor
  50: _clang_visitChildren
  51: clang_sys::clang_visitChildren
             at /Users/pcwalton/.cargo/registry/src/github.com-1ecc6299db9ec823/clang-sys-1.0.3/src/link.rs:165:17
  52: bindgen::clang::Cursor::visit
             at ./src/clang.rs:406:13
  53: bindgen::ir::comp::CompInfo::from_ty
             at ./src/ir/comp.rs:1292:9
  54: bindgen::ir::ty::Type::from_clang_ty
             at ./src/ir/ty.rs:1138:35
  55: bindgen::ir::ty::Type::from_clang_ty
             at ./src/ir/ty.rs:1178:28
  56: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_with_id
             at ./src/ir/item.rs:1646:22
  57: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_or_ref_with_id
             at ./src/ir/item.rs:1496:20
  58: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_or_ref
             at ./src/ir/item.rs:1469:9
  59: bindgen::ir::template::TemplateInstantiation::from_ty::{{closure}}::{{closure}}
             at ./src/ir/template.rs:236:25
  60: core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &mut F>::call_once
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/ops/function.rs:280:13
  61: core::option::Option<T>::map
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/option.rs:487:29
  62: <core::iter::adapters::map::Map<I,F> as core::iter::traits::iterator::Iterator>::next
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/iter/adapters/map.rs:101:9
  63: alloc::vec::Vec<T,A>::extend_desugared
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc/src/vec/mod.rs:2501:35
  64: <alloc::vec::Vec<T,A> as alloc::vec::spec_extend::SpecExtend<T,I>>::spec_extend
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc/src/vec/spec_extend.rs:18:9
  65: <alloc::vec::Vec<T> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<T,I>>::from_iter
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc/src/vec/spec_from_iter_nested.rs:37:9
  66: <alloc::vec::Vec<T> as alloc::vec::spec_from_iter::SpecFromIter<T,I>>::from_iter
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc/src/vec/spec_from_iter.rs:36:9
  67: <alloc::vec::Vec<T> as core::iter::traits::collect::FromIterator<T>>::from_iter
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc/src/vec/mod.rs:2406:9
  68: core::iter::traits::iterator::Iterator::collect
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/iter/traits/iterator.rs:1798:9
  69: bindgen::ir::template::TemplateInstantiation::from_ty::{{closure}}
             at ./src/ir/template.rs:233:17
  70: core::option::Option<T>::map_or
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/option.rs:514:24
  71: bindgen::ir::template::TemplateInstantiation::from_ty
             at ./src/ir/template.rs:227:29
  72: bindgen::ir::ty::Type::from_clang_ty
             at ./src/ir/ty.rs:794:19
  73: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty_with_id
             at ./src/ir/item.rs:1646:22
  74: <bindgen::ir::item::Item as bindgen::parse::ClangItemParser>::from_ty
             at ./src/ir/item.rs:1543:9
  75: bindgen::ir::context::BindgenContext::resolve_typerefs
             at ./src/ir/context.rs:925:36
  76: bindgen::ir::context::BindgenContext::gen
             at ./src/ir/context.rs:1157:9
  77: bindgen::codegen::codegen
             at ./src/codegen/mod.rs:4227:5
  78: bindgen::Bindings::generate
             at ./src/lib.rs:2349:32
  79: bindgen::Builder::generate
             at ./src/lib.rs:1469:9
  80: bindgen::main::{{closure}}
             at ./src/main.rs:54:17
  81: std::panicking::try::do_call
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/std/src/panicking.rs:379:40
  82: ___rust_try
  83: std::panicking::try
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/std/src/panicking.rs:343:19
  84: std::panic::catch_unwind
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/std/src/panic.rs:431:14
  85: bindgen::main
             at ./src/main.rs:53:34
  86: core::ops::function::FnOnce::call_once
             at /Users/pcwalton/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/ops/function.rs:227:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

Expected Results

We don't care about the generated bindings for this class, but we need to not panic.