Bootstrapped and regtested on x86_64-pc-linux-gnu, OK for trunk? -- >8 --
Currently, reading a variable definition always marks that decl as DECL_NOT_REALLY_EXTERN, with anything else imported still being considered external. This is not sufficient for vtables, however; for an extern template, a vtable may be generated (and its definition emitted) but nonetheless the vtable should only be emitted in the TU where that template is actually instantiated. While playing around with various settings of DECL_EXTERNAL I also noticed that we mark variables not declared 'inline' as external, which makes sense (there's a definition in another TU, while for vague linkage variables we'll be importing the definition too), but we also do so for 'static constexpr' members that aren't directly marked 'inline'. This fixes that for consistency, if nothing else (I wasn't able to cause an actual issue exploiting this currently), but may become relevant with https://github.com/itanium-cxx-abi/cxx-abi/issues/170. PR c++/114229 gcc/cp/ChangeLog: * module.cc (trees_out::core_bools): Count 'static constexpr' vars also as inline. (trees_out::write_var_def): Stream DECL_NOT_REALLY_EXTERN for vtables. (trees_in::read_var_def): Read it. gcc/testsuite/ChangeLog: * g++.dg/modules/virt-2_c.C: * g++.dg/modules/virt-3_a.C: New test. * g++.dg/modules/virt-3_b.C: New test. * g++.dg/modules/virt-3_c.C: New test. * g++.dg/modules/virt-3_d.C: New test. Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com> --- gcc/cp/module.cc | 15 +++++++++++++-- gcc/testsuite/g++.dg/modules/virt-2_c.C | 14 +++++++++----- gcc/testsuite/g++.dg/modules/virt-3_a.C | 9 +++++++++ gcc/testsuite/g++.dg/modules/virt-3_b.C | 6 ++++++ gcc/testsuite/g++.dg/modules/virt-3_c.C | 3 +++ gcc/testsuite/g++.dg/modules/virt-3_d.C | 7 +++++++ 6 files changed, 47 insertions(+), 7 deletions(-) create mode 100644 gcc/testsuite/g++.dg/modules/virt-3_a.C create mode 100644 gcc/testsuite/g++.dg/modules/virt-3_b.C create mode 100644 gcc/testsuite/g++.dg/modules/virt-3_c.C create mode 100644 gcc/testsuite/g++.dg/modules/virt-3_d.C diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc index 67f132d28d7..771e56245dc 100644 --- a/gcc/cp/module.cc +++ b/gcc/cp/module.cc @@ -5418,7 +5418,7 @@ trees_out::core_bools (tree t) && !(TREE_STATIC (t) && DECL_FUNCTION_SCOPE_P (t) && DECL_DECLARED_INLINE_P (DECL_CONTEXT (t))) - && !DECL_VAR_DECLARED_INLINE_P (t)) + && !DECL_INLINE_VAR_P (t)) is_external = true; break; @@ -11799,6 +11799,12 @@ trees_out::write_var_def (tree decl) } tree_node (dyn_init); } + + /* For vtables we need to know if they're actually extern or not, + even if we get a definition; for other kinds of variables we + can assume that if we have a definition they can be emitted. */ + if (streaming_p () && VAR_P (decl) && DECL_VTABLE_OR_VTT_P (decl)) + u (DECL_NOT_REALLY_EXTERN (decl)); } void @@ -11816,6 +11822,11 @@ trees_in::read_var_def (tree decl, tree maybe_template) tree dyn_init = init ? NULL_TREE : tree_node (); unused -= vtable; + /* Assume for most vars that if we have a definition it's not extern. */ + bool not_really_extern = true; + if (vtable) + not_really_extern = u (); + if (get_overrun ()) return false; @@ -11826,7 +11837,7 @@ trees_in::read_var_def (tree decl, tree maybe_template) if (installing) { if (DECL_EXTERNAL (decl)) - DECL_NOT_REALLY_EXTERN (decl) = true; + DECL_NOT_REALLY_EXTERN (decl) = not_really_extern; if (VAR_P (decl)) { DECL_INITIALIZED_P (decl) = true; diff --git a/gcc/testsuite/g++.dg/modules/virt-2_c.C b/gcc/testsuite/g++.dg/modules/virt-2_c.C index 7b3eeebe508..8969cb04911 100644 --- a/gcc/testsuite/g++.dg/modules/virt-2_c.C +++ b/gcc/testsuite/g++.dg/modules/virt-2_c.C @@ -9,8 +9,12 @@ int Foo () return !(Visit (&v) == 0); } -// We do emit Visitor vtable -// andl also we do emit rtti here -// { dg-final { scan-assembler {_ZTVW3foo7Visitor:} } } -// { dg-final { scan-assembler {_ZTIW3foo7Visitor:} } } -// { dg-final { scan-assembler {_ZTSW3foo7Visitor:} } } +// Again, we do not emit Visitor vtable +// but we do emit rtti here + +// but see https://github.com/itanium-cxx-abi/cxx-abi/issues/170: +// we should only emit RTTI in virt-2_a.C, alongside the vtable + +// { dg-final { scan-assembler-not {_ZTVW3foo7Visitor:} } } +// { dg-final { scan-assembler-not {_ZTIW3foo7Visitor:} { xfail *-*-* } } } +// { dg-final { scan-assembler-not {_ZTSW3foo7Visitor:} { xfail *-*-* } } } diff --git a/gcc/testsuite/g++.dg/modules/virt-3_a.C b/gcc/testsuite/g++.dg/modules/virt-3_a.C new file mode 100644 index 00000000000..a7eae7f9d35 --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/virt-3_a.C @@ -0,0 +1,9 @@ +// PR c++/114229 +// { dg-additional-options "-fmodules-ts -Wno-global-module" } +// { dg-module-cmi modA } + +module; +template<class> struct basic_streambuf { virtual void overflow() { } }; +extern template struct basic_streambuf<long>; +export module modA; +export basic_streambuf<long> *p; diff --git a/gcc/testsuite/g++.dg/modules/virt-3_b.C b/gcc/testsuite/g++.dg/modules/virt-3_b.C new file mode 100644 index 00000000000..4d87b965bbf --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/virt-3_b.C @@ -0,0 +1,6 @@ +// PR c++/114229 +// { dg-additional-options "-fmodules-ts -fno-module-lazy" } +// { dg-module-cmi modB } + +export module modB; +import modA; diff --git a/gcc/testsuite/g++.dg/modules/virt-3_c.C b/gcc/testsuite/g++.dg/modules/virt-3_c.C new file mode 100644 index 00000000000..224bb4aed49 --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/virt-3_c.C @@ -0,0 +1,3 @@ +// PR c++/114229 +template<class> struct basic_streambuf { virtual void overflow() { } }; +template struct basic_streambuf<long>; diff --git a/gcc/testsuite/g++.dg/modules/virt-3_d.C b/gcc/testsuite/g++.dg/modules/virt-3_d.C new file mode 100644 index 00000000000..b3a0aad7abe --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/virt-3_d.C @@ -0,0 +1,7 @@ +// PR c++/114229 +// { dg-module-do link } +// { dg-additional-options "-fmodules-ts -fno-module-lazy" } + +import modA; +import modB; +int main() { } -- 2.43.2
