On Tue, 18 Oct 2022, Patrick Palka wrote: > For an enum declaration, has_definition returns true iff its TYPE_VALUES > field is non-empty. But this will wrongly return false for an enum that's > defined to have no enumerators as in the below testcase. > > This patch fixes has_definition for such enums by checking OPAQUE_ENUM_P > instead, which should always give us the right answer here.
Whoops, it looks like the other patch[1] alone fixes both this testcase and its own testcase, and thus this change to has_definition isn't necessary if the other patch goes in. The problem in the below testcase is that the enum defines no enumerators, so has_definition returns false, and therefore we never stream the ENUMERAL_TYPE's TYPE_MIN/MAX_VALUE, which leads to a crash in the middle end due to these fields being empty. The other patch arranges that we always stream TYPE_MIN/MAX_VALUE for ENUMERAL_TYPE regardless of whether we think the enum is defined, so this has_definition false negative doesn't matter anymore. So feel free to ignore this patch if you think the second one looks good :) [1]: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/603831.html > > Tested on x86_64-pc-linux-gnu, does this look OK for trunk? > > PR c++/102600 > > gcc/cp/ChangeLog: > > * module.cc (has_definition): For an enum declaration, check > OPAQUE_ENUM_P instead of TYPE_VALUES. > > gcc/testsuite/ChangeLog: > > * g++.dg/modules/enum-9_a.H: New test. > * g++.dg/modules/enum-9_b.C: New test. > --- > gcc/cp/module.cc | 3 ++- > gcc/testsuite/g++.dg/modules/enum-9_a.H | 5 +++++ > gcc/testsuite/g++.dg/modules/enum-9_b.C | 8 ++++++++ > 3 files changed, 15 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/modules/enum-9_a.H > create mode 100644 gcc/testsuite/g++.dg/modules/enum-9_b.C > > diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc > index 2c2f9a9a8cb..cc704817718 100644 > --- a/gcc/cp/module.cc > +++ b/gcc/cp/module.cc > @@ -11443,7 +11443,8 @@ has_definition (tree decl) > if (type == TYPE_MAIN_VARIANT (type) > && decl == TYPE_NAME (type) > && (TREE_CODE (type) == ENUMERAL_TYPE > - ? TYPE_VALUES (type) : TYPE_FIELDS (type))) > + ? !OPAQUE_ENUM_P (type) > + : TYPE_FIELDS (type) != NULL_TREE)) > return true; > } > break; > diff --git a/gcc/testsuite/g++.dg/modules/enum-9_a.H > b/gcc/testsuite/g++.dg/modules/enum-9_a.H > new file mode 100644 > index 00000000000..1aecabfd0bd > --- /dev/null > +++ b/gcc/testsuite/g++.dg/modules/enum-9_a.H > @@ -0,0 +1,5 @@ > +// PR c++/102600 > +// { dg-additional-options -fmodule-header } > +// { dg-module-cmi {} } > + > +enum class byte : unsigned char { }; > diff --git a/gcc/testsuite/g++.dg/modules/enum-9_b.C > b/gcc/testsuite/g++.dg/modules/enum-9_b.C > new file mode 100644 > index 00000000000..aa1fdf21444 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/modules/enum-9_b.C > @@ -0,0 +1,8 @@ > +// PR c++/102600 > +// { dg-additional-options -fmodules-ts } > + > +import "enum-9_a.H"; > + > +void push(byte) {} > +void write(char v) { push(static_cast<byte>(v)); } > +int main() { write(char{}); } > -- > 2.38.0.118.g4732897cf0 > >
