https://gcc.gnu.org/g:77772f8a3da8ea30066d2201f8148714a8e89da5
commit r14-9356-g77772f8a3da8ea30066d2201f8148714a8e89da5 Author: Nathaniel Shead <nathanielosh...@gmail.com> Date: Tue Mar 5 15:17:09 2024 +1100 c++: Stream DECL_CONTEXT for template template parms [PR98881] When streaming in a nested template-template parameter as in the attached testcase, we end up reaching the containing template-template parameter in 'tpl_parms_fini'. We should not set the DECL_CONTEXT to this (nested) template-template parameter, as it should already be the struct that the outer template-template parameter is declared on. The precise logic for what DECL_CONTEXT should be for a template template parameter in various situations seems rather obscure. Rather than trying to determine the assumptions that need to hold, it seems simpler to just always re-stream the DECL_CONTEXT as needed for now. PR c++/98881 gcc/cp/ChangeLog: * module.cc (trees_out::tpl_parms_fini): Stream out DECL_CONTEXT for template template parameters. (trees_in::tpl_parms_fini): Read it. gcc/testsuite/ChangeLog: * g++.dg/modules/tpl-tpl-parm-3.h: New test. * g++.dg/modules/tpl-tpl-parm-3_a.H: New test. * g++.dg/modules/tpl-tpl-parm-3_b.C: New test. * g++.dg/modules/tpl-tpl-parm-3_c.C: New test. Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com> Reviewed-by: Patrick Palka <ppa...@redhat.com> Reviewed-by: Jason Merrill <ja...@redhat.com> Diff: --- gcc/cp/module.cc | 41 ++++++------------------- gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3.h | 12 ++++++++ gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_a.H | 5 +++ gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_b.C | 5 +++ gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_c.C | 15 +++++++++ 5 files changed, 47 insertions(+), 31 deletions(-) diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc index 80b63a70a62..f7e8b357fc2 100644 --- a/gcc/cp/module.cc +++ b/gcc/cp/module.cc @@ -10126,23 +10126,12 @@ trees_out::tpl_parms_fini (tree tmpl, unsigned tpl_levels) tree dflt = TREE_PURPOSE (parm); tree_node (dflt); - if (streaming_p ()) - { - tree decl = TREE_VALUE (parm); - if (TREE_CODE (decl) == TEMPLATE_DECL) - { - tree ctx = DECL_CONTEXT (decl); - tree inner = DECL_TEMPLATE_RESULT (decl); - tree tpi = (TREE_CODE (inner) == TYPE_DECL - ? TEMPLATE_TYPE_PARM_INDEX (TREE_TYPE (decl)) - : DECL_INITIAL (inner)); - bool original = (TEMPLATE_PARM_LEVEL (tpi) - == TEMPLATE_PARM_ORIG_LEVEL (tpi)); - /* Original template template parms have a context - of their owning template. Reduced ones do not. */ - gcc_checking_assert (original ? ctx == tmpl : !ctx); - } - } + /* Template template parameters need a context of their owning + template. This is quite tricky to infer correctly on stream-in + (see PR c++/98881) so we'll just provide it directly. */ + tree decl = TREE_VALUE (parm); + if (TREE_CODE (decl) == TEMPLATE_DECL) + tree_node (DECL_CONTEXT (decl)); } } } @@ -10160,24 +10149,14 @@ trees_in::tpl_parms_fini (tree tmpl, unsigned tpl_levels) { tree parm = TREE_VEC_ELT (vec, ix); tree dflt = tree_node (); - if (get_overrun ()) - return false; TREE_PURPOSE (parm) = dflt; tree decl = TREE_VALUE (parm); if (TREE_CODE (decl) == TEMPLATE_DECL) - { - tree inner = DECL_TEMPLATE_RESULT (decl); - tree tpi = (TREE_CODE (inner) == TYPE_DECL - ? TEMPLATE_TYPE_PARM_INDEX (TREE_TYPE (decl)) - : DECL_INITIAL (inner)); - bool original = (TEMPLATE_PARM_LEVEL (tpi) - == TEMPLATE_PARM_ORIG_LEVEL (tpi)); - /* Original template template parms have a context - of their owning template. Reduced ones do not. */ - if (original) - DECL_CONTEXT (decl) = tmpl; - } + DECL_CONTEXT (decl) = tree_node (); + + if (get_overrun ()) + return false; } } return true; diff --git a/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3.h b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3.h new file mode 100644 index 00000000000..b0dcf353c23 --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3.h @@ -0,0 +1,12 @@ +// PR c++/98881 + +template <typename P> struct X {}; + +template<template <typename> typename TT> +struct X<TT<int>> { + template<template <typename> typename UU> + void f (X<UU<int>>&); +}; + +template<template<class> class TT> struct Y; +template<template<class> class UU> struct Y { }; diff --git a/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_a.H b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_a.H new file mode 100644 index 00000000000..47464081f25 --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_a.H @@ -0,0 +1,5 @@ +// PR c++/98881 +// { dg-additional-options "-fmodule-header" } +// { dg-module-cmi {} } + +#include "tpl-tpl-parm-3.h" diff --git a/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_b.C b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_b.C new file mode 100644 index 00000000000..1e3cc6c444f --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_b.C @@ -0,0 +1,5 @@ +// PR c++/98881 +// { dg-additional-options "-fmodules-ts -fno-module-lazy" } + +#include "tpl-tpl-parm-3.h" +import "tpl-tpl-parm-3_a.H"; diff --git a/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_c.C b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_c.C new file mode 100644 index 00000000000..5edba6cc64f --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_c.C @@ -0,0 +1,15 @@ +// PR c++/98881 +// { dg-additional-options "-fmodules-ts" } + +import "tpl-tpl-parm-3_a.H"; + +template <typename T> struct A {}; +template <typename T> struct B {}; + +void foo() { + X<A<int>> a; + X<B<int>> b; + a.f(b); + + Y<A> y; +}