On 9/20/22 15:54, Patrick Palka wrote:
The modules streaming code seems to rely on the invariant that a TEMPLATE_DECL and its DECL_TEMPLATE_RESULT have the same TREE_TYPE.
It does indeed.
But for a templated VAR_DECL with deduced non-dependent type, the two TREE_TYPEs end up diverging: cp_finish_decl deduces the type of the initializer ahead of time and updates the TREE_TYPE of the VAR_DECL, but neglects to update the corresponding TEMPLATE_DECL as well, which leads to a "conflicting global module declaration" error for each of the __phase_alignment decls in the below testcase (and for the xtreme-header testcases if we try including <barrier>). This patch makes cp_finish_decl update the TREE_TYPE of the corresponding TEMPLATE_DECL so that the invariant is maintained > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk?
Ok, thanks
gcc/cp/ChangeLog: * decl.cc (cp_finish_decl): After updating the deduced type of a VAR_DECL, also update the corresponding TEMPLATE_DECL if there is one. gcc/testsuite/ChangeLog: * g++.dg/modules/auto-3.h: New test. * g++.dg/modules/auto-3_a.H: New test. * g++.dg/modules/auto-3_b.C: New test. --- gcc/cp/decl.cc | 6 ++++++ gcc/testsuite/g++.dg/modules/auto-3.h | 10 ++++++++++ gcc/testsuite/g++.dg/modules/auto-3_a.H | 4 ++++ gcc/testsuite/g++.dg/modules/auto-3_b.C | 4 ++++ 4 files changed, 24 insertions(+) create mode 100644 gcc/testsuite/g++.dg/modules/auto-3.h create mode 100644 gcc/testsuite/g++.dg/modules/auto-3_a.H create mode 100644 gcc/testsuite/g++.dg/modules/auto-3_b.C diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc index 070f673c3a2..80467c19254 100644 --- a/gcc/cp/decl.cc +++ b/gcc/cp/decl.cc @@ -8180,6 +8180,12 @@ cp_finish_decl (tree decl, tree init, bool init_const_expr_p, return; } cp_apply_type_quals_to_decl (cp_type_quals (type), decl); + + /* Update the type of the corresponding TEMPLATE_DECL to match. */ + if (DECL_LANG_SPECIFIC (decl) + && DECL_TEMPLATE_INFO (decl) + && DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (decl)) == decl) + TREE_TYPE (DECL_TI_TEMPLATE (decl)) = type; }if (ensure_literal_type_for_constexpr_object (decl) == error_mark_node)diff --git a/gcc/testsuite/g++.dg/modules/auto-3.h b/gcc/testsuite/g++.dg/modules/auto-3.h new file mode 100644 index 00000000000..f129433cbcb --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/auto-3.h @@ -0,0 +1,10 @@ +template<class> +struct __tree_barrier { + static const auto __phase_alignment_1 = 0; + + template<class> + static const auto __phase_alignment_2 = 0; +}; + +template<class> +inline auto __phase_alignment_3 = 0; diff --git a/gcc/testsuite/g++.dg/modules/auto-3_a.H b/gcc/testsuite/g++.dg/modules/auto-3_a.H new file mode 100644 index 00000000000..25a7a73e73e --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/auto-3_a.H @@ -0,0 +1,4 @@ +// { dg-additional-options "-fmodule-header" } +// { dg-module-cmi {} } + +#include "auto-3.h" diff --git a/gcc/testsuite/g++.dg/modules/auto-3_b.C b/gcc/testsuite/g++.dg/modules/auto-3_b.C new file mode 100644 index 00000000000..03b6d46f476 --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/auto-3_b.C @@ -0,0 +1,4 @@ +// { dg-additional-options "-fmodules-ts -fno-module-lazy" } + +#include "auto-3.h" +import "auto-3_a.H";
-- Nathan Sidwell
