Ping for https://gcc.gnu.org/pipermail/gcc-patches/2023-November/637768.html.
(I've changed the summary message a little from that email but the patch
is otherwise unchanged.)
On Wed, Nov 22, 2023 at 10:33:15PM +1100, Nathaniel Shead wrote:
> Bootstrapped and regtested on x86_64-pc-linux-gnu. I don't have write
> access.
>
> -- >8 --
>
> When merging duplicate instantiations of function templates, currently
> read_function_def overwrites the arguments with that of the existing
> duplicate. This is problematic, however, since this means that the
> PARM_DECLs in the body of the function definition no longer match with
> the PARM_DECLs in the argument list, which causes issues when it comes
> to generating RTL.
>
> There doesn't seem to be any reason to do this replacement, so this
> patch removes that logic.
>
> PR c++/112588
>
> gcc/cp/ChangeLog:
>
> * module.cc (trees_in::read_function_def): Don't overwrite
> arguments.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/modules/merge-16.h: New test.
> * g++.dg/modules/merge-16_a.C: New test.
> * g++.dg/modules/merge-16_b.C: New test.
>
> Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com>
> ---
> gcc/cp/module.cc | 2 --
> gcc/testsuite/g++.dg/modules/merge-16.h | 10 ++++++++++
> gcc/testsuite/g++.dg/modules/merge-16_a.C | 7 +++++++
> gcc/testsuite/g++.dg/modules/merge-16_b.C | 5 +++++
> 4 files changed, 22 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/g++.dg/modules/merge-16.h
> create mode 100644 gcc/testsuite/g++.dg/modules/merge-16_a.C
> create mode 100644 gcc/testsuite/g++.dg/modules/merge-16_b.C
>
> diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
> index 4f5b6e2747a..2520ab659cc 100644
> --- a/gcc/cp/module.cc
> +++ b/gcc/cp/module.cc
> @@ -11665,8 +11665,6 @@ trees_in::read_function_def (tree decl, tree
> maybe_template)
> DECL_RESULT (decl) = result;
> DECL_INITIAL (decl) = initial;
> DECL_SAVED_TREE (decl) = saved;
> - if (maybe_dup)
> - DECL_ARGUMENTS (decl) = DECL_ARGUMENTS (maybe_dup);
>
> if (context)
> SET_DECL_FRIEND_CONTEXT (decl, context);
> diff --git a/gcc/testsuite/g++.dg/modules/merge-16.h
> b/gcc/testsuite/g++.dg/modules/merge-16.h
> new file mode 100644
> index 00000000000..fdb38551103
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/modules/merge-16.h
> @@ -0,0 +1,10 @@
> +// PR c++/112588
> +
> +void f(int*);
> +
> +template <typename T>
> +struct S {
> + void g(int n) { f(&n); }
> +};
> +
> +template struct S<void>;
> diff --git a/gcc/testsuite/g++.dg/modules/merge-16_a.C
> b/gcc/testsuite/g++.dg/modules/merge-16_a.C
> new file mode 100644
> index 00000000000..c243224c875
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/modules/merge-16_a.C
> @@ -0,0 +1,7 @@
> +// PR c++/112588
> +// { dg-additional-options "-fmodules-ts" }
> +// { dg-module-cmi merge16 }
> +
> +module;
> +#include "merge-16.h"
> +export module merge16;
> diff --git a/gcc/testsuite/g++.dg/modules/merge-16_b.C
> b/gcc/testsuite/g++.dg/modules/merge-16_b.C
> new file mode 100644
> index 00000000000..8c7b1f0511f
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/modules/merge-16_b.C
> @@ -0,0 +1,5 @@
> +// PR c++/112588
> +// { dg-additional-options "-fmodules-ts" }
> +
> +#include "merge-16.h"
> +import merge16;
> --
> 2.42.0
>
