From: Nathaniel Shead <nathanieloshead@gmail.com>
To: gcc-patches@gcc.gnu.org
Cc: Jason Merrill <jason@redhat.com>, Nathan Sidwell <nathan@acm.org>
Subject: Re: [PATCH] c++/modules: Prevent overwriting arguments when merging duplicates [PR112588]
Date: Wed, 3 Jan 2024 09:49:13 +1100 [thread overview]
Message-ID: <659492ed.170a0220.662d6.e972@mx.google.com> (raw)
In-Reply-To: <657d80e6.170a0220.8f619.b47f@mx.google.com>
Ping for https://gcc.gnu.org/pipermail/gcc-patches/2023-November/637768.html.
On Sat, Dec 16, 2023 at 09:50:10PM +1100, Nathaniel Shead wrote:
> 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 <nathanieloshead@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
> >
next prev parent reply other threads:[~2024-01-02 22:49 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-22 11:33 [PATCH] c++/modules: Prevent overwriting arguments for " Nathaniel Shead
2023-12-16 10:50 ` [PATCH] c++/modules: Prevent overwriting arguments when merging " Nathaniel Shead
2024-01-02 22:49 ` Nathaniel Shead [this message]
2024-01-06 22:32 ` [PATCH] c++/modules: Prevent overwriting arguments for " Nathan Sidwell
2024-01-07 14:29 ` Nathaniel Shead
2024-01-08 17:04 ` Patrick Palka
2024-01-17 16:28 ` Jason Merrill
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