commit:     f29cc45282812f48bdabb4c0e59020515ed13e17
Author:     Sam James <sam <AT> gentoo <DOT> org>
AuthorDate: Tue Apr  1 22:42:28 2025 +0000
Commit:     Sam James <sam <AT> gentoo <DOT> org>
CommitDate: Tue Apr  1 22:42:53 2025 +0000
URL:        https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=f29cc452

sys-devel/gcc: disable musttail again; C++ lifetime fix for 15.0.1_pre20250330

Hopefully the remaining musttail bits will land soon.

Bug: https://bugs.gentoo.org/952964
Signed-off-by: Sam James <sam <AT> gentoo.org>

 ...gcc-15.0.1_pre20250330-lifetime-extension.patch | 168 +++++++++++++++++++++
 sys-devel/gcc/gcc-15.0.1_pre20250330-r1.ebuild     |  55 +++++++
 2 files changed, 223 insertions(+)

diff --git 
a/sys-devel/gcc/files/gcc-15.0.1_pre20250330-lifetime-extension.patch 
b/sys-devel/gcc/files/gcc-15.0.1_pre20250330-lifetime-extension.patch
new file mode 100644
index 000000000000..42eed3f6bb86
--- /dev/null
+++ b/sys-devel/gcc/files/gcc-15.0.1_pre20250330-lifetime-extension.patch
@@ -0,0 +1,168 @@
+https://inbox.sourceware.org/gcc-patches/[email protected]/
+
+From d1ddf83b25fbe6c7c247007c754b7858cfaea916 Mon Sep 17 00:00:00 2001
+Message-ID: 
<d1ddf83b25fbe6c7c247007c754b7858cfaea916.1743458566.git....@gentoo.org>
+From: Marek Polacek <[email protected]>
+Date: Mon, 31 Mar 2025 16:59:08 -0400
+Subject: [PATCH] c++: fix missing lifetime extension [PR119383]
+
+Since r15-8011 cp_build_indirect_ref_1 won't do the *&TARGET_EXPR ->
+TARGET_EXPR folding not to change its value category.  That fix seems
+correct but it made us stop extending the lifetime in this testcase,
+causing a wrong-code issue -- extend_ref_init_temps_1 did not see
+through the extra *& because it doesn't use a tree walk.
+
+This patch reverts r15-8011 and instead handles the problem in
+build_over_call by calling force_lvalue in the is_really_empty_class
+case as well as in the general case.
+
+       PR c++/119383
+
+gcc/cp/ChangeLog:
+
+       * call.cc (build_over_call): Use force_lvalue to ensure op= returns
+       an lvalue.
+       * cp-tree.h (force_lvalue): Declare.
+       * cvt.cc (force_lvalue): New.
+       * typeck.cc (cp_build_indirect_ref_1): Revert r15-8011.
+
+gcc/testsuite/ChangeLog:
+
+* g++.dg/cpp0x/temp-extend3.C: New test.
+---
+ gcc/cp/call.cc                            |  9 ++++---
+ gcc/cp/cp-tree.h                          |  1 +
+ gcc/cp/cvt.cc                             | 13 +++++++++
+ gcc/cp/typeck.cc                          | 10 +++----
+ gcc/testsuite/g++.dg/cpp0x/temp-extend3.C | 32 +++++++++++++++++++++++
+ 5 files changed, 55 insertions(+), 10 deletions(-)
+ create mode 100644 gcc/testsuite/g++.dg/cpp0x/temp-extend3.C
+
+diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc
+index c1c8987ec8b1..b1469cb5a4c9 100644
+--- a/gcc/cp/call.cc
++++ b/gcc/cp/call.cc
+@@ -10828,10 +10828,8 @@ build_over_call (struct z_candidate *cand, int flags, 
tsubst_flags_t complain)
+       if (is_really_empty_class (type, /*ignore_vptr*/true))
+       {
+         /* Avoid copying empty classes, but ensure op= returns an lvalue even
+-           if the object argument isn't one. This isn't needed in other cases
+-           since MODIFY_EXPR is always considered an lvalue.  */
+-        to = cp_build_addr_expr (to, tf_none);
+-        to = cp_build_indirect_ref (input_location, to, RO_ARROW, complain);
++           if the object argument isn't one.  */
++        to = force_lvalue (to, complain);
+         val = build2 (COMPOUND_EXPR, type, arg, to);
+         suppress_warning (val, OPT_Wunused);
+       }
+@@ -10852,6 +10850,9 @@ build_over_call (struct z_candidate *cand, int flags, 
tsubst_flags_t complain)
+         tree array_type, alias_set;
+ 
+         arg2 = TYPE_SIZE_UNIT (as_base);
++        /* Ensure op= returns an lvalue even if the object argument isn't
++           one.  */
++        to = force_lvalue (to, complain);
+         to = cp_stabilize_reference (to);
+         arg0 = cp_build_addr_expr (to, complain);
+ 
+diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
+index 2f2122dcf241..927f51b116b3 100644
+--- a/gcc/cp/cp-tree.h
++++ b/gcc/cp/cp-tree.h
+@@ -7079,6 +7079,7 @@ extern tree convert_to_reference         (tree, tree, 
int, int, tree,
+                                                tsubst_flags_t);
+ extern tree convert_from_reference            (tree);
+ extern tree force_rvalue                      (tree, tsubst_flags_t);
++extern tree force_lvalue                      (tree, tsubst_flags_t);
+ extern tree ocp_convert                               (tree, tree, int, int,
+                                                tsubst_flags_t);
+ extern tree cp_convert                                (tree, tree, 
tsubst_flags_t);
+diff --git a/gcc/cp/cvt.cc b/gcc/cp/cvt.cc
+index bd1f147f2c56..f663a6d08c89 100644
+--- a/gcc/cp/cvt.cc
++++ b/gcc/cp/cvt.cc
+@@ -575,6 +575,19 @@ force_rvalue (tree expr, tsubst_flags_t complain)
+   return expr;
+ }
+ 
++/* Force EXPR to be an lvalue, if it isn't already.  */
++
++tree
++force_lvalue (tree expr, tsubst_flags_t complain)
++{
++  if (!lvalue_p (expr))
++    {
++      expr = cp_build_addr_expr (expr, complain);
++      expr = cp_build_indirect_ref (input_location, expr, RO_ARROW, complain);
++    }
++  return expr;
++}
++
+ 
+ /* If EXPR and ORIG are INTEGER_CSTs, return a version of EXPR that has
+    TREE_OVERFLOW set only if it is set in ORIG.  Otherwise, return EXPR
+diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc
+index c8e4441fb8b4..4f4dc683b5a0 100644
+--- a/gcc/cp/typeck.cc
++++ b/gcc/cp/typeck.cc
+@@ -3870,13 +3870,11 @@ cp_build_indirect_ref_1 (location_t loc, tree ptr, 
ref_operator errorstring,
+         return error_mark_node;
+       }
+       else if (do_fold && TREE_CODE (pointer) == ADDR_EXPR
+-             && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0)))
+-             /* Don't let this change the value category.  '*&TARGET_EXPR'
+-                is an lvalue, but folding it into 'TARGET_EXPR' would turn
+-                it into a prvalue of class type.  */
+-             && lvalue_p (TREE_OPERAND (pointer, 0)))
++             && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
+       /* The POINTER was something like `&x'.  We simplify `*&x' to
+-         `x'.  */
++         `x'.  This change the value category: '*&TARGET_EXPR'
++         is an lvalue and folding it into 'TARGET_EXPR' turns it into
++         a prvalue of class type.  */
+       return TREE_OPERAND (pointer, 0);
+       else
+       {
+diff --git a/gcc/testsuite/g++.dg/cpp0x/temp-extend3.C 
b/gcc/testsuite/g++.dg/cpp0x/temp-extend3.C
+new file mode 100644
+index 000000000000..3eab88d0076e
+--- /dev/null
++++ b/gcc/testsuite/g++.dg/cpp0x/temp-extend3.C
+@@ -0,0 +1,32 @@
++// PR c++/119383
++// { dg-do run { target c++11 } }
++
++int g;
++
++struct base {
++  virtual base *clone() const = 0;
++  ~base() { }
++};
++
++struct impl : virtual base {
++  base *clone() const { return new impl; }  // #1
++  impl() { ++g; }
++  ~impl() { --g; }
++};
++
++const base *
++make_a_clone ()
++{
++  const base &base = impl{}; // #2
++  return base.clone();
++}
++
++int
++main ()
++{
++  make_a_clone ();
++  // impl::impl() is called twice (#1 and #2), impl::~impl() once,
++  // at the end of make_a_clone.
++  if (g != 1)
++    __builtin_abort ();
++}
+
+base-commit: aa3aaf2bfb8fcc17076993df4297597b68bc5f60
+-- 
+2.49.0
+

diff --git a/sys-devel/gcc/gcc-15.0.1_pre20250330-r1.ebuild 
b/sys-devel/gcc/gcc-15.0.1_pre20250330-r1.ebuild
new file mode 100644
index 000000000000..795b82277a85
--- /dev/null
+++ b/sys-devel/gcc/gcc-15.0.1_pre20250330-r1.ebuild
@@ -0,0 +1,55 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+TOOLCHAIN_PATCH_DEV="sam"
+TOOLCHAIN_HAS_TESTS=1
+PATCH_GCC_VER="15.0.0"
+PATCH_VER="50"
+MUSL_VER="2"
+MUSL_GCC_VER="15.0.0"
+PYTHON_COMPAT=( python3_{10..13} )
+
+if [[ -n ${TOOLCHAIN_GCC_RC} ]] ; then
+       # Cheesy hack for RCs
+       MY_PV=$(ver_cut 1).$((($(ver_cut 2) + 1))).$((($(ver_cut 3) - 
1)))-RC-$(ver_cut 5)
+       MY_P=${PN}-${MY_PV}
+       GCC_TARBALL_SRC_URI="mirror://gcc/snapshots/${MY_PV}/${MY_P}.tar.xz"
+       TOOLCHAIN_SET_S=no
+       S="${WORKDIR}"/${MY_P}
+fi
+
+inherit toolchain
+
+if tc_is_live ; then
+       # Needs to be after inherit (for now?), bug #830908
+       EGIT_BRANCH=master
+elif [[ -z ${TOOLCHAIN_USE_GIT_PATCHES} ]] ; then
+       # Don't keyword live ebuilds
+       #KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~loong ~m68k ~mips ~ppc 
~ppc64 ~riscv ~s390 ~sparc ~x86"
+       :;
+fi
+
+if [[ ${CATEGORY} != cross-* ]] ; then
+       # Technically only if USE=hardened *too* right now, but no point in 
complicating it further.
+       # If GCC is enabling CET by default, we need glibc to be built with 
support for it.
+       # bug #830454
+       RDEPEND="elibc_glibc? ( sys-libs/glibc[cet(-)?] )"
+       DEPEND="${RDEPEND}"
+fi
+
+src_prepare() {
+       local p upstreamed_patches=(
+               # add them here
+               
80_all_PR119376-tailc-Don-t-fail-musttail-calls-if-they-use-or-could.patch
+       )
+       for p in "${upstreamed_patches[@]}"; do
+               rm -v "${WORKDIR}/patch/${p}" || die
+       done
+
+       toolchain_src_prepare
+       eapply "${FILESDIR}"/${P}-lifetime-extension.patch
+       eapply "${FILESDIR}"/${PN}-15.0.1_pre20250323-disable-musttail.patch
+       eapply_user
+}

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